GEOLOGICAL SURVEY OF GEORGIA S. W. McCALLIE, State Geologist BuLLETIN No. '21 A REPORT ON THE LIMESTONES AND MARLS OF THE COASTAL PLAIN OF GEORGIA BY J. E. BRANTLY, Assistant State Geologist ATLANTA, GA. THE BLOSSER COMPANY 1916 LIMESTONES OF THE COASTAL PLAIN OF GEORGIA FRONTISPIECE-PLATE 1. J,!MES'rO 'Fl QUARRY ON GRADY PflOPEUTY. 2 1\ITLES SOUTH OF TTVOLA, HOT STON CO THE ADVISORY BOARD OF THE Geological Survey of Georgia IN THE YEAR 1916 (Ex-Officio) Hrs ExcELLENCY, NAT. E. HARRIS ........... Governor of Georgia PRESIDENT OF THE BOARD HoN. PHILIP COOK ......................... Secretary of State RoN. W. J. SPEER ............................. State Treasurer RoN. W. A. WRIGHT ....................... Comptroller-General RoN. CLIFFORD WALKER ...... _........... .'Attorney-General HoN. J.D. PRICE ................... Commissioner of Agriculture HoN. JYI. L. BRITTAIN ....... _... Commissioner of Public Schools LETTER OF TRANSMITTAL GEOLOGICAL SURVEY OF GEORGIA, ATLANTA, JUNE 1, 1916. To His Emcellency, NAT. E. HARRIS, Governor and President of the Advisory Board of the Geological f$urvey of Georgia. SIR: I have the honor to transmit herewith the report of Mr. J. E. Brantly, Assistant State Geologist, on the Limestones and Marls of the Coastal Plain of Georgia, to be published as Bulletin No. 21, of this Survey. Very respectfully, 8. W. l\1C0ALJ..~IE, State Geologist. TABLE OF CONTENTS ADVISORY BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LETTER OF TRANSMITTAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . LIST OF ILLUSTRATIONS PAGE iii iv v-viii ix-x P .A.RT I PHYSIOGRAPHY, STRUCTURE AND GEOLOGY OF NORTH GEORGIA ........... Coastal Plain of Georgia ........................................... . Physiography ...-................................................ . Structure ....................................................... . Geology ........................................................ . Cretaceous system .............................................. . Lower Cretaceous series ...................................... . Upper Cretaceous series ...................................... . Tertiary system ............................................... . Eocene series ............................................... . Midway formation ......................................... . Wilcox formation ....................................... . Claiborne group ........................................... . Jackson group ............................................ . Undifferentiated Eocene and Oligocene ......................... . Oligocene series ....................................... : ..... . Appalachicola group ....................................... . Chattahoochee formation ................................. . .Alum Bluff formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Undifferentiated Oligocene to Pleistocene, inclusive.............. . Miocene series .............................................. . Marks Head marl. ....................................... . Duplin marl ............................................ . Pliocene series ............................................... . Charlton formation ...................................... . Quaternary system ............................................ . Pleistocene series ........................................... . Recent series ................................................ . Superficial gray sands of the upland ............................. . General discussion of limestone ...................................... . Classification of rocks ...................... .t. .................... . 1-43 1-38 1-3 3 4-38 4-5 4-5 5 5-34 5-24 5-6 6-7 8-9 9-23 24-25 25-29 25-29 25-28 28-29 30 31-32 31 31-32 33-34 33-34 34-37 34-36 36-37 37-38 38-43 38 v Origin of limestone ............................................... . Varieties of limestone ............................................ . Classi:fication according to texture ............................... . Classification according to composition ........................... . PAGE 38-40 40-43 41-43 43 PART II DESCRIPTION OF CALCAREOUS DEPOSITS IN THE COASTAL PLAIN OF GEORGIA. 44-210 Limestone and marl. ............................................ 44-209 Burke County ......................................... : . . . . . 44-55 Screven County ... , .............. , . . . . . . . . . . . . . . . . . . . . . . . . . . 55-57 Washington County .................... , . . . . . . . . . . . . . . . . . . . . . 57-63 Johnson County .................................... ,, , . . . . . . . . 63 Wilkinson County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Bleckley County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64-69 Twiggs County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69-79 Bibb County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80-81 Houston County .............................................. 81-104 Pulaski County .............................................. 104-111 Dooly County ................................................ 111-115 Macon County ............................................... 115-118 Sumter County ............................................... 118-122 Schley County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,, .. 122-123 Webster County ............................................. 123-124 Stewart County .................-...................... , . . . . . . 125 Randolph County ..................... , ....................... 125-128 Clay County ................................................. 128-132 Calhoun County .............................................. 132-134 Dougherty County ...........................................134-137 Lee County .............................. , ................... 137-152 Crisp County ................................................ 152-163 Worth County ............................................... 163-165 Mitchell County .............................................. 165-169 Baker County ...... ' ......................................... 169-170 Early County ................................................ 170-172 Decatur County .............................................. 172-182 Grady County ............................................... 182-190 Thomas County .............................................. 191-197 Brooks County ...................... ' ....................... 197-201 Lownc1es County ............................................. 201-203 Echols County ............................................... 203-206 Charlton County ............................................. 206-207 Camden County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Glynn County ............................................... 208-209 Oyster shells ................................................... 209-210 Vl PART III PAGE USES AND PREPARA.TIO~ OF LIMESTONE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211-291 Agricultural uses of limestone and lime ........................... 211-223 Soil corrective ............................................... 211-222 Properties of limestone ...................................... 211-213 Lime ...................................................... 213-216 Value of limestone and lime ................................. 216-220 Quantity of limestone to apply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Preparation of soil and wlten to apply ........................ 220-221 Metltods of applying ........................................ 221-222 Literature on agricultural uses of lime. . . . . . . . . . . . . . . . . . . . . . . . 220 Insecticides and fungicides .................................... 222-223 Cruslted limestone .............................................. 223-224 Mortar ........................................................ 224-225 Plaster ........................................................ 225-226 Use of hydrated lime with Portland cement........................ 226 Hydraulic cements ............................................. 226-232 Sand-lime brick ................................................ 232-235 Materials .................................................. 233-234 Manufacture of ............................................ 234-235 Industrial chemistry ............................................ 235-241 Bleaching agents ........................................... 235-236 Soda ...................................................... 236-237 Ammonia and illuminating gas.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 Calcium carbide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~37 Calcium cyanamide and nitrate............................... 237 Lime light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 Recovery of mercury.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 \Vater softening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 Glass manufacture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 Ceramics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Sugar manufacture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Distillation of wood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 Paper manufacture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 Glycerine, ~lubricants and soap.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Tanning .............................. : ...... , . . . . . . . . . . . . . 241 Metallurgy .................................................... 241-243 Blast furnace fl.ux .......................................... 241-242 Lining of basic open-hearth furnaces. . . . . . . . . . . . . . . . . . . . . . . . . . 242 Basic open-hearth furnace fl.ux ............................... 242-243 Quarrying limestones ........................................... 243-252 Type of workings and location ............................... 243-245 Stripping ................................................. 245-246 Drilling and blasting........................................ 246-249 Blocking .............. : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 Loading and haulage ........................................ 249-252 I PAGE Steam shovel excavating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 The manufacture of lime ........................................ 252-262 Kilns ..................................................... 253-257 Burning ................................................... 257-258 Classification of properties of lime ............................ 258-260 Cost of lime manufacture .................................... 260-261 Hydrated lime ................. ,. ........................... 261-262 Machines for preparing limestones ................................ 262-279 Rock breakers ..................... ".................. "' ........ 262-279 Jaw crushers .............................................. 263-266 Spindle or gyrating breakers ................................. 266-269 Rolls ...................................................... 269-271 Grinders and pulverizers .................................... 271-275 Screens ................. .................................. 275-277 Bucket elevators . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . 277 Conveyors ........... , .... .' ................................ 277-278 Dryers .................................................... 278-279 Kilns .............................. :. . . . . . . . . . . . . . . . . . . . . . 279' Plants for crushing and grinding limestones ...... ; ................. 279-286 APPENDIX A, Limestone quarries of North Georgia ...................... 286-291 viii ILLUSTRATIONS I. Limestone quarry on Grady property, 2 miles south of Tivola, Houston County ........................................ Frontispiece II. A.. Ostrea Georgiana bed at Shell Bluff, Savannah River, Burke County 32 B. Exposure of limestone of the Jackson formation in a gully at Rich Hill, 5 miles southeast of Roberta, Crawford County. . . . . . 32 III. A. Limestone exposure on G. S. & F. R. R., south of Tivola, Houston County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 B. Old limestone quarry on G. S. & F. R. R. right-of-way, south of Tivola, Houston County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 IV. A.. Old limestone quarry, 31h miles south of Perry, Houston County.. 64 B. Limestone exposure on Mossy Ridge, 5 miles south of Perry, Houston County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Y. A.. Limestone and fullers earth outcrop on Small property, 41h miles east of Kathleen, Houston County. . . . . . . . . . . . . . . . . . . . . . . . . . 80 B. Limestone boulders along Perry-Elko road, 3lh miles south of Perry, Houston County. . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 80 VI. A.. Limestone ridge on Small property, 41h miles east of Kathleen, Houston County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 B. Limestone quarry and kiln on Hardin property, 3lh miles north of Hawkinsville, Pulaski County ............................... 112 VII. A.. Primitive lime kiln on Small property, 4lh miles east of Kathleen, Houston County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 B. Lime kiln at Deal Lime Works, 2 miles south of Gainesville, Hall County .............................................. 144 VIII. A. Limestone exposure, west barik of Ocmulgee River, T%_ miles below Hawkinsville, Pulaski County. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 B. Limestone bluff on Armstrong property, Flint River, Crisp County 176 IX. A.. Limestone Bluff, east side of Kinchafoonee Creek, Lee County. . . 208 B. Limestone Bluff, east side of Kinchafoonee Creek,. Lee County. . . 208 X. A.. Exposure of :flint and limestone of the Jackson group just above Devvitt Ferry, Flint River, Mitchell County. . . . . . . . . . . . . . . . . . 240 B. Sink in Chattahoochee limestone showing the limestone at edge of pond, Original Pond, 3 miles west of Metcalf, Thomas County. . 240 XL A.. Exposure of limestone of the Chattahoochee formation at Stony Lake Bluff, Withlacoochee River, 7 miles southeast of Quitman, Brooks County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 B. Exposure of Chattahoochee limestone in bank of Withlacoochee River, New Bridge (or Horn Bridge), 3 miles below the Valdosta Southern Railroad bridge, Lowndes County. . . . . . . . . . . . . . . . . . . 272 ix FIGURES PAGE 1. Sketch map of B. T. Rawlings property, near Sandersville, Washington County .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 2. Sketch map of limestone ridge on Fitzpatrick property, Twiggs County. . 78 3. Section at Greer Cave, Randolph County .............................. 127 4. Section showing limestone on Rawson property, Lee County ............ : 147 5. Sketch map of Cocke property, near Armena, Lee County. . . . . . . . . . . . . . . 150 6. Ingersol-Rand piston drill on tripod. , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 7. Ingersol-Rand Jackhammer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 8. Vertical (Keystone) lime kiln. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 9. Sectional elevation of the Blake rock crusher. , . . . . . . . . . . . . . . . . . . . . . . . . 263 10. Sectional view of Gates gyratory breaker. . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 266 11. McLanahan-Stone single roll crusher. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 12. Jeffrey swing hammer pulverizer .................................... 271 13. "Allis-Chalmers Hummer" pulverizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 14. {'Allis-Chalmers L.B.H. Hummer'' crusher and pulverizer. . . . . . . . . . . . . . 282 MAPS Geological map of South Georgia, showing limestone deposits. . . . . . . . . . . . . . . 16 X LIMESTONES AND MARLS OF THE COASTAL PLAIN OF GEORGIA PART I. PHYSIOGRAPHY, STRUCTURE AND GEOLOGY OF GA. The State of Georgia is divisible into :five distinct physiographic provinces-the Cumberland Plateau, the Appalachian Valley, the Appalachian Mountains, the Piedmont Plateau, and the Coastal Plain-each of which can be further divided into lesser districts. Geologically the State is divisible into three provinces-the area of Paleozoic strata which includes the Cumberland Plateau and the Appalachian Valley, the metamorphic and igneous rocks of the Appalachian Mountains and the Piedmont Plateau, and the Cretaceous and later strata of the Coastal Plain. A large percentage of the Paleozoic rocks is limestone and dolomite, while marble (crystalline limestone) is found along the western edge of the Appalachian Mountains and in a few localities in the northern part of the Piedmont Plateau area. These deposits haye been describ~d by T. Poole Maynard in the report on "Limestone and Cement Materials of North Georgia," Bulletin Georgia Geological Survey No. 27, 1912. The lime: stones of the Coastal Plain are djscussed in this report. COASTAL PLAIN PHYSIOGRAPHY The Coastal Plain of Georgia includes all of that portion of the State south of the "Fall };ine," an irregular line running through Columbus, :Yiacon, ~filledgeviJle and Augusta, and comprises an area 2 GEOLOGICAL SURVEY OF GEORGIA of approximately 35,000 square miles, more than half the area of the State. The. region is a comparatively low plain sloping gently to the southeast. The highest elevations are along the Fall Line where they vary from 500 to 700 feet above sea level. A slo:pe of 3 or 4 feet per mile is general from this line to the Atlantic Coast. .L4.._lthough, when compared with the topography of those areas north of the Fall Line, the surface relief is slight it is not without distinctive features. The most notable topographic feature is that belt along the Fall Line known as the Fall Line Hills. This belt extends entirely ac1~oss the State with a width varying from 30 to 40 miles, with the Fall Line the northern boundary. This area has a maximum relief of about 350 feet, considering the larger streams as the base, which shows a much more mature topography than the portion of the plain to the south. Cretaceous sands and clays, the principal materials underlying the area, are easily erpded and have caused deep gullies and washes throughout the belt. To the north the Fall Line Hills merge into the C~ystalline area and to the south into the Dougherty Plain, another distinctive topographic feature of the Coastal Plain. The Dougherty Plain is a level to rolling area extending from the southwestern corner of the State to the Oconee River a few miles north of Dublin. Its greatest width is from Fort Gaines southeastward, about 60 miles, while it comes to a point at its eastern extremity. These are the limitations given by Otto Veatch, formerly Assistant State Geologist, but it seems that the belt should be extended to the Savannah River, including Sandersville, Louisville, and Waynesboro. The Altamaha Upland lies to the southeast of the Dougherty Plain with its southeastern border along a line extending from the southwestern 'corner of the Okefenokee Swamp to the Savannah River a few miles below the mouth of Briar Creek, Screven County. Northwest of a line from Valdosta to the above point on the Savannah River the elevations of the Dougherty Plain and the Altamaha Upland are about the same, considering the general slope toward the PHYSIOGRAPHY, STRVCTVRE, AND GEOLOGY 3 Atlantic seaboard-300 to 450 feet along the northern edge of the former belt and 200 to 250 feet along the Valdosta-Briar Creek line. The surface material over both districts as well as the general topography is very similar, therefore it seems that the two belts should be combined as one subdivision of the Coastal Plain. The Okefenokee Plain lies to the southeast of the Altamaha upland, paralleling the coast about 30 miles inland, \vhile the ~atilla Coastal Lowland occupies this 30-mile belt along the Atlantic Coast. In the southwestern part of the State there is a district including the southern portions of Decatur, Grady, Thomas, Brooks, Lowndes, and Echols counties to which the name Limesink region has been given because of the numerous ponds, lakes, and caverns due to "lime sinks." There are comparatively few surface streams in this belt, most of the meteoric waters being carried off through subterranean channels. Occasional well-like sinks disclose the water in these underground streams. S'l'RUCTURE The strata over the larger portion of the Coastal Plain dip to the southeast while along the southern border of the State, west of the Okefenokee Swamp, they have a slight southward dip. The strata of Cretaceous age have the greatest dip-a few feet to 30 or 40 feet per mile-while the beds of the youngest formations are nearly level: The early Eocene has a probable average dip of 12 to 15 feet per mile and the late Eocene 6 to 10 feet per mile, while the dip of the more recent beds is less. Two slight anticlines have been recognized by Veatch-the Chattahoochee Anticline, with its axis along the Chattahoochee River from Columbus into Florida, and the Withlacoochee Anticline, which includes the drainage basins of the Allapaha, Withlacoochee and Ochlockonee rivers. 4 GEOLOGICAL SURVEY OF GEORGIA GEOLOGY THE CRETACEOUS SYSTEM1 The Cretaceous deposits of Georgia include representatives of both the Lower and Upper Cretaceous series, which are divided as follows: Upper Cretaceous. Ripley fbrmation. Providence sand member. Marine beds. Cusseta sand member. Eutaw formation. Tombigbee sand member. Sands, clays anc1 marls, chiefly of marine origin. Unconformity. Lower Cretaceous. Arkose sands and clays. Not c1ifferentiated. LOWER CRETACEOUS SERIES Beds of Lower Cretaceous age outcrop in an extremely irregular belt, 2 to 20 miles in width, extending from the vicinity of Columbus on the Chattahoochee River to the vicinity of Augusta on the Savannah River. These deposits rest unconformably upon ancient crystalline rocks of probable pre-Cambrian age. The surface of these basement rocks is very uneven in detail, but, in general, slopes south and southeast beneath the Lower Cretaceous deposits at the rate of 30 to 75 feet per mile, according to calculations from well borings at several places. Between the Chattahoochee and Ocmulgee rivers the Lower Cretaceous is overlain unconformably, by the Upper Cretaceous strata, while northeastward from the Ocmulgee River to the Savannah River strata of Eocene age rest unconformably upon the Lower Cretaceous beds. These last mentioned strata have a thickness of from 350 to 600 feet. The strike varies from due east at Columbus to N. 65 E. northeast of Macon, while the dip probably averages from 25 to 30 feet per mile to the south and southeast. The Lower C1etaceous deposits consist predominantly of arkosic sand, with a consjderable amount of clay in the form of interbed(!.ed 1 Abstractl'd from Veatch anc1 Stepllenson, Geology of the Coastal Plain of Georgia: BulL Ga. GeoL Survey, No. 26, 1011, pp. 66-215. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 5 lenses. In places the sands have been indurated and form friable sandstones. The lenses of clay vary widely in lithologic character, shape and extent; in thickness they range .from 1 inch or less to 40 feet, and in horizontal ext~nt from a few square feet to many acres. Many of the clays are very white and approach kaolin in composition. They are worked extensively east of ~1acon for paper filler and various ceramic products,- Bauxite occurs locally, in the kaolin beds, in Wilkinson County. UPPER CRETACEOUS SERIES The Upper Cretaceous series in Georgia is exposed between the Chattahoochee and Ocmulgee rivers, outcropping for a distance of about 55 miles along the former stream and for a few miles along the latter. These formations rest unconformably upon the Lower Cretaceous and are overlain unconformably by deposits of Eocene age. The total thickness of the Upper Cretaceous beds is estimated to be about 1500 feet. The strike varies from nearly due east just east of the Chattahoochee River to N. 60-75 E. as the Ocmulgee River is approached. The dip ranges from 20 to 40 feet per mile to the south and southeast. The deposits of Upper Cretaceous age are composed mainly of unconsolidated sands, clay lenses, calcareous sand, and marl. The clay frequently resembles the kaolins of the Lower Cretaceous and locally are of commercial value. Some of the marls may be of value for local agricultural uses. TERTIARY SYSTEM EOCENE SERIES MIDWAY FORMATIOY1 The Midway formation outcrops in a relatively narrow northeastsouthwest belt, extending from Fort Gaines on Chattahoochee River to Montezuma on Flint River and thence for a short distance into Houston County. On the Chattahoochee the formation has a width 1 Abstracted from Stephenson, L. w., and Veatch. Otto, Underground waters of the Coastal Plain of Georgia: Water Supply Paper, U. S. Geol. Survey, No. 341. 6 GEOLOGICAL SURVEY OF GEORGIA of about 8 miles, on the Flint a width of about 15 miles, and between the two rivers an average width of 8 to 10 miles. The formation appears at the surface over parts of Clay, Quitman, Stewart, Randolph, :Marion, Schley, Webster, and Macon counties and extends eastward from Flint River probably as far as Myrtle on the Perry branch of the Central of Georgia Railway in Houston County. No occurrence is known east of Ocmulgee Riv~r, beyond which the for" mation is probably overlapped by higher Eocene formations. The Midway formation rests unconformably upon the Upper Cretaceous and is unconformably overlain by the Wilcox formation. It consists of sands, clays, marls, and limestones, having a thickness estimated at 200 to 400 feet. The dip is from 20 to 30 feet per mile1 to the southeast. The limestones which are confined chiefly to the upper part of the formation occur in beds from 2 to 25 feet in thickness. These calcareous deposits seem to be locally developed. At Browns Mill near Fort Gaines, Clay County, a soft, white limestone is exposed for a thickness of 20 feet immediately beneath the vVilcox beds. In the northern part of the same county, 6 miles south of Hatcher Station, there is an excellent exposure of hard, comparatively pure limestone that in years past was used for the manufacture of lime. Another exposure of this same type of limestone underlain by an arenaceous limestone occurs at Greer Cave, 9 miles north of Cuthbert, Randolph County. Both of these varieties of the limestone are exposed on the Flint River near Montezuma, l\:Iacon County. WILCOX FORMATION1 The vVilcox formation outcrops in a belt exteuding northeastward from the vicinity of Fort Gaines on Chattahoochee River probably to Flint River in the northeastern part of Sumter County; east of the Flint it has not been certainly recognized. The width of the outc~~p is believed to average not more than 5 or 6 miles. The :formation is .. 1 Abstracted from Stephenson and Veatch's report on the underground waters of the Coastal Plain of Georgia: Water Supply Paper, U. S. Geol. Survey, No. 341. PHYSIOGRAPHY, STEVCTUEE, AND GEOLOGY 7 to some extent overlapped and concealed by deposits of later Eocene. The Wilcox formation includes the strata lying unconformably between the Midway formation and the Claiborne group. It is made up of sandy, glauconitic shell marl, dark colored, laminated, largely lignitic sandy clay, in places consolidated into mudstone, and often dark or gray glauconitic and lignitic sand. In Schley and Macon counties and in the vicinity of Andersonville, the strata, which might be referred to this formation on the basis of geographic position, are mainly red and vari-colored sands with massive beds of very pure, white clay in the nature of sedimentary kaolin, bearing little resem- blance to the strata on Chattahoochee River. Langdon1 estimated the thickness of the formation on Chattahooche,e River at 402 feet; but this is excessive, for at Fort Gaines the thickness is _certainly not more than 60 or 75 feet. A natural exposure of the formation at Peterson Hill, 41;2 miles northwest of Cuthbert reveals about 100 feet of strata. There is no positive proof that strata of vVilcox age outcrop on Flint River, where the formation may be entirely overlapped by the Claiborne group, but if the strata between the Midway and the McBean or Vicksburg formations at Dripping Bluff, 9 miles south of Oglethorpe, are Wilcox, the thickness of the latter is perhaps 100 feet. The maximum thickness at any place in the area of outcrop probably does not exceed 150 or 200 feet The area underlain by the formation is small and presents no notable physiographic features. The topography of the area is rather broken and hilly, resembling that of the area to the north underlain by the Midway formation. The \iVilcox strata strike about N. 55 o E. and dip southeastward at a rate that cannot be accurately estimated but that is probably less than 30 feet to the mile over the area of outcrop and is perhaps less than half as much under cover of the later formations to the south. 1 Langdon, D. W., Geology of the Coastal Plain of ~labama: Ala. Geol. Survey, 1894. 8 GEOLOGICAL SURVEY OF GEORGIA CLAIBORNE GROUP The Claiborne group in Georgia has ueen divided by \yeatch and Stephenson1 into two formations, the McBean at the base and the Barnwell overlying. The two formations are given as occurring over that portion of the State between the Oconee and Savannah rivers mapped as Claiborne and "Undi~erentiated Eocene" in this report~ They cover portions of Wilkinson, Twiggs, and Houston counties. A narrow belt is ~lso described as extending from Houston County to the Chattahoochee River below Fort Gaines. During the field work for this report and work done by Shearer, Assistant State Geologist, for the reports on fullers earth and bauxite, certain conclusions have been reached that differ widely from those of the above mentioned authors. However, sufficient data were not collected to do more than show the necessity for closer investigation. This point is brought out in the description of the Jackson formation in this report. The Congaree clay member of the McBean formation of previous reports, which extends from the Ocmulgee River eastward to the-savannah River, together with the fossiliferous strata immediately underlying, seems to be a continuation of the Jackson limestone and fullers earth of Houston County. The so-called Barnwell sands which overlie these beds seem to be equivalent to the residual sands called Vi~ksburg in Veatch and Stephenson's report, which are here described as Claiborne and "Undifferentiated Eocene and Oligocene." The residual sands covering the_ central and northern portions of Houston County also seem to belong to the last mentioned series of beds. The narrow belt of outcrops of Claiborne strata \Yhich extends southwestward from Houston County to the Chattahoochee River was not studied during the field work for this report, hence nothing is known about it other than that of previously published reports. i Veatch, Otto, and Stephenson, h W., Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, 1911, pp. 235-296. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 9 ..Between the Oconee and Savannah rivers there are beds of sand, day, fossiliferous flint, limestone, and marls which, according to fossil collections made by various persons, are referable to the Claiborne group. These exposures cover a comparatively small portion of the section in which they occpr. Sufficient work was not done to accurately separate on a map these outcrops from those of the overlying_, formation nor have the contacts been definitely determined, consequently on the map accompanying this report the several beds are mapped as Claiborne and "Undifferentiated Eocenek" The Claiborne group lies between the Wilcox formation below and the Jackson group above. A well-mari:.:ed unconformity was recognized between the vVilcox and the Claiborne formations_ by Veatch and Stephenson. No exposures show definitely an unconformity between the Claiborne and the Jackson. There are, however, certain conditions which ,indicate unconformable relations. The formation consists of sands, clays, marls, limestones, and fossiliferous flint. The first three occur mainly west of the Flint River, .while the last two, together with marls, make up the larger portion Qf the outcrops east of the Oconee River. The thickness of the Claiborne group east of the Oconee River has been estimated to be 400 to 500 feet. This-includes those strata which are evidently of later age. Subtractilig 150 feet for the latter beds, it leaves 250 to 350 feet, which is probably about the thickness of the Claiborne east of the Oconee River. The thickness of the grou:p has been estimated to be 250 to 300 feet on the Chattahoochee River. The strata dip southward and southeastward at the rate of 8 to 15 feet per mile. .JACKSO~ GROGP The name Jackson group, or Jackson formation, is so-called from the type locality near Jackson, Mississippi. Veatch an"d Stephenson used the latter title for the group of beds in Georgia in their report Qn the Geology of the Coastal Plain. Mor.e recent work by C. Wythe Cooke of the U. S. Geo.logical Survey, has show-n th'at beds originally / 10 GEOLOGICAL SURVEY OF GEORGIA correlated with the Vicksburg formation are in reality of Jackson age. These deposits are exposed along the Flint River from the upper part of Crisp County to Bainbridge, Decatur County. The outcrops near Bainbridge, Vaughan correlated with the Ocala formation of Florida which Cooke1 has subsequently determined to be the upper formation of the Jackson group. Based upon this work, Dr. Vaughan of the U. S. Geological Survey, has suggested in a letter to McCallie that the name "Jackson formation" be changed to "Jackson group," since it is divisible into at least two formations. This suggestion is followed in this report. The exposures near Albany and between Albany and Bainbridge are referred to as belonging to the Ocala formation. The entire area underlain by this group has not yet been studied thoroughly, therefore, it is indicated on the accompanying map as "Undifferentiated Eocen~ and Oligocene," except the area described as Jackson by Stephenson and Veatcp. and portions of Twiggs and Wilkinson counties formerly described as Claiborne. The total area covered by those outcrops which are known to be of Jackson age is comparatively small. There are, however, two large areas which have heretofore been considered to be within the surface terranes of the Claiborne group and Vicksburg formation in which the exposed strata may be of Jackson. The recognized Jackson area extends westward from Johnson through \Vilkinson, Twiggs, Bleckley, Pulaski, Houston, Macon, Dooly, and Suniter counties and for a short distance into Crisp County. R. S. Bassler2 of the U. S. National Museum, has discovered Bryozoa of Jackson age in specimen of white mad from above the OstTea geoTgiana bed at Shell Bluff, Savannah River, collected -by Sloan3 from stratum "b" of the latter's section. The Ostrea geo1giana bed is exposed in several places along the Savannah River and between this stream and the Oconee River, with 1 Cooke, Charles Wythe, the age of the Ocala limestone: Prof. Pape1, 95-I, U. S. Geol. Survey, 1915. 2 Oral communication to Dr. Vaughan. 3 Sloan, Earle, Catalogue of the Mineral Localities of South Carolina: S. C. Geol. Survey, Ser. 4, Bull. 2, 1908, p. 271. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 11 fullers earth immediately overlying. Red and mottled residual claysands overlie the fullers earth. This residual material covers the greater portion of that section between the two above mentioned rivers formerly mapped as Claiborne. Hence, it seems that the district is within the terrane of the Jackson formation. There are numerous exposures, along streams, of fossiliferous beds beneath the Ostrea georgia1w bed that are of probable Claiborne age. This is borne out by the identification of fossils from numerous collections made within recent years. Dr. Cooke and the writer made a number of collections of fossils from the limestone strata exposed along the Flint River from Crisp County to the Florida line. Cooke has determined the age of the limestone to be Jackson from near the center of Crisp County to Bainbridge, Decatur County. The results of this work are not as yet ready for publication, therefore the strata are mapped "Undifferentiated Eocene and Oligocene." Strata of Jackson age have been determined on Ichawaynochaway Creek, 1Y2 miles below Cordray Mill, Calhoun County/ and on Chattahoochee River near Alaga, Alabama.2 There is also a small, isolated area at Rich H.ill near Roberta, Crawford County. ~ The Jackson group comprises the uppermost Eocene strata exposed in Georgia, lying between the Claiborne group below and the Vicksburg formation (Oligocene) above. The line of division between the Jackson group and the Claiborne group has not been definitely determined, therefore, it cannot be said whether deposition was interrupted or continuous between the older and the younger formations. If the 20-foot bed of sand immediately overlying the Lower Cretaceous in the pits of the Georgia Kaolin Company near Dry Branch, Twiggs County, is Claiborne, the very slight unconformity is indicative of an erosion period between deposition of the two formations. However, this unconformity has not been definitely 1 Veatch and Stephenson, Geology of the Coastal Plain of Georgia: BulL Ga. Geol. Survey, No. 26, 1911, p. 299. 2 Langdon, D. W., Report on the Coastal Plain of Alabama: Ala. Geol. Survey, 1898, p. 383. 12 GEOLOGICAL SURVEY OF GEORGIA. recognized. It is possible that the irregular surface is due to wave action over the shallow water in which the sand was laid down. In. this case the bed probably belongs to the Jackson group, which means i:hat the Claiborne group is entirely overlapped. Lithologically, the Claiborne and the Jackson are very closely related. Crider1 states that in Alabama "even where the two formai:ions have been best studied there seems to be a gradation in both fossils and the stratigraphy from the upper Claiborne to the lower Jackson." In this State, the Jackson has not been described as a .separate group or formation and very little has been published regarding its relationship to the underlying Claiborne. From the de:scriptions by Langdon,2 in the report on the Geolog'y of the Coastal Plain of Alabama, a close relationship, both lithologically and faunally, is evident. No unconformities between the two formations are mentioned. Xn exposures where the Jackson group and Vicksburg formation .are in contact, no evidence of unconformabl~ relations are visible. This is well shown on the Ocmulgee River near Hawkinsville, Pulaski County, where the lower beds are Jackson and the upper beds prob.ably Vicksburg. At Rich Hill near Roberta, Crawford County, .according to Veatch and Stephenson,S the Jackson rests directly on the Lower Dretaceous. Their section shows a bed of sand, which they put in the Jackson, between the Jackson limestone and the Cretaceous clay.' 'This being the case, then, it is possible that the bed of sand occupying the same position at the Georgia Kaolin Company's pits near Dry Branch is also a part of the Jackson. The marine deposited material in the Jackson here indicates that the group originally over- lapped a portion of the Crystalline rocks to the northward. The Jackson group consists of white to cream colored, massive :and thin-bedded, highly fossiliferous limestone, fos~iliferous clays or 1 Crider, A. F., Geology and Mineral Resources of Mississippi: Bull. U. S. Geol. Sur- vey, No. 283, 1906. pp. 38 and 34. ' 2 Op. Cit., pp~ 111, 128, 381, and 383. a Op. cit., pp. 2!)7, 209-:300. PHYSIOGRAPHY, STBVCTUBE, AND GEOLOGY 13 marl, fullers earth, and beds of other clays. The limestone beds which occur at or near the base of the Jackson vary from 15 feet in thickness in the northern part of Twiggs County to 45 feet at the 'quarry, 2 miles .south of Tivola, Houston County. The overlying fullers earth has a thickness of 90 feetl in the northern partof T1viggs and in Wilkinson counties and is about 50 feet in Houston County. Together with the other beds the total thickness of the group varies from 100 to 125 feet between the Flint and Oconee rivers. At Americus, Sumter County, a well record shows the group to be 157 feet thick. If, as is now supposed, the limestone exposures along the Flint River from Crisp County to and below Newton, Baker County, be- long to the Jackson group, the thickness is probably greater through this section than that given above. The more highly fossiliferous bed of limestone in the group is made up almost entirely of Bryozoa with scattered Pecten, Orbitoides, Periarchus and other fossils. This bed is the lower limestone stratum and is immediately overlain by a thinner bed containing a greater variety of fossils among which are species of Bryozoa, Lunulites, Flabellum, Endopachys, Dentalium, Leda, Crassatellites and others. Turritella is rathei common in all of the limestone strata. Some fragments of the whale-like mammal Zeuglodon (Basilosaurus)-, a characteristic Jackson fossil, have been found in Georgia. Sharks' teeth are rather common in the fullers earth bed.s in certain localities. Ostrea georgiana is comnion in the bed underlying the fullers earth of the Savannah River. That portion of the Coastal Plain between the Oconee and Flint rivers immediately underlain by the Jackson group is characterized by a comparatively rugged topography. Prominent escarpments occur along practically all of the larger streams with the limestone outcropping along the lower edges of the slopes. As would be ex pected the scarps are usually along the southeast sides of the streams; this is due to the fact that the strata dip to the southeast and the ten- 1 Sbearer, H. K., Assistant State Geologist of Georgia: unpublished notes, 1915. 14 GEOLOGICAL SURVEY OF GEORGIA dency of the streams is to work al~:mg the strike of the beds. The surface relief, considering the Ocmulgee River as the base, is about 250 feet. The strata are so nearly horizontal that the dip cannot be de- ' tected in any one exposure. By recording the elevations of the contacts of two beds in one exposure and of the same beds in another outcrop the dip of the strata has been calculated to average between 5 and 8 feet per mile. Neither regional nor local disturbances of the strata have been detected, other than an occasional small sink due to the solution of the limestone and the caving of the overlying material. From an economic standpoint the Jackson group is one of the most important series of beds in the Coastal Plain. A large portion of the workable limestone deposits in the southern portion of the State belong to this group as well as the fullers earth deposits of Twiggs and Wilkinson counties, which are among the most extensively worked in the United States and furnish an excellent grade of material. DETAILED DESCRIPTIONS OF THE JACKSON GROUP OF EXPOSURES The object of the detailed descriptions of the exposures which follow is mainly to show the distribution of strata of Jackson age in the district between the Savannah and Oconee rivers, throughout Wilkinson and Twiggs counties, in the southern part of Bibb County, the western part of Dooly County and along the Flint River. It is not within the scope of this, an economic report, to determine definitely the horizon of each of the numerous exposures studied. However, it seems expedient to give here brief descriptions of a few of the more prominent exposures, in the localities mentioned above, to show the necessity of closer investigation before the relationship between the Claiborne and Jackson groups and the Jackson group and Vicksburg formation can be as definitely determined. PHYSIOGRAPHY, STRUCTURE, AYD GEOLOGY 15 :Burke County Shell Bluff.-The strata exposed at Shell Bluff, on the Savannah River, 40 miles below Augusta, have been studied by various geologists and paleontologists during the past century, fe-w of whom have exactly agreed as to the stratigraphic position and age of the beds. The most recent published opinions are by Veatch, Stephenson, and Vaughan/ who determined the strata to be of Claiborne age. :More recent studies of the fossil collections by Vaughan and Bassler have shown Bryozoa of Jackson age above the Ostrec& georgiaFw bed. This bed occurs from 80 to 100 feet above the level of the river. 2 At Griffins Landing, 16 miles by river below Shell Bluff, the Ostrea georgiana bed is immediately overlain by fullers earth. Keys J.lfill (m.ap locality Bu-9) .-The following section was ob- served at Keys Mill, on Brushy Creek, 22 miles northwest of St. Clair: Section at Keys il1ill Eocene. 1:1 eet 4. Residual reel sands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Jackson group. 3. Fullers earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2. Large oyster shells in arenaceous fullers earth. . . . . 7 1. Covered . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . 5 Pond level ................................... . The residual sands of the upper bed are similar in every respect to those which cover the larger portion of this section of the State. The fullers earth of bed No.3 is apparently the same as that at Grif fins Landing and near Louisville. The oyster shell bed beneath the fullers earth is apparently a continuation of the Ostrea georgiana bed at Shell Bluff and near Louisville. The elevation of the top of bed No. 2 is 270 feet by aneroid reading. One mile south of Keys Mill silicified oyster shells were seen in the red sands at an elevation of 320 feet by aneroid barometer reading. 1 Report on the Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, 1911, pp. 243-248. 2 Op. cit., p. 247. 16 GEOLOGICAL SVJWEY OF GEORGIA Jefferson County Near Lo~tisville.-A bed of Ostrea, georgia,na, shells in calcareous fullers earth is exposed on the south side of the Ogeechee River, 200 yards up-stream from Cowarts Bridge, 21'2 miles sout}l of Louisville. The bed is entirely similar to those at Griffins Landing and Keys MilL A collection was made at this exposure by S. W. McCallie, State Geologist, and the oyster identified by Vaughan. Up Rocky Comfort Creek from the bridge one mile north of Louisville, there are several exposures of fullers earth near the water's edge and 35 to 40 feet above. The lowest of the exposures is at least several feet above the oyster shell bed on the Ogeechee River south of Louisville. Red, yellow and white, argillaceous sands occur above the fullers earth. Baldwin County Stevens Pottery.-H. K. Shearer collected Bryozoa (Rich Hill horizon, identified by Bassler) from a bed of gray, fossiliferous marl which immediately overlies Cretaceous kaolin in the pits of the Stevens Bros. Company. Fullers earth overlies the Bryozoa bed. The section and material bears a very close resemblance to the exposures in the northern part of Twiggs County and on the Carswell property in Wilkinson County. Wilkinson County Nea,r :roomsboro.-H. K. Shearer, Assistant State Geologist of Georgia, has furnished the following section of exposures on the property of pr. N. T. Carswell, 3 miles west of Toomsboro: Section on Cu1swell Prope1ty; 3 Miles 1Vest of Toomsboro E()cene. Elev. 5. Residual sands cap high hills. Jackson group. 4. Fullers earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 3. Hard and soft, yellow, argillaceous, bryozoan limestone ............................... 270-290 Unconformity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 17 Cretaceous. 2. Bauxite, lenses. 1. Kaolin and kaolinic sands. Bassler determined Bryozoa of the Rich Hill horizon of the Jackson in a collection from bed No. 3. Other exposures of a similar nature occur throughout the county. Crawford County Rich Hill.1-0ne of the most interesting localities of the Jackson formation is at Rich Hill, 5 miles southeast of Roberta. The hill rises about 150 feet above the small valley on the south side, and is a conspicuous topographic feature. This is an isolated exposure and indicates that the northward extension of the group was formerly much greater than at present.. The hill is capped by brilliant red sand, probably referable to the Jackson group, overlying the calcareous beds undoubtedly belonging to the Jackson; the latter rests upon white clays and sands of the Lower Cretaceous. The hill is deeply trenched by erosion gullies in which the strata are laid bare. The following section was made from exposures in the gullies on the south side: Section at Rich Hill Eocene. Jackson group.(~) }i'eet Jn. 13. Brilliant red sand, capping the hill and forming ''creep'' on the upper slopes. . . . . . . . . . . . . . . . . . 30 Jackson group. 12. Purplish and yellow sand, containing thin clay laminre . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 11. Greenish, laminated clay, thin lignitic partings .. . 4 10. Plastic, calcareous clay with fossils ............. . 0 6 9. Drab, jointed laminated clay, with sand partings .. 6 8. Fossiliferous, nodular, calcareous layer ......... . 0 12 7. Drab, soft, laminated clay with fossils; contains nodular, calcareous layers ................... . 12 6. Limestone, generally soft and friable but in places hard and compact; in places it is a bryozoan marl so soft that it may be scraped up with the 1 Reprint from Veatch and Stephenson, Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, 1911, pp. 299-300. 18 GEOLOGICAL SURVEY OF GEORGIA : .c ] hands. Fossils chiefly Bryozoa, Pecten perplanus, and Mortonia sp.; fish teeth are also abundant in places . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5. Brown and yellow unconsolidated' sand which in places is replaced by limestone. . . . . . . . . . . . . . . . 12 Lower Cretaceous. 4. White, micaceous clay; maximum................ 10 a. White, cross-bedded clayey sand................. 10 2. White, micaceous clay......................... 3 1. Coarse, white sand. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 List of Ji'ossils from Rich Hill (Identified by T. ltV. Tla-ughan) Mortonia sp. Plejona sp. Calyptrea aperta (Solander) Ostrea georgiana Conrad Pecten perplanus ])t!orton Pecten, probably P. nuperus (Con- rad) young and poor specimens Venericardia sp. Lucina sp., (found also 52 miles south of Perry) Panoprea sp. (The Mortonia refened to above is also found at Castle Hay~e and Wilmington, N. C., and 9 miles east of Waynesboro, Burke Co., Ga.) Twiggs County Dry Branch.-There is an exposure of Jackson strata in the pits of the Georgia Kaolin Company, 2 miles east of Dry Branch. A comparison of the section given below with that at Rich Hill, Crawford County, given above, shows a very close similarity between the two exposures. Another outcrop of the calcareous Jackson bed occurs in a gully one-half mile southeast of the Georgia Kaolin Company. This exposure was studied by Veatch and Stephenson1 and i ihe determination of the fossils collected by Vaughan. Sect'ion at Geo1gia Kaolin Company's Pits Feet In. 8. Top soil, reddish, sandy clay... . . . . . . . . . . . . . . . . . . 2 Eocene. Jackson group. 7. Gray fullers earth (weathered), blackish, probably organic, stains in thin partings................. 18 1 Veatch, Otto, and Stephenson, L. W., Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, 1911, p. 304. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 19 6. Whitish, highly fossiliferous sandy fullers earth; Bryozoa, Orbitoides, Pecten perplanus Morton... 6 Claiborne~ 5. Coarse grained, brownish sand, black at base.. . . . . . 1 6 4. Wavy, thin-bedded, coarse, red, gray, and black sand 2 6 3. Grayish-yellow, coarse grained sand............... 12 2. Hard to soft fossiliferous sand, containing clay pebbles .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Unconformity. Lower Cretaceous. 1. White kaolin, sand said to underlie. . . . . . . . . . . . . . . 20 Dr. C. Wythe Cooke makes the following statement in a letter to the writer regarding collections sent him from this locality: "The calcareous material (bed No. 6) is Jacksonian." He recognized Mesalia vetusa (Conrad) in the collection from bed No. 2 and places the horizon as "probably Claiborne." A very doubtful unconformity exists between beds Nos. 5 and 6. Vaughan identified the following list of fossils from the 15-foot exposure of "soft, white, argillaceous marl" one-half mile. southeast of the Georgia Ka?lin Company's pits, and, upon the evidence furnished by the species, determined the horizon to be Jacksonian :~ List of Fossils from Ravine One-half .:.viile Southeast of the Georgia Kaolin, Oompany':s Pits (Vaughan) Platytrochus stokesi (Lea) Mortonia Leda multilineata Conrad Pecten perplanus Morton Proto cardia Tellina Corbula densata Conrad Bryozoa (very numerous) Lowe 1Vall Property (map locality T-1) .-There is on the Lowe Wall place, 2 miles south of Pikes Peak Station, a 12-foot exposure of soft, cream colored, limestone composed almost entirely of fossils. This stone is similar both lithologically and faunally to that of the various other exposures of Jackson limestone in this and the contiguous counties. Black, tough clay-soil, probably derived from fullers earth, overlies the limestone. Cooke identified Bryozoa, Periarchus 1 Op. cit. 20 GEOLOGICAL SURVEY OF GEORGIA piletts-sinensis (Rav.) and Pecten perplanus Morton in a collection from this exposure. Map locality T-2.-A si:rp.ilar exposure to the above occurs on the south side of an abandoned railroad cut 32 miles southeast of Stony Creek church. The following section is descriptive of the strata exposed: Section 3 1/2 J.lfiles Southeast of Stony Creek Church Jackson group. Feet 3. Gray fullers earth, topped by tough, black clay-soil. 6 2. Soft, white, highly fossiliferous limestone with thin, medium hard, layers. Lower 2 feet argillaceous. . 16 1. Argillaceous sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Dr. Cooke identified the following fossils in a collection from this exposure and determined the horizon to be Jacksonian : List of Fossils from 3 1/2 Miles Smttheast of Stony Greek Chttrch Bryozoa (Rich Hill fauna) 1 Periarchus pileus-sinensis (Rav.) Ostrea sp. Pecten pmplanus Morton Proctocardia sp. Cra.ssatellites sp. Near Bond's Store (tnap locality T-3).-A deep gully on the east side of the public highway, 11;4 miles south of Bond's store, exposes 13 feet of soft, white, highly fossiliferous limestone of Jackson age. The stone is overlain by fullers earth which is in turn overlain by red and mottled residual sands. Cooke identified Bryozoa (Rich Hill horizon), Periarchus sp. and Pecten perplamts Morton from this exposure. The residual sands capping the hill is probably residual of beds of late Eocene or Oligocene age. Fitzpatrick Place (map locality T-6) .-Several exposures of the characteristic Jackson limestone of this section occur on the Fitzpatrick place, between Tarversville .and Westlake. Bryozoa (Rich Hill fauna), Periarchus piletts-sinensis (Rav.) and Pecten perplanus Morton were determined by Cooke from a collection obtained from an exposure on Crooked Creek, 32 miles northeast of Westlake. 1 Dr. R. S. Bassler h'as kindly identified the Bryozoa in this and other collections. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 21 Near Danville.-On the east side of the Macon, Dublin & Savannah Railroad, 11/2 miles north of Danville, excavating for road bed mate"'rial has uncovered a bed of Ostrea georgiana shells (identified by Cooke) in an arenaceous, calcareous matrix. Casts of other fossils are likewise present but unidenti:fiable. One mile east of this exposure, at "Kaolin Spring" there is an exposure of bluish fullers earth at an altitude of at least several feet higher than the shell bed. :Bibb County Near Old Bond P. 0. (map locality Bi-1).~Jacksonian limestone is exposed on the Ard place, 1:Y2 miles northeast of the old Bond P, 0. The stone outcrops in several gullies and on the gentie slopes of a low knoll. No difference between this material and that of exposures of the Jackson limestone in Twiggs and Houston counties was noted. Bryozoa, Periarchus sp. and Pecten perplanus Morton were recognized. :Bleckley County Near Ainslie Station (rnap locality B-1).-An excellent exposure of limestone of Jackson age occurs on the east side of Shellstone Creek, 1~ miles east of Ainslie, on the Weatherly place. The following section is descriptive of the strata exposed: Section on Weatherly Place, East Side of Shellstone Creek, 1 1/4 Miles East of Ainslie Station Residual Jackson. Feet 6. Red argillaceous sands to top of escarpment. No sharp line of contact between this and the underlying bed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Jackson group. 5. Cream colored fullers earth (weathered) with some sand ...... : ........................ .'........ 20 4. Hard, pinkish, partly crystalline limestones, Turritella sp.................................. . . . . 1 3. Medium hard, white, highly fossiliferous limestone. 5 2. Soft, white, porous, friable, highly fossiliferous limestone .......... , . . . . . . . . . . . . . . . . . . . . . . . . . 15 22 GEOLOGICAL SUEVEY OF GEOEGIA Recent. 1. Creek pottom land. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 0. Creek bed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Cooke identified the following fossils from collections made at this exposure : List of Fossils f1om 11j41J!liles East of Ai.nslie Station (See above section) Upper 1 foot of bed 3 Periarchus sp. Semele~ sp. Bed No.2 Bryozoa (Rich Hill fauna) Periarchus pileus-sinensis (Rav.) ~ Pecten perplanus Morton Lowm 1 foot of bed No.3 Lunulites sp. Flabellum wailesii Conrad~ Endopachys maclurii (Lea) ~ Dentalium sp. Leda. multilineata Conrad Panope sp. Crassatellites sp. Houston County Snwll Place (map locality H-6).-An excellent section of the Jackson group strata is exposed on the Geo. L. Small property, 4 miles east of Kathleen, in a gully one-half mile northwest of the Small residence. Section on Small Place) 4 M'iles East of Kathleen --------------'Residual Jackson. Feet 8. Red sands, mottled arenaceous clays and flint. . . . . . 50 Jackson group. 7. Medium soft, cream colored, highly fossiliferous limestone .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6. Cream colored fullers earth (weathered).. . . . . . . . . 16 5. Hard, white limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4. Cream colored, arenaceous fullers earth (weathered). Six layers of harc1, white limestone 4 to 6 inches thick ........................................ 28 3. Mottled clay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Hard, cream colored, partly crystalline limestone. Fossils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Soft, white, porous, highly fossiliferous limestone. Fossils in lower 10 feet mainly Bryozoa with PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 23 Periarchus sp. and Pecten perplanus Morton. Upper 8 feet has a greater variety.. . . . . . . . . . . . . . . 18 0. Talus to creek bottom........................... 5 List of Fossils from Small Pkwe, 4 .Jliles East of Eathleen, Bed No.7 of the above section (Identified by C. TVythe Cooke) Lunulites sp. Periarchus sp. Ostrea georgiana Conrad Pecten perplanus Morton 1 Corbula sp. Venericardia sp. Descriptions of other exposures in Houston County are given in pJace in this report on "Individual Locality Descriptions" and in the report on the "Geology of the Coastal Plain of Georgia" by Veatch and Stephenson, Georgia Geological Survey Bulletin No. 26, 1911. Dooly County Carter Place ( rnap locality D-3) .-There are several exposures of highly fossiliferous fullers earth and limestone on the J. M. Carter place, l:If2 miles southeast of Lilly, on the northwest side of Penne- hatchie Creek. From a colJection of fossns, mainly Bryozoa, sent to Dr. Cooke, he determined the horizon to be middle Jackson, probably the Rich Hill horizon. Flint River The limestone at Bainbridge, Decatur County, formerly referred to the Vicksburg formation, has recently been discovered to be of Ocala (Jackson) age by Cooke,1 who has also determined .from fossils collected by himself and the writer that the limestone exposed along and near the Flint River from near the northern boundary of Crisp County to Bainbridge is also of Jackson age. The data upon which this opinion is based are not yet ready for publication. On the map accompanying this report this and the contiguous territory nuderlain by this limestone is mapped as "Undifferentiated Eocene and Oligocene." ,. 1 Cooke. C. W.. The age of the Ocala. limestone : Prof. Paper, U. S. Geo!. Survey, No. 95-I, 1915, p. 110. 24 GEOLOGICAL SURVEY OF GEORGIA UNDIFFERENTIATED EOCENE AND OLIGOCENE The "Undifferentiated Eocene and Oligocene" of this report includes those portions of the Coastal Plain formerly mapped as the Vicksburg formation. This change is b.ased upon investigations near Albany by Dr. Vaughan1 and Dr. Cooke's study of the fossils collected by himself and the writer from the limestones along the Flint River between Crisp County and Bainbridge. The limestone from Albany to Bainbridge is correlated by Cooke with the Ocala formation of Florida, the upper division of the Jackson group. The complete data are not yet ready for publication. These strata outcrop over a large area in the southwestern and north central parts of the Coastal Plain and over small areas along and near the Savannah River, in Burke and Screven counties. In the large area the beds cover parts or all of Laurens, Bleckley, Pulaski, Dodge, 'VVilcox, Houston, Dooly, Crisp, Sumter, Webster, Lee, Terrell, Randolph~ Clay, Calhoun, Dougherty, ~itchell, Baker, Early, Miller, and Decatur counties. The limestone exposures along and west of the Flint River are of Jackson age and the outcrops at and below Hawkinsville on the Ocmulgee River are of ViCksburg age._ The strata of this group lie between the lower part of the Jackson group (Eocene) below and the Chattahoochee formation (Oligocene) above. Southwest of Sumter County the beds overlap the lower lime-stone of the Jackson and rest unconformably on the Claiborne and Wilcox formations. East of the Flint River deposits of later than the Oligocene overlap these undifferentiated beds. Limestones, clays, flint, and residual clays and sands make up the beds under consideration. Limestones outcrop along the Ocmulgee and Flint rivers and in several localities west of the latter streams, notably along Kinchafoonee and Fowltown creeks in Lee County and along Spring Creek in Calhoun and Decatur counties. Residual red and mottled sands and sandy clays cover all of the uplands underlain by the limestone beds. Fossiliferous flint is very generally distributed. 1 Veatch, Otto, and Stephenson, h W., Geol-ogy of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, 1911, pp. 316-317. PHYSIOGRAPHY, STRUCTURE; AND GEOLOGY There are excellent exposures of huge boulders of this silicified limestone along Spring, Ichawaynochaway, and Chickasawhatchie creeks. Superficial Pleistocene sands cover large areas of the strata along the terrace planes of the larger streams in the area underlain by these undifferentiated strata. The thickness of these strata was estimated by Veatch1 to be around 300 feet in the southwestern part of the State and less than 100 feet in Randolph and Webster counties. The area underlain by these deposits is generally rolling to level. Along a few of the larger streams there are occasional steep escarpments Jess than 100 feet high. Shallow ponds and depressions due to the solution of the limestone and ~ubsequent caving of the roofs are frequently seen throughout the area but more especially in the southwestern part of the State. These depressions frequently cover a hundred acres or more. APALACHICOLA GROUP2 The Apalachicola group of the Oligocene series in Georgia includes the Chattahoochee and Alum Bluff formations. CHATTAHOOCHEE FORMATION The Chattahoochee formation appears at the surface in relatively small areas, being largely concealed by the overlying Alum Bluff and later formations. Good exposures occur along Flint River and in lime sinks near Recovery in Decatur County. Strata belonging to the formation were noted by Langdon3 on Chattahoochee River, 9 miles above River Junction, Fla. The formation appears at Forest Falls and other lime sinks in the northern part of Grady County, in the vicinity of Metcalf and Thomasville, Thomas County, and in the beds and bluffs of Ochlockonee, Withlacoochee, and Allapaha rivers near the Georgia-Florida line. On Ocinulgee River near Abbeville and near t Veatcli, Otto, and Stephenson, L. W., Geology of the Coastal Plain of Georgia : Bull. Ga. Geol. Survey, No. 26, 1911, p. 309. 2 Abstracted from Geology of the Coastal Plain of Georgia : Bull. Ga. Geol. Survey, No. 26, 1911. 3 Am. Jour. Sci., 3rd ser., Vol. 38. 1889, p. 324. 26 GEOLOGICAL SURVEY OF GEORGIA Hawkinsville the formation is be]jeved to be represented by fragmentary beds and by residual fHnt masses containing corals. Limestone, which outcrops near Jacksonboro on Briar Creek in Sci'even County, has been correlated by Vaughan with the Chattahoochee formation. Limestone, which outcrops in a small area northwest of Millen, Jenkins County, is provisionally considered as a part of the same formation; but the evidence for this classification is admittedly very meager. Limestone of the Chattahoochee formation occurs near Cordele, Crisp County, and probably also 7 miles northwest of Syl-vester, 3 miles west of Bridgeboro, and 5 miles northwest of Sale City. Strata of this formation are believed to outc1~op in the escarpment east of Flint River from Crisp County to Decatur County but are largely obscured by weathering. Buried representatives of the formation are believed to underlie nearly all the Coastal Plain of Georgia southeast and south of the areas of outcrop. The formation has been recognized on paleontologic evidence in a well.boring at Tarboro, Camden County, between the d:epths of 375 and 400 feet. Pumpelly1 and Vaughan2 have recognized an erosion unconformity between the Chattahoochee and the underlying limestone in Decatur County. At Blue Springs, on Flint River, 4 miles south of Bainbridge, both formations are present, but the contact between the two is much obscured by weathering of both. At Red Bluff, 7 miles north of Bainbridge, a contact similar to that at Blue Springs is e:rposed. The Chattahoochee formation appears as fragments of flint in residual sandy clay, and the weathered limestone of the Jackson group appears at the base of the bluff. There is evidence of an erosion unconformity at this localit}r, and also at the bluff back of the old factory about 2 miles above Bainbridge. Sedimentation was probably continuous from the beginning o.f Chattahoochee to the end of Alum Bluff, for no evidence of an erosion interval separating the two formations has been observed in the 1 Am..Tour. Sci., 3rd ser., Vol. 46, 1893, pp. 445-447. Science, new ser., Vol. 12, 1900, pp. 873-875., PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 27 :field. McCallie/ however, has noted an unconformity at the old Toy phosphate pit, 31h miles west of Boston; but whether this is due to erosion or to solution and irregular weathering of the limestone has not been determined. When this locality was visited by the writer the relations of the clay to the limestone had become obscured by the debris :filling the pits. The Chattahoochee formation is, in general, calcareous and varies from compact, pure, crystalline limestones to earthy argillaceous limestones and calcareous sands and sandstones. Compact, gray, drab, or white fossiliferous limestones make up the bulk of the formation. A brecciated or conglomeratic structure is characteristic of some of the beds, the phenomenon being observed at nearly all localities where there are good exposures. The rock is phosphatic ai a number of places, containing brown or black rounded pebbles of phosphate or fragments of bones. and teeth. The limestones at the base of the formation have been replaced by silica at several localities and at others are represented by fragmental beds of flint containing coraJs and other fossils in a matrix of residual clay. The fiin t closely resembles that of the underlying formation and cannot everywhere be easily distinguished from it. Northwest of Facev-ille, Decatur County, the Chattahoochee formation has a probable total thickness of 100 feet. At Forest Falls, or Limesink, in the northern pa~t of Grady County, it has an exposed thickness of 85 or 90 feet. No very reliable data are at hand for estimating its total thickness to the east and northeast, but its maximum probably does not exceed 250 feet. In portions of Decatur, Grady, Thomas, Brooks, and Lowndes counties, where the Chattahoochee formation lies near the surface, the topography is a little more hilly and rugged than in other parts of southern Georgia. Lime sinks, lakes, and ponds due to the underground solution and consequent caving in of the limestones of the formation are notable features of the topography. 1 McCallie, S. W., Phosphates and Marls of Georgia: Bull. Ga. Geol. Survey, No. 5-A, 1896, p. 62. 28 GEOLOGICAL SURVEY OF GEORGIA The formation is tilted slightly southward and southeastward. The dip is low, probably not over 8 feet to the mile. The top of the formation is estimated to be about 225 feet above sea level at Forest Falls or Limesinlt, and about 200 feet above sea level near Face-ville, approximately 24 miles ~o the southwest... At Red Bluff, 7, miles north of Bainbridge on Flint River, where Vaughan has determined paleontologically the presence of the Chattahoochee, its base can hardly be more than 20 feet above the river, and at Blue Spring, 4 miles below Bainbridge, is about 10 feet above the river. This . indicates a very low dip. Local dislocation~ of beds, due to underground solution and consequent sinking, have been observed in Thomas and Decatur counties. . ALUM BLUFF FORMATION The Alum Bluff formation outcrops in southern and south-central Georgia throughout a large area extending from Decatur County northeastward to Savannah River. The limit of the deposits of the Alum Bluff is on the north approximately Waynesboro, Tennille, and Vienna; on the west the west-facing escarpment which separates the Altamaha upland from the Flint River valley; and on the east a line extending from Savannah River near the niouth of Buck Creek through Sylvania, Reidsville, and Blackshear to the western edge of Okefenokee Swamp. Except along stream, escarpments near streams, and near the Florida line, the entire area underlain by the Alum Bluff formation is mapped as "Undifferentiated Oligocene to Pleistocene; inclusive." The Alum Bluff formation conformably overlies the Chattahoochee formation. On Savannah and Altamaha rivers it is separated from the overlying lVIiocene by an erosion unconformity probably of minor importance. Throughout the greater part of the area underlain by the Alum Bluff formation its weathered products are believed to form the surface material, but in southeastern Georgia it is overlain by lithologically similar undifferentiated deposits, ranging in age from Miocene to Pleistocene. In narrow areas along all the PHYSIOGRAPHY, STBVCTUBE, AND GEOLOGY 29 larger streams the formation is overlain by thin terrace deposits of Pleistocene age. The Alum Bluff appears in a number of different lithologic phases, including subordinate beds .of pebbles, coarse angular sands, coarse grained, aluminous sandstones or grits, sandy clays, fullers earths, phosphatic sands, quartzites, sandstones, silicified clays, and limestones or calcareous layers and nodules of local extent. Greenish or gray argillaceous sands and sandy laminated clays form the greater part of the formation. The thickness of the Alum Bluff formation in Georgia is estimated to be 70 to 200 feet. At no known locality can the full thickness of .the formation be seen in natural exposure, and the estimate is based chiefly on well records. The higher divides and uplands underlain by the Alum Bluff and mapped as "Undifferentiated Oligocene to Pleistocene, inclusive," present a peculiar topography. Part of this _area constitutes the Altamaha upland, one of the major topographic divisions of the Coastal Plain of Georgia, an area of low hills with gentle slopes and sofened outlines, of shallow saucer-shaped valleys, rriany of which are not more than 40 or 50 feet deep, of sluggish clear-water streams bordered by swamps and sand hammocks and of "bays" and cypress ponds. Altamaha and Oconee rivers have cut deep valleys, and the precipitous bluffs along their courses form an exception to the gen- eral type of topography of the area. The formation has a very low southward and southeastward dip, certainly much less than that of the older Eocene formations. On Savannah River the dip does not exceed 4 or 5 feet to the mile, and near the Florida line the beds must be almost horizontal, for the streams have cut through them, exposing the underlying formations. No evidence of broad :flexures nor even minor folding and faulting was observed in the natural exposures of the strata. However, the probability that a broad arch exists in the southern part of the State has been mentioned. 30 GEOLOGICAL SURVEY OF GEORGIA UNDIFFERENTIATED OLIGOCENE TO PLEISTOCENE~ INCLUSIVE 1 The materials designated "Undifferentiated Oligocene to Pleistocene, inclusive," on the geologic map have been partly discussed under Alum Bluff formation, and under Miocene series. The bulk of the deposits previously in.cluded by Stephenson and Veatch, and by others in the Altamaha formation and referred questionably to the Pliocene are now regarded by them as Oligocene and as probably contemporaneous with part of the Alum Bluff formation. This material consists of irregularly bedded, locally indurated sands, clays, and gravels. On the whole the individual beds are homogeneous, but locally they are a heterogeneous mixture. The indurated sands and the conglomerates contain a peculiar greenish or greenish-gray disseminated clay and are described as "gray or greenish aluminous grits." The pebbles are predominantly subangular, many of'them lath shaped, and the sands are universally.harsh or in sharp angular grains. Feldspar is present in great abundance, both as pebbles and as semi-decomposed disseminated grains, and phases of the deposits may be appropriately described as "feldspathic grit." Calcareous phases are totally absent. The weathered surface materials are mottled and splotched in red, yellow, purple, and gray, the surface aspects differing in this respect from those of any other formation of the Coastal Plain. These striking effects are probably due to unequal weathering, oxidation, and unequal distribution of iron material. This peculiar surface phase is not a later deposition, but results from weathering, although in many places it appears to overlie unaltered beds unconformably. The materials are very coarse grained, even at points 100 miles from their northern margin. The beds that have been locally indurated to sandstones, conglomerates, and claystones, do not differ essentially in composition from the nonindurated materials. The age of most of this material west of a line from Rocky Ford to Waycross is believed to be Upper Oligocene. East of that line it probably ranges in age from Miocene to Pleistocene. 1 Abstracted from Water Supply Paper, No. 341, TT s Geol. Survey. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 31 MIOCENE SERIES 1 MARKS HEAD MARL The Marks Head marl has been differentiated at and in the vicinity of Porters Landing, Savannah River, Effingham County, and is doubtless represented in the undifferentiated Miocene in the sections above Porters Landing, at least as far as Hudsons Ferry, and in the sections between Porters Landing and Sisters Ferry. The formation is almost entirely concealed by younger sediments outcropping only in the bluffs of streams. For this reason it has had little or no influence on either the topography or the soil of the region. So far as can be determined from natural exposures, it lies almost horizontal, having only a very slight dip southward, probably not more than 4 feet to the mile. The Marks Head marl rests upon the Alum Bluff formation of the Oligocene, from which, according to exposures on Savannah River, it is separated by an erosion unconformity. The formation is overlain unconformably by the Duplin marl, and as the Marks He!id marl is early Miocene and the Duplin marl late Miocene the unconformity separating them is important. The beds of the formation consist of gray or brownish compact argillaceous sands containing large calcareous nodules and, in places, of friable phosphatic sands containing shells. The phosphatic sands consist mainly of quartz grains with subordinate percentages of phose phate in the form of small, brown and black, smooth or water-worn particles of bones and teeth, disseminated clay, and calcium carbon ate in the form of shells and calcareous nodules. A maximum observed thickness of 45 feet occurs in some of the sections in the vicinity of Porters Landing on Savannah River. DUPLIN MARL The Duplin marl has been differentiated in the sections at Porters Landing and at Mount Pleasant Landing, 1% miles below Por- 1 Abstracted from Veatch and Stephenson's report on the Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey. No. 26, 1911. 32 GEOLOGICAL SOEVEY OF GEORGIA ters Landing. The formation is doubtless represented in undifferentiated Mio~ene beds recognized in bluffs above Porters Landing as far as Hudsons Ferry, and below Porters Landing perhaps as far as Purisburg, S. C., 23 miles above Savannah. The formation has also been differentiated at Doctortown, at Buzzards Roost Bluff, and at Bugs Bluff on Altamaha River. The terrane probably underlies superficial formations throughout much of the region intervening between its exposures on Altamaha and Savannah rivers. The Duplin strata dip southeastward at a low angle, probably not greater than 3 or 4 feet to the mile. Except. in a few st:eam bluffs the formation is probably concealed over the entire area of its occurrence by superficial deposits, and for this reason has had little or no part in determining the topographic features of the character of the soils. The Duplin marl rests unconformably upon the Marks Head marl, or, where the latter is absent, upon the Alum Bluff formation of the Oligocene. The former relations were observed in ections examined at and in the vicinity of Porters LanQ.ing, Savannah River, and the latter relations are believed to obtain in sections on Altamaha River, at the bluff at Doctortown, at Buzzards Roost Bluff, and at Bugs Bluff. In the vicinity of Porters Landing the formation is overlain by terrace deposits of Pleistocene age. The formation as exposed on Savannah River is mainly a shell marl, consisting of shells in a matrix of coarse phosphatic sand, but in places is a :fine gray or brown quartz sand containing scarcely any fossils or calcareous matter. On Savannah River it probably does not reach a thickness of more than 10 to 12 feet. On Altamaha River the Duplin marl consists of 12 or 15 feet of friable, sandy, and pebbly shell marls,_ and bluish, compact, fine grained, argillaceous, fossiliferous sands. It overlies, unconformably, strata of probable Alum Bluff age and is in turn overlain by undifferentiated, vari-colored sands and clays which probably belong, in part, to the Pliocene and, in part, to the Pleistocene. LIMESTOYES OF T17E COA T A L PLA I A OF GEORGIA PLATT? 11 HE OF Ll;\IE ' TO?\E OF TUE .TdC KSO X il'0101ATIO?\ IX A G ' LLY F IV E )liLES SOuTHEAST OF ROBERTA, CllA WFOllD CO NTY. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 33 PLIOCENE SERIES 1 Although the existence of strata of Pliocene age in Georgia has not been definitely proved, certain deposits have been referred with greater or lesser degree of confidence to this epoch. The deposits of the Atlantic and Gulf Coastal Plain to which the name Lafayette formation 'has been appEed have for many years been regarded as of probable Pliocene age. The Lafayette formation is represented by McGee as covering the entire Coastal Plain of Georgia, and has been descr-ibed by different investigators from numerous localities in Georgia. Recent investigations have shown, however, that many and perhaps all of these correlations were erroneous. Certain fossiliferous strata exposed on Satilla and St. Marys rivers have, on paleontologic evidence, been considered as probably of Pliocene age and are described under the name Charlton formation. These marine strata probably have littoral shallow-water representatives in the undifferentiated Oligocene to Pleistocene deposits to the north in Ware, Pierce, Appling, and 'Wayne counties. CHARLTON FORMATION The name Charlton is derived from Charlton County, Ga., and is applied to an argillaceous limestone and clay formation exposed in the banks and bluffs of St. Marys River from Stokes Ferry, 11 miles south of St. George, Charlton County, to Orange Bluff, near Kings Ferry, Fla. From a study of the fossil collections from the St. Marys: localities T. W. Vaughan has classified the formation as probably Pliocene. Fossiliferous marls probably referable to the formation have been. observed on Satilla River at Burnt Fort, 12 miles northeast of Folks- ton, Charlton County; on land of vV. M. Thrift, 6 miles east of Wino- kur, Charlton County; and at the King plantation, 6 miles south of Atkinson, Wayne County. Fossils from the last-named locality have 1 Abstracted from Veatch and Stephensons report on the Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, lDlL 34 GEOLOGICAL SURVEY OF GEORGIA been referred by Aldrich1 and DalP to the Pliocene. General considerations based on structure and on the lithologic character of the materials seem to justify the reference of this marl bed to the Charlton formation. The relations of the Charlton formation to the Miocene are not definitely known. From Stokes Ferry, where the to.p of the formation is perhaps 30 or 35 feet above sea level, the upper non-conformable surface descends gradually down-stream and finally reaches tide level. According to the geologic map of Florida, by Matson and Clapp/ the Jacksonville formation (lVliocene) outcrops at elevations of 50 to 100 feet above sea level a short distance south and east of St. Marys River. Beds from which T. W. Vaughan has identified Miocene fossils, are exposed at low tide at Owens Ferry, Satilla River, Camden County. In view of these occurrences of Miocene the Pliocene beds on St. Marys River, if correctly correlated, may occupy an erosion basin in Miocene strata, or, if the latter are absent beneath them, they may rest in a similar basin in pre-Miocene strata probably referable to the Alum Bluff formation (Oligocene). The great thickness attributed to the Miocene at Jacksonville, 460 feet, and the fact that the Miocene there is supposed to lie unconformably upon the Vicksburg makes the former alternative seem the more probable. There are no data for estimating the thickness of the formation, for Only 12 or 15 feet of strata have been observed in natural exposures. QUATERNARY SYSTEM; PLEISTOCENE SERIES The Pleistocene deposits consist of thin accumulations of sand, day, and gravel on terraces of fluviatile and marine origin. The only systematic description of the Pleistocene of the Coastal Plain 1 Nautilus, Vol. 24, No. 11, 1011, p. 131. 2 U. S. Nat. Mus. Proc., Vol. 46, 1013, pp. 226, 227. 3 Florida Geology Survey, Second Annual Report, 1909. 4 Abstracted from Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, 1911. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY .35 of Georgia previously given is that of McGee1 . McGee first studied the Pleistocene in the District of Columbia, gave it the name Columbia formation, and differentiated it into three phases, the fluvial, interfluvial, and low-level phases, all of which he recognized in Georgia. The classification given in the present report is based largely on ~. topography, and the formations are here described in greater detail than in McGee's report. The name Columbia as a group term is retained. The divisions are as follow'S: Satilla formation. Marine terrace deposits. Fluviatile deposits. Okefenokee formation. Coastal terrace sand. Fluviatile deposits. The solution of the Pleistocene problems of Georgia, and in fact those of the Atlantic Coast region in general, depends largely on a knowledge of topographic details, which cannot be available until detailed topographic maps are made. In Georgia the Pleistocene formations are not superimposed one upon the other, but occupy terraces at different topographic levels. During the Okefenokee epoch 2 to 15 feet of gray sands and other sediments were laid down on a terrace plain of probable marine origin, now 60 to 125 feet above sea level, and contemporaneous fluviatile deposits of gravel, sand, and loam, having a maximum thickness of 50 feet, were laid down on the "second" terrace skirting the larger rivers_ During the Satilla epoch gray sands and muds a few to 50 feet in thickness were I aid down on a marine terrace, a flat plain 20 to 40 miles broad, bordering the coast at elevations of 15 to 40 feet above sea level, and corresponding terrace alluvium was deposited along the rivers. Although the available data are too incomplete to permit positive statements, it is not improbable that an older Pleistocene terrace plain exists west of and at a higher elevation than the Okefenokee terrace. Evidence of such a plain is to be seen in the topographic. 1 McGee, W. J., The Lafayette formation : U. S. Geol. Survey, 12th Ann. Rept., Pt. 1, 1891, pp. .'384-407. . 36 GEOLOGICAL SURVEY OF GEORGIA aspect of the country along the Atlantic Coast Line Railroad between Valdosta, Lowndes County, and Waycross, Ware County; along the Atlantic Coast Line Railroad between Pearson, Coffee County, and Waycross; and along the Southern Railway between Baxley, in Appling County, to near Jesup, Wayne County. The gen- eral surface of the belt of country crossed by these railroads is a nearly level plain which gradually descends toward the coast. Along the :first mentioned railroad there is a descent from an elevation of 215 feet at Valdosta to 140 feet at Waycross; along the second there is a descent from 205 feet at Pearson to 140 feet at Waycross; and along the third a descent from 206 feet at Baxley to 155 feet at Odum. The northern part of Effingham and the southern parts of Screven and Bulloch counties also present the aspect of a plain similar to the ,Okefenokee plain. RECENT SERIES The Recent deposits, or those formed since the close of the Pleistocene or the uplift of the Satilla or latest Pleistocene terrace and now in the process of formation, consist of (1) marsh and tide-swamp muds, (2) beach and dune sands, (3) river flood-plain deposits, (4) inter-stream swamp deposits, and (5) certain terrigenous deposits, semi-alluvial in character. 'l'he processes by which the Satilla terrace, with its accompanying deposits, was formed are being repeated at the present time along the coast. The Recent terrace thus being formed is largely submarine. Beach sands are being laid down on the ocean front, sands and clays are being deposited in the estuaries, and muds are being deposited in the marsh and tide-swamp land' s. Though observations have :o.ot been made at many localities, it may be said that the thickness of the Recent deposits in the area inundated by the tides probably does not exceed 6 feet. The composition of the muds is indicated by the following analysis of a sample from St. Simons Island, collected by PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 37 S. W. McCallie and analyzed by Edgar Everhart: Analysis of J,htd from St. Simons Island Moisture at 100 C... . . . . . . . . . . . . . . . . . . . . . . . . . . Loss on ignition............................... Soda (Na,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime ( CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,03 ) Ferric oxide (Fe,03 ) . Titanium dioxide (TiO,)....................... Sulphur trioxide (S03 ). Phosphorus pentoxide (P 02 5 ). Chlorine (Cl) .. . .. .. .. .. .. .. . .. . .. .. . .. .. .. .. . Silica (Si02 ) 4.62 9.94 3.06 1.13 .40 1.28 13.67 4.86 1.01 .24 .22 1.77 57.95 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _. 100.15 In places the Satilla terrace is separated from the Recent terrace by bluffs 10 to 15 feet high, and at other localities the two merge into each other. In the southeastern part of the Coastal Plain of Georgia are numerous swamps ranging in size from a single acre to the immense tract known as Okefenokee Swamp. Peaty accumulations or decayed plant matter with more or less silt and sand are being formed in these swamps. In the Okefenokee Swamp acc;umulations of peat 4 to 8 feet thick have been observed. Some of the swamp areas are densely wooded and have been the roosting places of birds for perhaps centuries, and a phosphatic muck is being slowly formed from their dung and dead bodies'. SUPERFICIAL GRAY SANDS OF THE UPLAND Superficial grayish or brownish, incoherent quartz sands a few inches to 30 feet thick cover large portions of the inter-stream uplands of the Coastal Plain of Georgia at elevations higher than the Pleistocene terrace plains. Because of the sterility of the soils which these sands produce and their influence on the topography and tree growth, they attract the attention even of those not interested in geology. The sands are not everywhere of the same origin. Much of 38 GEOLOGICAL SUEVEY OF GEOEGI.A the sand is residual and cannot be referred to any one geologic period or formation. ,However, in places there are wind-blown accumulations, and at long intervals marks 'Of stratification can be detected. In this report no attempt has been made to subdivide or to map these sands; a part of such mapping, indeed, would fall within the province of a soil survey. GENERAL DISCUSSION OF LIMESTONE CLASSIFICATION OF ROCKS The cruE~t of the earth is made up of three different classes of rocks-igneous, metamorphic, and sedimentary. Igneous rocks include granite, diorite, trap rock and numerous others, solidified from the molten state at or beneath the surface. A metamorphic rock is one in which the texture and mineral composition of the original rock, either igneous or sedimentary, has been altered by pressure, c;hemical agencies, heat or combinations of these agencies. Schist, gneiss, and marble (crystalline limestone) are representative of this group. Sedimentary rocks are those which have been deposited on land 01' in the water by either mechanical, chemical or organic agencies. Samples of this class of rocks are sandstones, shales and limestones. ORIGIN OF LIMESTONE Practically all igneous rocks and most metamorphic and sedimentary rocks contain calcium in combination with other elements. The calcium mineral is usually insoluble, or nearly so, but the continued action of weathering agents and the addition of acids to the water allow a very small percentage to be held in solution as the sulphate, carbonate or other salts of calcium. One liter of pure water at a temperature of 8.7 C. will dissolve 0.01 gram of .calcium carbonate (Ca003 ) 1 When this water at 15 0~ is saturated with carbon dioxide the solubility of the carbonate is hicreased to 0.385 gram per liter. 2 Meteoric waters falling through 1 Seidel, Atherton, Solubilities of inorganic and organic substances, 1907, p. 86. D. Van Nostrand Co., New York. 2 Idem., p. 87. PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 39 the air and sinking through the soil absorb small quantities of carbon dioxide which increases their power of taking up calcium carbonate in proportion to the amount of the acid gas (carbon dioxide) held. When this water percolates through the soil and rocks the acid acts on the calcium carbonate encountered, changing it to calcium bicarbonate (CaH2 ( C03 ) 2 ), the condition in which the limestone is practically always held in solution in natural waters. These waters :finalJy find their way to the ocean where the deposition of the compounds take place when the conditions are favorable. This deposition may take place in several ways-through the action of organisms, precipitation from evaporating waters, and precipitation through the action of other chemical compounds. The greater portion of the limestone deposits was probably formed by the secretions or she11s of living organisms such as foraminifera, corals, mollusks, etc. Dr. T. wayland Vaughan states that "In the ~ shoal waters of southern Florida and the Bahamas, bacteria are the most important agency whereby calcium carbonate is taken from the sea-water.m Before the shell of the sea animals reaches its final position in the bed of limestone being formed, it was frequently so highly comminuted by the action of the waves that no trace of the original form of the sheD was left. Again the animals lived and left their sheJJs in still waters forming beds made up largely or entirely of well-preserved fossils. An excellent example of this is the highly fossiliferous limestone bed in the Jackson formation of the Coastal Plain of Georgia. 'When a body of water containing calcium carbonate in solution is evaporated down to such a volume that it can no longer hold all of the compound in solution, the calcium carbonate will be precipitated, thus forming a bed of limestone. This is well illustrated in certain inland salt water seas or lakes that have no outlet. Other deposits. of limestone similar to these are formed when the calcium carbonate 1 Vaughan, T. Wayland, answer to discussion of: Coral reefs and reef corals of the southeastern United States, their geologic history and significance: Bull. Geol. Soc. of Am., Vol. 26, No. 1. March, 1915. 40 GEOLOGICAL SURVEY OF GEORGIA in water comes into contact with other compounds which will cause its precipitation. Limestones frequently contain varying proportions of magnesium carbonate. A stone containing 54.35 per cent calcium carbonate and 45.65 per cent magnesium carbonate is true dolomite.1 In common usage, however, a stone containing from 20 to 25 per cent of m~g nesium carbonate is known as dolomite. Below this percentage it is known as magnesian limestone. These dolomitic limestones are believed to have been formed by the replacement of a part of the calcium <;arbonate by magnesium carbonate either before or after the bed emerged from the water. VARIETIES OF LIMESTONE 2 The varieties of limestone are based on their physical character or texture and their che'mical compositions. The following varieties are common to the Coastal Plain of Georgia: Classi:fication according to texture: 1. Compact, dense, fine grained to granular limestone. 2. Partly crystalline to crystalline limestone. 3. Fossiliferous limestone. 4. Chalky or ' '1otten' ' limestone. 5. Oolitic and pisolitic limestone. 6. Brecciated limestone. 7. Sandy or arenaceous limestone. 8. Marl. Classification according to chemical composition: 1. High-calcium limestone. 2. Magnesian limestone. 3. Dolomite. 4. Argillaceous limestone. 5. Siliceous limestone. Under both of these classifications the varieties grade into each other to such an extent that the characteristics of two varieties are frequently present in one piece of stone. 1 Dana, E. S., A text book of mineralogy, p. 358, John Wiley & Sons, New York, 1910. 2 A modification of tlle classification scheme used by Burchard, E. F., The Source of Lime: Mineral Resomces U. S. for 1913, U. S. Geol. Survey, 1914, l't. 2, p. 1515. PHYSIOGRAPHY, STRUCTURE, AYD GEOLOGY 41 CLASSIFICATION ACCORDING TO TEXTURE Compact_. DenJ5e_. Pine Grained to Gra1Lular Limestone.-This type of limestone is not verv extensivelv distr~ibuted over the Coastal Plain v v of Georgia in deposits of sufficient extent to be worked alone, but it does occur in thin strata and in a few thick beds along the west of the Flint River. It is well adapted to the manufacture of lime when of sufficient purity, while the harder and tougher varieties can be used for road metal, concrete aggregate and railroad ballast. Its value for agricultural uses depends upon its composition, which is usually comparatively low in impurities. Partly Crystalline to Crystalline Limestone.-ln the majority of cases this variety of stone was probably originally a dense, compact stone that has been re-crystallized by the action of water and in some cases, also, pressure. This stone is rather extensively distributed over the limestone regions of the southern part of the State but always in thin beds. It is suitable for those uses mentioned in the previous paragraph. J?ossiliferous Limestone.-This is rather an indefinite term and may mean a stone containing an occasional fossil or one made up entirely of fossils. In this report the term, when used to describe the appearance of the stone, indicates that it is made up largely or entirely of fossils. This variety of limestone makes up practically all of the Jackson limestone beds of Georgia exposed in the section between the Oconee and the Flint rivers. The stone is of good quality, chemically, but its softness eliminates it from uses where strength and wearing qualities are essential. Chalky or a Rotten"-' Limestone.-The chalky limestone of the Coastal Plain of Georgia is a soft, white, fine grained limestone frequently containing some clayey material. The purer beds are usually inter-bedded with a hard, compact stone and are exposed along the ,Flint River while the impure variety occurs as a massive bed on the Ocmulgee River in the vicinity of Hawkinsville. This stone, because of its softness, is only suited for agricultural purposes except in a 2 GEOLOGICAL SURVEY OF GEORGIA few places where the composition is such that it will make a hydraulic lime. Oolitic and Pisolitic Limestones.-These types of limestones are formed generally in shallow waters where the volume of the water has been evaporated down to such an extent that it is no longer capable of holding the calcium carbonate in solution. The limestone will then precipitate out and if there are present sand grains, clay particles, or, according to some authorities, gas bubbles, the carbonate will gather around thee particles to form oolites, or, if larger than a pin head, pisolites. These two types of stone make up a thick, massive bed at the base of the Chattahoochee formation along the southern border of the State. This stone is of exceptional purity and is therefore well suited for those uses which require a high grade of limestone. The stone is hard but not of sufficient toughness to make a first-class road metal or railroad ballast.. Brecciated Limestone is made up of an aggregate of angular limestone fragments in a matrix of softer limestone. The only occurrence o~ this type of stone is in a thin bed in the upper part of the Ghatta~ hoochee formation, along the southern border of the State. Its value depends upon its composition and strength. Sandy or Arenaceous Limestone is one that was deposited near shore or where the current was strong enough to carry sand in suspension to the point where the calcium carbonate was being deposited. This stone is distributed throughout the Coastal Plain limestone regions. Its value depends upon its composition, hardness, and toughness. J.Warl is a term that is frequently misused by others than geologists to indicate various types of clay and comparatively pure limestones, as well as true marls. The term has no definite meaning other than a calcareous material containing high percentages of sand or clay or both. The proportions may vary to a point where it would be preferable to caJl the material a sandy or argillaceous limestone o1 in the other direction a calcareous sand or clay. The calcium car- PHYSIOGRAPHY, STRUCTURE, AND GEOLOGY 43 bonate content may be, and frequently is, due to fossils. Marls are distributed throughout the limestone sections of south Georgia. Their principal value is for local agricultural uses. CLASSIFICATION ACCORDING TO COMPOSITION H'igh-calcium Limestone.-Limestones which contain little or no magnesium carbonate and only a small percentage of impurities are known as high-calcium limestones. Upon being burned they make a lime which will give off a great deal of heat when slaked with water -hot lime. This type of stone is used very extensively in industrial chemical works where magnesium is detrimental to the object in view. It is also valuable for agricultural purposes. Magnesian Limestones contain varying percentages of magnesium carbonate up to the theoretical percentage of dolomite. These limestones are used for the manufacture of lime7 in industrial chemical works, and as a soil corrective. Dolomite is the double carbonate of calcium and magnesium containing 54.35 per cent calcium carbonate and 45.65 per cent magnesium carbonate, when pure. In common usage any high-magnesian limestone is called dolomite. Argillaceous Limestone is one containing a relatively large per- centage of clayey matter but not sufficient to be called a marl. It is formed in still waters where the current from the land streams is strong enough to bring the clay particles in suspension and then deposit them when the still water is reached. This stone is suitable for local agricultural uses when the carbonate content is not too low and for the manufacture of hydraulic limes and cements. A1enaceous or Siliceous Lime-Stones are those which contain silica in one or more of its several forms. The silica may be present as spicules of sponges or from other organic sources, as sand grains or :finely divided siliceous material. The :first mentioned stone is formed similarly to other fossiliferous stones while those containing sand grains were deposited near shore. The last mentioned are formed under the same conditions as argillaceous limestones. DETAILED DESCRIPTION OF CALCAREOUS DEPOSITS BY COUNTIES LIMESTONE AND MARL BURKE COUNTY Practically the wh-ole of the upland of Burke County is covered by red and mottled argillaceous sands, while limestones and marls are exposed along the Savannah River and its larger tributaries. In the report on the Geology of the Coastal Plain of Georgia by Veatch and Stephenson, these deposits are correlated with the Olaiporne group; in this report they are classed as undifferentiated Upper Eocene. The topo'graphy is rolling over the greater portion of the county, with steep, comparatively high hills along the principal streams. W. L. Morris Place (rnap locality Bu-1).-An exposure of greenish, glauconitic, fossiliferous, arenaceous marl occurs in the bed of McBean Creek on the W. I..~. Morris place, 5 miles south of Elwood, overlain by several feet of unconsolidated yellow sand. This exposure is at the base of an escarpment which has a 40 per cent slope and reaches an elevation of 40 feet above the creek bed. A sample of the marl shows the following chemical analysis :1 Analysis of JYiarl Sample frorn W. L. Morr'is Place, J.lfcBean Oreelc (Sample No. 113) Soda (Na20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 .12 40.84 .46 Alumina (Al20 3 ) ( Ferric oxide (Fe20n) \ Phosphorus pentoxide (P 02 5 ) Silica (Si02 ) and insoluble. . . . . . . . . . . . . . . . . . . . . Undetermined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406 .30 16.12 37.94 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 1 All analyses in this report were made by Dr. Edgar Everhart, unless otherwise stated. DESCRIPTION OF CALCAREOUS DEPOSITS 45 Calcium carbonate (CaC03)..................... Magnesium carbonate (MgC03). Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 73.04: .96 74.00 'l'he position of this deposit beneath the bed of the creek, is such that it could not be worked profitably even though the stone was of much higher grade, except where a smaJl quantity of the material is desired for local agricultural uses. E. C. Lanier Place (map locality Bu-2) .-There are several exposures of limestone on a low ridge or terrace which extends northward from the foot of the steep escarpment on the south side of McBean Creek. The deposit is on the property of E. C. Lanier, 3 miles up McBean Creek from the Central of Georgia railroad tressel. Years ago this stone was quarried, burned and used for building purposes. The o1d kiln built of the limestone is still intact. The pits show the only exposures of the stone at the present time. The limestone is medium hard, cream colored and arenaceous. It contains numerous species of very poorly preserved fossils. A sample shows the following analysis: A_ nalysis of Sctmple from E. C. Lanier Place: Burke County (Sample No. 110) Soda (NazO) .......................... . Potash (K20) _............................... . Li1ne ( CaO) ................................ . Magnesia (MgO) ............................ . Alumina (Alz03) I . Ferric oxide (Fez03) \ ................... . Phosphorus pentoxide (P 02 5 ) Silica (Si02 ) and insoluble ..................... . Undetermined ................................ . .20 .21 43.02 .42 1.78 .25 10.53 43.59 Total ................................. . 100.00 Calcium carbonate (CaC03 ) Magnesium carbonate (MgC03) Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 76.90 .90 77.80 46 GEOLOGICAL SURVEY O.F GEORGIA This deposit occurs in a low ridge about 300 feet long and 200 feet wide, slightly more than an acre. It has a height of 12 feet with limestone exposed from 3 feet above the bottom land to the surface of the ridge. The overburden is only a few inches. It is probable that prospecting would prove up the limestone in similar and larger terraces which occur along the base of the main creek escarpment. The low carbonate content, the distance from means of transportation, and the apparent small quantity of stone, sedously interferes with the deposits from becoming of commercial importance. It is, however, a valuable stone for local agricultural uses. Newton PalmeT Place (map locality Bu-3) .-Exposures of limestone occur in the escarpment along the south side of McBean Creek just west of the Central of Georgia Railway on the Newton Palmer property. A complete section of the different strata could not be seen, but tlie following seems to be fairly representative: Section on Newton Palmer PTopertyJ McBean Creek) liVest Side of OentTal of GeoTgia Railway) Burke County Feet 6. Concealed, sandy soil on top of hill. . . . . . . . . . . . . . . 34 5. Soft, white, argillaceous, ''rotten'' limestone. . . . . . 7 4. Medium hard, highly fossiliferous limestone; fossils poorly preserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Soft, ''rotten'' to consolidated, cream colored, ar- gillaceous limestone . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Swamp level. 2. Blue, glauconitic, fullers earth-like clay. . . . . . . . . . . 6 1. Hard, arenaceous, fossiliferous limestone. . . . . . . . . . 2 0. Creek bed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 96 DESCRIPTION OF CALCAREOUS DEPOSITS 47 Samples for analyses show the following chemical composition: Analyses of Limestone SaTnples from Newton Palrner PropeTty Sample No. ........................ I1 107 108 I I Soda (NazO) ...... I Potash (K"O) ....................... , Lime (CaO) .. . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . .17 .17 45.62 1.66 .15 .02 47.52 . .28 Alumina (Al203) ( ............. . Ferric oxide (Fe20 3 ) \ Phosphorus pentoxide (P"O") ......... \ .38 1.44 .04 [ .04 Silica (Si02) and insoluble ............ 1 14.35 [ 12.41 Undetermined . . . . . . . . . . . . . . . . . . . . . . . 37.61 \ 38.14 [ 1 - [ - Total ......................... 1100.00 1 100.00 Calcium carbonate (CaC03 ) ... [ Magnesium carbonate (MgCOs) ........ \ 81.50 .80 I 84.92 \ .58 I ~- Total carbonates ............... \ 82.30 \ 8_5__.5_0_ _ __ Sample No. 107 was taken from beds 5 and 6 of the section. Sample No. 108 was taken from the lower 20 feet of bed 3. More general samples could not be secured, due to the incompleteness and weathered condition of most of the exp~ures. This deposit probably belongs to the upper portion of the Claiborne group. The dip of the strata could not be determined, but they are apparently practically level, or dip slightly to the southeast. These exposures extend along the lower half of this high escarpment for a distance of nearly one-half mile, beginning 200 yards west o:f the railroad and extending westward. An average profile of the escarpment for this distance shows a 50 per cent slope with the limestone occurring from the base to 54 feet above. There is from 1 to 2 feet of soil and humus over the limestone under the -slope. Taking the figures given in this paragraph into consideration there is in the ,escarpment a body of limestone under a 1- to 2-foot overburden which has a triangular cross section with the vertical side 54 feet high and ihe base 110 feet long. This body js near one-half mile in length. 48 GEOLOGICAL SURVEY OH GEORGIA These dimensions are merely estimates and are only intended to give an idea of the probable workable extent of the limestone deposit. Natural drainage would be retained within the lower limit given. The chemical analyses show rather low-grade limestones which, however, are well adapted to agricultural uses. The railroad being within 200 yards of the deposit increases its value to a great extent. However, the comparative low grade of the stone will prevent its being shipped great distances, due to the inert material upon which freight charges must be paid. As mentioned in the above sectional description of the limestone it is very soft. The rotten stone can be excavated with a shovel, while the harder material can be dug with a pick. This will eliminate the cost of drilling and blasting and preliminary crushing and greatly increase. the capacity of the pulverizer. In fact, the softer material which makes up a large percentage of the surface of the stone at least, is in such a state of :fineness that it may be applied to the soil without being further pulverized. Evans-Miller Place (map locality Btt-4).-An exposure of soft, rotten, argillaceous limestone overlying medium soft, white, fossiliferous limestone occurs on the Evans-Miller property, on the south side of McBean Creek, three-fourths mile up-stream from the AugustaSavannah highway. The soft, rotten strata are exposed in a vertical space for 14 feet while 3 feet of the fossiliferous stone underlies it. Red argillaceous sand immediately overlies the.limestone for 12 feet, while the face of the escarpment is covered with soil from this P?ini" to the top, a height of 45 feet. LIMESTONE 0 1' 'l'll E GOA '1'AL PLLll N OF GEORG I A PLA1'E ill 1:. OLIJ LDII:: ." 'l'O:\E QL\HH Y 0:\ t: . S. &. F . HI U IIT-0 1>' 1\' A\ , i:>Ol' Tll U F Tl\'0 1..\ . HOu 'TOX COu :\TY. DESCRIPTION OF CALCAREODS DEPOSITS 49 Samples of the limestone of the two strata show the following chemical composition : A.nalyses of Samples t1om the Evans-Mille1 Place_, Bu,rke County II Sample No. . ....................... 111 I I Soda (Na20) \ Potash (K20) ....................... Lime (GaO) .. . . . . . . . . . . . . . . . . . . . . . . . 1 Magnesia (MgO) .................... \ Alumina (Al203 ) I j Ferric oxide ( F e 2 0 3 ) . l 1 I Phosphorus pentoxide (P 02 5 ) Silica (Si02 ) and insoluble ........... -~ Undetermined .. . . . . . . . . . . . . . . . . . . . . . . .19 .17 47.12 .46 1.78 .12 11.73 38.43 Total ......................... \ 100.00 II Calciu~ carbonate (CaC03 ) 84.20 Magnesmm carbonate (MgC03 ) . 1.00 Total carbonates .............. 1 85.20 112 .04 .18 39.02 .44 2.20 1 1.84 I 25.29 30.99 II I 1oo.oo 1 69.62 1 .9o I- I 70.52 Sample No. 111 is from lower and sample No. 112 from upper limestone bed. This deposit is a continuation of that on the Palmer place, 2 miles west, (see the above locality description) which is probably of Claiborne age. This exposure occurs at the base of a practically vertical escarpment and on account of the heavy overburden is not economically workable. Up- and down-stream from this deposit the escarpment slope is gentle and it is quite probable that there are workable deposits contained therein. The impure quality of the upper bed is such that the deposit is of little or no commercial value, however, the stone is so easily worked that it could be used very profitably for local agricultural purposes. The soft stone in its rotten condition can be readily worked with a shovel and is so finely divided that it should give excellent results without being further pulverized. 50 GEOLOGICAL SUEJTEY OF GEOEGIA 1J1. H. UshuT PropeTty (map locality Bu-4).-Small.exposures of this rotten arenaceous limestone occur on the l\f. H. Ushur place along the River road on the south side of McBean Creek, one-half mile east of McBean Station. These outcrops are in small washes and road cuts at the_ foot of a steep escarpment. 'l'he immediate overburden of the limestone is 1 to 3 feet of soil and humus. The deposit is of little commercial value, except locally, due to the comparative small quantities under light overburden and the distance from means of transportation. The rotten stone is in such a state of pulverization that it can be worked and applied to the soil without grinding. Jarnes Mobley PT01Jerty (map locality B~t-5).-A 6-foot exposure of soft, arenaceous, fossiliferous limestone occurs on the James l\Iobley place, 2:lj2 miles east of Shell Bluff post office and one-half mile east of the old Mobley residence. A sample of the material shows the following analysis : -Analysis of Sample front James Mobley Place (Sample No. _109) Soda (Na20) .......................... . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al20 3 ) } Ferric oxide ( F e 2 0 3 ) Phosphorus pentoxide (P 02 5 ) ; . . . . . . . . Silica (Si02) and insoluble.. . . . . . . . . . . . . . . . . . . . Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 .16 41.72 .27 202 .06 21.38 34.26 Total . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (Ca003 ) . . . . . . . . . . . . . . . . . . . . . Magnesium carbonate (Mg003 )................. 'rotal carbonates 74.40 .60 75.00 DESCRIPTION OF CALCAREOUS DEPOSITS 51 'l'lle material is lithologically similar to the rotten limestone along McBean Creek and is probably at the same horizon, in the Claiborne group. The exposure is in the face of a long excavation along the base of an escarpment of Min~ral Spring Branch. The escarpment face is rather steep and if the top of the exposure is the top of the limestone bed the overburden will be prohibitive a few feet back from the foot of the escarpment. Considerable quantities of the limestone could be worked along the lower edge of the escarpment, but not sufficient quantities to make the deposit of value except for local use. Also, the quality and distance from means of transportation prevent its being of commercial importance. Shell Blttff (map locality Bu-6) .-On the Savannah River, 40 miJes below Augusta, is one of the classic exposures of the Georgia Coastal Plain. The strata exposed have been studied and described by various geologists within the past century. A hasty examination of the strata was made, during the field work, for this report, for economic rather than stratigraphic purposes. The following section is descriptive of the strata exposed: Section of Shell Bluff) Savannah River) 40 miles below Augusta Feet 6. Covered with soil and humus; reddish clay sand exposed near top ............................. 100 5. Rotten, arenaceous limestone. . . . . . . . . . . . . . . . . . . . . 22 4. Soft, arenaceous limestone; fossiliferous near top. . 8 Yz 3. Soft, fossiliferous, arenaceous limestone.... . . . . . . . 6 2. Rotten, cream colored, arenaceous limestone. . . . . . . 9 1. Fossiliferous limestone; fossils hard, matrix soft. . . 1 Yz River level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 147 The exposures of the strata are rather poor, making it necessary to work for some distance along the bluff in order to complete the section. 52 GEOLOGICAL SURVEY OF GEORGIA Samples of the stone show the following analyses: Analyses of Samples fr(i)m Shell Bluff) Savannah River Sample No......................... 1I 114 115 ------------ :-------:-------------- Soda (Na20) ....................... . Potash (K,O) ...................... . I Lime (CaO) ........................ .Magnesia (MgO) ................... . J Alumina (Al20 3 ) (_ Ferric oxide (Fe20s) Phosphorus pentoxide (P20.,) ......... . Silica (Si02 ) and insoluble ........... . Undetermined ....................... . .18 .16 44.44 .23 .90 .10 17.68 36.31 .15 .14 48.82 .32 1.32 .28 10.40 38.57 Total . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 100.00 Calcium carbonate (Ca003 )........... Magnesium carbonate (MgC03) 79.34 .46 I Total carbonates .............. 79.80 87.12 .68 87.80 Sample No. 114 was taken from 8 to 22 feet above the water and sample No. 115 from 22 to 47 feet above the water. Dr. T. Wayland Vaughanrhas.'made a study of the Shell Bluff strata within recent years and places the limestone strata given in the above section in the Claiborne formation.1 Shell Bluff has a river frontage of more than 1000 feet, with the face of the bluff very steep. The limestone strata, which are largely covered by soil and humus, extend from the river surface to 47 feet above. ~rhere is no point where the overburden on the top of the limestone is light, hence only the stone along the face could be worked. The nearest railroad is some 15 miles to the east, and, as a consequence, the only method of transporting the limestone would be by water. A wagon road could be built to the deposit, but owing to the steep face of the bluff it would be rather expensive. 1 Geology of tht> Coastal Plajn of Georgja: Bull. Ga. Geol. Survey, No. 26, 1911. p. 244. DESCRIPTION OF CALCAREOUS DEPOSITS 53 'fhe stone is of low grade, but, owing to its softness which makes it very cheaply worked, it could probably be used profitably for local agricultural purposes. Utley Point Bluff (map locality Bu-y).-Limestone strata are exposed in Utley Point Bluff on the Savannah River one-half mile below Hancock I~anding. The limestone is somewhat similar to that exposed in Shell Bluff 12 miles up-stream. See the foregoing locality description. The following section is descriptive of the strata exposed: Section at Utley Point Bl,uff) Savannah River Feet 8. Mainly covered, a 6-foot bed of arenaceous lime- stone is exposed 50 feet above the river; large oyster shells overlie this bed ................... 100 7. Hard, fossiliferous, glauconitic, arenaceous limestone ........................................ . 6. Hard, :fine grained, compact, dove colored limestone. 1 5. Greenish gray laminated calcareous fullers earth .. . ~~~ 4. Ash colored, calcareous sand .................... . 11;2 3. Fine grained, white, argillaceous limestone . . . . . . . . 1/2 2. Gray, calcareous sand .......................... . 4 1. Talus ........................................ . 7 River 0 127 A sample for analysis was taken from Bed No. 7, which gave the following results: _4_n::tlysis of Limestone Sample from Utley Point Blnff1 Savannah River (Sample No. 116) Soda (Na00) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) .,., . . . . . . . . . . . . . . . . . . . . . . . . . . . Alurr:ina _(dA120(F3) ) l ....................... F erne ox1 e eo0 3 j Phosphorus pentoxide (P 00 5 ). . . . . . Silica (Si02) and insoluble. . . . . . . . . . . . . . . . . . . . . Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 .08 47.82 .24 2.64 .10 9.98 39.00 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 54 GEOLOGICAL SURVEY OF GEORGIA Calcium carbonate (CaC03)........... Mag-nesium carbonate (Mg003 ) 85.4(') .50 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 85.90 I The strata here exposed are considered to belong to the Claiborne group. The only workable part of the limestone exposed is in a small shelf, covering one-half acre, of bed 7 of the above l:!ection. The only practicable means of transportation is the river. The nearest railroad is some 15 miles and the bluff face is so steep that a wagon road would be very expensive to construct. The quantity of the stone is so small that a plant to supply more than a very limited demand would soon exhaust the available supply. Blue Bluff (map locality Bu-8).-A bluish, massive bedded, shel~ marl outcrops at the lower 15 feet of Blue Bluff on the Savannah River, 2 miles below Hancock I.Janding. Fossiliferous sand and clay overlie the marl for a thickness of 20 feet. From this point to the top of the hill, 75 feet above, the strata are concealed, but the roots of trees, which have been blown down, show red, argillaceous sand. There is no workable material here, due to the low calcium carbonate content and the position under heavy overburden. However. a sample for analysis was taken from the lower marl bed. Analysis of Marl Sample from Blue Bluff) Savannah River (Sample No. 117) Soda (Na20) ..... . _, .......... : ....... ._....... Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) ............................. :.... Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al20a) } Ferric oxide (Fe20 3 ) Phosphorus pentoxide (P 02 5 ) . . . . . . . . . . . . . . . Silica (Si02) and insoluble ......... o.-........... Undetermined .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 .27 31.04 .29 2 72 .08 35.00 30.28 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03 ) ~....... Magnesium carbonate (Mg003 ) . 55.50 .60 Total carbonates .......... , . . . . . . . . . . . . . 56.10 DESCRIPTION OF CALCAREOUS DEPOSITS 55 There are several other bluffs farther down-stream which show exposures of limestones and marls, but none are of economic importance. All qf the exposures of strata in place have been studied by Veatch and Stephenson and the results published.1 SCREVEN COUNTY All of Screven County with the exception of narrow strips along its main creeks and the Savannah River, is covered by sands and clays of the Altamaha formation. Numerous limesinks dot the northern portion of the county which, together with the long leaf pine, sandy soil with yellow or red clay-sand subsoil and rolling topography, gives it a very similar appearance to those regions in south and southwest Georgia immediately underlain by the Chattahoochee and Alum Bluff formations. Limestones of Oligocene age outcrop in several localities along Beaver Dam and Briar creeks in the northern portion of the county. These exposures are described briefly as follows: Jno. Reddick Place (m(tp locality S-1).-Exposures of limestone occur on the John Reddick property, 1 mile northwest of Reddick's store and 6 miles northeast of Sylvania, near old Jacksonboro. The best exposure is the face of an old quarry near Beaver Dam Creek, one-fourth mile south of Blue Spring. Other outcrops are in the creek and spring. The following section js descriptive of the strata: Section of Quw-ry on John Reddick Place; Screven Co1-mty Feet 3. Soil ancl humus ancl unexposed overburden......... 27 2. Soft, white, granular limestone. . . . . . . . . . . . . . . . . . . 6 1. Medium soft, white, granular, fossiliferous limestone 10 43 The fossils of bed No. 1 are very poorly preserved and could not be determined. A sample taken from the entire quarry face shows 1 Veatch, Otto. and Stephenson, L. W., Geology of the Coastal Plain of Georgia: Bull. Ga. Geol. Survey, No. 26, 1911. pp. 243-251. 56 GEOLOGICAL SURVEY OF GEORGIA the following analysis: Analys'is of Li1nes.1tone Sample frorn Reddick Place1 near ,Jaclcsonbom (Sample ;:..--:a. 118) Soda (Na"O) ................................ . Potash (K20) ............................... . Lime (CaO) ................................. . Magnesia (MgO) ...... , ..................... . Alumina (Al20 3) Ferric oxide (Fe"03) r / ....................... . Phosphorus pentoxide. (PeOo) .................. . Silica (Si02) and insoluble .................... . Undetermined ................................ . .10 .05 51.66 .14 .42 .15 6.32 41.16 Total ................................. . 100.00 Calcium carbonate (Ca003 ) Magnes1.um carbonate (MgCO~) ................ . 92.26 .30 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 92.56 Dr. T. wayland Vaughan visited this locality in 1902 and from the collection of fossils obtained he decided that the limestone was of Vicksburg age (Oiigocene). The strata are evidently in their original position, dipping very slightly to the southeast. The exposure under discussion occurs in a hillside quarry in the escarpment on the south side of Beaver Dam Creek. 'J:Ihe quarry face is about 50 feet long and 15 feet high. At this height the limestone and soil o-rerburden meet. The overburden reaches an apparent thickness of 27 feet some 50 or 75 feet back from the quarry face. It is quite probable that the limestone occurs at a higher elevation in the hill than is indicated by the exposure. The escarpment is prac tically continuous along Beaver Dam and Briar creeks and it is quite ppssible that prospecting would show up other deposits. 'l'llis deposit is about Gmiles from the nearest point on a railroad, but quite a large territory in the immediate vicinity of the exposure may be supplied with agricultural limestone if the deposit can be economirally worked, \Vhich depends largely upon the thickness of the overburden. DESCRIPTION OF C..dLC.AREOUS DEPOSITS 57 This quarry was, according to Jack Reddick, worked before the Civil war, the stone being burned for lime, which was used for building purposes. One-fourth mile north of this old quarry, 2 or 8 feet of limestone is exposed in Blue Spring. rrhe stone is the same as in the base of the quarry. Haddocks Landing (map locality S-2) .-At Haddocks Landing on Briar Creek, 11/2 miles northeast of Reddick's store there is an exposure of several feet of limestone at the water's edge. This is a medium hard, pinkish, fossiliferous limestone similar, lithologically, to an outcrop in Spring Creek, Decatur County, 5 miles south of Brinson. The stone is at the foot of a steep, high escarpment. An old kiln on top of this hill is said to have been used in burning small quantities of stone from the deposit at the foot of the bluff. WASHINGTO:s" COUNTY Washington County is overlain mainly by red and mottled argillaceous sand. Fossiliferous flint and fullers earth are exposed in the north central portion of the county and fullers earth and kaolin along Buck Creek and the Oconee R.iver in the western portion. Limestone is exposed in several sinks and along the streams between Sandersville and Tennille, near Sunhill, and in the escarpment of the Oconee River in the southwestern part of the county. The topography of the county is generally level to rolling with hills along Buck Creek and Oconee River. B. T. Rawlings Place (map locality TV-1).-Soft to medium hard, granular, argillaceous limestone containing fossils is exposed in several small sinks and along the br:anches on the B. T. Rawlings property, one-half mile south of Sandersville on the west side of the new Tennille road. The best exposure is in a well-like sink, 50 yards west of the public road and a few feet north of the farm road. Here 14 feet of limestone is visible, the lower part is rather hard while the upper part is some\vhat softer. For 6 feet above the limestone the strata are covered. Above this there is a ~-foot ledge of sandstone 58 GEOLOGICAL SURVEY OF GEORGIA exposed with 6 or 8 feet of soil overlying. One-fourth mile downstream, below a dam, calcareous sandstone underlies the limestone. 'The top of tbjs sandstone is 25 feet below the top of the limestone at the sink near the road. At this exposure and at the 14-foot exposures in the sink, samples were taken for analyses, which gave the following results: A_nalyses of Samples from B. T. Rawlings Place_, One-half Mile South- af sandersville Sample No. . . .. . .. ~~ . ... 98 I Soda (Na20) ......................... , Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) ........................ 1 Magnesia (MgO) . .. .. .. .. .. .. .. .. .. . AFl~ina 'd(Alz(OF8 ) O)} . . . . . ... . . . . . . . . . erne ox1 e e2 a I Phosphorus pentoxide (P 02 5) Silica (Si02) and insoluble............ Undetermined .. . . . . . . . . . . . . . . . . . . . . . . trace trace 52.00 .04 1.48 trace 5.23 41.25 .08 .08 51.38 trace 1.28 .03 6.59 40.56 Total ......................... ,100.00 I Calcium carbonate (Ca008 ) 93.00 100.00 91.70 Sample No. 97 was taken from the 14-foot exposure at the sink, and sample No. 98 from the 5-foot exposures below the dam. This limestone was correlated with the Clajborne formation by Veatch and Stephenson in their report on the Geology of the Coastal Plain of Georgia. This, however, seems to be doubtful, according to - the information gathered during the field work for this report. The exposures are not sufficiently extensive to determine the dip of the strata; however, it is probably a few feet per mile to the southeast. The Sketch map (Fig. 1) will serve to give an idea of the extent and conditions under which the deposit occurs. At A there is a 14foot exposure of limestone in a sink. Running west from the bottom of the sink there is a subterranean stream channel which is said to Fig. 1.-Sketch map of B. T. Rawlings property, near Sandersville, Washington County, Georgia 60 GEOLOGICAL SURVEY OF GEORGIA have been passable at one time for several hundred feet. Fifty feet southeast of this sink the farm road passes over a small area of limestone, at B. Surrounding this exposure there is a practically level area of abotit one,half acre. Fifty feet west the limestone is again exposed in a well-like sink for a thickness of 10 feet. At C is, a third exposure with a thickness of 8 feet. The immediate overbur, den surrounding the 4 exposures mentioned in this paragraph is about 1 foot. Going northwest up the side of the escarpment as indicated by the contour lines on the sketch the overburden will, of course, get heavy. Some 500 feet west of the above group of exposures the limestone is exposed in a small spring, D. This exposure is 3 feet lower than the base of the exposure A. Hence, the limestone should occur in the escarpment just west of the spring at least 17 feet above the level of the spring. It is exposed in a sink 25 feet west of D and 9 feet above, under 1 foot of soil and humus. Between 0 and D on the gentle slope of the escarpment there are no exposures, but prospecting would probably show limestone a foot or two beneath the surface. No limestone is visible in the escarpments west of D or south across the branch. Exposures occur in the southern escarpment of the branch below the dam, one-fourth mile west of A. The base of the limestone here is about 11 feet below the base at A, therefore the bed has a probable thickness of about 25 feet. These deposits could be worked to the level of the branch and natural drainage retained. The Augusta Southern Railroad is about one-half mile east of the deposits. It is seen from the above discm;sion and the sketch that the JO :> ." Y HIJ )(JI':.:; >I I LI~ ::i S U Ot;ST0 :-1 COL' :'\'J''l. DESCRIPTION OF CALCAREODS DEPOSITS 65 The main limestone beds, the lowest and the one overlying, are comparatively pure, soft, friable, and easily worked. As in Houston and Twiggs counties the exposures occur along the base of the escarpments, in steep bluffs and as low ridges and terraces. Weatherly Place ('rnap locctlity Bl-1) .-An exposure of Jackson limestoiJ.e occurs in the steep escarpment on the east side of Shell- stone Creek, one-half mile southeast of the public road, 11,4 miles east of Ainslie Station. The following section is exposed at this point: Election East Bank of Shellstone Creek) near Jl'inslie Station Oligocene(~) Feet 6. Red argillaceous sands to top of escarpment. There is no sharp line of contact between this and under- lying bed. Eocene. Jackson group. 5. Cream colored fullers earth with some sand. . . . . . . . 20 4. Hard, pinkish, partly crystalline limestone; fossili- ferous, Turritella most prominent. . . . . . . . . . . . . . 1 3. Medium hard, white, porous limestone. Fossils numerous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Soft, white, porous, friable limestone, highly fossil- iferous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1. Creek bottom land. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 44 A sample from a -vveathered exposure of the lower limestone bed shows the foJJowing analysis: A..rialysis of San'tple from Weatherly Place (Sample No. 2-B) Soda. (NazO) Potash (K"O) Lime (CaO) Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alun:ina '(dAlzO(~j ) F erne ox1 e J:f ez0 , 1j_ .. . .. ... . .. . .. .. . . .. . .. . Phosphorus pentoxide (P00,)................... . Silica (Si00 ) and insoluble. . . . . . . . . . . . . . . . . . . . . Undetermined ........ -................. , . . . . . . . trace trace 52.34 .12 _98 trace 4.69 41.87 Total ......................... : . . .. . . . . . 100.00 66 GEOLOGICAL SURVEY OH GEORGIA Calcium carbonate (CaCO.) .. :................. Magnesium carbonate (MgC03) .'... 93.44 .26 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 93.70 The residue, insoluble in hydrochloric acid, consists of clay, clear quartz grains .1 to .3 mm. in diameter and siliceous and glauconitic casts of Bryozoa about .1 mm. in diameter and .5 to .8 mm. long The escarpment, in which the above section occurs, has a slope of about 30 from the foot to the upper l:lmit of the fullers earth, bed 5 of the section. This means that the overburden of clay on the limestone is too heavy to allow economic working. The bluff has an extent of 600 feet northeast and southwest. Prospecting on the more gentle slopes adjacent to the bluff would possibly prove up a workable deposit of limestone, but even if this be the case the distance from a railroad, 1% miles, is too great for the deposit to be of economic importance except for local use. Ainslie Station (map locality Bl-2).-0n the E. B. weatherly place, in the northwestern part of Bleckley County, limestone deposits occur in two low ridges or benches extending westward from the foot of a high escarpment, 200 yards east of Ainslie Station. The principal' limestone is soft, white, porous, and friable, composed largely of Bryozoa, Orbitoides, and Pecten perplanus. A harder stone of the same general character, but containing a larger variety of fossils, is also present. The general section is as follows: Section at Ainslie Station; Bleakley County Feet 4. Vari-colored, argillaceous sand.................. . 15 3. Cream colored, calcareous fullers earth.. . . . . . . . . . . 20 2. Limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1. Bottom land, black soil. . . . . . . . . . . . . . . . . . . . . . . . . . 0 60 The similarity between this section and those given in above locality descriptions is quite inarked. No sharp line of contact can be seen between the clay and the overlyi:n,g sand~. DESCRIPTION OF CALCAREOUS DEPOSITS 67 The stone at these deposits is not visible in place, but as loose boulders and fragments covering the surface. By digging through a few inches of black soil, however, the solid limestone may be seen. The larger of the deposits, 300 yards southeast of the station, covers an area of 5 acres, with a maximum thickness of ~5 feet. The average thickness is much less than here given, due to the gently sloping ides of the terrace. Continuing up the escarpment from the upper limit of limestone there is a gently sloping area covering 2 acres with an average of a 4-foot clay overburden. Beyond this area the escarpment is rather precipitous. Across a shallow valley 100 yards north of this deposit there is another spur covering 1% acres, with limestone on the surface as described above. The upper limit of the stone here is at the same elevation as in the deposit to the south, while the lower limit is 5 feet above, due probably to the meadow being higher at this point. This gives a maximum thickness of 20 feet of limestone with the average about half as great. The overburden consists of a few inches of soil and limestone fragments. Beginning at the top of this deposit there is a comparatively level tract of 5 acres with an average elevation of 4 or 5 feet above the limestone. Farther east the escarpment face is steep. Other ridges similar to the above two occur along the escarpment within a distance of three-fourths mile, but no limestone is visible. Prospecting is necessary to determine the extent of the underlying limestone. J. T. Deese Property (map locality BZ-3).-Limestone occurs on the property of J. T. Deese, 10 miles north of Cochran. The exposures are along an escarpment on the southeast side of Shellstone Creek on land lots 204 and 217 of the 24th district of Bleckley County. The limestone has a stratigraphic thickness of 11 feet, the lower 6 feet of which is soft, very porous, cream colored and friable, composed almost entirely of Bryozoa and numerous Orbitoides, Pecten, Periarchus and other fossils. The upper 5 feet consists of a 68 GEOLOGICAL SURVEY OJP GEORGIA harder stratum of stone of the same general character, but containing a much greater variety of fossils. Overlying the limestone is a foot or two of soil. In the bed of a small tributary of Shellstone Creek, coming in from the south near the northeastern end of the limestone bluff, a 30-foot bed of blue fullers earth-like clay is exposed immediately above the limestone. This material occurs at the same horizon in the formation as the cream colored clay just above the limestone at other described localities in Bleckley, ':Pwiggs and Houston counties. This exposure is comparatively fresh and unweathered, and is probably the original type of material from which the. cream colored fullers earth was derived. A sample taken from the entire thickness of the limestone bed sho1vs the following analysis: Analysis of Li'ntestone Sarnple fro'm the Deese Place (Sample No. 21) Soda (Na20) ................................ . Potash (K20) ........... ................... . Lime (CaO) ................................ . .Magnesia (MgO) ............................ . Alumina (Al20 3) ) J!'erric oxide (Ji'e20s) \ . .. Phosphorus pentoxide (P 02 0 ) Silica (Si02 ) and insoluble .................... . Undetermined ................................ . trace trace 53.02 trace 2.24 .04 3.71 40.99 Total ................................. . 100.00 Calcium carbonate (CaC03 ) 94.72 rl'he residue ]eft from the solution of the limestone in hydrochloric acid is composed of greenish glauconitic casts of Bryozoa and minute siliceous sponge-like casts. Quartz grains are scarce. The deposit is in the upper part of the lower limestone bed of the Jackson group. 'l'he outcrop gives no evidence of disturbances which have altered the original position of the strata~ No joints apparently have been developed. DESCRIPTION OF CALCAREOUS DEPOSITS 69 As mentioned in a preceding paragraph, the visible deposit has an average thickness of about 11 feet with a horizontal extent of about 1000 feet. The creek swamp is at the base of the outcrop while Shellstone Creek itself is 2 to 3 feet lower. This indicates that the entire thickness of the exposure may be worked and natural drainage retained. If the workings are sunk below the level of the creek, however, mechanical means of drainage must be resorted to. The immediate overburden consists of 1 to 2 feet of soil. Extend ing southeastward from the edge of the escarpment there is a level area approximately 1000 feet wide. No exposures of stone occur over this area, hence no definite idea of the thickness of the overburden could be obtained. It is, however, probably not more than a very few feet, provided the strata dip only a few feet per mile to the southeast. Certain exposures of the continuation of this limestone bed in Twiggs and Houston counties show an average stratigraphic thickness of about 45 feet. There is every reason to believe that the de posit has about the same thickness in this locality. The stone is of excellent quality for agricultural purposes, but its physical character makes it unsuitable for most other uses. The distance of the deposit from a railroad, about 3 miles, decreases its value as a commercial proposition.. It is, however, admirably suited for development for local use. TWIGGS COUNTY The limestone exposures of Twiggs County occur at wide intervals throughout the entire county with the exception of a narrow strip dow-n the Ocmulgee River, the western boundary, and along the creeks in the northern portion of the county. ';['he most important variety is a soft, white to c~eam colored, very porous, friable limestone composed almost entirely of Bryozoa and numerous other fossils among which are Orbitoides, Echinoids, Pecten, Leda, Protocardia, and Corbula. The beds are frequently glauconitic. Immediately overlying this soft stone in the southern po-rtion of the county is a hard, white to cream or pinkish colored, partly crystalline limestone 70 GEOLOGICAL SURVEY OH GEORGIA containing scattered fossils, the most prominent of which is Turritella. Analyses of various samples taken from the different exposures of the soft limestone show calcium carbonate contents varyirig from 80 to 97 per cent. The above limestone bed occurs at the base of the Jackson group and is made up of alternating layers of soft and slightly harder stone with no distinct bedding planes. The softer stone makes up the greater portion of the bed. The strata exposed are apparently in their original position, dipping slightly to the southeast. There are no outcrops in the county of sufficient extent parallel to the direction of the dip to allow the determination of the slope of the beds. Exposures in the banks of the Ocmulgee River about 15 miles to the south show a dip of 8 to 12 feet per mile to the southeast. Immediately overlying the limestone is a bed of calcareous fullers earth from 45 to 90 feet thick, frequently containing thin layers of both original and apparently concretionary limestone. The clay is cream colored on its weathered surface and blue below the zone of weathering or the level of the ground water. Red sands, mottled, arenaceous clays and flint, all probably residual of Oligocene formations, overlie the clay and continue to the surface of the plateaus, which are frequently 200 feet above the limestone in the northern portion of the county. The topography of Twiggs County is comparatively rugged, having high, precipitous scarps and deep, narrow valleys. In the northern portion of the county Cretaceous clays and sands lie along the base of the escarpments with the Jackson limestone and fullers earth o-verlying. The residual red and mottled argillaceous sands and flint of Oligocene age lie immediately above the Jackson strata and cap the ridges and plateaus. In the southern portion the limestone occurs at the base of the hills with the sands and flint overlying. The workable limestone deposits occur in creek bluffs and low ridges, benches and terraces which extend out from the foot of the escarpments. Up to the present time no development work has been done on the limestone of this county, although the material is ad- DESCRIPTION OF CALCAREOUS DEPOSITS mirably suited for use in agriculture, as may be seen from the analyses accompanying the following locality descriptions: Lowe Wall Property (map locality T-1).-0n the property of Lowe Wall, 2 miles southeast of Pikes Peak Station, there are several exposures of limetone near the western end of a low ridge, on the northeast side of the road, one-fourth mile southeast of the Adam Burkett residence. The best of these outcrops is in a 12-foot vertical face of a gully, on the north side of the ridge, 100 yards from the road. The stone is soft, white, friable, massive bedded limestone, composed almost entirely of Bryozoa with a few Pecten and Periarchus. A good exposure of the underlying stratum is not visible, but it seems to be sand. The tough, black, clay-soil on the ridge indicates the presence of fullers earth above the limestone. A comparison of the descriptions of the above exposure and those of the southern portions of T\viggs and Houston counties shows the close similarHy between the materials. The other exposures around the end of this limestone ridge show the same type of stone, together with a harder stone containing fewer fossils. These outcrops conform to the general slope of the hillside. A sample of the stone from the gully shows the following analysis: A.nalysis of Limestone from Lowe TVall Property (Sample No. 101) Soda (N aoO) ................................ . Potash (KP) ..................... Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al203) ) Ferric oxide (Fe 03) j' 2 Phosphorus pentoxide (P200 ) .. Silica (Si02 ) and insoluble..................... Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 .08 48.72 .20 1.16 .06 11.35 38.28 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate ( CaC03) . . . . . . . . . . . . . . . . . . . . . Magnesium carbonate (MgC03) . . . . . . . 89.00 .40 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 89.40 72 .. GEOLOGICAL SURVEY 0.1!' GEORGIA 'rhis limestone belongs to the Jackson group. The strata apparently occupy their original position, dipping slightly to the southeast. No joints have been developed. The outcrops of the stone on this ridge are not sufficiently extensive to give a conclusive idea of the character of the deposit. The maximum thickness exposed is 12 feet. Other exposures occur around the end of the ridge, conformable to the gentle slope. The base of the limestone exposed is above the bottom of the gully in which it occurs and is, therefore, above drainage level. The top of the hill, 150 feet east of the gully exposure, is 30 feet above the top of the stone, which indicates the thickness of overburden. On the south side of the ridge the slope is more gentle, there being an area of an acre or more upon which there is practically no Dverburden. The quality of the stone and the distance from a railroad probably preclude it from being of commercial importance, ex-cept locally. Three 111-iles. So~~tlwast of Stony Creek Ch,urch (map locality T-2). -There is a deposit of limestone 3 miles southeast of Stony Creek church near an old railroad right-of-way. The exposures occur in the sides of a gully 100 yards south of the dght-of-way. The principal stone is the soft, white to cream colored, friable limestone cornposed almost entirely of Bryozoa with Pecten, Periarchus, and occasionally other fossils. 'l'he following section was observed at this exposure: 'Section S Miles So,utheast of Stony Ureek Ghwch Jackson group. Feet 3. Gmy fullers earth overlain by tough, black clay-soil 6 2. Soft, white, fossiliferous limestone containing thin, medium hard layers; lower 2 feet argillaceous. . . 16 1. Argillaceous sanrl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 24 The marked ~dmilarity between this section and those seen in the southern portions of Tw1ggs and Houston couuties may be readily observed by comparison. A sample from the limestone bed shows the following analysis: DESCRIPTION OF CALCAREOUS DEPOSITS 73 Analysis of Limestone Sa1nple front 3 Jii.le.c:; Southeast of Stony Creek Chutch (Sample No. 10') Soda (NaoO) ................................ . Potash (K20) ............................... . Lime (CaO) ................................ . Magnesia (MgO) ............................ . Alumina (Al20,) ) Ferric oxide (Fe,O,) j' Phosphorus pentoxide (P 02 0 ) Silica (Si02 ) and insoluble .................... . Undetermined ................................ . .28 .14 44.08 .46 2.20 .06 16.89 35.89 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaCO,)..................... Magnesium carbonate (MgC03 ). 78.70 .95 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 79.65 These strata belong to the Jackson group. No disturbances of the original position of the strata seem to have taken place. The limestone outcrops continuously in a gully for a distance of 150 yards, on the east side of which there is an area of about 4 acres underlain by the stone at a probable depth of 6 feet, but farther back from the exposure the overburden is much heavier. West of the gully a 3-acre area slopes very gently from 2 feet above the limestone to the base of the bed. The entire deposit is above drainage level. This deposit is at too great a distance from the railroad and the quantity of limestone under a light overburden is too small to be of commercial value except for local agricultural use. The calcareous material can be very advantageously used in its present condition. The exposed stone can be easily worked with a pick and shovel and readily breaks down to a size suitable for agricultural use. One and One-fourth Miles South of Bond)s Store (map locality T-3).-ln a deep gully on the east side of the public highway, 1:1;4 miles south of Bond's store, there is a 13-foot exposure of soft, white to cream colored, friable, massive bedded limestone of Jackson age composed almost entirely of Bryozoa with Pecten, Periarchus and 74 GEOLOGICAL SURVEY OF GEORGIA other fossils. Yellowish fullers earth immediately overlies the limestone with red and mottled sands and clay-sands above to the top of the ~ill, which is about 100 feet above the lhnestone. The exact thickness of the fullers earth could not be determined, but it is at least 25 feet. The elevation of the top of the limestone is 455 feet above sea level, according to aneroid barometer reading. This deposit is of little economic importance on account of the thickness of the overburden. TVimbe'i'ly Place (map locality 'P-4).-Jackson limestone is exposed in a creek escarpment known as Oak Ridge, 4 miles east of Adams Park on the property of Minter Wimberly. The exposure has a maximum thickness of 20 feet with 14 feet of massive, soft, white, porous, highly fossiliferous limestone at the base and 6 feet of slightly harder limestone of the same general character overlying. Both of these beds are slightly glauconitic. Fragments of hard, white crystalline limestone occur on and in the thin soil on top of the ridge. A sample taken from the lower bed shows the following analysis: A_nalysis of Sample of Limestone f1'0'rn 1Vintberly Place (Sample No. 16) Soda (Na20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) .... , . . . . . . . . . . . . . . . . . . . . . . . . .02 .09 51.56 .08 !lun;-ina .(dA.lz(OF3 ) O ) } . . . . . . . . . . . . . . . . . . . . . . . . -" erne ox1 e < ez a Phosphorus pentoxide (P 02 5 ). . Silica (Si02 ) and insoluble..................... Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ] .14 .08 7.29 39.74 Total ................ ,. ......... , . . . . . . . 100.00 Calcium carbonate ( CaC03).. . . 92.06 The residue insoluble in h~rdrochloric acid consists of clear quartz grains .05 to .1 mm. in diameter, glauconitic casts of Bryozoa, and clay. DESCRIPTION OF CALCAREOUS DEPOSITS 15 The escarpment has a maximum elevation above the creek swamp of 27 feet. The lowest limestone exposure in place is 6 feet above the swamp and the highest 26 feet, giving a thickness of 20 feet of limestone underlying an overburden of 1 to 2 feet. The steep escarpment is continuous along the edge of the swamp for a distance of 1200 to 1500 feet. The top of the ridge is practically level for a distance of several hundred feet at the southern end and about 1500 feet at the northern end. These :figures are rough estimates and are only intended to give a general idea of the extent of the deposit. The fragments of hard, partly crystalline limestone which occur on top of the ridge indicate that the 20-foot exposure is the upper part of the lower Jackson limestone. In Houston County the hard limestone is found immediately on top of a 45-foot bed of soft fossiliferous limestone. Should this condition obtain on the Wimberly property it would seem that there is a thickness of about 25 feet of limestone below the lowest exposure in the escarpment. In working this deposit the quarry will have natural drainage if the floor is kept slightly above the creek swamp. The distance from a, railroad prevents it from being developed on a large commercial scale at the present, but it is well situated for development for local agricultural uses. The stone is too soft and impure to be used for most of the other purposes to which limestones are adapted. 1Vimberly Place; 4 miles east of Adams Park (map locality T-5). -The road from the plantation quarters on the Minter Wimberly place to Adams Park crosses an area covered by limestone fragments of the east side of Savage Creek, 2 miles west of the quarters. The fragments consist of soft, white, porous, highly fossiliferous, friable limestone, similar to and at the same horizon as the exposure at Oak Ridge, 1 mile north. These fragments occur on the surface of a low limestone ridge covering one acre and extending westward from the main high es- . carpment. The limestone occurs over a stratigraphic thickness of 18 feet, with the lo>ver limit 6 feet above the surrounding meadow. Cream colored fullers earth overlies the limestone and continues for , 76 GEOLOGICAL SURVEY OF GEORGIA some distance up the side of the escarpment. No exposures of the limestone in place occur, but by digging through about 6 inches of soil the solid stone may be struck at almost any point on the ridge. It is quite probable that the greater thickness of limestone occurs beneath the lower limit of the stone as seen. Natural drainage can be .,secured by keeping the floor of the quarry above the level of the meadow, which would g'ive a maximum thickness of 25 feet of limestone. Across a shallow vall_ey, 100 yards north of the above deposit, is another limestone ridge similar to the one near the road, but covering only about one-half acre. In addition, two other small limestone spurs similar to the above occur one-fourth mile north of the road which, together, cover an area of about one acre. No exposures in place occur on any one of the above ridges, but the solid limestone is usua11y found from 6 inches to 1 foot beneath the soil. No satisfactory sample for analysis could be obtained, but the sample taken on Oak Ridge from similar limestone at the same horizon gives an idea of the chemical character of the stone. Fitzpatr'iclc Place (map locality T-6) .-A small ridge of Jackson limestone occurs on the Irwin Fitzpatrick place, 3 miles northeast of West Lake on the plantation road from the latter place to Tarversville. The ridge is covered with fragments of soft, white, porous, highly fossiliferous limestone with a few small natural exposures in the road, 10 feet above the lower limit of the loose material., The stone is made up entirely of Bryozoa, Echinoids, Pecten, and other fossils, named in the order of their importance. Some of the layers are slightly glauconitic. The stone is in every way similar to that at the other localities in Twiggs and Houston counties, and is apparently at the same horizon. A sample taken from one of the small, slightly weathered exposures in place shows the following analysis: Analysi8 of Sample fro'nt Fi,tzpatriclc Place) 3 Miles NoTthea.81 This analysis shows a lower calcium carbonate content than is usual for this type of stone, but this is probably due to the fact that it was secured on partially weathered exposures. The limestone of this deposit belongs to the Jackson formation, being the upper part of the limestone bed which occurs at the base of the formation. The strata seem to occupy their original position, dipping slightly to the southeast. The outcrops of limestone are scattered over the surface of a low knoll, which covers an area of 2 or 3 acres, and in a small excavation on the south slope of the hill. The lowest exposure is in the base of the excavation, while the highest is near the top of the knoll which gives a total exposed thickness of 14 feet. The upper exposure is ., probably the top of the bed, while it is possible that the bottom of the pit is some distance above the base of the limestone bed, although, in the northern part of Twiggs County to the east of this exposure, the bed is only from 12 to 15 feet thick. A bed 40 feet thick could be worked before mechanical drainage would be necessary. The burden ov.erlyingthe stone :for the area given is probably not more than a foot at any point. The distance of this deposit from transportation, 2 miles, greatly decreases its commercial value, but it is well located for local agricultural uses. The stone removed in the small excavation on the side of the hill was burned for lime for building purposes some 40 or 50 years ago, according to information received. HOUSTON COUNTY The limestone exposures of Houston County are confined to a narrow belt crossing its southern portion from the western to the eastern boundary and then bending north and continuing to Bonaire, on the Georgia Southern and Florida Railway. The principal stone occurring is a soft, white, porous limestone, composed almost entirely of fossil Bryozoa, Orbitoides, Echinoids, and Pecten perplanus) named in the order of their importance. Other fossils also occur, but they are not so abundant. Some of the beds are glauconitic, but usually 82 GEOLOGICAL SURVEY 0.1!' GEORGIA free from visible quartz grains. Overlying this bed, with frequently a thin clay parting, is a thiri stratum of hard, white, partly or wholly crystalline limestone. The analyses of the various samples taken from the above limestones show an average calcium carbonate content of from 90 to 95 per cent. The above mentioned soft limestone is contained in a 45-foot bed occurring at the base of the Jackson. This bed is in 1- to 15-foot layers of soft and slightly harder stone, with the soft predominating. The whole has a massive appearance, there being no distinct bedding planes. rrhe strata seem to be in their original position and have no joints. The dip is about 8 feet per mile to the southeast, accordin!?; to the exposures along the Ocmulgee River. The limestone belt is characterized by a rugged topography with hills and ridges rising frequently 125 feet above the valleys. The limestone is exposed in bluffs and terraces along the lower slopes of the hillsides, with 40 to 50 feet of overlying yellow fullers earth, con7 taining original and concretionary limestone layers. "" This clay is always yellow on the surface, due probably to weathering. It occupies the same stratigraphic position as the blue fullers earth mentioned in the description of the Deese property in Bleckley County. These beds are, in turn, overlain by residual, ferruginous sands, mottled, arenaceous clays and fossiliferou.s flint, derived from deposits of late Eocene or early Oligocene. In the eastern edge of the county, east of Kathleen, the deeper valleys are below the horizon of the Jackson, while from the western border to within a few miles of the Ocmulgee River the creeks are within the horizon of the limestone. Up to the present time practically no work has been done toward developing the limestones of the county with the exception of asmall quarry on the Georgia Southern and Florida Railway near Tivola, from which a quantity of material has been quarried and used for road metal. This quarry, which is described on succeeding pages, has not been worked for several years. At a few localities the remains of old kilns may still be seen, where the stone was burned for build- DESCRIPTION OF CALCAREOUS DEPOSITS 83 ing purposes before the ad-vent of railroads. (See plate VII.) At other localities are small pits from which the material has been worked for local highway building. The Georgia Southern and Florida and the Ocilla Southern railroads and the Ocmulgee Ri-ver, all within a few miles of these deposits, offer means of transportation. Ra'ilroad Out) Bonai1e ( rnap locality H-1) .-On the Georgia Southern and Florida Railway, one-fourth mile north of Bonaire, in the northeastern part of Houston County, there occurs an 8-foot exposure of soft, white, porous, highly fossiliferous limestone. The cut is through the western end of a low limestone ridge one-half mile in length. Near the eastern end of the ridge a well exposes 45 feet of limestone beneath an o-verburden of 3 feet. The ridge has an elevation of about 15 feet above the -valley and a width at its base from - 100 to 1000 feet, the greater width being near the western end. Scattered over the surface of theridge are numerous fragments of cream colored limestone considerably harder than that exposed in the cut. The above data indicate that there is present in this ridge a deposit of limestone about one-half mile long, 100 to 1000 feet wide (average 750 feet) and from 30 to 45 feet in thickness (average about 38 feet), with an overburden of from 3 to 5 feet. The correctness of these estimates can only be verified by prospecting. The imperfect exposures made it impracticable to collect an average sample for analysis, however, the following analysis of a sample taken from the weathered exposure will give an idea of the character of the stone: Analysis of Sample from G-. S. & F. Ra.ilway Out) One-fotwth J.l!Iile North of Bonai1e (Sample No. H-1) Soda (Na,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,03) } Ferrie oxide (Fe 0 ) 23 Phosphorus pentoxide (P,O,)................... .04 .04 52.00 .00 1. 62 .00 84 CJ-EOLOGIC.AL SURVEY OJ/ GEORGIA. Silica (Si02 ) and insoluble.. . . . . . . . . . . . . . . . . . . . 5.49 Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40.81 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate ( CaC03) . 92.85 In working this deposit natural drainage can be secured by working the upper 12 feet of the limestone. If the workings are carried below the level of the valley the water must be removed by mechani cal means. The nearness of the railroad to the deposit and the light overburden adds materially to its economic value.. Sasser Place (map locality H-2).-On the Sasser place, from onehalf to 1% miles west of Bonaire, a few scattered exposures of limestone were seen on the gentle slope at the foot of a high escarpment. These exposures occur in holes where trees were blown up, which holes give evidence of not more than 2 or 3 feet of overburden. No satisfactory data could be secured as to the extent and conditions of this deposit. The few exposures which occur over an area upward of 100 acres, together with the nearness to a railroad, indicate that the property is well worth prospecting. . DISTRICT BETWEEN THE G. S. & F. RWY. AND THE OCMULGEE RIVER, NORTH OF BIG INDIAN CREEK This region is characterized by a comparatively rugged topography, consisting of a main plateau some 150 feet above the river, dissected by deep ravines along the creeks and branches. The lime stone exposures occur along the lower edge of the escarpments, usually in the form of low ridges or terraces extending out from the main hillsides, and in creek bluffs and isolated knolls. The following is a generaljzed section of tb.e eastern part of the county and also of Twiggs County. GeneTalized Section, H o~tston and Twiggs Ootmties Feet 3. Residual red sands, mottled, arenaceous clays anu fossiliferous :flint . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0-60 DESCRIPTIOS OF CALCAREOUS DEPOSITS 85 .Tackson group. 2. Cream colored (weathered) fullers; earth containing _thin layers of original and concretionary limestone 30-50 1. Massive, white, porous limestone composed almost entirely of fossils, with soft and harder layers varying from 1 to 15 feet in thickness. A 1- to 3-foot bed of hard, white, partly crystalline limestone occurs on top of the massive bed with frequently a 2-foot clay parting between it and the lower limestone bed ............... -. . . . . . . . . . . 40-50 Deposits 1 1/2 .Miles East of Kathleen (map locality H-3).vVater-worn fragments of hard, white, partly crystalline, fossiliferous limestone, together with fragments of soft, white, highly fossil-_ iferous limestone, cover the surface of three smaJl knolls 1:1f2 miles east of Kathleen. The tops of these small, rounded hills are 18 to 20 feet above the surrounding bottom land, each of which covers an area offrom 2 to 3 acres. No gene1~al sample could be secured from which the quality of the stone of these deposits could be accurately determined, but the weathered fragments seen show a very distinct similarity to the stone of the other deposits in this section. The fragments of stone, together with the tough black clay-soil covering the knolls, indicate a very high overburden. The deposits are admirably situated for development fo:e local agricultu-ral use. Three Miles East of Kathleen (rnap locality H-1;.).-_Fragments of soft, white, highly fossiliferous and hard, partly crystalline, fossiliferous limestone occur on the surface of a terrace-like projection at the base of a high escarpment, 1 mile south of Thompson Mill and 3 miles east of Kathleen. The top of this terrace is 20 feet above the floor of the valley and some 200 feet wide, extending from the public road, about 500 feet to the southeast, where it disappears beneath the main hillside. No exposures in place occur, but the loose fragments and black, tough clay-soil indicate a very light overburden. Across the valley from this escarpment, one-fourth mile west, there is a similar terrace at the same elevation, but of less extent. 86 GEOLOGICAL SVIWEY Olt' GEORGIA The surface of this terrace is likewise covered with limestone fragments and black soil with no exposures in place. The deposit over which the overburden is light is about 250 feet long, 100 feet wide and 20 feet thick, from the bottom land to the upper limit of the limestone fragments. The overburden is probably not more than 2 or 3 feet. Red sands and clays occur from the top of the limestone to the top of the main hill, 40 feet above. The fullers earth bed is apparently covered by this material. A general sample could be obtained from neither of the above localities, but the limestone being exactly similar to that occurring at other points in this section of the country, it is quite probable that a sample would show approximately the same analysis. These deposits are well worth prospecting and it is probable that the information thus obtained would show the character and quality of stone to be of commercial value, at least for local agricultural purposes. Geo. L. Small Property ( rnap locality H-5) .-Exposures . of limestone and clay occur in the escarpments along a small branch running northward through lots 122, 123, 132 and 133, 11th district of Houston County, on the Geo. L. Small property, 4 miles east of Kathleen. An excellent exposure of the several beds occurs on the west side of the branch at a point one-half mile northwest of the Small residence. The following section, which is descrjptive of the mate rial of the individual beds, -vvas observed at this locality. Section on Geo. L. Sn'wll Place) 4 Miles East of Kathleen Feet 8. Residual reSure to Armena, but no stone is seen in place. CRISP COUNTY The western third of Crisp County is immediately underlain by the Jackson g-roup, which is limestone bearing, and residual red argillaceous sands and flint of the Vicksburg formation. The most of these formations are covered, however, by sands of probable Pleistocene age. The only limestone exposures are in sinks in a strip about 12 miles wide down the Flint River an,d in the river banks and creek beds near the river from Gum Creek to Swift Creek. The Altamaha beds cover the eastern two-thirds of the county except a s~all area in the south central border underlain by the Alum Bluff and Chattahoochee formations, according to Veatch and Stephenson. The general topography of the county is rolling to level. Clegg Place (map locality 0-1).-A small exposure of soft, white, argillaceous limestone occurs at the "lime spring" on the Clegg place, 200 yards west of the Daphne-Drayton road, 2 miles north of Daphne. This deposit is at the foot of a hill rising 20 feet above the valley. DESCRIPTION OF CALCAREOUS DEPOSITS 153 Numerous wells on this plantation, where the surface of the ground is about level with the top of the above hill, expose no limestone at depths ranging from 20 to 35 feet. Byrom Property (map locality C-2).-A number of limesinks on the S. B. and W. H. Byrom property, within a radius of 1 mile of Daphne Station, offer excellent exposures of a cream colored to white, argillaceous limestone, frequently called ;;chimney rock." Underlying this bed is a stratum of harder limestone containing Bryozoa, Orbitoides and a Pecten, probably P. perplamts. This lower bed is rather poorly exposed except in the sinks near Nigger Den, an old underground stream channel, three-fourths mile southwest of the station. At this point the following section is visible: Section at Nigger Den) Byrom Property Feet 3. Overburden of red clayey sand and gray soil. . . . . . . 18 Jackson group. 2. Soft, porous, cream colored to white, argillaceous limestone, ''chimney rock.' ' Fossils rare ... :. . . . 18 1. White, fossiliferous limestone, slightly harder than overlying bed. Fossils: Bryozoa, Orbitoides and Pecten . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Surface of water in sink .... 47 154 GEOLOGICAL SVRVEY 01!' GEORGIA Samples taken from the above exposure and an outcrop threefourths mile northeast of the station, near the site of an old saw mill, show the following analyses: Analyses of Samples from Byron~ P1operty Sample No. ...............II Bed No. .................. I Soda (Na."O) I I 0 Potash (K20) . . . . . . . . . . . 0 Lime (CaO) 0 Magnesia (MgO) ........... Alumina (Al20 3) } Perric oxide (Fe203) ...... I Phosphorus pentoxide (PzOo) Silica (Si02 ) and insoluble ... 1 Undetermined .............. r 32 1 .10 .08 50.76 .10 1.50 .04 6.62 40.80 Total ............... I 100.00 II Calcium carbonate (CaCO,). 90.76 I Magnesium carbonate (MgC03 ~ .21 33 2 .12 .15 46.72 .06 .76 I trace I 10.93 I 41.26 1- 1 1oo.oo I 83.30 I .13 I 31 I Near 1 saw mill I ,15 I .14 I 48.30 .06 .78 .02 7.84 42.71 100.00 86.30 .13 Total carbonates .... I 90.97 ,-83.43 96.43 The silica is partly in the form of minute clear quartz grains. There also occur spicules of sponges and a very small species of coral, both replaced by a mineral, apparently glauconite, insoluble or only slightly solubl-e in hydrochloric acid. The larger proportion of insoluble impurity seems to be in the form of clay. These limestone strata belong to the Jackson group and probably are near the middle of the series. The contact of the two strata exposed is not of su:f:fident extent in any one exposure to determine accurately the dip of the bed, comparison with other outcrops, however, indicate that the beds are almost horizontal or dipping slightly to the southeast. No indications of either regional or local distur ban.ces were seen. No joints seem to have been developed. Imme diately overlying the limestone is a varying thickness of reddish, clayey sand, probably residual from limestone. DESCRIPTION OF CALCAREOrS DEPOSITS 155 The best exposures on this property occur near Nigger Den, threefourths mile southwest of the station and 300 yards north of Hugunen Ferry on the Flint River. Two hundred yards east of the Den there is exposed in a long narrow limesink, through which a large stream of water flows, 29 feet of limestone with 18 feet of overburden. South of the sink there is a level field covering several acres, the surface of which has an elevation of 47 feet above the underground stream, and 50 feet above the water of the Flint River, 200 yards to the south. At the time the observations were made the river was a few feet above low water. This exposure can be traced to the Den where the stone outcrops again in practically the same section. The samples, Nos. 32 and 33, of which the analyses are given on a precedi:p.g page, were secured at this point from the entire thickness of the exposure. It is entirely probable that the upper limit of the limestone is several feet above the top of the exposure. No wells or pits were available from which this could be determined. North of the line of outcrop from the long narrow sink to Nigger Den there is a narrow strip of bottom land 20 feet above the level of the water in the sinks or 9 feet lower than the top of tb.e limestone exposure. The overburden covering of this area could not be determined without prospecting. Natural drainage for quarries in the foregoing deposits may be retained by working the upper 30 feet of the limestone. Near the sHe of an old saw mill, 1 mile northeast of Daphne Station, there is a limesink exposing 10 feet of soft argillaceous limestone, with a 10-foot overburden, similar to bed No. 2 of the section at Nigger Den. This sink contains water to the base of the outcrop and is at least 20 feet deep below this level. Two hundred feet south of the sink a well shows the limestone to be 10 feet below the surface. Another exposure 100 yards east of the well shows the same thickness of overburden. In two other sinks 300 and 500 yards, respectively, south of the above sink, similar ]jmestone is exposed from 12 feet below the sur- 156 GEOLOGICAL SURVEY OJ!' GEORGIA face of the surrounding field to the water in the bottom of the sink, 10 feet lower. In the southernmost of the sinks a bold stream of water flows northward, which would indicate that all of these sinks are along an underground stream. Sample No. 31, see analysis on the preceding page, was taken from the outcrop to the south over the entire thickness of the exposure. The field immediately surrounding these sinks covers an area of about 100 acres, the surface of which has an elevation of 10 to 12 feet above the limestone. West of the line of sinks there is a large level area covering several hundred acres with an elevation of about 20 feet above t_he limestone. The "Big House" is in the center of the latter area. Another exposure occurs at "Jacobs Well," a limesink one-half mile northwest of the station or one-half mile southwest of the "Big House." The stone here is similar to bed No. 1 of the section at Nigger Den, only 1 foot of stone, however, is exposed above the water irr the sink. Immediately surrounding the sink is a :field covering a few acres, sorrie 6 feet above the limestone. It then gradually rises to the elevat,ion of the field mentioned in the foregoing paragraph. Two hundred yards west of Daphne, on the south side of the railroad, the soft, argillaceous limestone is again exposed in Blue Spring, the mouth of an underground stream flowing about 1000 gallons of clear blue water per minute. The overburden here seems to be about 20 feet. Across the railroad from the spring there are several deep sinks exposing limestone in their bottoms under an overburden of at least 20 feet. The following is the log of the Byrom artesian well between the station and the mill on Gum Creek, about 300 yards apart: Log1 of Byrom liVell) Daphn,e) Crisp Co1t,nty Feet Yellow clay to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Limestone to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 1 McCallie, S. W., Underground Waters of Georgia: BulL Ga. Geol. Survey, No. 15, 1908, p. 94. DESCRIPTION OF CALCAREOUS DEPOSITS 157 Cavity to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Limestone to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Cavity to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Bluish clay to ......................... _....... __ 154 Dark colored sancl to __ .. ___ ....... - . - .. _.. _... _. __ 250 Limestone, flint and sand to_ .. _.... _... _. __ ..... _. 304 This log indicates that the limestone occurs to a depth of 144 feet below the surface of the ground at this point. The drill record shows the upper 54 feet to be "yellow clay." The surrounding exposures indicate that this thickness was originally occupied by limestone, hence the clay is probably residual and of local occurrence. The cavities were probably dissolved out of the limestone. The surface of the ground at the well is 15 feet lower than the field to the south or 11 feet lower than the top of the limestone exposure at Nigger Den three-fourths mile to the southwest. Hence, the probable thickness of the limestone is 125 feet. _It seems, from the above data, that the overburden on the limestone of all the exposures on the By:t>om property is rather heavy, but not necessarily prohibitive to development. The exposures were not of sufficient number to give an accurate idea of the extent of the entire deposit, hence, prospecting is necessary. On account of the comparatively flat surface of the section it would be necessary to work the limestone by pit-quarry methods. Natural drainage could be retained by working the upper 30 feet of the deposit only. The chemical analyses show rather low-grade limestones best suited for agricultural uses. Averitt Place (map locaUty C-3) .-Two exposures of limestone occur on the Averitt place, 1 mile south of Daphne Station. One exposure is in a small valley 150 yards south of the Cordele-Americus highway and 1000 yards- east of Flint River. The stone here is a medium soft, highly fossiliferous, white limestone. The fossils are mainly Bryozoa with an occasional Pecten. The other exposure occurs in a sink about 300 yards east of this exposure, at which point 17 feet of earth overlies 23 feet of limestone. The stone is a soft, 158 GEOLOGICAL SURVEY OJ!' GEORGIA glauconitic, argillaceous limestone with a harder, fossiliferous ledge on top. The soft stone is simi1ar to that occU"rring on the Byrom property previously described, -vvhile the harder stone is similar to that of tb.e first mentioned exposure in this paragraph. A sample taken from the 5-foot exposure in the gulley on this property shows the following analysis : Analysis of Lirnestone Sample f-rorn Averitt Place Soda (Na20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) .:................................ Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FAlm~ina. '(dAl20(Fa) O . } ................ , . . . . . . . erne ox1 e e. a) Phosphorus pentoxide (P 02 0 ). Silica (Si02 ) and insoluble..................... Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . trace .06. 47.62 .32 1.26 .56 6.78. 43.40 '],'otal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03).................. . Magnesium carbonate (MgC03 ). 85.08 .67 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 85.75 These exposures belong to the Jackson group. The strata evidently occupy their original position, dipping slightly to the southeast. The exposure in the valley from which the sample was taken has a vertical extent of 5 feet and is a few feet above the bottom of the gulch and 12 feet below the surface of the level field immediately west. A smalYquantity of this stone has been excavated and burned for lime within recent years. This small quarry could be continued along the edge of the hill and a considerable quantity of stone removed, which at present lies under very light overburden. Back into the hill, however, the apparent overburden is too heavy to allow economic working. The stone could be worked for a few feet below the floor of the valley and drainage retained by ditching. It is of low grade, but could be used locally for agricultural purposes. DESCRIPTION OF CALCAREOUS DEPOSITS 159 Armstrong Place (map locality C-4).-Severallimesinks occur on the Armstrong place, 2 miles south of Coney. In one of these sinks limestone is exposed for a thickness of 25 feet with an overburden of 6 feet. The exposure is in such a position that a section could not be made nor could a fair sample of the stone be secured. Fragments lying at the foot of the exposure are of soft, argillaceous, granular limestone and fossiliferous limestone containing Bryozoa, both simiJar to other exposures of limestone in Crisp County which are described in this report. One hundred feet west of the above exposure the apparent thickness of the overburden is 12 feet. From this point westward and southwar~ there is a level area reaching a mile or more in both directions. Several wells in this area show only mottled sandy clay fo~ depths of 25 to 30 feet. A considerable quantity of limestone could be worked at this exposure before an excessive overburden would be encountered; The distance of the deposit from transportation, limits its usefulness to the contiguous plantations. (Map locality C-4).-0ther exposures of limestone on the Arm- strong place are in the Flint River bluff, 1% miles west of the above mentioned outcrop. In this bluff the stone is exposed continuously to the mouth of Cedar Creek, 1% miles above. At the upper end of the bluff the limestone outcrop is 15 feet thick, and continues for more than one-half mile down-stream. The visible limestone 1 mile above Cedar Creek is 38 feet thick and continues for a little less than one-half mile down-stream. The following section of the higher bluff is descriptive of the different starta : Section of Limestone Bluff on Armstrong Place Feet In. 11. Pleistocene sands and gravel, surface of second terrace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Jackson group. 10. Mostly concealed, but with several small exposures of soft, white granular limestone and hard, partly crystalline, light gray limestone. . . . . . . . . . . . 8 160 GEOLOGICAL SDRVEY 01!' GEORGIA 9. Hard, light gray, crystalline limestone. . . . . . . . . . . 8. Alternating 6- to 10-inch layers of soft and slightly harder, white, granular limestone.. . . . . . . . . . . . . 7. Hard, light gray, crystalline limestone........... 6. Alternating 6- to 10-inch layers of soft and slightly harder white, granular limestone. . . . . . . . . . . . . . . 5, Medium hard, white, partly crystalline limestone. . 4. Soft, white, granular limestone. . . . . . . . . . . . . . . . . 3. Medium hard, white limestone containing Bryozoa. 2. Soft, light gray, granular limestone containing flint nodules ............ , . . . . . . . . . . . . . . . . . . . 1. Hard, white, partly crystalline limestone, irregu- larly weathered. Lunulites, Flabellum and Bryozoa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 3 1 6 0 3 7 6 4 4 4 8 2 6 0 47 The stage of the river was about 2 feet above low water at the time the exposure was investigated. The section of the up-stream end of the bluff is practically the same as the. lower 15 feet of the foregoing section. Along the bluff the river has a due south course. The limestone strata here are. dipping practically with the grade of the river, which, provided the true strike of the beds is east-northeast, .would make the dip a few feet per mile to the south-southeast. A sample taken from beds 5 to 1~, inclusive, shows the following analysis: Analysis of Sarnple from High Portion of Armstrong Bluff (Sarnple No. 58) Soda (Na20) ................................ . Potash (K20) ............................... . Lime (CaO) ................................. . Magnesia (MgO) ............................ . 1 Alun:ina ~A120(3F) ) } ....................... . F erne oXIc e e20 3 Phosphorus pentoxicle (P 02 5 ) Silica (Si0 2) and insoluble .................... . Uncletermined ................................ . .04 .04 49.16 .30 4.76 .00 5.28 40.42 Total ................................. . 100.00 DESCRIPTION OF CALCAEEOVS DEPOSITS 161 Calcium carbonate (CaC03).................... Magnesium carbonate (MgC02). . . . . . . . . . . . . . . . . Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 87.77 .63 88.40 This is a comparatively low-grade limestone, but well suited for agricultural uses where the shipping distance is not too great. The overburden of the lower portion of Armstrong Bluff is from 5 to 10 feet, which is probably continuous for the width of the first terrace, one-fourth mile. The overburden over the stone of the higher part of the bluff is 7 feet as indicated in the above .section. The level area at this elevation runs northeast and east from the bluff for a distance of a mile or more. It is possible that prospect pits in this area would prove the overburden less in places than that indicated at the exposure. How-ever, even if this be the case, the distance of the deposit from transportation would prohibit it from being of commercial importance at the present at least. I. williams Property (nwp locality C-4}.-An excellent exposure of limestone occurs 100 yards down-stream from the mouth of Cedar Creek in a river bluff very similar to the Armstrong Bluff, previously described. The bluff together with surrounding land is owned by I. Williams, Raines, Ga. The following section is descriptive of the material of the strata exposed: Section of Limestone Bluff 100 Yards below the Mouth of Cedar Creek) Flint River Feet In. 8. Unconsolidated sands of probable Pleistocene age; second terrace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Jackson group. 7. Hard, white, partly crystalline limestone.. . . . . . . . . 1 6. Soft, white, granular limestone. . . . . . . . . . . . . . . . . . 3 3 5. Hard, cream colored, partly crystalline limestone. . . 0 9 4.. Soft, white, granular lin1estone. . . . . . . . . . . . . . . . . . 3 3. Medium soft, white limestone; g,mttsittm ocalan1.tm ( ~) 1 2. Soft, white, granular, argillaceous limestone. . . . . . . 8 1. Hard, white, crystalline limestone. . . . . . . . . . . . . . . . 4 River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 39 0 / 162 GEOLOGICAL SUEVEY OF GEORGIA The close similarity between this and the section of Armstrong Bluff is readily seen on comparison. The following analyses are of samples taken from the face of this exposure: Analyses of Samples from Bluff 100 Yards Do'Wn-st1eam from Mouth of Cedar Creek Sample No......................... . 36 59 Bed No............................ . 2 3 to 8 Soda (Na20) ....................... 1 .14 Potash (K20) .................. 1 .18 Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . 44.60 Magnesia (MgO) . . . . . . . . . . . . . . . . . . . e .08 Alumina (Al20 3) } Ferrie oxide (Fe20 3 ) Phosphorus pentoxide (P 02 5 )... Silica (Si02 ) and insoluble. . . . . . . . . . . . Undetermined .. . . . . . . . . . . . . . . . . . . . . . . 1 62 trace 14.14 39.24 Total . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 trace .18 50.36 1.00 .94 .12. 8.66 38.74 100.00 Calcium carbonate (Ca003)........... Magnesium carbonate (Mg008)........ 79.60 .17 Total carbonates 79.77 89.90 2.10 92.00 The analysis of the sample from bed 2 shows 14.14 per cent insoluble material, which is probably clay. The river at this point runs southwest which is very nearly along the strike of the beds, therefore no information as to the dip could be gained. As indicated by the above section the overburden on the lime- stone is 18 feet which is, of course, too great to allow profitable quarry operation. Cedar Creek, just north of the bluff, ]?.as cut a channel through the lower soft beds of the limestone for a distance of one- DESCEIPTION OF CALC.AEEOUS DEPOSITS 163 fourth mile from the river. The creek bottom land is 10 to 15 feet above the bed of the stream with the limestone frequently within a foot or two of the surface. Sufficient quantities of stone for local agricultural use could be worked here comparatively cheap. WORTH COUNTY The northern part of Worth County is underlain by the Jackson, Vicksburg and Chattahoochee formations. The Jackson is represented by limestone strata exposed along Flint River. The Vicksburg is probably represented by residual red and mottled sands, but seems to be very thin through this section. The Chattahoochee limestone is exposed in several sinks north of Bridgeboro and is represented by residual red sands along the s:urface. The west slope of a ridge several miles back from the river contains the Chattahoochee strata. The two following sections give ari idea of the exposures of the Jackson limestone : Section 5 Miles above G. SW. & G.' Tressel, Flint River (Map locality vVo-1) Feet 2. Pleistocene red sands and pebbles with :flint of probable Vicksburg age at base................ 10 Jackson formation. 1. Medium hard, white, compact limestone. Bryozoa, foraminifera .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 15 Section One-half Mile above Dougherty Cmmty Line (Map locality Wo-2) Feet 2. Flint and soil. ................................ . 1. Medium hard, grayish limestone grading into white at top. Bryozoa, foraminifera:. . . . . . . . . . . . . . . 5 Other exposures occur along the river at thicknesses of from 1 to 4 feet. None are of economic value. In Lee County, limestone was seen as high as 30 feet above the river, then it is reasonable to be- 164 GEOLOGICAL SURVEY 01!' GEORGIA lieve that the same is the case in Worth County, just across the river. Prospecting along some of the creek escarpments would possibly prove up workable deposits. Alforcl Prope1ty (map locality "fVo-3).-There is an exposure of limestone in a si:p.k 3 miles northwest of Bridgeboro, 100 yards south of the Albany road on the Alford property. This sink is in the top of a low hill in the open piney woods and has the shape of a funnel, 10 feet in diameter at the bottom, 100 feet at the top, and 40 feet deep. The following section is descriptive of the strata: Section in Lirnesink on Alford Place Feet 3. Clayey sand subsoil and sand top soil.. . . . . . . . . . . . 6 2. Hard, cream colored, fossiliferous limestone. Fos- sils poorly preserved. (Elevation 270 feet)...... 15 1. White, concretionary-like, oolitic, comparatively soft lhnestone ................................... _ 20 . 41 A comparison of this section with those of other descriptions shows the similarity of the strata. A sample taken from the en tire thickness of limestone shows the following analysis: Analysis of Sam1Jle f1"01n Alford Property (Sarnple No. 104) Soda (Na20) ............................ Potash (K20) ........................... Limestone (CaO) ............................ . Magnesia (MgO) ............................ . .08 .06 52.12 .12 Alun:ina .ULE S BE LO W IIA\YKI::\ 'YJLLE, l'CLA. Kl COC::\TL B . LL\.LE:->TO::\E BIXFF O X ALD1 'THO:\ T l'H O PI':IITY . FLIXT HI\"E 11 , C HISP CO I "XTL DESCRIPTION OF CALCAEEOVS DEPOSITS 177 Plain showing an appreciable percentage of magnesia, which is probably only a local condition. The following section was noted one-fourth mile from the river on Sanborn Mill Creek : Section One-fourth .Mile from River, Sanborn Mill 01eek 4. Soil, some flint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. Medium hard, white, arenaceous limestone..... 2. White, fine grained sand..................... 1. Medium hard, white, arenaceous limestone..... Feet 4 to 7 8 3 6 24 A sample from bed 3 shows the following analysis: A.na.lysis of Sample f1'om Sanborn Mill Greek, One-fourth Mile from Flint River (Sam.ple No. 48) Soda (:Na00) ............ .................... . Potash (KzO) ............................... . Lime (CaO) ................................ . Magnesia (MgO) ............................ . Alumina (.Al20 3 ) Ferric oxide (FezOs) J) Phosphorus pentoxide (P 02 5 ) Silica (Si02) and insoluble ............ -~ ...... . Undetermined ................................ . .39 .15 43.86 2.60 1.30 trace 14.32 37.38 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate ( CaC03 ). . Magnesium carbonate (MgC03 ). . . . . . Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 78.30 5.40 83.70 The silica is in the form of clear quartz grains. Numerous exposures of the medium hard to soft white arenaceous limestone occur along a branch that enters Sanborn Mill Creek from the northeast, in lot 265, 21st district, one-half mile from Flint River. 178 GEOLOGICAL SURVEY OF GEORGIA .Analys'is of Sample taken from a 10-foot Exposure) 1 1/1 Miles Up- stream from the Flint River) Lot 263)? 21st District (Sample No. 49) Soda (Na20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Alun:ina ~dAl,O(3F) ) } . . . . . . . . . . . .. . . . . . . . . . . . . F erne OXl e e20 a Phosphorus pentoxide (P 02 5 ) , Silica (Si02 ) and insoluble..................... Undetermined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 .44 42.22 .47 1.48 ~04 22.07 32.84 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03)..................... Magnesium carbonate (MgC03)................. 75.42 .90 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 76.32 This analysis shows a low-calcium limestone with the silica in the form of clear quartz grains. Another sample was taken from an 8-foot exposure one-fourth mile up-stream from the above outcrop. Analys,is of Sample from Lot 384) 20th DistrictJ Decatur Oottnty (Sample No. 50) Soda (Na20) .. .. . . .. . .. .. . . . . . . . .. . .. . .. .. . .. Potash (K20) .................. -.............. Lime (CaO) . .. .. . . . . . . . . . . . . . . . . . . . . . . . . .. .. Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al20") } Ferric oxide (Fe 0 ) 23 Phosphorus pentoxide (P 02 5 ). Silica (Si02) and insoluble.. . . . . . . . . . . . . . . . . . . . Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 .20 41.30 .90 104 trace 23.11 33.13 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03 )..................... Magnesium carbonate (MgC03 ) . . . . 73.70 1.90 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 75.60 This is an impure limestone containing clear quartz grains as the DESCRIPTION OF CALCAREOUS lJEPOSITS 179 principal impurity. It is generally soft, but contains hard calcareous concretions of irregular shapes and sizes. W. M. Duke Place (map locality De-6) .-On the W. M. Duke property, 3 miles northwest of Faceville, several low limestone ridges extend from the main escarpment toward the river. The stone is a hard, whitish, partly crystalline, fossiliferous variety, having an irregular fracture. A sample of the rocks shows the following analysis: Analysis of Limestone Sample} W. M. Duke Place, 3 JY1ile8 Northwest of Faceville (Sample No. 51) Soda (Na,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alulllina _(dAl20(Fs) ) } ........ ; . . . . . . . . . . . . . . . F erne on e e20 :r Phosphorus pentoxide (P 02 5 ) . Silica (Si02) and insoluble. . . . . . . . . . . . . . . . . . . . . Undetermined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . trace trace 54.70 .12 _70 trace 1.38 43.10 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03 ) . . . Magnesium carbonate (MgC03). . . . 97.70 .26 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 97.96 This deposit probably belongs to the upper middle beds of the Chattahoochee formation. The stratum appears to be in its original position, dipping a few feet per mile to the southeast. The best exposures occur on a ridge one-half mile north of the Duke house. Here are a number of flat outcrops of the limestone with loose fragments and boulders scattered over the surface of the ridge. Other exposures occur on similar limestone ridges east of the above. These deposits are about 100 feet above low water mark of the Flint River and are near no stream that would hinder working by flooding the quarry; consequently natural drainage can be secured. 180 GEOLOGICAL SURVEY OF GEOEGJA. These deposits, which are about 5 in number cover areas from 2 to 10 acres each, with an average height above the valleys of 15 to 18 feet. The overburden of soil an_d humus, appears to be usually less than 2 feet. The deposits are easily accessible from both the Atlantic Coast Line Railway, 2 miles south, and the Flint R.iver, one-half mile north, which is navigable from Albany, to the Gulf of lVIexico. The above analysis shows an exceptionally pure limestone, well suited for agricultural uses and for building lime.~ The stone is also hard enough to be used for ballast, aggregate for concrete and pos- sibly road metal. The surrounding hills and bottoms are well thnbered and would furnish adequate fuel for power generation or lime burning. It is quite probable that numerous other outcrops of limestone occur along the foot of the ridge that follows down the east side of the Flint River. The region is full worthy o.f closer investigation than was permissible on this survey. Recove1y (map locality De-7).-:b'"'rom 1 to 1Jj2 miles south of Re covery along the AtJantic Coast Line Railway, there are a number of limesinks exposing a soft, cream colored, granular, menaceous limestone containing harder masses of a like texture from one-half to twelve inches in diameter. A sample of this stone shows the following ana]ysis: Analysis of F.!ample FJeoured 1 1/4 Miles FJottthwest of Recovery (FJample No. 52) Soda (Na20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K20) ........................ :. . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) ............................. .46 .12 26.74 16.47 Alull_lina _(dAlzO(Fa) ) lJ . . . . . . . . . . . . . . . . . . . . . . . . F erne ox1 e 620 a Phosphorus pentoxide (P 02 5 ) Silica (Si02) and insoluble..................... Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2_16 trace 14.68 39.37 Total ........................... : . . . . . . 100.00 DESCRIPTION OF CALCAREOUS DEPOSITS 181 Calcium carbonate ( CaCO,) ......... , . . . . . . . . . . . 47.74 Magnesium carbonate (MgCOo) . . . . . . . . . . . . . . . . . 24.70 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 72.44 This analysis shows a high-magnesian limestone containing a large percentage of silica, which is in the form of clear quartz grains. This limestone is lithologically and chemically similar to the bed from which sample No. 47 was taken. These exposures occur in the steep sides of two or three compara- tively recent limesinks, the most prominent of which is a well-like sink some 50 feet in diameter .into which a small stream flows and :finds an outlet through underground channels. At the time of the visit the sinks were almost full of water, so that a complete section could not be seen. These exposures occur in a narrow flat bottom between a ridge on the north and a creek on the south, through which the Atlantic Coast I..ine Railway runs. The tops of the exposure are usually a few feet below the rails and are overlain, in the bottom land, by an overbur- den of from 0 to 10 feet. This limestone is again exposed- 1 mile farther southwest in a small stream bed beneath the railroad. Here are large flat concre- tions of comparatively pure limestone. The overburden is quite heavy. This stone is probably of no value at the present time. The cal- cium content is too low to be worked on a commercial scale for agri- cultural limestone and the silica sand content prevents its being used for the manufacture of hvdraulic lime. v Near Florida Line (map locality De-8) .-Fron... 000 yards north of to the Florida State line, a soft, white, siliceous limestone is exposed -in the cuts along the Atlantic Coast I.Jine Railway. No fossils could be found in the material. A sample of the limestone showed the follow- ing analysis: Analysis of Limestone Sarnple front Florida Line, A. C. L. Railway (Sample No. 53) Soda (Na,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49 Potash (K,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86 182 GEOLOGICAL SUEVEY Olf' GEOEGIA Lime (CaO) .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alurr.lina .(d.Al20(Fa) ) } . . . . . . . . . . . . . . . . . . . . . . . . F erne ox1 e e20 a Phosphorus pentoxide (P20 5 ) Silica (Si02) and insoluble..................... Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.40 8.87 264 .06 47.02 26.66 Total ................... , . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03 )...... Magnesium carbonate (MgC03 )................. 23.90 18.60 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 42.50 The above analysis shows a highly siliceous magnesian limestone or dolomite. The silica is in the form, principally, of very :finely divided particles, but some :fine quartz grains also occur. Better exposures of this stone occur across the State line in Florida. At one locality on the railroad, 1 mile north of River Junction, numerous fossils were seen in a flat exposure at a lower horizon than the exposures in the railroad cuts. This stone is frequently used throughout this section for building chimneys and has hence acquired the name of "chimney rock." GRADY COUNTY 'I'he larger portion of Grady County is covered with sand and clays of the Altamaha formation with Alum Bluff and Chattahoochee strata exposed along the Ochlockonee River and in the southeastern and northwestern parts of the county. The surface is gently rolling to level. The limestone exposures are confined to the southern and northwestern parts of the county. Wa,ter Falls (1nap local,ity G-1).-Probably the best exposure of the Chattahoochee and the lower part of the Alum Bluff formations occurs in the limesink known as Water FaJls, 11 miles north of vVhigham on the I. E. Maloy property. This sink is of comparatively recent origin, 50 feet in diameter, with perpendicular sides some 50 feet DESCRIPTION OF CALCAREOUS DEPOSITS 183 deep and then a steep slope going 50 feet deeper. The strata, especially the limestone, are similar to those seen at various localities throughout this section of the State. The following section is descriptive of the strata exposed. Section at lVater Palls Altamaha (Lafayette(~) ) Feet In. 16. Drift to top of hill, reddish, sandy soil. ......... . 18 15. Yellow and gray mottled, argillaceous sand with flint fragments at base; yellow soil at top ..... . 10 Alum Bluff. (Unconformity) 14. Greenish, slightly plastic clay, exact thickness not determined, probably about................... 3 13. Hard, irregular calcium carbonate concretions in a matrix of white, calcareous, sandy clay. . . . . . . . . 10 12. White, calcareous sand. . . . . . . . . . . . . . . . . . . . . . . . . 6 11. White, calcareous clay. . . . . . . . . . . . . . . . . . . . . . . . . . 0 6 10. White, arenaceous limestone.. . . . . . . . . . . . . . . . . . . . 0 2 9. White, calcareous clay .......... :. . . . . . . . . . . . . . . 0 6 8. White, arenaceous limestone. . . . . . . . . . . . . . . . . . . . 0 2 7. Soft, white, calcareous sandstone................ 6 6. Greenish, probably calcareous sand....... . . . . . . . 6 Chattahoochee. 5. Bed of apparently brecciated material similar to that of bed 4 in a matrix of white, argillaceous, sandy limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Hard, compact, grayish limestone, fossils rare; occasional oolites; conchoidal fractme. . . . . . . . . . . 20 3. Hard, compact, yellowish-gray limestone with deli- cate, irregular brownish bands in places; fossils rare; conchoidal fracture. . . . . . . . . . . . . . . . . . . . . 5 2. Hard, white, minutely crystalline, porous limestone; concretionary-like structure; several species of cephalopods. Highly oolitic in pockets; weath- ers into pisolitic-like mass; pisolites one-half to 2 inches in diameter ; conchoidal fracture; resembles lower bed at '' Limesink".. . . . . . . . . . . . 50 1. Medium hard, white, fossiliferous limestone. Ech- inoids, Pecten (perplanus ?) , Orbitoides and Bry- ozoa. Bears close resemblance to limestone seen along Flint River below Newton.............. 20 160 4 184 GEOLOGICAL SURVEY OF GEORGIA Samples from the different strata show the following analyses: Analyses of 8amples from vVater Falls Sample No............... , 71 72 Bed No. . . . . . . . . . . . . . . . . . 1 2 Soda (Na20) 0 0 0. Potash (K 0) 2 0. 0 Lime (CaO) 0 0 0 I trace .06 trace .03 55.46 52.16 .31 .19 42.78 Magnesia (MgO) 0 .16 .40 1.23 Alumina (Alz03) } Ferric oxide (Fe20s) : .32 .50 .80 Phosphorus pentoxide (Pz05) 0 0 trace trace .04 Silica (Si02 ) and insoluble .50 4.73 Undetermined 0. 0 43.56 42.12 -- -- 18.98 35.67 Total 100.00 0 0. 0 0 100.00 100.00 .60 .23 26.68 5.61 1.76 .08 37.33 27.71. 100.00 Calcium carbonate (CaC03) Magnesium carbonate (MgC03 ) 0 0 0 Total carbonates ... 98.96 93.16 .34 .84 -- 99.30 94.00 76.40 47.68 I 2.60 11.74 79.00 1 59.42 As seen from the above section this limestone belongs to the Chat tahoochee formation. It is massive bedded. with probably a slight dip to the southeast. The water which flows into this sink d11ring . ~ wet seasons flows out through underground channels. This deposit has a visible vertical extent of 100 feet. One-fourth mile west of this exposure the stone of bed 3 of the above section out crops at Rock Cave. Between these two exposures there is a large field having a regular slope from the top of the former down to the latter outcrop. East of the Water Falls the overburden on the lime stone consists of the complete section given above. On the west side the overburden has a maximum thickness at the mouth of the sink of 25 feet, from which point the :field slopes westward. At the Rock dave the overburden is apparently about 10 feet. Surroundin~ these exposures there are fields covering from 200 to 300 acres at about the same level as that immediately suirounding the cave. No accurate DESCRIPTION OF CALCAREOUS DEPOSITS 185 idea of the actual extent and workability of this deposit could be . gained from the two exposures. Prospect pits are necessary. This deposit is about 10 miles from the nearest trunk line railroad, but a log railroad which connects with the Atlantic Coast Line west of Whigham is within about 4 miles of the property. Blowing Cave (nwp locality G--2).-At Blowing Cave, one-half mile north of the Water Falls, on the Barrow place, hard, white lime~ stone similar to that of bed 2 at the Water Falls (see section) is exposed. A sample of the stone, taken principally from loose boulders, shows the following analysis : Analysis of Sam_ple from Bloioing Cave (Sample No. 70) Soda (Na20) : . ........... ..................... . Potash (K20) ................................ . Lime (CaO) ................... ............. . Magnesia (MgO) ........................... : . Alun:ina .CdAl20(F3) ) } ....................... . F erne ox1 e e20 s Phosphorus pentoxide (P20,) .................. . Silica (Si02 ) and insoluble .................... . Undetermined ................................ . trace trace 54.54 .30 .68 .00 .95 43.53 Total ................................. . 100.00 Calcium carbonate (CaC03) .................... . Magnesium carbonate (:frfgC03 ) Total carbonates ....................... . 97.34 .63 97.97 This exposure is on the top of a low hill some 25 feet above the surrounding bottom land, and consists principally of loose boulders of stone with a few in the mouth of the cave probably in place. There is an overburden of apparently not more than 3 or 4 feet. The hill covers 40 to 50 acres. This deposit is at too great a distance from a railroad to be of commercial importance, but it is well situated and the stone of excellent quality to be worked for local use. 186 GEOLOGICAL SVEVEY 01!' GEORGIA ]11orest Falls (map locality G-3) .-At Forest Falls or Limesink, 8 miles north of Whigham, limestone is exposed in a vertical bluff 40 feet high. A small stream falls over this precipice and then :finds an outlet through underground channels. The following section was observed: Section at Forest Falls r Feet 9. Drift, red sand, gray sand and grave] ......... 10 to 50 Alum Bluff. (Unconformity) 8. White, calcareous, arenaceous clay with a few hard B+ calcium carbonate concretions.................. 7. White, :fine grained sand....................... . 2 6. Soft, yellowish, calcareous sandstone (7 ft.) grading into hard, white, calcareous sandstone (8 ft.) . . . 15 Chattahoochee. 5. Apparently brecciated hard, white, compact limestone in a matrix of soft, white, argillaceous limestone. Irregular brownish bands run through aggregate and matriX: without break.............. 3 4. Soft, white, argillaceous limestone with brownish, concentric bands ........................... ; . 2 3. Hard, compact, yenowish, minutely crystalline limestone. Fossils rare .................. -. . . . . . . . . . 15 2. Hard, gray, granular limestone. . . . . . . . . . . . . . . . . . . 3 1. Hard, white limestone with concretionary-like structure. Oolitic, small caverns with calcite crystals. Weathered in small marble-size balls. Fossils numerous, principally cephalopods. . . . . . . . . . . . . . . . 15 73 to 113 By comparing this section with the Water Falls section the close resemblance of the strata may be observed. DESCRIPTION OF CALCAREOUS DEPOSITS 187 Samples of this stone show the following analyses: Analyses of Samples from Limesink Sample No...................... 1 67 I 68 . 69 11, Bed No ........................ 2 & 31 4 & 5 6 I I I I Soda (Na20) .................. trace I Potash (K20) .................. trace I Lime (CaO) ................... 50.50 .33 .28 23.88 .59 .98 12.82 Magnesia (MgO) . . . . . . . . . . . . . . . . .46 14.60 3.31 t Alumina (Alz03) Ferric oxide (Fe20 3) j 76 Phosphorus pentoxide (P20,) ..... 1 trace I 280 1 .06 1 86 .04 I Silica (SiOJ and insoluble........ 8.63 21.88 1 60.90 .Undetermined ................... 1 39.65 36.17 I 20.50 Total ..................... 100.00 11 100.00 1100.00 1 I I I Calcium carbonate (CaCOs) ....... 1 90.26 1 42.68 1 22.92 I Magnesium carbonate (MgC03 ) .90 l 30.50 I 6.93 !-I-.- I Total carbonates ......... 91.16 1 73.18 1 29.85 This deposit is probably of little economic importance due to the useless quality of the upper beds, which are therefore overburden. On the east side, this material, together with overlying sandy soil, quickly reaches a thickne8s of 50 feet, while on the west side of the sink no limestone is exposed. The original sink was probably larger than the present dimensions and was subsequently partially filled by drift sands and clays from the Altamaha. Ldtle Limesink (map locaJity G-4) .-Limestone is exposed in Little I..imesink, 5 miles north of Whigham. The following section js descriptive of the strata: Section at Little Limesink Feet 10. Covered to top of hilJ, gray sandy soil. . . . . . . . . . . . 7 9. Boulder of hard, gray compact limestone (in place~) 4 8'. Concealed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 188 GEOLOGICAL SVEVEY OF GEORGIA 7. Fine grained, yellow, cross-bedded sand, apparently in place . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Chattahoochee. 6. Soft, white, argillaceous, siliceous limestone; pisolitic structure; probably weathered phase of a lime-. stone with concretionary structure. . . . . . . . . . . . . . 12 5. Hard, gray, compact limestone; pinkish at base. Few fossils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4. Hard, white, compact limestone .. ~ . . . . . . . . . . . . . . . 3 3. Greenish clay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Soft, white, siliceous limestone; probably weathered phase of harder limestone. No fossils seen. . . . . . 6 1. Rarc1, grayish, compact limestone. Pecten. . . . . . . . . 15 79 This section resembles those observed at the Limesink, 4 miles northeast, and the Water Falls, 8 miles northeast, in a general way only. These exposed strata seem to be, however, more highly weathered; it is possible that this hides the true character of the original material. Fossils here are very rare and poorly preserved. The contact of the Chattahoochee and Alum Bluff was placed in this section by comparison with other sections rather than by evidence furnished by the exposed strata. DESCRIPTION OF CALCAREOUS DEPOSITS 189 Samples of the limestones show the following analyses: Analyses of Samples from Little Limesink I Sample ::Jo.............. -j 75 76 1 77 78 Bed No: ................. 1 1 2I 5 6 I Soda (Na00) ............ 1 .06 Potash . (K00) ........ -. -~ .04 .:nlI .36 .60 .26 .37. .23 Lime (CaO) . . . . . . . . . . . . . 46.68 40.94 35.84 19.44 Magnesia (MgO) ........ I .80 l - I Alumina (Al"Oa) I Ferric oxide (Fe,OJ j . .42 .54 9.85 I .7 1 94 14.08 2.04 Phosphorus pentoxille I 1 .o su~~~0(~io") ~~~1-~~~~1~;;1~ 114:~~ I Undetermined ........... "37.58 1 19:~~ 36.92 In:~~ 1 39.91 / 4 :~:~~ '------1-- 1 1 Total .............. 100.00 1100.00 1100.00 1100.00 I Calcium carbonate (CaC03 ) 73.38 73.14 64.04 / 34.74 Magnesium carbonate 1 (MgC03) . . . . 1.70 1.14 I 20.55 I 29.40 1-1-,, 1- Total carbonates .. I 75.08 1 74.28 84.59 1 64.14 From the evidence furnished by the analyses of the samples, all of these limestones are rather impure, probably too impure to be ground for agricultural purposes, except for local use. It is possible, however, that after being burned they would have hydrauli~. proper- ties and would, therefore, make a natural cement. The overburden, which contains a thin bed of limestone as indicated by the above section, is 21 feet. It is possible that this thin bed is much thicker than is indicated by the section. On the whole, the existing conditions at the exposure were such that a definite idea of the extent and workability of the deposit could not be secured. The quantity of the stone and apparent overburden are such that prospecting is warranted, however, the analyses show a limestone that is suited for only the manufacture of natural cement. 190 GEOLOGICAL SURVEY OJJ' GEORGIA There are other exposures of limestone in the northwestern part of Grady County, notably at Bay Sink, but none of t11em are of economic importance. At this sink Chattahoochee limestone and flint are exposed in the bottom, the sides of which are covered by soil. James Blackshear Place (ma1J locality G-5).-l\iedium hard, grayish limestone is exposed on the Jas. Blackshear place, 8 miles south of Cairo, in the escarpment on the east side of Ochlocknee River, 200 yards south of Bonnet Lake. A sample of the stone shows the following analysis : Analy8'is of Limestone on the J as. Blackshear Place, Grady County (Sample No. 90) Soda (Na20) .............--: . . . . . . . . . . . . . . . . . . . Potash (K20) ............... :. . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AFlun:ina ~dAl20(Fa) ) } ..... . . . . . . . . . . . . . . . . . . . erne ox1 e e20 a Phosphorus pentoxide (P 02 5 ) . . . . . . . . . . . . . . . . . . . . Silica (Si02) and insoluble..................... Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .08 .12 29.60 17.43 1 .30 .05 7.22 44.20 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calciu~ carbonate (CaC03) . . . . . . . . . . . . . . . . . . . . . Magnesium carbonate (MgC03) 52.90 36.60 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 89.50 This limestone is probably Chattahoochee, though no fossils were seen by which the age could be determined. The exposure has a thickness of 13 feet, with the river swamp at the foot. The overburden reaches a thickness of 18 feet some 150 feet back from the exposure. The limestone can be traced for about one-fourth mile along the escarpment. The distance of this deposit from a railroad and the compara. tively small quantity under a light overburden eliminates the deposit from being of commercial importance, except probably for local use DESCRIPTION OF CALCAREOUS DEPOSITS 191 THOMAS COUNTY The limestone exposures of Thomas County are confined to that portion south of an east and west line through Thomasville. In this section the Chattahoochee form3:tion outcrops along the main streams and in several sinks. The northern part of the county is covered mostly by sandy loams of the Altamaha formation. Within the terrane of the Chattahoochee and Alum Bluff formations the land is usually rather rough, with low hills and narrow valf"eys. ~McK-innon Property (map locality Ts-1).-An exposure of magnesian limestone occurs on the :M:. D. McKinnon property, 5 miles east of Thomasville, one-fourth mile south of the 5-mile post on the Boston road and one-fourth mile north of the 5-mile post on the Atlantic Coast Line Railroad, in a broad piney woods area. The stone is a hard cream colored semi-crystalline variety which breaks rather easily with a conchoidal fracture. A sample of the stone taken from the 1-foot exposure shows the following analysis: Analysis of Sample from McKinnon Property (Sample No. 81) Soda (Na,O) ................................ . Potash (K20) ........ : ...................... . Lime (CaO) ................................ . Magnesia (MgO) ............................ . Alumina (Al20 3 ) l Ferric oxide (Fe 0,.) ) 2 Phosphorus pentoxide , (P20 5 ) Silica (Si02) and insoluble, ................... . Undetermined ................................ . .31 .35 25.26 14.95 2.00 .04 20.12 36.97 Total ................................. . 100.00 Calcium carbonate (CaCO,;) .................... . 45.10 Magnesium carbonate (MgCO~) ................ . 31.55 Total carbonates ....................... . 76.65 No fossils were seen by which the age of this deposit could be determined, but it undoubtedly belongs to the Chattahoochee forma- 192 GEOLOGICAL SURVEY OF GEORGIA tion. The stone does not bear a striking resemblance to any seen in this formation except in this immediate vicinity and near Faceville. ~ehe exposure is flat, covering an area about 30 feet square in and level with a piney woods area of upwards of 100 acres, which slopes slightly to the south. The extent of the deposit and the thickness of the overburden could not be determined. Before the advent of railroads in this section this stone was quarried and burned for building purposes. The old workings are now filled with talus so that the quantity of stone removed could not be estimated. The remains of the old kiln are still visible. The analysis shows a rather siliceous limestone, but it is probable that better material underlies the outcrop. The stone is of sufficient hardness to be used for railroad ballast and concrete aggregate. Mitchell P1ope1ty (map locality Ts-2) .-An exposure of mediumhard, grayish limestone, similar to the stone in the southern part of Grady County, was seen in the steep slope of an old limesink, 7 miles west of Thomasville and one-half mile north of the 'rhomasville-Boston public road, near the eastern boundary of the Mitchell property. 'rhe exposure has a thickness of only 1 foot, occurring 30 feet above the bottom of the sink and 12 feet below the top of the slope. It belongs to the Chattahoochee formation. A sample of the partially weathered stone shows the following analysis: Analysis of Sarnple from J.l!Jitchell P'rope1ty, Thonu:ts County (Sample No. 82) Soda (Na,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AFlm~ina ~dA120(3F) O ) } . . . . . . . . . . . . . . . . . . . . . . . . erne ox1 e Altamaha formation with Alum Bluff strata exposed along the main creeks and rivers throughout the county and the Chattahoochee limestone along the Withlacoochee River in the extreme southern portion of the county. River terrace sands of probable Pleistocene age cover a great 202 GEOLOGICAL SURVEY OF GEORGIA portion of all of these forma~ions. The northern portion of the county is rather rolling while the southern portio' n is fiat piney woods. Map loca_lity L-1.-0n the north side of the river, 2 miles below the Georgia and Florida Railroad tressel, there is a 10-foot exposure of Chattahoochee limestone at the base of a bluff 30 feet high. The bluff is so steep that the limestone could not be examined in detail. The overlying strata were concealed and could not be determined. No other exposures were seen between this bluff and the wagon bridge, 1 mile below. Map locality L-2.-A good exposure of limestone occurs in the north bank of the Withlacoochee River, 100 .yards below the wagon bridge, 3 miles down-stream from the Georgia and Florida Railroad tressel. The following section is descriptive of the strata exposed: Section on Withlacoochee River) 3 Miles below G. & F. Railroad Tressel Pleistocene. Feet 4. Loose, white sand. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5 Chattahoochee formation. 3. Badly weathered, apparently originally hard, partly crystalline limestone in softer matrix, probably breccia ... : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Medium hard, very white, granular limestone. . . . . . 5 1. Hard, partly crystalline, cream colored limestone.. . 4 18-20 Bed 3 resembles very closely the breccia occurring at the top of the Chattahoochee formation in the several exposures in the northern part of Grady County. DESCEIPTION OF C.ALCAEEOUS DEPOSITS 203 A sample taken from the lower 12 feet of the exposures shows the following analysis : Analysis of Limestone from Withlacoochee River, 3 Miles below Geor- gia and Florida Railroad tressel (Sample No. 89) Soda (N~O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K%0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alun:-ina ~dA120(3F) ) } . . . . . . . . . . . . . . . . . . . . . . . . F erne on e e20 , Phosphorus pentoxide (P 02 5 ) Silica (Si02) and insoluble.. . . . . . . . . . . . . . . . . . . . Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . trace .00 53.28 .03 _82 .00 2.68 43.19 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 100.00 Calcium carbonate (CaC03 )..................... 97.10 The limestone of this exposure is the upper part of the Chattahoochee formation. The beds are dipping slightly to the southeast. This exposure is continuous along the river for several hundred feet. The overburden is 3 to 5 feet which is probably an average for a level area which extends from 100 to several hundred feet back from the river. The distance of this deposit from transportation and its nearness to the water prevent it from being of much commercial importance; however, it is well situated and the stone is of excellent quality for local agricultural purposes. It will also make a good grade of lime upon being calcined. The lower strata is of sufficient hardness and toughness to make a fair ballast and concrete aggregate. ECHOLS COUNTY The southern half of Echols County is underlain by the Alum Bluff formation while the northern part is within the terrane of the Altamaha. These formations are rarely exposed, being covered by several feet of sand. The surface ofthe county is flat with an occasional shallow pond, due probably to the caving in of -the roof of Hmestone caverns beneath the surface. Allapaha River, the principal stream, traverses the county from north to south. The only good ex- 204 GEOLOGICAL SURVEY OF GEORGIA posures of beds in place are .confined to the hanks of this river along which are excellent exposures of Alum Bluff and Chattahoochee strata above and below Statenville. At a point 214 miles up-stream from the bridge at Statenville there is an 11-foot exposure of a dark blue fullers earth. Underlying the fullers earth there are sands which are exposed from 2 miles above to 1 mile below the bridge. The upper part of the sand stratum is regularly bedded coarse quartz sand. There are apparently several lenses of arenaceous limestone about 2 feet thick in the upper part. At one point about 1 mile above the bridge the limestone is uncovered over an area of about 100 feet square in the side of the river, the top of the shelf being only about 2 feet above the water. Beginning just below this limestone shelf there is a bed of crossbedded, coarse sand. This stratum looks to be thin-bedded, dipping north with an unconformity between it'and the overlying beds and cutting the thin layers off almost horizontally. This bed is exposed to 1 mile below the bridge with occasional calcareous lenses and small nodules. Beginning 1 mile below the bridge and continuing 4 miles downstream limestone is exposed on both sides of the river almost continuously. The upper part of the limestone stratum is the hard brecciated material seen in the counties to the west-Lowndes, Brooks, Tb.omas, and Grady. Beneath this is a hard, dove colored, oolitic limestone with occasional large sand pockets. These pockets were probably subterranean stream channels and pools at one time, subsequently filled with sand. The limestone exposed in the banks of the stream varies from a few inches to 18 feet in thickness and is covered by loose, whitish sand, except near the outcrops of the overlying cross-bedded sands. The river banks are usually about 25 feet high, swamps and low, wet hammocks being very rare. The limestone stratum evidently belongs to the Chattahoochee formation while the cross-bedded sands and ihe fnlJers earth are of DESCRIPTION OF CALCAREOUS DEPOSITS 205 the Alum Bluff beds. The loose sand described as overburden on the limestone is probably of the Okefenokee or Satilla formation. The following locality description is of the most representative exposure along the stream. J. I. Peterson Place.-One of the best exposures of limestone along the Allapaha River in Echols County is on the property of J. I. Peterson, 3:Y2 miles below the bridge at Statenville, on the west bank of the river. The stone here is hard; dove colored, oolitic limestone, the upper few feet of which seems to have been brecciated. At the lower end of the deposit there is a bed of grayish, argillaceous sand about 10 feet thick, while the upper end of the bed changes suddenly to limestone. The sand bed is exposed for about 50 feet and apparently occupies what was at one time a cavern that had been dissolved out by the underground waters and subsequently :filled with sand. Unconsolidated sand overlies the limestone for a thickness of 8 feet, which forms the surface of the broad. level piney woods country so characteristic of this section of the State. A sample .taken from the vertical face of the limestone shows the following analysis: A.nalysis of Sample from J. I. Peterson Place) Echols County (Sample Noo 121) Soda (Na20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) ............. , .. . .. .. . .. .. .. . ~lm~.ina _(d.AlzO(Fs) ) erne ox1 e ez0 s l J . . . . . . . . . . . . . . . . . . . . . . . . Phosphorus pentoxide (P20,)................... Silica (Si02) and insoluble..................... Undetermined .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 .18 27.66 14.43 3_28 .70 15.32 38.07 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03)..................... Magnesium carbonate (MgC03). 49.50 30.30 Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 79.80 206 GEOLOGICAL SUEVEY OF GEOEGIA The lithology and the geographic and topographic position of this magnesian limestone indicates that it belongs to the Chattahoochee formation. No disturbance of the strata seems to have taken place. They are apparently dipping slightly to the south or southsoutheast. The limestone bluff is continuous along the river for several hundred feet ranging from 15 to 18 feet in height. It is overlain by 6. to 10 feet of loose sands, which form the overburden. 'The Statenville railroad is about 2 miles northeast of the deposit. The above analysis shows a magnesian limestone low in combined carbonates, comparatively high in phosphorus and a noticeable percentage of petash. These together make the stone well suited for agricultural purposes. The low carbonate content will probably prevent its being shipped outside of a rather restricted territory. The stone is of sufficient hardness and strength to make a fair-grade crushed stone for highway foundations, ballast and concrete aggregate. CHARLTON COUNTY The eastern half of Charlton County is a flat, almost featureless, sandy plain, while the western half is covered by a part of the Okefenokee Swamp. Exposures of the strata beneath the superficial sands are confip.ed largely to the banks of the. Satilla and St. Marys rivers, both of which have cut their channels down to nearly sea level as far as 50 miles from the coast. The former stream is affected by tides to a few miles above Burnt Fort and the latter some distance above Traders Hill. Exposures of thin strata of limestones and marls of the Charlton formation occur in the banks of the St. Marys River. None of these deposits are of sufficient extent to be of commercial importance except for local use. The following descriptions of exposures are from the report of Veatcb and Stephenson, on Geology of the Coastal Plain of Georgia, pp. 392-400 : DESCRIPTION OF CALCAREOUS DEPOSITS 207 Schoolhouse Bltcff (map locality Ch-1).-The following section is exposed at Schoolhouse Bluff, St. Marys River, 4 miles below the Georgia Southern and Florida Railway tressel. Section at Schoolhouse Bluff Pleistocene. Feet In. 7. Gray or white sand at top of bluff.. . . . . . . . . . . . . . 4-5 6. Orange colored, argillaceous sand with clay at base, and beneath the clay a thin line of small quartz pebbles .................................... :12-15 Pliocene ( ~). Charlton formation. 5. Greenish, fine grained, sticky clay. . . . . . . . . . . . . . . . . 3 4. Soft limestone, and siliceous, fossiliferous material with Ostracods and Bangia cuneata. . . . . . . . . . . . . 1 3. White, calcareous clay. . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Hard, earthy, argillaceous limestone. . . . . . . . . . . . . . 0 4 1. Chalky, argiilaceous limestone with small gastropods 2 6 25-29 10 This section shows 14 feet of limestone under about 25 feet of overburden. A similar exposure occurs at Rand Landing, 1 mile down-stream from the above section. Nettles Landing (map locarity Ch-'2) .-Six to 7 feet of limestone is exposed at the base of a 40-foot bluff near Nettles Landing, St. Marys River, 10 miles south of Folkston. The position of the lime-stone is such that it could not be worked economically except possibly for a very limited local use. Three miles below the above exposures, near Sawpit Landing, there is an outcrop of 8 feet of calcareous clay and chalky limestone beneath 3 feet of stiff, greenish clay. This deposit could probably be worked economically for local agricultural use. 208 GEOLOGICAL SUEVEY OF GEOEGIA CAl\'DEN COUNTY Camden County, in the southeastern corner of the State, is a low, flat area covered with Pleistocene sands and clays. As in Charlton County the best exposures of the materials beneath the superficial Pleistocene sands and clay occur in the branches of St. Marys and Satilla rivers. Limestone and marl are present in several of these outcrops, but the beds are usually too thin and the overburden too heavy to allow ~he economical exploitation of the deposits. McCallie1 mentions beds of limestone and marl a few inches to 2 feet thick on the Satilla River near Burnt Fort and several miles farther up-stream on the King plantation. The marls on the latter place are said to have been used for agricultural purposes with very satisfactory results. Other exposures are mentioned along ,White Oak Creek in the eastern part of the county. A marl deposit containing shells and fragments of bones is exposed at low tide beneath the railroad tressel near White Oak Station. GLYNN COUNTY Glynn County is a low, fiat, sandy area which differs but little in general appearance from the other counties along the coast of Georgia. The surface of the county is of thin beds of Pleistocene sands and clay. The only exposures of consequence of strata beneath the surface sands occur along the. creeks and rivers. In a few of these outcrops there are thin beds of limestone and marl, few of which are workable on account of the thinness of the beds and the heavy overburden. McCallie2 mentions a thin bed of limestone exposed at low tide on College Creek, several miles west of Brunswick. Six feet of sandy, fosE}iliferous marl overlies the limestone. This latter material con- 1 McCallie, S. W., l'hosphates and Marls of Georgia: Bull. Ga. Geol. Survey, No. 5-A, 1896, pp. 86-89. 2 Ibid., pp. 89-92. LIME TONES Oli' TilE CO.d T AL PLAIN Oli' GEOlWIA PLA1' E IX A. LI~IES'I 'ON I ;; l:IL!Wl<'. I :A~' l ' !; IIH~ KIN "' IIAii'OO:'Iilc lc C I~EIDK , Lim OITNTY B . LI~.I E~'l'O :\F: I:IL I'l<', I~ A ".L' S JU I~ KI.N ' lJAL' 01\l!JE I!EEK, LI~ P. 0 N'l'Y DESCRIPTION OF CALCAREOUS DEPOSITS 209 tains calcium carbonate and from one-half to 2 per cent phosphoric acid and should therefore be of considerable value for local agricultural uses. There are _probably other exposures of this and similar materials that could be economically worked for local use. OYSTER SHELLS A possible small supply of calcium carbonate for agricultural and other uses may be obtained from oyster-shell piles which accumulate . at canneries and along the shores of the mainland, islands and saltwater marshes along the coast of Georgia. There are canneries near Savannah, on St. Catherine Island, near Darien, and at Brunswick that produce from 250 to 1000 bushels of shells each per day for a period of 6 months out of the year. These "green'' shells are at present used mainly in highway construction, but are also crushed to the size of cracked corn and sold to poultry raisers. They might be pul. verized and sold to the agriculturists, but the quantity is small and the price received for the shells for other purposes is as much or more than could be realized when sold in the pulverized state. There are occasional beaches along the coast that are covered with the so-called "dead" shells that have been washed up from the bottom of the bays and estuaries by the high spring tides. An excellent example of this type of deposit occurs on the shore of a saltwater marsh 3 miles west of St. Simons Light near Brunswick..The deposit is several hundred yards in length and at low tide is 75 feet wide with the top of the shell pile 14 feet above the water. The thick-. ness of the bed could not be determined, but it is probably several feet. A number of these shell banks are visible at low tide between. Brunswick and St. Simons and Jekyl islands. There is a small plant near Brunswick that pulverizes the shells from the~e deposits for agricultural use. The shells are loaded from the banks upon lighters and then towed to the plant where they are re-handled to the pulverizer by shovel and wheelbarrow. This is a comparatively expensive operation, but where a good price can be obtained for the product the deposits ean be pro:{itably worked. 210 GEOLOGICAL SURVEY OF GEORGIA , The following analysis is of a general sample from an oyster .shell pile at the Atwood cannery at Valona, Mcintosh County: Analysis of \(Green)) Oyster Shells from Atwood Cannery (Sarnple No. 119) Soda (Na20) ................................ . Potash (K20) .. , ....................... ... . Lime (CaO) ................................ . Magnesia (MgO) ............................ . FAlu~ina ~dAl20(3F) ) } ....................... . erne OXJ. e e20 s Phosphorus pentoxide (P 02 5 ) Silica (Si02) and insoluble .................... . Undetermined ................................ . trace trace 53.04 trace .04 4.02 42.90 Total ............ ............... : . .... . 100.00 Calcium carbonate (CaC03 ) 94.64 Oyster shells are practically pure calcium carbonate. The silica and insoluble is the sand and mud which adheres to the shells. PART III. USES AND PREPARATION OF LIMESTONE AGRICULTURAL USES OF LIMESTONE AND LIME SOIL CORRECTIVE The use of limestone and lime for soil improvement dates back some two thousand years. Later writings show that the practice was subsequently adopted in England, Germany, France, and other European countries. It was used in the United States at least as early as the latter part of the eighteenth century and probably before. The primary object of applying limestone or lime is to correct by neutralization the acidity of the soil. All soils are not acid or "sour," nor do all crops thrive better on a "sweet" soil; hence, the use of the corrective should be governed by the soil under consideration and the crops which are to be planted therein. The limestone or lime also helps the physical condition of the soil and acts directly as a fertilizer when the soil is de:ficient in calcium. The :final and greatest value of limestone for the soil, the restora- ation and increase of permanent fertility, is due to the combined ef- fects of the various individual actions. Thus, by neutralizing the acids in the soil the legumes are capable of storing up larger quantities of nitrogen-forming humus, which supplies subsequent crops with nitrogen, as well as makes the soil more pulverulent and fallow and hence more retentive of plant food and the proper amount of nfbisture. The physical action of the limestone and lime on the dif- ferent soils, which will be discussed later, likewise leads to the same end. By improving its physical condition the soil is also more re- sponsive to cultivation and is more easily tilled. PROPERTIES OF LIMESTONE Limestone, marble, chalk, marl, and oyster shells are all calcium carbonates or lime carbonates containing impurities, usually sand and clay. The carbonate percentage may vary from a few per cent 212 GEOLOGICAL SURVEY Oli' GEORGIA to practically 100 per cent. Experimental data seem to show that these varieties of lime carbonate have equal value for the uses to which they are put in agriculture. Dolomite, when pu1e, contains both magnesium and calcium carbonates in the ratio of 0.86 to 1. All authorities on the subject do not agree on the relative values of the calcium and magnesium carbop.ates; the concensus of opinion seems to be, however, that values are about equal, provided the stone contains considerably more calcium than magnesium. The chemical and physical activities of the two carbonates are practically the same, but probably slower in the case of the dolomite since it is less readily attacked by acids. Chemical Action.-According to Hopkins the principal and, in most cases, the only justifiable reason for applying limestone or lime to the soil is to neutralize the acids contained therein, or to "sweeten" the "sour" soil. These acids are carbonic, nitric, lactic, acetic, and various others, derived principally from the decomposition and fermentation of organic matter. ' Limestone is the product of the action of carbonic acid on lime thus: H 2C03+Ca0=Ca003 or (Ca0.002)+H20 (water) It is therefore a neutral salt. When this salt comes into contact with an acid it gives up its carbon dioxide (002 ) and unites with or neutralizes the acid thus: . C a . C 0 3 + 2 H N 0 3 (nitric acid) =0a(N03 ) 2 (a neutral salt) + C 0 2 +H:o!O The reactions with other acids are similar. J_,imestone also aids in breaking down organic matter, making the nitrogen more readily available. It is seen, then, that unless the supply of humus is replenished the soil will become exhausted of this matter. This action by the carbonate is very slow when compared to caustic lime. When limestone is added to soils containing large amounts of insoluble phosphorus or potash salts it reacts slowly upon them, changing them into soluble plant food. Caustic Hme has the same effect USES AND PREPARATION OF LIMESTONE 213 as limestone, but it acts more rapidly. This activity is doubted by some authorities, while experiments by others seem to bear it out. The latter being the case it is seen that the soil must be supplied with these fertilizers-phosphorus and potash-other,vise it \'{rill become depleted of the plant food and :finally sink to a poorer state of fertility than if neither fertilizer nor limestone was used.1 Hence the old adage "Lime enriches the father and impoverishes the son." When phosphates are added to soils containing little calcium they have a tendency to unite with iron and aluminum into an unavailable form. If calcium is also present the phosphate reacts with it forming a slowly available plant food. Calcium and magnesium are both plant foods, therefore limestone and dolomite have direct manurial value and should be added to all soils deficient in these constituents. Physical Properties.-When limestone is applied to a tough claysoil it tends to make it less plastic and more pulverulent, and hence more permeable and less apt to form hard clods upon drying out. On a sandy soil it has the opposite effect, holding the sand granules together and making it more retentive of moisture and plant food applied as fertilizers. The mechanical effects are said to become more evident as the limestone becomes more thoroughly mixed with the soil or after the continued use. LIME As stated on preceding pages, limestone or calcium carbonate is represented in chemistry by the symbol Ca003 or CaO. C02 When this material is heated to a temperature of about 900 C. the gas, carbon dioxide (C02 ), is driven off thus: The lime (CaO) is 56 per cent and the carbon dioxide (002 ) 44 per cent of the weight of the calcium carbonate or pure limestone. There- 1 It should be noted that the weathering of the underlying rocks is a perpetual source of supply of plant food. 214 GEOLOGICAL SURVEY OF GEORGIA fore, since lime or calcium oxide is the part bf limestone which neutralizes the acids of the soil, 1120 pounds of lime is equivalent to 2000 pounds of pure limestone. When lime is left in the air for a few days or weeks, according to the percentage of moisture in the atmosphere, it is seen to crumble to a fine powder. This is due to the water in the air entering into chemical combination with the lime forming calcium hydroxide (Ca (OH) 2), hydrated lime or air-slaked lime. This result may be accomplished more quickly by pouring water on the lime, as is the case when lime is slaked for making building mortars. By_ this action 1120 pounds of caustic lime yields 1480 pounds of hydrated or slaked lime. The lime or calcium oxide is the active constituent in neutralizing adds. Hence one- ton of pure limestone when applied to the soil will have the same value as 1120 pounds of lime or 1480 pounds of slaked lime. When lime is left in the air for a considerable length of time it will absorb carbon dioxide from the air and revert to the original composition of the limestone from which it was derived. The same action takes place iri. the soil. Hence, whether limestone, lime or slaked lime is applied there will in the course of time be limestone in the soil. Ohernical and Physical Action.-The action of limestone and lime in the neutralization of the soil acids is the same, but the action of caustic lime on the humus or organic matter is much more rapid and violent. When the lime comes in contact with the decaying vegetable matter it hastens the action by tearing down the cells or "burning" and in this way releasing a large proportion of the valuable nitrogen contained therein. Care should be taken then to return to the soil that quantity of humus destroyed by the lime unless the land is unusually rich in organic matter, such as swamp or peat lands. If the soil is deficient in calcium or magnesium for plant food the limestone and lime have the same value, proportionately to the percentage of lime and magnesia in the limestone. U_SES AND PREPARATION OF LIMESTONE 215 The physical action of the lime on the soil is similar to the action of the limestone, which has been mentioned in a preceding paragraph. From the above statement it is seen that the action of limestone and lime when applied to the soil is practically the same except that the latter tends to destroy the valuable humus. The results of the experiments by the various State Agricultural Experiment Stations in the North and South seem to indicate that the limestone gives slightly better results than the caustic or hydrated lime. However, the difference is so slight that the material to be used should be governed by the cost, remembering that 1120 pounds of lime is equal in value to 1480 pounds of slaked lime or 2000 pounds of limestone. Since these materials vary widely in purity the approximate analysis should be known by the buyer and purchased on the basis of the calcium and magnesium content. In order to determine the availability for plant food of the potash and phosphoric acid of limestone, three similar tests were made. Three limestone samples obtained in South Georgia were selected and 100 grams of pulverized stone weighed out from each, which were placed in separate tin cans with 3 liters of distilled water. Oarbon dioxide was then passed into the water to make it as similar as possible to meteoric water. The carbonated water remained on the limestone for 3 months, the cans being well shaken each day for the first month. 216 GEOLOGICAL SURVEY OF GEORGIA At the end of the third month the water was analyzed with the following results: Analyses for SolubUUy of Potash and PhosphaTic Acid of Limestone I Sample No.................. 6 57 I . 84 Analysis of I I I Lime- Soluble Lime- Soluble Lime- Soluble stone in stone in stone in sample water sample water sample water I I II I Soda (Na20) 0 4 0 0 0 0 Potash (K 0) 2 ......... 0 0 0 0 Lime (OaO) 0 0 .22 .38 52.98 .0084 trace .06 47.62 .003 ..0135 ', .009 25.88 Magnesia (MgO) ....... 0 0. 0 .... .22 .32 15.01 Alumina (A120 3 ) } Ferric oxide (Fe20 3 ) 1.00 1.26 3.14 Phosphorus pentoxide (P~05 ) .10 trace .56 I trace .09 Silica (Si02) and insoluble ..... 2.84 Undetermined 42.26 0. 0 0 0 0 0 Total . .. .. . ... +00.00 1 6.78 17.17 I I 43.40 38.53 1- 1100.00 I 100.00 trace These results show that 2.2 per cent of the potash of sample No.6 'vas soluble, 5 per cent of sample No. 57, and 6 per cent of sample No. 84:. The phosphoric acid was only slightly soluble. VALUE OF LIMESTONE AND LIME FOR AGRICULTURAL PURPOSES The :first thing to be taken into consideration when the use of limestone or lime is contemplated is the crops to be grown. Certain plants grow best on 'a slightly acid or sour soil, while others require a neutral or sweet soil. In the :first group are such plants as cotton, peanuts and watermelons; in, the second, all of the leguminous plants, grains, grasses and most vegetables. Some experts include cotton and peanuts in the list of the benefited plants, leaving watermelons as one of the few plants that are injured. The vines of this last named plant grow very luxuriantly under limed conditions but the fruit is small and unsound. USES AND PREPARATION OF LIMESTONE 217 Experiments and practice show that alfalfa, the clovers, and other legumes are practically always failures when seeded in an even slightly acid soil. The nitrogen gathering bacteria of these legumes can only develop properly in sweet soils, consequently in sour soils such plants do not have the power they should have to collect atmospheric nitrogen by means of the root-tubercle bacteria. Hence, their value as soil enrichers as well as the proper yield of the crop itself is lost unless limestone is used or the soil is already sweet. Experiments with wheat, oats, rye, corn, etc., show a varying increase in yield when seeded in a limed soil. Certain authorities state that caustic lime prevents "rust" or "smut" on these plants. A majority of truck or vegetable plants yield more abundantly on a sweet or neutral soil, while others are but little affected by the use of lime. Under the former are such crops as beets, cantaloupes, cucumbers, squash, tomatoes, peppers, etc., and under the latter, potatoes, egg plant, etc. Experiments by the Rhode Island Agricultural Experiment Station indicate that lime is very valuable for pasture and hay grasses and a detriment to the common weeds. A notable fact about the limestone ridges of the Coastal Plain of Georgia is that they are almost without exception covered with an abundant growth of such hard woods as the oak and the hickory and the haws, crabapple, red bud, and other plants. The absence of pine, especially long-leaf, is very noticeable. Hence) we conclude that the species of the first group desire a sweet soil, while the pines grow more favorably on sour land. Experiments, according to information received direct from several agriculturists in South Georgia, indicate that the growth of pecan trees is greatly increased by the use of limestone. This is borne out by the selection of the limestone soils by the hickory which is very closely related to the pecan. After the crop desired is known it should be determined whether or not the soil is in need of a neutralizing agent. Since calcium carbonate is soluble to a slight extent in meteoric waters it is leached out of the top soil and carried downward. This, together with the action of humic acids on the lime and that taken up by plants, 218 GEOLOGICAL SVlWEY OF GEORGIA causes the large majority of soils to lack sufficient alkalies to maintain a neutral condition of the soil. In the following table partial analyses are given of several types of soil in the Coastal Plain area of Georgia: Partial An' alyses of So~bth Georgia Soils (Analyses b.Y Chemical Department of the Georgia Department of Agriculture) Sample No. ! 2 3 4 5 6 7 8 9 10 11 12 13 14 'l'ype of soil Total Phosphoric acid Sand-clay .14 Sandy .04 Sanc1y .06 Clay-sand .04 Clay subsoil .12 Sandy .04 Clayey .56 Sandy .10 Sandy .06 Clayey .06 Sandy .08 Sandy .08 Sandy .08 Clay-sand .10 Potash.. Acidity .12 Neutral .06 Acid .05 Acid .05 Acid .06 Acid .06 Slightly Acid .05 Acid .06 Acid .04 Acid .05 Acid .05 Acid .10 Acid (a) Acid (a) Acid Description of Samples 1. Pebbly, yellow, sand-clay soil. One-half mile south of railroad station, Ten- nille, Washington County. . 2. Sandy soil. One-fourth mile north of courthouse, Homerville, Clinch County. 3. Dark gray, sandy soil, from bottom land, 8 miles north of Valdosta, Lowndes County. 4. Brown, pebbly, clay-sand soil, 2 miles north of Valdosta, Lowndes County. 5. Brown, pebbly soil, yellow clay subsoil, 1 mile west of Quitman, Brooks County. Good crop of cotton on land. 6. Sandy soil from between Blue Spring and the Withlacoochee River, Brooks County. 7. Yellow, clay-soil from near olc1 Toy Phosphate pits, 31/z miles west of Boston, Tho.mas County. 8. Sandy soil from 1 mile north of Thomasville, Thomas County. 9. Sandy soil from near Pine Park, Grady County. 10. Pebbly, clay-soil from 2 miles north of Whigham, Grady County. USES AND PREPARATION OF LIMESTONE 219 11. Sandy soil from 2 miles west of Faceville, Decatur County. A poor crop of corn and peanuts on land. 12. Dark gray, sandy soil from 6 miles west of Bainbridge, Decatur County. 13. Sandy soil, Abbeville, Wilcox County. 14. Clay-sand soil, Preston, Webster County, 250 yards northeast of courthouse. Of the 14 samples analyzed, 1 is neutral, 1 slightly acid and the remaining 12 acid. Therefore, 13 out of the 14 soils are in need of some neutralizing agent. Limestone is the cheapest and most effective material that can be used. The phosphoric acid percentages show the total in the soil, while the potash given is that soluble in a 20 per cent solution of hydrochloric acid. The potash in the feldspar, mica, etc., of the soil is not shown. A total of 25 or 30 samples of several types of soil from Twiggs, Bleckley and Jefferson counties were tested with litmus paper by the writer. All samples proved to be acid with the exception of 4, which were secured from a bottom at the foot of a limestone ridge. These results tend to show that the large majority of the soils of South Georgia are acid and, therefore, in need of lime or limestone. The quantity of the neutralizer to apply depends upon the. acidity of the soil and the crops to be grown. A natural indicator of acidity is the common sour grass, which according to certain authorities, grows only on sour land. A simple test of the soil may be conducted as follows: Secure from a druggist a bottle of fresh blue litmus paper. To take a sample of soil, dig a hole about 6 inches deep and take from it a tablespoon of dirt 2, 4, and 6 inches below the surface, using a clean spoon. Put the material thus obtained in a clean bowl or cup and mix to a thin paste with rain water, melted ice, or distilled water obtained from a druggist. Take a strip of tbe litmus paper and insert one end in the paste, allowing it to remain about 30 minutes. Care should be taken that the fingers do not touch the part ofthe paper put in the paste. Remove and rinse in the pure water. If the color has changed to a decided pink the soil :is very sour; if only a pinkish tint is noticed the soil is only sHghtly acid. if no change takes place the soil is neutr~l. There is an instrument made by the Standard Soil Tester Company, of Mil- 220 GEOLOGICAL SURVEY OF GEORGIA waukee, Wis., for testing soils for calcium carbonate. It is so calibrated that it reads directly the number of thousand pounds of calcium carbonate contained in a plowed acre. The principal is the displacement of water by carbon dioxide derived from a certain weight of soil by the action of hydrochloric (muriatic) acid. The instrument has never been tested by the writer, but is highly recommended by a number of agricultural demonstrators and agricultural school instructors. To test an acre, if the soil is uniform, a sample should be secured from each corner and one from the center. Knowing the quantity of calcium carbonate in the soil and the quantity there should be for the best results the quantity to be applied is readily computed. A more accurate test may be had by sending a sample of the soil to a chemist to be analyzed. One author says :1 " Any-soil containing less than 1 per cent of calcium carbonate will be benefited by liming, and when the percentage falls to one-fifth per cent lime becomes a necessity to enable the manures to exert their proper action." QUANTITY OF LIMESTONE TO APPLY One ton of ground limestone per acre or the equivalent weight of caustic lime or hydrated lime, is usually sufficient to neutralize the acidity of most soils. To obtain the best results, however, a larger quantity should be added in order to have a reserve supply in the soil to neutralize any acids that m_ay develop subsequent to the first application. The best practice seems to be to apply 2 or 3 tons of ground limestone per acre first and then about 1 ton per acre every four or five years thereafter. This quantity is sufficient to supply that neutraljzed by acids, removed by the plants, and carried off by leaching. PREPARATION OF SOIL AND WHEN TO APPLY LLVIE The soil to be limed should first be broken up and harrowed, the ground limestone or lime then spread and harrowed in. The more 1 Hall, A. D., Fertilizers and Manures, 1910, p. 253. VSES AND PREPARATION OF LIMESTONE 221 closely the lime is incorporated with the soil the better the results. Since the tendency of the lime is always to go downward it should never be turned under with a plow. Although limestone can be applied at any time during the year with beneficial results, it should be applied several months previous to the preparation of the seed bed for a leguminous crop such as peas or clover. If the legume is to follow oats or wheat the limestone should be applied to the seed bed for the grain crop in the Fall, as early before the sowing or drilling as possible. Neither limestone nor lime, especially the latter, should ever be drilled in with the seed. In the first case its effectiveness in reaching all parts of the soil is materially decreased, in the second the caustic lime is apt to destroy the life of the seed. Limestone should never be mixed with fertilizer or manures or used in their place. The land should be limed as needed and the fertilizer then used without regard to the liming. METHODS OF APPLYING In applying 2 tons of ground limestone per acre, piles containing 80 pounds should be placed 30 feet apart over the area. From these piles the material may be easily spread by means of a shovel. If a large area is to be treated it would probably be more economical to purchase a spreader constructed for that purpose. Several agricultural implement manufacturers have these machines on the market. A very efficient spreader is described by C. E. Thorne1 as follows: Make a hopper similar to that of an ordinary grain drill, except that it should be 8 feet long with sides and top 18 to 24 inches wide. Let the bottom be 5 inches wide in the clear and cut in it a row of oval holes, 1 inch wide, 2 inches long and 8 inches apal't. Make a false bottom with holes in it of the same size and shape as those of the main bottom, and so spaced that they will register. Let this false bottom slide loosely under the hopper, moving upon supports made by leaving a space for it above bands of strap iron, which should be carried around the hopper every 2 feet to strengthen it. Both bottom pieces should be of smooth, seasoned hardwood, seven-eighths inch thick and well oiled or painted. To the lower strip rivet a V-shaped arm, extending an inch in front of the hopper, with a half inch hole in the point of the V, in which drop the end of a strong lever, bolting the lever 1 Thorne, C. E., The Maintenance of Fertility (Liming the Land) : Bull. Ohio .A.gri. Exp. Sta., No. 279, July, 1914, p. 23. 222 GEOLOGICAL SURVEY OF GEORGIA loosely but securely to the side of the hopper, 3 or 4 inches above the bottom. Let the lever extend 6 or 8 inches above the top of the hopper, and fasten to the side of the hopper a guide of strap iron, in which the lever may move freely back and forth. The object of this lever is to regulate the size of the openings by moving the bottom plate. Make a frame for the hopper, with a tongue to it, similar to the frame of an ordinary grain drill. Get a pair of old mowing machine wheels, with ratchets in the hubs, and two pieces of round axle of sufficient length to pass through the wheels and frame and into the ends of the hopper, where they are welded to a bar of iron 11,4 inch in diameter and the length of the inside of the hopper. The axles should be fitted with journals, bolted to the underside of the frame. Make a reel to work inside of the hopper by securing 8 short arms of one-fourth inch by three-fourths inch iron to the axle, and fastening to these 4 beaters or wings of three-eighths inch by five-eighths inch iron, and about an inch shorter than the inside of the hopper, the reel being so adjusted that the wings will almost scrape the bottom of the hopper but will revolve freely between the sides. These arms should be made of 2 pieces, bent so as to fit around the axle on opposite sides, and secured by small bolts passing through the ends and through the beater which is held between them. The diameter of the completed reel is about 5 inches and its length an inch or so less than that of the inside of the hopper. This reel serves as a force feed. Literature on AgrioultuTaZ Uses of Lime Broughton, L. B., How is Lime Distributed and Lost from Soil~: Bull. Maryland Agri. Exp. Sta., No. 166, 1912. Gardner, Frank G., The Use of Lime on Land: Bull. Penn. State College Agri. Exp. Sta., No. 131, 1914. Hopkins, C. G., Permanent Soil Improvement: Mooers, C. A., Liming for Tennessee Soils: Bull. Agri. Exp. Sta. of Univ. of Tenn., No. 97, 1913. Mooers, C. A., Hampton, H. H., and Hunter, W. K., Bull. Agri. Exp. Sta. of Uniy. of Tenn., No. 96, Parts II and III, 1912. Thorne, C. E., Liming the Land: Bull. Ohio Agri. Exp. Sta., No. 279, 1914. Westgate, J. M., Alfalfa: Farmers' Bull. U.S. Dept. Agri., No. 339, 1908. Wheeler, H. J., Liming of Soils: Farmers' Bull. U.S. Dept. Agri., No. 77, 1905. Wheeler, H. J., and Adams, G. E., Influence of Lime Upon Plant Growth: Bull. Agri. Exp. Sta. of the Rhode Island College of Agri. and Mech. Arts, No. 98, 1903. INSECTICIDES AND FUNGICIDES Lime is used in the preparation of a number of solutions and pow- ders to be sprayed or dusted on vegetation to destroy insects and fungi. Calcium oxide is the only useful constituent of the lime and hence impurities, such as magnesia, alumina, etc., act as adulterants. For this use the lime must be free from sand grains or other coarse USES .AND PREPARATION OF LIMESTONE 223 particles, otherwise the solution will not go through the sprayer nozzle or duster. The following are some of the more important insecticides and fungicides in which lime enters as one of the main ingredients: Paris green solution, lime-sulphur wash, and Bordea':IX mixture. CRUSHED LIMESTONE Concrete Aggregate.-Orushed limestone is used very extensively in certain sections of the country as the coarse aggregate for concrete. The requirements are that the stone shall be hard, tough, and have a high crushing strength. The size of the aggregate depends largely upon the purpose for which the concrete is used. In ordi- nary street or foundation work, stone that will all pass a 22 inch and rest on a one-half inch ring is used. In monolithic concrete construction the aggregate may be somewhat coarser while stones weighing several tons are placed in the concrete in such a way that they will not touch. There are certain deposits of limestone in South Georgia that would furnish a good grade of stone for concrete work though not being of equal value to the harder stone of North Georgia. These deposits are in the Midway, Ocala and Chattahoochee fDrmations in Macon, Randolph, Clay, Calhoun, Lee and Worth counties and the counties along the Georgia-Florida State line, west of Echols County. Road Metal.-Crushed limestone is used in road construction for foundation and surfacing material. The requirements are similar to those for concrete aggregate. The crushed stone that will all pass a 2Yz inch ring with the fines screened out is used for the foundation material. A bituminous or other type of binder-may then be used or the fine stone spread over the top and worked down to fill the voids among the coarser stone. Limestone has the advantage over other types of stone of having relatively high cementing properties. Ballast.-For railroad ballasting material a stone that has high crushing strength, and will neither chip nor dust easily is required. The stone crushed to a size that will pass a 21;2 inch and rest on a 224 GEOLOGICAL SURVEY OF GEORGIA one-half inch ring is most commonly used. It is spread along the road bed over the cross-ties and then tamped beneath the ties with shovels or especially made tools, hence the necessityfor a tough stone. Some of the stones listed under "Concrete aggregate," above, will furnish a fair grade of material for this work. MORTAR By far the most important use of lime is in makin' g ordinary building mortar. The variety of lime that should be used depends largely upon the experience of the mixers and the cost, as well as the properties of the lime itself. A laborer who has been accustomed to working with a "hot" or quick-slaking lime will probably not be able to get the best results with a "cold" or slow-slaking variety. The loca- tion of the construction work with reference to the place of manufac- ture of the different limes will govern the cost. There are three properties of the lime to be taken into considera- tion, namely, the volume of mortar it will produce, the workability of the mortar, and the :final strength. High-calcium limes, containing not more than 5 per cent of impurities, not including magnesia, will here be considered. A high-calcium lime slakes rapidly and evolves much heat. If properly prepared it will yield a larger volume of paste than the low- calcium limes; but on the other hand, if it is allowed to burn while slaking the volume will be materially decreased. The paste is sticky which, together with the increased volume, means that a large quantity of sand can be used in the :final mortar. High-magnesian or dolomitic limes slake slowly and evolve much less heat than the high-calcium limes and thereby lessen the danger of burning. They likewise yield a smaller volume of paste, which is less plastic and as a consequence produce a smaller volume of mortar. In setting,.the shrinkage of magnesian-lime mortar is much less than mortars made from high-calcium limes. From the brick mason's point of view the high-magnesian Urnes are the more desirable, since they are not so sticky and hence more VSES AND PBEPABATION OF LIMESTONE 225 easily troweled; furthermore, they set more slowly, which allows him to spread a larger area with mortar before placing the brick. On the other hand, however, high-calcium limes are preferred by the contractor, because they yield a larger volume of mortar and harden more rapidly, enabling him to complete the work sooner. Magnesian limes are said to yield the stronger mortars, but since the pressure to which they are subjected in a brick wall. or other structure is comparatively small the relative strength need not be considered for ordinary work. Hydrated lime is taking the place of caustic lime, to some extent, in making mortar. By using the former the danger of burning is eliminated, also a more efficient mortar is assured since all of the inert lumpsare screened out subsequent to the hydration by the manufacturer. The cost is, of course, somewhat greater than for lump Jime, but this is largely offset by the saving of the expense of slaking and seasoning. The hardening of a mortar is due to the combination of the carbon dioxide of the air with the lime of the mortar, thus forming limestone or calcium carbonate, which is similar in composition to the stone from which the lime was originally derived. The outer surface of the mortar takes up the carbon dioxide first which seals the pores, more or less, and prevents the inner part of the mortar from hardening. PLASTER I.ime to be used for plastering must fill several requirements-it must not "pit" or "pop," must work smoothly under the trowel, and the shrinkage due to setting should be as little as possible. If the lime is to be used for the finish coat it should be white, or nearly so. "Popping" or "pitting" seems to be due to impurities in the lime which form chemical combinations with the calcium and slake very slowly. This slaking may take place partly after the plaster has been spread and since expansion takes place a soft spot will develop from which the material will eventually fall out, leaving a pit. Particles oflime burned.during slaking will likewise hydrate slowly and, there- 226 GEOLOGICAL SURVEY OF GEORGIA fore, may cause pits. There is less danger of burning magnesian limes than high-calcium limes during the hydration process. Magnesian limes yield a plaster that is more easily spread than that made from high-calcium limes, the latter, however, will yield a larger volume and hence cover a larger surface. The shrinkage of magnesian lime plasters due to setting is less than that of high-calcium limes, hence cracks are more liable to develop when the latter is used. The cracking, however, may be .largely overcome by the use of hair, wood fiber, or some similar material. For the finish coat magnesian limes are to be preferred since they are generally more nearly white. Hydrated lime may be used in the place of lump lime for plastering. It is generally more pure than lump lime and hence shoufd give better results. USE OF HYDRAT.ED LIME WITH PORTLAND CEMENT Hydrated lime is used to some extent with Portland cement for two purposes-to increase the workability of the cement mortar and to decrease the porosity. Cement mortars have little or no plasticity and hence their working quality is poor. It has been found that the addition of 5 to 15 per cent of hydrated lime will make the mortar more responsive to the trowel without materially injuring the hydraulicity or strength of the cement. Also, the hydrated lime is more finely divided than the cement and will, therefore, occupy the space between the cement particles. In this way the hardened mortar is made more impervious to water. HYDRAULIC CEMENTS It was mentioned under the head of "lime manufacture" that when the temperature of the lime kiln is 1200 C. or over, a c~emical combination takes place between the lime and its impurities such as silica, ferric oxide and alumina. This material will set under water, USES AND PREPA.RA.TION OF LIMES'.JO,NE 227 and is known as hydraulic cement. The setting is caused by the crystallization of the silicates and aluminates of lime. There are several varieties of hydraulic cements, such as, Puzzolan cement, hydraulic lime, natural cement, and Portland cement. Puzzolan cement consists of a mixture of slaked lime and blast furnace slag or volcanic ash. Hydraulic lime is formed by burning siliceous or argillaceous limestone at a temperature slightly above that of decarbonization. Under these conditions silicates, aluminates and ferrites of lime are formed. There must be enough of the calcium~ silicate present to cause the burned limestone to set under water and also enough free lime to cause the lumps to slake upon the addition of water. The following table1 has been prepared by Eckel as representing the ideal composition of hydraulic lime. Composition of Ideal Hydraulic Limestone and Hydraulic Lime (Eckel) Silica (Si02 ) .... II Lime (CaO) .. Carbon dioxide (C02 ) ........ \ I Water (H20) ... "I Total ..... I I ~ Hydraulic Hydraulic lime limestone before I efore slaki~g After slaking burning 13.20 86.80 0.00 100.00 21.20 78.80 0.00 0.00 100.00 I 19.08 I 70.92 I I 0.00 I 10.00 I 100.00 I ' . This exact composition is rarely if ever found in a limestone as iron and alumina are practically always present. In the following 1 Eckel, E. C., Cements, Limes and Plasters, 1905, p. 175. 228 GEOLOGICAL SURVEY OF GEORGIA tablel analyses of limestones of Europe used for the manufacture of hydraulic limes are given : Analyses of Hydraulic Lime Rock (R,ies) 1 Silica (Si02 ) 0. 0. 0. 0 0 Alumina (A1 02 3 ) 0 0 0 Iron oxide (Fe20s) ........ 14.30 .70 .80 Lime (CaO) 46.50 0 0 0 Magnesia (MgO) Undet 0 Carbon dioxide (C02) ..... 36.54 . . - - Water. (H20) .. . .. . . . . . 0 Total 98.84 0. 0 2 3 I 11.03 7.60 } 3.75 5.07 .75 43.02 50.05 I 1.34 .30 35.27 . .... f 41;30 -- 99.48 1100.00 4 17.00 1.00 44.80 .71 35.99 99.50 1, Teil, France; 2, Haurenbergen, Germany; 3, Malain, France; 4, Senonches, France. The silica content must, of course, be in very finely divided particles or in clay, otheiwise, the combination with the lime will be incomplete. Magnesia acts the same as lime, molecule for molecule, taking into consideration, of course, the respective atomic weights. There are a great many limestones in South Georgia approximating the above analyses, but in the majority the silica occurs as rather coarse sand grains. The analyses given below are of stones suitable for the manufacture of hydraulic limes. Analyses Hyd1"aulic Limestones Sample No......................... . 13 59 1 Silica ( Si02 ) Lime (CaO) ........................ . Magnesia (MgO) ................... . Alumina (Al2 03~) ( Fenic oxide (Fe203). f Cmbon dioxide ( C02) : ...... .. I Water (H20) (approx.) .............. . 11.20 46.76 tlace 2.06 36.75 2.50 11.33 48.04 .36 2.56 37.70 Total ........................ . 99.27 99.99 No 13, from Colliers Bluff,, Ocmulgee River, 5 miles above Hawkinsville" No. 59, from mouth of Cedar Creek, Flint River. 1 IUes, H., Economic Geology, 1910, p. 141, USES AND PEEP.AEATION OF LIMESTONE 229 Hydraulic lime is burned in the same type of kiln as is used in the manufacture of ordinary lime. After burning, it is slaked by adding just enough water to hydrate the free lime. Its advantage over quick lime is its. ability to set under water, a property less marked than in Portland cement. Little or no hydraulic lime is manufactured in the United States at present, but it is much used in Europe. A small quantity is imported by this country and sold under the name of "Lafarge." Natural cement is the oldest of that group of cements possessing hydraulic properties. It was manufactured and used by the early Egyptians, Greeks, and Romans for purposes which required a mortar that would set or harden under water. The industry, although of great importance in the European countries, has been largely replaced in the United States by Portland cement. Natural cements are manufactured by burning argillaceous limestone containing 15 to 35 per cent clayey material, of which 10 to 25 per cent is silica and 5 to 15 per cent alumina and ferric oxide. Magnesia may take the place of about two-fifths of the lime; the action of both being the same, molecule for molecule, provided the stone is not burned to the point of insipient vitrification. Like hydraulic lime, the hydraulic property of natural cement depends upon the chemical combination of lime with the silica, alumina and iron. It differs from hydraulic lime, however, in that there is not sufficient free lime to cause the burned material to slake upon the addition of water; hence, it must be ground. Natural cement possesses greater hydraulic properties and shows much greater strength after setting than the hydraulic lime, but it is not so strong as Portland cement, which has a more definite chemical composition, as will be seen later. Natural cements vary from brownish yellow to brown. The initial set takes place in about 20 minutes after being mixed with water and the final set 3 to 5 hours later. 230 GEOLOGICAL SURVEY OF GEORGIA Analyses of Natural Cement Rocks from Northwest Georgia1 1 2 3 Silica (SiO~) 6 ~ Alumina (Al20 8) l Ferrie oxide (Fe,Oa) j Lime (CaO) .................... Magnesia (MgO) ................ Sulphur trioxide (SOa) ............ Phosphorus pentoxide (P205) ...... } Clay bases (Al20a, K20, NazO) ..... Carbon dioxide (C02) ......... Water (H20),, 5.28 2.62 30.60 17.25 .02 .04 3.83 40.36 6.52 .96 47.98 1.25 trace 2.58 40.71 22.93 4.16 33.80 .45 .03 .02 10.43 28.18 Total 100.00 100.00 1100.00 00 0 0 I o o 0 0 0 0 0 0 o o 0 0 0 0 0 0 1. Natural cement rock from Cement, Bartow Couuty, Georgia. 2 and 3. Natural cement rock from Rossville, Walker County, Georgia. Natural cements are burned in kilns quite similar to the ordinary lime kiln, but larger. The kilns are operated continuously with the fuel and limestone fed in at the top, together or in alternating layers. As mentioned above the temperature used for burning is only slightly above the temperature of de-carbonization. The burned stone is drawn from the bottom, cooled and ground so as to pass 40 or 50 mesh. Descriptions of kilns and grinding machines are given in other parts of this report. Pmtlcmcl cement is the resulting material from an artificial or natural mixture of calcium carbonate, silica, alumina, and iron oxide, in definite proportions, burned to the point of incipient vitrification and the clinker ground to a :fine powder. Calcium carbonate and silica are the principal ingredients of the raw material, which after being burned forms a tri-calcium silicate. There must be present, however, some other material to act as a flux which lowers the tem- perature of vitrification sufficiently to put it on a commercial basis. 1 Maynard, T. Poole, Limestone and Cement Materials of North Georgia: Bull. Ga. Geol. Survey, No. 27, 1912, p. 35. USES .AND PEEP.AE.ATION OF LIMESTONE 231 Alumina serves this purpose. Ferric oxide is 3:lways present and may be considered to act similarly to alumina, molecule for molecule. The ratio of lime to silica plus alumina plus iron oxide in the final cement should be about 2 to 1, but may vary slightly. The ratio of silica to alumina plus iron oxide should be between 2 to 1 and 3.5 to 1. The magnesia content of the final cement should be less than 5 per cent. Yarious combinations are used to obtain these proportions. The sources of calcium are marl, argillaceous limestone, chalk, hard, high-calcium limestone and marble, while silica and alumina are derived from clay, shale, and slate. Sand grains and pebbles must be absent in these materials. In the following table are given analyses of the limestone, clay, mixture and the finished cement: Analyses of Cement Materials and Finished Ptoduct (Eckeljl Raw rnaterials i Finished products Limestone) Clay II I Silica (Si02 ) 1.16 57.06 Alumina (Al20 3 ) 1 .75 10.01 I Ferric oxide (Fe20 3 ) 1 .75 Lime (CaO) ..... 49.44 5.37 8.32 Magnesia (MgO) . 1 2.04 5.22 Loss (H20,CO.,etc.) 1 46.04 Total ..... II -- 1oo.1s 14.00 99.98 I Mixture ) Cement I I 22.20 22.42 I 5.02 I 5.68 2.85 3.22 65.79 I 62.24 4.o6 1 3.22 1 undet'd. undet'd. 1 99.92 96.78 In preparing the raw materials to be burned, analyses are made of the limestone and clay, or whatever the materials may be, and the properties of each to be added to make the mixture calculated. They are then ground and mixed thoroughly. The mixture is then ready to be burned. It is fed into the upper end of a rotating kiln which . slopes gently to the lower or firing end. The kilns are from 5 to 7 feet in diameter and 60 to 200 feet long. The outside is of sheet steel and the inner lining fire brick. Pulverized coal, gas or oil, which is 1 Eckel, E. C., Cements, Limes and Plasters, 1905, p. 397. 232 GEOLOGICAL SURVEY OF GEORGIA blown in through a small pipe at the lower end of the kiln, may be used for fuel. As the kiln rotates the mixture works its way to the lower end of the kiln where it is discharged as a clinker which has been burned to the point of incipient -vitrification. The clinker is seasoned for a number of hours and then ground. In this state the cement will "set" too rapidly, hence a small quantity of gypsum is added to retard this. The prospects for the manufacture of Portland cement in South Georgia seem to be rather remote; the raw materials occur in quantity, but the distance is too gr.eat from the source of fuel supply. The uses of hydraulic cement are so well known that it seems useless to dwell upon them here. The manufacture of hydraulic cements has been touched on rather lightly in this report, but is gone into more thoroughly in Bulletin 27 issued by the Geological Survey of Georgia. SAND-LIME BRICK Sand-lime brick, although-little used in the South, are reaching a very extensive use in some of the Northern states and Canada. In Germany the industry has reached a higher state of development than in any other country, there being some 300 plants within its borders. The brick is essentially a mixture of silica sand a,nd lime molded and pressed into brick form and then subjected to steam under a pressure of 100 to 150 pounds per square inch for from 4 to 10 hours. The steam causes a chemical combination between the silica and the calcium of the lime, forming calcium silicates. The brick has been gradually evolved from the old "mortar brick" of some fifty or more years ago, which was a mixture in about equal proportions .of hydrated lime and sand molded into brick form and allowed to harden in the atmosphere. The hardening in this process was by the absorption of carbon dioxide by the lime to form calcium carbonate. This is the change that is undergone in ordinary lime mortars and plasters of the present day. USES AND PREPARATION OF LIMESTONE 233 The following table1 shows the quantity and value of sand-lime brick produced in the United States in 1913 and 1914. Qtwntity and Value of Production of Sand-Lime Brick in the Un-ited States, 1913 and 1914 Year 1913 1914 I No. active firms I [ reporting I I 68 I I 62 I Quantity (thousands) 189,659 172,629 Value $1,238,325 1,058,512 In the year 1903, practically the :first year of the industry in the United States, the value of sand-lime brick produced was $155,040. :\:IATERIALS As the name indicates, sand-lime brick are made of sand and lime. Since the strength and hardness of the brick depends upon the chemical combination of silica and calcium the sand must necessarily be silica. Any impurities act as adulterants and may affect the strength of the product provided there is enough present. Clay derived from the decomposition of feldspar is the principal impurity met with. When the clay present is less than 10 per cent of the sand it is probably not injurious while as much as 2.5 per cent might be desirable, as it fills the voids and makes the brick less porous. 2 A medium grained sand containing enough :fines to :fill the interstices between the larger grains is considered best, that is, a sand all of which will pass 40 mesh and 10 per cent through 150 mesh. Sharp sand has better binding qualities, molds more easily, and better retains its sharp edges and corners. Tests made by different investigators tend to show that a highcalcium lime is better for making sand-lime brick than magnesian lime. High-calcium lime is more readily slaked, and hence assures all of the lime in the molded brick to be in the form of the hydroxide 1 Middleton, .Jefferson, Mineral Resources of the U. S. for 1914, Part II. Sand-L_ime Brick, p. 2. 2 Peppel, S V., Ohio Geological S11rvey, Bull. 5, 4th Ser., 1905, p. 33. 234 GEOLOGICAL SURVEY OJ/ GEORGIA hefore going to the hardening cylinder, otherwise the brick is liable to be ruptured by the expansion of the slaking magnesian oxide. Also, the calcium hydroxide is a much stronger base than magnesium hydroxide and attacks and unites with the silica more readily, thus making the operation more rapid. M.ANUFA.CTURE OF SA.ND-LIME BRICK Practically the only variation in the manufacture of sand-lime brick is the methods of mixing the sand and the slaked lime previous to going to the press. There are two main methods each of which has several variations: (1) mixing hydrated lime, sand and water, and (2) mixing causti~ lime and sand and then adding sufficient water to hydrate the lime and form a stiff putty. In the first method the hydrated lime and sand may be mixed in the dry state and then water added or the lime may be slaked with enough water to leave a stiff putty after the sand is incorporated. In the second method a _part or all of the sand may be mixed with ground or lump lime and then slaked and well mixed in a suitable mill. The putty may be pressed into brick at once or allowed to season for about 24 hours. The "seasoning" is for the purpose of thoroughly slaking the lime, otherwise the brick is liable to be ruptured by the expansion of the slaking lime. When the damp mixture of hydrated lime and sand is obtained it is molded and pressed by a machine similar to those used in the manufacture of dry-pressed brick. According to PeppeJl the best results are obtained by using a pressure of 15,000 pounds per square inch. After the brick have been molded they are stacked on cars and rolled into a long steel cylinder. These cylinders are usually 7 fe'et in diameter and 40 to 60 feet long. The brick are here subjected to steam under a pressure of 125 to 150 pounds for from 4 to 8 hours, and upon cooling are ready for use. 1 Peppel, S. V., The Manufacture of .Artificial Sandstone or Sand-Lime Brick: Bull. Ohio Geol. Survey, No. 5, 4th Ser., 1905, p. 44. USES AND PREPA.RA.TION OF LIMESTONE 235 The following is compiled from five tests made by Peppel1 on sandlime brick mQlded under 15,000 pounds pressure and hardened in a pressure of 150 pounds of steam: Strength of Sand-Lime Brick (Peppel) Hours in steam 4 8 Maximum 7896 7404 Crushing strength Minimum 4441 4491 Average 5447 5654 Absorption tests show from 6.5 to 12 per cent porosity, average about 8.3 per cent. The summary of the averages of a series of tests made on common clay brick by Dr. H. Ries2 is as follows: Maxipmm Crushing strength . . . . 5796 Minimum 1192 Average 3207 The porosity varies from 7 to 17 per cent, averaging about 12 per cent. A comparison of the results in the two tables shows the sand-lime brick to be superior to common brick. Pressed or hard-burned clay brick show a higher crushing strength and lower absorption percent- age than sand-lime brick. The cost of manufacture of sand-lime brick depends mainly upon the cost of labor, sand, lime, and fuel. The cost per thousand, accord- ing to different authorities, varies from $3.50 to $5.00, averaging probably $4.50. INDUSTRIAL CHEMISTRY BLEACHING AGENTS Limestone is used in the manufacture of the bleaching powder known as chloride of lime (calcium hypochlorite). Only very pure high-calcium limestones are. use~; those which leave little or no resi- lOp. cit., p. 46. 2 llies, H., Building Stones and Clay Products, 1912, p. 302. 236 GEOLOGICAL SURVEY OF GEORGIA due when treated with acid. The stone is first burned in ordinary lime kilns and then hydrated and allowed to stand for several days. The dry calcium hydroxide powder is then spread over the floor of lead or iron chambers for a thickness of 3 to 4 feet. Oh~orine gas is passed in at the top of the chamber which quickly permeates the hydrated lime and forms calcium hypochlorite. This material is used as a disinfectant, an oxidizing agent and more especially for bleaching cotton fabric. The greater portion of chloride of lime is produced by electrolytic alkali works in order to utilize the large quantities of chlorine gas generated. The United States imports a large quantity annually from Europe. SODA The LeBlanc process for the manufacture of soda or sodium carbonate is by heating to redne~s in a small rotary kiln a mixture of sodium sulphate, obtained by treating salt (NaCl) with sulphuric acid (H2S04 ), coal or coke and limestone. By this treatment a mixture of sodium carbonate, calcium sulphide, and impurities contained in the coal and limestone is obtained. This mixture is placed in suitable vats and the soda leached out by water, the calcium sulphide is practically insoluble. The solution is then evaporated and the soda recovered. Soda is manufactured by the Solvay process as follows: Carbon dioxide, generated by calcining limestone, is passed into a saturated solution of common salt (NaCl) and ammonia (NH40H). Sodium bicarbonate (NaHC03 ) precipitates out and the liquid is filtered off. Upon heating the sodium bicarbonate in a suitable kiln sodium carbonate remains. The filtered solution from the sodium bicarbonate is treated with lime in order to recover the ammonia, a solution of calcium chloride results which is recovered by evaporating the water of the solution. Soda is used in large quantities in the manufacture of soap, glass, paper and many sodium salts, in laundries, preparation of textile USES AND PREPARATION OF LIMESTONE 237 fibers and dyeing. Calcium chloride is used largely by artificial ice factories for the brine solution. AMMONIA AND ILLUMINATING GAS Most of the ammonia (NH3 ) used today is prepared as a byproduct in the manufacture of metallurgical coke or illuminating gas. The gases distilled off from coal are passed through water which absorbs the ammonia. When the "mother liquor" thus obtained is heated in suitable vats with lime, gaseous ammonia is distilled off and is passed through sulphuric acid. Ammonium sulphate crystallizes out. If aqueous ammonia is desired water is used instead of sulphuric acid. This process serves two purposes; it cleans the illuminating gas of some of its objectionable constituents, as well as recovers the valuable by-product. Ammonia is used in laundries, dyeworks, textile print works, color factories and the manufacture of ice. Ammonium sulphate is used to a great extent in Europe as a nitrogen-supplying fertilizer. A comparatively small quantity is produced in the United States annually. CALCIUM CARBIDE Calcium carbide, so widely used for generating acetylene gas for illuminating purposes and high temperature flames, is manufactured by fusing in an electric furnace a mixture of high-calcium lime and charcoal. CALCIUM CYANAZ.1IDE AND NITRATE Calcium cyanamide and calcium nitrate are manufactured by treating milk of lime with nitrogen dioxide which is made by an electric spark in air in a suitable receptacle. These materials have been placed on the market within recent years as fertilizers. . 238 GEOLOGICAL SURVEY OF GEORGIA LIME LIGHT When a flame of intense heat plays upon a piece of calcium oxide or lime a very brilliant light is obtained. These lights are used mainly in lighthouses. RECOVERY OF MERCURY Mercury. is recovered from its ore cinnabar (HgS) by some producers by heating a mixture of cinnabar and lime. In this way comparatively pure mercury is distilled off, l.eaving calciu~ sulphide and calcium sulphate. WATER SOFTENING The "hardness" of some waters is due to the presence of calcium bicarbonate. If the carbon dioxide can be driven off in some way the larger proportion of the calcium carbonate will precipitate. This may be accomplished by heating, which method, however, is not practicable for a city water supply. If caustic or hydrated lime is added to the water it will combine with the carbon dioxide to form calcium carbonate which will precipitate, together with that already held in solution. . GLASS MANUFACTURE There are four principal varieties of glass, namely, plate, window, green bottle, and flint. The first three mentioned are essentially silicates of sodium and calcium and are made by fusing in a suitable refractory pot a mixture of silica (sand), sodium sulphate or carbonate, and calcium carbonate (limestone). The limestone is from 15 to 26 per cent of the mixture, varying with the variety of glass. The mixture from which lime-flint glass is made contains about 8 per cent calcium hydroxide (slaked lime), while lead-flint glass contains no calcium. The limestone used in this industry must be practically free from iron, clay, magnesium, etc., except in the manufacture of green bottle glass. USES AND PREPARATION OF LIMESTONE 239 CERAMICS Limestone, both high-calcium and magnesian, are used to some extent in the manufacture of certain grades of porcelain and pottery. For wares burned at moderate temperatures certain authorities state that calcium oxide tends to bring together the points of vitrification and fusion of the clay, while magnesium oxide tends to separate them and at the same time lower the temperature of vitrification and decrease the shrinkage and warping due to burning. If vitrification of the clay begins before the limestone is thoroughly de-carbonated pin or blow holes may be developed. In this case it is necessary to use the oxides or hydrates. Limestone is also used in certain processes of glazing pottery. SUGAR MANUFACTURE High-calcium limestones are used in both the beet and cane sugar industries. Lime and carbon dioxide are both desired, hence the limestone is burned in kilns arranged so that the gas can be recovered. The juice pressed from cane and beets contains organic impurities which would color the :final sugar and hinder its crystallization if not removed. In order to accomplish this removal the juice is boiled with an excess of lime. The lime neutralizes the organic acids and unites with the other impurities with the formation of insoluble salts. These are allowed to settle and the solution of sugar and excess lime drawn off. The lime has entered into chemical combination with the sugar. Since lime has a greater affinity for carbon dioxide than for the sugar compound, this gas is passed into the solution and calcium carbonate precipitates, leaving a clear pure solution of sugar. If silica is present in the lime it will gelatinize and clog the filters. If magnesia is present it will remain partly in solution after the treatment with carbon dioxide and form scales on the evaporating pans. 240 GEOLOGICAL SUBVEY. OF GEOBGIA DIS'l'ILLA'I'ION OF WOOD Wood alcohol, acetic acid, and acetone are derived from the distillation of wood. The crude acid is treated with an excess of caustic or hydrated lime and distilled. Alcohol passes off leaving acetic acid in solution with the lime. Upon the addition of sulphuric acid, calcium sulphate is formed, and the acetic acid released. It may then be distilled off. If acetone is desired the solution of acetic acid and lime, known as "gray acetate of lime," is distilled dry. In order to purify the wood alcohol it is re-distilled in the presence of lime. Calcium oxide and carbon dioxide are the only usefuP constituents of the limestone, but the other impurities are not harmful, being adulterants. PAPER :MANUFACTURE Rags) etc.-In the manufacture of paper from rags, etc., caustic lime is used to destroy the grease and fatty materials absorbed in the cloth. wood P.uZzJ.-Lime is used in two processes for the manufacture of paper from wood pulp, namely, the soda process and the sulphite process. In the former method the wood is cooked by caustic soda, the latter taking up carbon dioxide and forming sodium carbonate. In order to change the carbonate back to caustic soda, so that it may be re-used it is treated with lime which unites with the carbon dioxide forming calcium carbonate. Bisulphite liquor, a solution of calcium and magnesium bisulphite and sulphur dioxide, is used in the "sulphite process" for cooking the wood pulp. The bisulphites are formed by treating limestone or lime in water with sulphur dioxide. High-magnesian limes are said to be more desirable because of the greater solubility of the magnesium bisulphite. It also gives a whiter color and causes tbe pulp to felt more easily. 1 Dumesun, P., and Moyer, J., Wood Products, Distillates and Extracts, p. 8. LIMESTONES OF THE COAST A L PLA I N OF GEORGIA PLATE X .\ . EXPOSUH I~ O L' Jc J, J:'\'L' Ai'\D LD II;; ~ r O KE 0 1' 'J'HE .lACK:>O:\" G IWu l ' J uST ABO\"E 1}1'; 1\" l'Fl' FE H HY, I' L I :\"' l' HlV E IL :lrT'L' ' IlEr,r, C() ( N'J'Y. IN CHAT'l'AHOOCI:IEE Lli\IE "TO NE, S UOWl:'\ G 'l'UJ:: Ll:llE::iT0:'\8 AT EDGE OF POND, ORIGINAL POND, 3 i\IILES WES'l' OF METCALF, THOMAS COUNTY. USES AND PEEPAEATION OF LIMESTONE 241 GLYCERINE, LUBRICANTS, AND SOAP In the manufacture of glycerine, lubricants and soaps and allied products, high-calcium lime is used to break up the fatty substances from which the products are derived. Glycerine is liberated upon the distillation of the fats with lime in water. The remaining material is used to manufacture lubricating greases for heavy machinery and for soaps. TANNING In the leather industry the hides are soaked in lime water to loosen the hair so that it can be easily removed by scraping. Both high-calcium and magnesian limes are use.d. METALLURGY BLAST FURNACE FLUX One of the most important uses of limestone is as a flux in iron blast furnaces. High-calcium limestones are more generally used, but in certain sections, namely, Birmingham, Ala., and vicinity, dolomite and dolomitic limestones are used almost entirely. The value of the stone depends upon its physical and chemical character, that is, it must be hard and compact enough not to dust easily, and it must contain as little silica, alumina, sulphur, and phosphorus as possible. Silica and alumina act as adulterants and must be fluxed off as well as the same impurities in the iron ore. Sulphur and phosphorus are detrimental to the iron itself if present above a certain low percentage, however, few limestones contain sufficient percentages of these~ elements to make them unfit for :fluxing purposes. The relative values of calcium and magnesium as bases for fluxing off the acidic content of the ore seems not to have been definitely determined by the manufacturers of iron or by research students, but both high-calcium and dolomitic limestones are used by successful iron producers. 242 GEOLOG-ICAL SURVEY OF OEOROIA The stone is crushed to sizes from 2 to 4 inches in diameter and charged into the top of the furnace alternately with ore and coke. The coke serves as the heating agent as well as producing the reducing action upon the oxides of iron in the ore. The calcium and magnesium of the limestone unite with the silica, clay bases and other im- purities to form silicates which compose the slag. IJINING OF BASIC OPEN-HEARTH FURNACES An important use of dolomite and dolomitic limestone, although a comparatively small tonnage is so employed, is the lining of basic open-hearth furnaces for the manufacture of steel. Magnesite is the ideal material for this purpose, but owing to its high cost it is being generally replaced by dolomite. The furnace has an outer wall several feet thick of common brick within which is a permanent lining of 2 to 3 feet of magnesite brick. Upon this lining 1 to 2 feet of crushed dolomite, together with a suitable binder, is tamped. The object of the crushed stone is to take care of the wear due to the mechanical and chemical action of the molten metal and slag, H be- ing much cheaper to replace than the refractory b~ick. To answer this purpose the stone must be as low as possible in silica and the clay bases and at the same time appr-oach very nearly a theoretic dolomite. It_ must also be hard so as to resist mechanical wear and must neither crack nor slake when the furnace is cooled. It is rather improbable that there are any limestones in South ,'Georgia which answer the above requirements. BASIC OPEN-HEARTH FURNACE FLUX Limestone iB used as flux in the manufaeture of steel by the basic open-hearth process. The fluxing action is similar to that in the blast furnace~ that is, it carries off the silica7 alumina, sulphur, manganese and phosphorus. Therefore, a stone aR low as possible in these impurities is desired. :Magnesium iR objectionable in that it has less affinity for sulphur and requires a higher heat to complete the fluxing USES AND PEEPABATION OF LIMESTONE 243 action. The stone in general use usually contains less than 5 per cent magnesia, less than 11j2 per cent alumina, and less than 1 per cent silica. Few limestones contain sufficient amount of sulphur and phosphorus to render them unsuitable for flux. The stone must be hard and compact enough to prevent its being ground into dust by hauling. In addition to iron smelting limestone is also used in copper and lead smelting. QUARRYING LIMESTONES Quarrying is the :first and one of the most important steps in the production of limestone and its products and yet very little has been published on and apparently little study given the operation. Practically every deposit of limestone is governed by certain local conditions and is a problem within itself, hence few general statements can be made which cover the work as a whole. Only one general method need be dwelled upon t.o any extent, namely, quarrying. It is sometimes necessary to resort to underground mining, but this is so expensive compared to the value of the limestone product that it need be considered only lightly. TYPE OF WORKINGS AND LOCATION There are two general types of quarries, the hillside type and the pit or open cut quarry. It is seldom that the operator has the oppor-. tunity to choose which of the two methods to work a given deposit by; usually the limestone body is so situated that only one type quarry can be opened. If the operator can make a choice, hcnvever, he should work the deposit as a hillside quarry since they are practically always cheaper to operate than pits. In the latter there is the extra expense of lifting the stone from the floor of the quarry to the top of the face and the removal of water from the working. The other costs are practically -the same as for hi11side quarries. The site for the workings shou1d be chosen with regard to (1) overburden, (:n ::;trike and dip of the strata, (~) drainage, (4) haul- age grade to mill or kilns, (5) mill or kiln site, and (6) transporta- 244 GEOLOGICAL SURVEY OF GEORGIA tion. 'l'hese factors are not arranged according to their impprtance, which is governed by the local conditions. The demand and composition or the stone are not taken into consideration, as it is supposed these are known. The overburden or superincumbent mqterial on the limestone governs to a great extent the workability of a given deposit. It is obvious that a great thickness of valueless material cannot be moved for a comparatively thin bed of limestone on an economic basis. Hence, it is necessary to locate the quarry where a minimum amount of overburden will have to be moved. The maximum thickness that can be handled is governed by the workable thickness of the underlying limestone. When limestone outcrops along the base or side of a hill it is evident that the farther the workings are extended into -the hill the heavier the overburden. Under these conditions it is usually practicable to move a greater maximum thickness of overburden than from a deposit under level ground, since on the hillside deposit the mean thickness is less than the maximum. Where the conditions are suitable it is more ec.onomical to "edge" the hill than to work straight in for any distance. Strike and dip need not be considered in the Coastal Plain deposits, since all of the beds are level, or practically so. In the hillside quarry the floor should be always kept above the drainage level if possible to avoid the necessity of removing such water as might accumulate from seepage, rain, or flood stages of a near-by stream. In a pit quarry it is, of course, impossible that the quarry be so situated that it will have natural drainage except where tunnels can be employed. An important item in the cost of quarrying is the hauling of the broken stone from the quarry to the mill. 1l It follows, therefore, that it is expedient to put the mill as close to the quarry as possible without it being in danger from blasting. If the conditions make it possible the haulage cost can be greatly reduce~ by working the deposit USES AND PEEPAEATION OF LIMESTONE 245 at such an elevation that the tram cars will run by gravity to the mill, preferably to the feed bin of the first crusher or the top of the lime kiln, as the case may be. The site for the plant is governed by the location of tlie quarry and possible location for the spur track from the main line of the railroad. Railroad construction is rather expensive, hence the necessity of locating the workings as near the main line as possible. This expense is usual]y partially borne by the railroads under certain con- ditions. STRIPPI~G Stripping or removing the overburden from a deposit of limestone may be done by one or more of a number of different methods, namely, pick, shovel and wheelbarrow, plow and scrapes, hydraulic giant, or steam shovel. There are other implements and machines in use, but those named are the most generally used, especially where the development-work is rather limited. The material to be moved governs to a great ext'ent the methods to be used. The deposits that this report deals with, however, are covered usually with sand, sandy clay, or clay with sometimes flint boulders, so that any one of the above meth ods can be applied. The most expensive method of excavating and removing overburden is by pick, shovel and wheelbarrow or wagon. These tools can only be applied economically where the overburden is very thin or the conditions such that other implements cannot be employed. The plow and scraper are probably the most efficient implements that can be employed on account of their adaptability and comparatively cheap operative cost. While costing more per yard to move the dirt than by other mechanical means the outlay of capital is comparatively small. The plow is necessary to loosen the earth before the scraper can be filled. Of the two types of scrapers the drag scrape is more suitable -for close work and short hauls and the wheel scrape for open work and long hauls. The latter should be used whenever possible. since it has a larger capacity than the former, and being on wheels is much easier on the team. 246 GEOLOGICAL SURVEY O.F GEORGIA A hydraulic giant is a large flexible water nozzle through which water is forced at high pressure and played upon the bank of material to be moved. The dirt is thus washed off of the underlying de posit. It is, of course, necessary to have an ample supply of water close at hand if the hydraulic giant is to be used. This is a comparatively cheap method, but the outlay necessary to install adequate pumping machinery is rather large. The cheapest means of excavating the overburde:o, provided it is heavy, is by the steam shovel. A steam shovel can operate most efficiently in loose material sufficiently thick to allow the shovel to be in the dirt from the lower to practically the upper limit of its stroke. But where the overburden is of such a thickness, say 15 feet, it usually will not pay to move it for the underlying limestone. DRILLING AND BLASTING After the overburden has been removed the next operation is breaking the stone from the bed into sizes that can be conveniently handled. 'l'his is most economically done by drilling and blasting with powder or dynamite. Holes in which the powder or dynamite is placed are drilled in the rock by hand or machine. Hand drilJs are of hvo types, one operated by two men, one holding the bar of drill steel while the other strikes the head with a heavy hammer, and the other type is a longer bar that is raised and dropped by one man. The drill must he rotated to prevent jamming. ,Water is nearly always poured in the hole to keep the chips and dust of stone loose so that they wi11 ~ot tighten the steel. Hand drming can be most economical1y employed where the rock is soft or the workings small. Machine drills suitable for the type of quarry operations to be met with in South Georgia are of two general types, the piston and the hammer drilJs. The piston drill (see Fig. 6) is the larger machine and operates from a trippd or other movable stand. These drilJs are operated by compressed air, frequently, together with a 1Ht1e steam. 'l'be movable parts of the DSES AND PREPARATION OF LIMESTONE 247 Fig. 6.- Ingersol-Ran rl Piston Drill on Tripod machine are the valve mechanism and the piston. The bos which holds the drill bit is made rigidly to the piston and hence the troke of the bit is the same as that of the piston, working somewhat along the. ame prin cipal of band . teel which is r aised and dropped. The e maclJines drill vertical or loping hole. 1 to 3 in ches in diameter and 1 to ~0 feet in depth , according to tl1e size machine u ed. The machines work on about 75 pounds air pressure. making 300 to 500 stroke. per minute. The drill steel u~ed is solid hexagonal bar. from three-f01ntb. to 114 inche.- in diameter. The steel hould be of the hest quality and properly tempered in order t o get t he maximum efficiency out of the machines. The bits rotate m1tomaticall~- . Two 248 GEOLOGICAL SURVEY OF GEORGIA men, the "machine man" and the "chucker" or helper, are necessary to operate the machine under ordinary conditions. The latter assists in placing the machine and feeds water into the drill hole. The ma- chine is so built that as the hole is driven the cylinder is moved down a slide bar to keep the drill bit hard against the bottom on the out stroke. This is operated by hand by the machine man. Mounted and ready to drill the machine weighs from 400 to 1200 pounds, ac- cording to size. The piston drills are used for hard rock and deep holes. The machine best suited for light work is the air hammer drill (See Fig. 7) . These are of light weight, varying from 40 to 75 pounds, and require no support, being held by hand. They can, there- fore, be carried from place to place with the greatest ease and set tq work immediately. The moving parts of the heavier hammer drills are the piston and valve. The steel slips up _into the lower end of the piston and js pounded either directly or through an anvil block by the piston. Three- fourths inch hollow steel is usually used. The hollow is for the purpose of blowing air into the bole to re- move the chips and du st. The steel is self-rotary in most hammer drills. Under the best conditions 100 to 150 feet of holes per day can be drilled, 75 to 100 pounds air pressure being most efficient. . These machines are especially Fig. 7.-Ingersol-Rand Jackhammer adapted to quarries where the benches are not over 10 feet and all or most of the drilling is vertical or nearly so. They are also useful for drilling shallow holes in boulders too big to be handled conveni- ently without breaking. USES AND PEEPABATION OF LIMESTONE 24:9 The powder or dynamite to be used in quarrying depends upon the hardness and toughness of the stone and the products to be made. A hard stone is more easily worked by dynamite, while a very soft one can be more satisfactorily broken with black powder. The percentage of dynamite and the grade of powder can best be determined by experience. Where crushed stone or agricultural limestone is the product the size of quarried rock may be practically any size that can be efficiently handled by the crushing machinery. When lime is the :final product it is desirable to have as much of the stone as possible above a minimum size to prevent choking the furnace and below a maximum to assure thorough calcination. BLOCKING "Blocking" is the process of breaking the large pieces of stone to sizes which can be conveniently handled by the quarrymen or the crushers. It is accomplished either by blasting or breaking with heavy sledge-hammers. The blasting may be done either by drilling and firing a shallow hole with dynamite, "pop" shooting, or by placing the explosive fiat on the rock and covering with clay and then firing. The latter is known by quarrymen and miners as a "mud" shot. LOADING AND HAULAGE The containers for conveying the broken stone from the quarry to the mill are in the large majority of quarries loaded by hand, where the operation is extensiv~::, however, steam shovels are fre quently employed. The haulage equipment varies widely in different quarries, being governed largely by local conditions. The following are the most common methods; wheelbarrow, cart, tram, and aerial tramway. The-wheelbarrow is used only when the haul is very short and the production small. It will :find its greatest use in South Georgia in conveying stone from the quarry to small machines for grinding agricultural limestone for plantation or local use, where the plant can be erected ver:v cloRe to the deposit. 250 GEOLOGICAL SURVEY OF GEORGIA Carts drawn by mules or horses are used in a great many quarries where the operation is on a comparatively sma11 scale and the haulage grade sJight. A two-wheeled dump cart has the advantage over a four-wheeled wagon because it can be turned around in a small space and can be easily backed up to the crusher bin and the ston,e dumped without a second handling. Tram cars with capacities of from one to five tons are most generally used in quarry operatim1. Temporary tracks that lead into the main line to the plant are laid along the quarry floor as close to the face as practicable. 'l'his allows a maximum number of cars to be loaded simultaneously. The method of conveying the cars from the quarry to the plant is governed by the distance and grade. vVhere the track is down grade to the plant the cars may run by gravHy. This is very desirable sinre it eliminates a considerable part of the haulage cost. The empty cars may be pushed back by hand or drawn by mules or other power, according to the grade and distance. Where the plant is some distance from the quarry and the track grade such that the cars require pushing or pulling, motor po-wer is most generally used, the cars being gathered at the loading point or on the main line where they have been pushed by the loaders. where the elevation of the crusher bin is considerably above that of the quarry floor it is usually necessary to draw the cars up by hoist and cab1e. The cars are msembJed at the main hoist track and thel'e attached to the cable, in groups or singly. Where the operation is on a large scale and the grade sufficiently steep two tracks can be used on the ineline, loaded cars going up while the empties are coming down. 'l'his, of course, lessens the po-wer neeessary, as the hoist haB the 'veight of the actual stone only to hoist and the friction to overcome. Aerial tramways are occasionally used in transporting the stone to the mill. This method of tran:::;portation ran be most satisfactorily app1if:d to pit quarry operations or to hi]]side quarrying when the erusher bin is considerably above the quarry floor. An aerial tram- USES AND PREPARATION OF LIMESTONE 251 way con::;ist~ of a large cable stretched overhead from a tower at each end, on which a two tandem wheeled carriage runs. The carriage is pulled either to or from the engine, at the mill end of the way, by wire rope or cable. The bucket which contains the stone is raised to the carriage or lowered to the quarry :f:l.oor by means of another cable, all controlled and manipulated by one operator. Several buckets may be w~ed so that no time is lost by the tramway in waiting for the bucket to be :filled. When the empty buckets are returned to the quarry loaded ones are picked up. The empties can be placed as desired, provided the distance is not too great, by being made to swing 1ike a pendulum or pulled over by a rope attached, or they may be set down on fiat tram cars and then placed as desired. The latter method is the most practical where the tramw-ay comes in at right angles to the quarry face. When the cableway is parallel to the quarry the matter is simplified until the face is worked back considerably. The capacity of the cableway depends upon the size of the equipment and the transportation distance. vVhere very large capacity is desired a continuous cableway is used. A number of buckets are moved at the smne time by this equipment. The empties are returned on one cable 'lvhile tbe loads go in on another. when a bucket is stopped or slowed down to be emptied all on the cab1e are momentarily affected. At this juncture the empties are set off in the quarry and the loads picked up. This heavy duty cableway will probably :find no use on the South Georgia limestone deposits. AJI tram cars or cable1vay buckets shouhl. be so constructed as to give a minimum amount of trouble in dumping the stone. Various deviees have been perfected which enable the canierR to dump their burdens automatically..The front end of the car is usually the door, swjnging from the top. This has a holding eatch which is knocked loose as it reaches the dumping point or tipple. The tipple may be so constructed that when the loaded car rolls onto a hinged section. of the track the front end of the car will be lowered and the stone sJjde out. When the car is relieved of its weight the track assumes 252 GEOLOGlC.!lL SURVEY Oil' GEORGIA its normal position. Where the tipple track is rigid the car is so balanced on its truck that it will tip easily to the front. The back end may be raised by hand or mechanism. S'.rEAM SHOVEL EXCAVATING Steam shovels are successfully used in some of the larger quarries in the country to hand!e the broken stone from the quarry floor into the cars. The operation must necessarily be on a comparatively large scale in order. to utilize the full capacity of the shovel. The steam shovel is most efficient in excavating earth in railroad grading, building sites, canal work, removing overburden from workable mineral deposits, and excavating clays and shales for brick and cement work. The steam shovel might be use~ to advantage in the development of certain limestone deposits in the southern portion of the State. As stated under "stripping" the steam shovel will find little or no work in the removal of overburden unless it can be also employed in the quarry. The Jackson group contains several beds of very soft, argillaceous limestone and soft, friable, fossiliferous limestone, which could probably be worked to an advantage with a steam shovel. THE MANUFACTURE OF LIME One of the most important uses of limestone is the manufacture of lime. The mortar and plaster used in masonry, other than cement and concrete, and in other construction work depends upon lime for its cementing or binding qualities. It also finds a great variety of uses in industrial chemistry, agriculture, sand-lime brick manufacture and other industries. Before the advent of railroads into South Georgia, the settlers found it necessary to burn their own lime. .This was done by very crude methods. Usually the stone was burned on the site of the deposit in crude, simple kilns. The limestone was heaped in round or elongated piles, 6 to 8 feet high, with one or more tunnels left at the base or trenched out of the soil below for the fire (see plate VII-.t\). USES AND PREPARATION OF LIMESTONE 253 The stone pile was subsequently plastered over with clay with an opening left at the top to allow the gases to escape. In sections where a soft limestone was used for the manufacture of lime the stone was frequently quarried on a hillslope, leaving the faces of the quarry vertical and smooth, and, when a sufficient quantity of stone had been removed, the kiln was built by piling the loose stone back into the excavation, after which it was plastered with clay on the exposed side and ignited from below through suitable fire boxes. Wood was always used for fuel in these kilns and was probably frequently placed in alternating layers with the stone, as well as burned beneath. It was necessary to fire the kiln for several days in order to obtain a satisfactory product. Compared with a lime produced in a modern kiln the product of these crude kilns was prob- ably poor, but it served very well the purposes to which it was ap- plied, namely, mortar and plaster. Near Sunhill, ViTashington County, there is a square, vertical kiln constructed of sandstone and chert braced with iron strips and rods. At Armena, Lee County, there is a kiln constructed along more modern lines, a sheet-iron cylindrical shell lined with fire brick. Neither of these kilns has been operated within recent years. KILNS There are two general types of kilns used almost altogether in the United States-the vertical shaft kiln and the rotary kiln. The latter type is notused to a great extent by lime manufacturers since the charge must be crushed to a small size, which makes it unsalable as lump lime. It is, however, well suited to the manufacture of hydrated lime. Rotary kilns will be referred to on page 27!3. Under the head of vertical shaft kilns is included a number of different designs, varying but little in principle. They will be discussed here briefly in a general way. A shaft kiln is a short stack usually from 5 to 10 feet inside diameter or width, and 15 to 30 feet high. They may have square, rectangular, circular or elliptical cross Fig. B.-Vertical Lime Kiln TJSES AND PREPARATION OF LIMESTONE 235 sections, lJoth inside and out. The shape is usually governed by the material of ,,llich the outer wall is made. Stone kilns are, as a rule, either s11nare or rectangular, while iron or steel and concrete are circular- in <:ross section. The outer 1valls of a stone kiln may be built 15 to 18 inches thick with a lining of the same thickness of :fire brick. Iron or steel rods should encircle the stone to add strength. If steel is used for the outside, a cylindrical shell is constructed of sheet steel, riveted together, and lined with 18 inches of fire brick. A 6- to 8-inch space should be left between the brick and steel to be packed IYith cinders, sand, or ~'ome other material of similar nature, to att a;.; an insulator. The stone kiln lo~es less heat by radiation than the steel shell kiln, but the latter is stronger and requires less repairing. Concrete combines the good qualities of both. The top of the kiln is left open to allow the gases to escape and for charging. 'rhe bottom is usually in the shape of an inverted, truncated cone supplied with a door through which the lime is drawn. A 1-tl"\:01..1~\ in no way separated the interior of the kiln may be described as being divided into three zones. In the upper zone, or hopper, the stone receives a preliminary heating and as the stone is drawn from the bottom of the kiln, it works its way into the middle or burning zone where it is de-carbonated. It finally goes into the lower zone or cooler from whence it is drawn into wheelbarrows, cars, or onto the floor. The burning zone is considered to extend to the level of the grate of the fire-box. There is no distinct plane of division between the two upper zones. The location of this plane in the kiln is dependent upon the size of the kiln, the temperature of the fire, and the distribution of tb.e heat. Two to four openings, according to the size of the kiln, are left in opposite sides of the kiln walls, 4 or 5 feet above the base, for the fire-boxe;;:. These boxes are similar to and about the size of those used under smal1 steam boilers, and necessarily extend out from the wall of the stack In certain types of kilns no fire-boxes are provided, the fuel is charged into the top of the kiln, alternately with the stone 256 GEOLOGICAL SUEVEY OF GEORGIA Thi,s method is objectionable on account of the mixing of the .ash with the lime. The construction of the kiln must be such, or mechanical means . provided, that sufficient draft is obtained for two purposes, namely, in order that the fire may have a certain amount of oxygen to enable it to burn properly and that the carbon dioxide released from the limestone may be carried off as rapidly as generated. If this gas is not removed re-carbonization of the lime may take place and the object of the burning defeated. Nor should too strong a draft be used since an excess of air will cool the kiln to a certain extent. The draft may be natural, induced, or forced. If the kiln is not high enough to produce sufficient draft, a stack may be erected o~ top with a door provided for charging. It is a well-known fact that the increase in the height of a smoke stack increases the draft. Induced draft is obtained by the employment of a suction fan in the stack at the top of the kiln: A combination of induced. and forced draft is accomplished by forcing a part of the gases from t~ stack through the fire. With certain elaborations this is known as the Eldred process. Forced draft is usually secured by blowing steam through the fire. This has other advantages than producing draft, as will be seen later. In all kilns where wood is used as fuel, natural draft has been found satisfactory.1 Kilns may be operated intermittently or continuously. By the former method the kiln is charged and then fired. When the de-carbonization is complete the kiln is allowed to cool and the charge then drawn. This is very wasteful of fuel, as the heat required to raise the kiln to the proper temperature takes no part in the de-car bonization, and, furthermore, much heat is lost in cooling. When a kiln is operated by the continuous process it is never alJowed to cool except for repairs or to curtail the production. The stone is charged 1 Emley, Warren EJ., The Manufacture and Use of Lime: Mineral Resources of the United States, 1913, Part II, p. 1570. ' USES AND PREPARATION OF LIMESTONE 257 and drawn at short intervals, according to the capacity of the kiln and the quantity of the charge. BURNING Limestone when pure consists of calcium carbonate expressed by the chemical formula CaC03 vVhen this matedal is heated to a certain temperature it breaks up into lime or c:akium o:x:jde (CaO) and carbon dioxide (C02 ), a gas, thus: CaC03 (limestone) +heat=CaO (lime) +C02 (carbon dioxide) If 100 pounds of limestone is used in this operation the result will be 56 pounds of lime, 44 pounds of carbon dioxide, the Jatter being driven off in the form of gas. Under ordinary conditions of pressure limestone dissociates into lime and carbon dioxide at about 900 C. (1652 F). Practically all limestone contains impurities, usually in the form of silica or clay. At a temperature near 1200 C. (2192 F.), these impurities form chemical combinations with the calcium oxide.1 When the stone has been heated to this temperature and above it is "over-burned." This is objectionable because it slakes very slowly and frequently has a yellowish color, which makes it unsuitable for certain purposes. Therefore, the temperature of the kiln should be kept between 900 C. and 1200 C. to obtain the best results. The combination of the calcium oxide with the impurities is said to be noticeable at an even lower temperature than the upper limit here given, hence the best lime is produced by keeping the temperature as low as possible. An exceptionally pure limestone may be heated considerably higher without over-burning. The length of time necessary to calcine the stone varies inversely with the temperature, hence a low temperature may be used for a long time or a high temperature for a shorter period. The physical properties of the stone govern to some extent the temperature that should be used. It naturally takes a higher temperature and a longer time to calcine a large piece than a smaller 1 Lime: Its Properties and Uses: Circular No. 30, Bureau of Standards. 258 GEOLOGICAL SURVEY OF GEORGIA one. The stone should not be so small, however, that it will prevent the easy passage of the gases through the kiln by the draft. Also a close, compact stone will conduct the heat mo"~'e readily than one which is porous/ and is, therefore, de-carbonized more quickly. In the preceding discussion only limestone has been considered. For most practical purposes the conditions are also applicable to dolomitic or magnesian limestone. Heat for burning the limestone is derived from several sources. Wood and coal are principally used, but gas is also employed. Wood is considered to be the best fuel for the following reasons ; the flame is longer than the coal flan::te and, therefore, carries th~ heat nearer. the center of the kiln, assuring a more evenly burned lime, and the flame is not so hot. as a coal or gas flame, so that the danger of overburning is less. Wood contains a rather large percentage of moisture which when changed to steam in the fire-box, greatly accelerates the de-carbonization and at the same time lowers the temperature of de-carbonization of the stone.2 When coal and gas are used as sources of heat, steam is introduced beneath the fire-box. This cools ihe :fire slightly as well as supplying moisture to assist the calcina tion of the stone. Coal is almost universally used by the large manufacturers owing to the scarcity of wood. Producer gas from coal is also used successfully. It eliminates the loss caused by unburned coal and coke falling through the grate bars. CLASSIFICATION OF PROPERTIES The National Lime Manufacturers' Association has adopted the following classification: Classification of Limes High-calcium lime contains 0 to 5 per cent magnesia Magnesian lime contains 5 to 25 per cent magnesia l Burchard, Ill. F., and 'rumley, W. E., The Source, Manufacture and Use of Lime: Mineral Resources of the United States, 1913, Part II, p. 1568. 2 Peppel, S. V., Bull. Ohio Geol. Survey, No. 4, 4th S.er., 1906, p. 294. USES AND PREPARATION OF LIMESTONE 259 Dolomitic lime contains 25 to 45 per cent magnesia Super-dolomitic lime contains over 45 per cent magnesia. Also the lime must contain not more than 5 per cent impurities, such as silica, oxides of iron and aluminum, etc., to meet usual specifications. When water iR added to lime it will slake; the water enters into chemical combination with the lime forming the hydroxide. Heat is generated by this union and the volume increases, causing the lumps to fall to a powder. If not too great an excess of water is added the heat generated will evaporate the moisture leaving a dry powder. If this material is exposed to the air for a length of time it will take up carbon dioxide and revert to the composition of the stone from which it was originally derived, that is, calcium carbonate (and magnesium carbonate). This is the re-action upon which the binding prop. erty of mortar is based. The chemical composition of the lime governs to a certain extent the degree to which it possesses the above properties. High-calcium or "hot" limes slake rapidly and evolve much heat on the addition of water, while magnesian, or "cold" limes, slake more slowly and generate less heat, in proportion to the percentage of magnesium oxide present. The latter also expands less and will consequently give a smaller volume for equal weights. If the lime contains over 5 per cent of such impurities as silica, iron and aluminum oxides it will slake slowly and is apt to have a yellowish color. These are known as "lean" limes. If the temperature of burning was sufficient to cause a chemical combination between the lime and the impurities it will have hydraulic properties, that is, it will set under water. Under-burned lime contains calcium carbonate, which affects the rapidity and completeness of its slaking. Since lime will absorb from the atmosphere carbon dioxide, it is important to keep it under conditions where as little air as possible 260 GEOLOGICAL SDRVEY OF GEORGIA can reach it. It is usually packed in wooden barrels in the lump, or in air tight bags in the ground state. COST .OF LIME l\'IA.NUFA.CTUREl The principal items in the cost of lime manufacture are: the interest on the capital invested, the _cost of quarrying, the cost of fuel for burning, and the cost of labor. Repair expenses should also be considered, but since this varies so widely it will not here be considered. The interest on the cost of quarry and plant will vary according to the regularity with which it is operated. This is, of course, dependent mainly on the demand for the product. The cost of quarrying depends on the variety of stone worked, whether it is easily drilled and broken down, or ]+ard and tough. The position of the quarry face with regard to the structure and bedding of the deposit governs this to some extent. The amount of stripping and the efficiency of the management and the labor are likewise important. "The plant should be located as near the quarry as practicable with the top of the kilns below the floor of the quarry. This will keep the haulage cost down to a minimum. Where pit quarrying is necessary inclines or elevators must be used to charge the kilns. Allowing for waste, 2 tons of limestone will produce about 1 ton of lime. This means that to 1 ton of lime the cost of quarrying 2 tons of stone must be charged. The cost of fuel is governed by the distance from the source of supply and the efficiency of the kilns and stokers as well as the first cost. When coal is used its consumption per ton of lime produced may vary from 300 to 500 pounds in modern kilns.1 The cost of labor at the plant and the overhead expenses may 1 Eckel, Edwin C., Cements, Limes and Plasters, 1905, p. 110. USES AND PREPARATION OF LIMESTONE 261 vary between wide limits. Eckel1 has compiled the following cost data: Total Cost of Lime 1J;fan'ufacture per Ton Interest on cost of plant and quarry ..... . Taxes, minor supplies, etc .............. . Cost of quarrying 2 tons of limestone .... . Cost of fuel for burning................ . Cost of labor, exclusive of quarrymen .... . $0.05 to $0.20 .10 to .25 .50 to .90 .30 to .75 .25 to .80 Total cost of burned lime per ton (2000 lbs.) in bulk ............ . $1.20 to $2.90 The minimum cost is for a modern plant run steadily undee eom petent management. HYDRATED LIME The slaking of lime by unskilled labor is often unsatisfactory) due to burning or the incompleteness of the operation. In order to elim- . inate this objectionable feature, certain lime manufacturers have placed on the market, within recent years, a product known as "hydrated lime," that is, lime that has been slaked by the manufacturer. This material may be used for any purpose in the place of lime with the same results. The one objection is that the consumer must pay the freight on the water combined with the lime in hydrating, but the cost of slaking is eliminated. The addition of water is all that is necessary to prepare the hydrated lime for use. In preparing the lump lime to be slaked it is first crushed or ground. The size to which the lime is broken varies with the manufacturer and the process of hydration used, but is usually less than one inch. The crushed material is then placed in a pan with agitators or in a horizontal revolving cylinder, containing slightly more than sufficient water to complete the hydration. The lime may all be added at once or gradually. The heat generated dries out the excess water, leaving a dry, finely divided powder. If the lime wa3 over-burned the material resulting from the combinatjon of the calcium with the impurities will not slake, IH{ewise 1 Ibid. 262 GEOLOGICAL SDEVEY OF GEOEGIA if it is under-burned the calcium carbonate will remain in lumps. The slaked lime is consequently screened, usually through 50 mesh, to remove these impurities. It is then put up in 40-pound paper bags or 100-pound burlap bags and is ready for the market. MACHINES FOR PREPARING LIMESTONES The machines to be used in plants for the preparation of limestone for the market depend on the type of stone and the products desired. It is very evident that a machine suitable for working soft limestone may not be capable of working hard limestones; also, a plant containing machines for the production of the various sizes of crushed stone differs widely from a cement plant. However, the systems interlock to a great extent. The product from a crusher contains stone from very fine dust up to the maximum size of the opening of the crusher discharge. It is desirable to market all sizes to prevent waste. The different machines will be discussed briefly on the following pages. ROCK BREAKERS Rock breakers for coarse crushing are divided into three general classes: (1) jaw crushers, (2) gyratory breakers, and (3) roll crushers. These machines vary in capacity from 5 to 500 tons per hour an~ crush to minimum sizes of one-half to 5 inches. The capacity varies with the size of stone discharged. For example, the capacity of a breaker crushing to a size that will pass a 11/2 -inch ring is only slightly more than half as great as when crushing to 2112 inches. The larger the machine used the larger the size of the minimum sized product, hence it is frequently necessary to use two or even three sets of breakers in order to reduce the stone to the desired dimensions. Screens are used between the breakers of different sizes to eliminate the stone broken to the desired size in the :first machine. USES AND PREPARATION OF LIMESTONE 263 JAW CRUSHERS Jaw crushers are the oldest of the heavy-duty, coarse-crushing machines, the first one having been built in 1858 after the design of Eli W. Blake, and has been since that time known as the Blake crusher or breaker. The principal parts of all jaw crushers are a stationary jaw plate, usua1Jy vertical, and a swing jaw plate which forms an angle with the stationary plate. The latter is given a reciprocating motion by a suitably arranged eccentric and pitman. Fig. 9 is a sectional view of a Blake breaker. Fig. 9.-Sectional Elevation of tb.e Blake Rock Crusher with Parts Indicated by Letters (after Chalmers & Williams) A. Flywheel. B. Swing Jaw. C. Swing Jaw Shaft. D. Set Screws for securing Set Jaw to Shaft. E. Swing Jaw Plate. F. Stationary Jaw Plate. G. Stationary Jaw. H. Frame. I. Side Plate. JJ. Toggle Plates. K. Pitman. LL. Steel Bearings for Toggle Plates. M. Toggle Block. N. Wedge Block. 0. Wedge Adjusting Bolt. P. Spring Rod. R. Spring. S. Set Screws for Toggle Block. T. Eccentric Shaft. U. Holding down Bolt for Swing Jaw Plate. V. Spring Washer. W. Spring Plate. The jaw crushers are divided into types according to movement of the swinging jaw: (1) those which a:J.:e pivoted so as to give the greatest movement on the smallest lumps-Blake type; (2) those which give an equal movement on all sizes; and (3) those which are GEOLOGICAL SURVEY OF GEORGIA pivoted belovv and give the largest movement on the largest lumpsDodge type. Only the :first and third of these types need be considered, since there are very few of the second in use. The choice between the Blake and the Dodge types of crusher de~ pends largely on the product desired. Since the g-reatest movement of the swinging jaw on the former is at the bottom and the latter at th_e top it follows that the Dodge will give the more uniform product. Hence, if it is desired that the crushed stone be as uniform in size as possible the Dodge is the crusher best adapted to the work. Experiments and practice show that the Blake type crusher will give a larger tonnage for the horsepower used than the Dodge. This is due to the free, open ~ischarge of the Blake resulting from the greater movement of the swinging jaw at the bottom. In the Dodge the rock has a tendency to jam or wedge, which condition gives a larger proportion of the :fines since the stone is in the crusher for a longer period of time. The difference in capacity per horsepower is also greatly affected by the difference in movement on the larger stone. Suppose of two pieces of stone the same size one is fed to a Dodge crusher and the other to a Blake crusher, both machines the same size. The maximum movement on the piece of stone in the Dodge will be 1 inch in a 7- by 8-inch machine and slightly more than 0.08 in a 7- by 10-inch Blake crusher. It is easily seen that the power necessary in the former is considerably greater than in the latter. The movement is the reverse at the discharge end, but even there the Dodge has a greater minimum movement than the maximum of the Blake. Then it will take more power here to break the stone in the Dodge than in the Blake. If this argument is cor'rect the Dodge requires considerably more power to break a given piece of stone than a Blake. The surplus power is consumed in producing a greater percentage of :fines in the Dodge. The Blake crm:!her has a greater range of sizes of products than the Dodge, being adjustable by a wedge between one toggle plate and the frame. The Dodge has no such adjustment. This means that the USES AYD PREPARATION OF LIMESTONE 265 Blake will have a much wider range of uses. It follows, therefore; that the Blake is the jaw crusher that will :find the widest :field in working the limestones of the Coastal Plain for agricultural uses, road metal, ballast, etc. Its usual place in the plant is the :first crusher. The folJowing tables gi,re the size, horsepower required, capacity. revolutions of pulley per minute, and the weight of the Blake and Dodge type machines : BLAKE CRUSHERS Sizes) Capacities) etc.) Compiled from Catalogs Capacities in tons I Size of jaw. per hour. opening Size of product Amount of H.P required 1" lllh"l 2'' I 22" I 10" X 7" 4 I 5 .. I ~%/ 15" X 9" 20" X 10" I 24" X 12" I .. . . 8 I I 10 .. I I I 10 15 20 12 1 17%1 I 25 7 10 15 25 R. P.M. 250 to 275 250 to 275 250 to 275 250 to 275 Weight I 6,500 12,000 15,000 25,000 The capacities given are only approximate and will vary greatly with the stone being worked, that is, a hard brittle stone will go through the crusher much faster than a tough stone. DODGE CRUSHERS Sizes) Capacities, etc., Compiled from Catalogs Size of jaw opening Capacities in tons per hour to nut size 7" X 9" I 8" X 12" I 11" X 15" I 1:Y2 to 2% 3 to 5 6 to 8 Approx. H.P. required 6 10 15 R. P.M. Weight 300 I 3,250 300 I 5,900 250 I 13,500 According to Richards1 the cost of crushing with a Blake breaker varies from 3 to 15 cents per ton under roughly the best and worst conditions. An average would be :J.bout 8 cents for a stone that is not too hard to break easily with a fair capacity and labor. Crushing 1 Richards, R. H., A Text Book of Ore Dressing, 1909, pp. 22-23. 266 GEOLOGICAL SURVEY OF GEORGIA with tbe Dodge will run slightly higher, due mainly to consumption of more power. SPI:-IDLE OR GYRATING BREAKER S There are three general types of these breakers: (1) those which have the greatest movement on the smallest lumps, (2) those which have equal movement on all lumps, and (3) those whic~ have the greatest movement on the largest lumps. Only the first type will here be considered. The secon d an d third types are built onl y for special purposes. Examples of th e first-mentioned tJpe are t he Gates and the McCully breakers. These machin es and others closely related are manufactured by a number of firms, but owing to their close similarity the type machin e only wm be di scussed very briefly. Fig. 10.-Gates Gyratory Breaker (Allis-Chalmers) USES AND PREPARATION OF LIMESTONE 267 The main axis of a gyratory breaker is vertical, see Fig. 10. The main shaft or spindle (25) is hung from the spider (6) at the top of the machine and is given a gyratory motion by an eccentric at the bottom operated by bevel gears. The stone falls into the hopper (7) and thence into the space between the crushing plate (19), an inverted truncated cone, and the head (18), a small vertical truncated cone :fixed by keys to the main shaft. Since the top of the spindle is :fixed and the lower end moves in a circle, the axis of the sha,ft describes a long, very acute cone in its gyrations. If the minimum opening between the head and the crushing plate is at a certain point . then on the opposite side of the head is the maximum opening. Due to the gyratory motion these positions move continuously around the crushing plate when the machine is in motion. As the stone is being crushed on one side of the machine it is slipping down on the other to be crushed again when the distance between the head and plate at that point is approaching a minimum. This is repeated until the crushed product falls through the discharge chute or spout (32). The crushers are built with this spout on the opposite side of the machine from the drive shaft or at right angles to the axis of the shaft (31). Other makes of machines differ to some extent in the details, but the essential principals of the breakers are the same. GYRATORY BREAKERS Size_. Capacity) etc.) Compiled from Catalog No. Dimensions of Capacities in tons I Approx. each of two per hour H.P. re- receiving open- quired I I ings in inches 11,6" 2:!" 3:!" I R. P.M. of driving pulley Weight 1 I 2 I 4 I I 5 6 I 5 X 20 6 X 25 8 X 30 10 X 38 12 X 44 . . I .. 15 I I .. .. 5-9 .. 7-12 I .. 30 .. 50 70 I 70 90 4-6 600 6-10 I 575 14-21 400 I 22-30 375 28-45 I 350 7,100 10,200 22,000 32,800 I 48,000 268 GEOLOGICAL SURVEY OF GEORGIA Cost of Crushing W'ith Gyratoty BTealcers.-The cost of crushing with gyratory breakers as estimated by Richards1 from catalog data, is shown in the following table:. Estimated Costs of Btealcing with GyTatory Bteakers N' o. of Breakers . . . . . . . . . . . . . . . . . . . . . . . . 0 2 4 6 Size of mouth in inches ................ . 4 X 30 6 X 50 8 X 68 12 X 88 Tons broken per hour . . . . . . . . . . . . . . . . . . / 3 Horsepower required ................... , 3 Cost of breaker .. , . . . . . . . . . .......... , . $375 10 8 II 30 - 16 62th 32.5 $760 $1,800 . $3,300 Costs in cents per ton for- oil ........... . For interest and depreciation ........ . For power .......................... . For labor .......................... . For wear ............................ . 0.020 0.169 0.541 5.556 0.971 For repairs ........................ . 0.308 'l'otal costs m cents per ton ............ ~ 1 7.565 0.020 0.108 0.546 1.754 0.971 0.308 1 3.617 0.020 0.081 0.288 O.fi56 0.971 0.308 1 2.224 0.020 0.071 0.281 0.267 0.971 0.308 \ 1.918 The conditions under which the cost data of the above table were compiled are rather ideal and hence the actual cost might be figured to run slightly higher under ordinary conditions. However, with certain of the soft limestones of the Coastal Plain the cost as given would probably prevail. Comparison of Jaw and Gyratory Cntshers.-Until within recent years the Blake type of crushers were used much more extensively than any other type of machine and probably still are in mining operation. In quarry work, however, the gyratory breakers are used inuch more generally. For machines of small capacity the jaw crushers are considerably Ughter and cost less and are hence more desirable than the gyratory breakers. For large machines, however, although the first cost of the gyratory breaker is slightly more than for the jaw crushers the former requires less power to operate, takes a larger lump, hence less labor is required in quarrying, and requires less expensive founda- 1 Richards, R. H., A Text Book of Ore Dressing, 1909, p. 39. USES .AND PEEP.AE.ATION OF LIMESTONE 269 tion and mill structure. The last mentioned item is due to the fact that there is considerably less vibration from a gyratory breaker in that the crushing is continuous, while in the jaw crusher the reciprocating motion means that the stone is being crushed slightly less than half the time. It is evident that under the latter condition a considerable vibration would be imparted to the foundation and building. This allows the gyratory breakers to be set higher in the mill on less expensive structure. Practice and experiments show that the jaw crushers yield a higher percentage of fines than the other type machine, due to the tendency to pack between the jaws. The cost of breaking is, according to most authors, in favor of the gyratory breakers, particul~rly in the large machines. ROLLS The roll breaker or coarse crusher is a machine that would, withcut doubt, give excellent results on the soft limestones of South Georgia. They have large capacities for the weight of the machine, will take large lumps, and are comparatively cheap. The horsepower consumption is claimed to be approximately the same as for the other breakers. There are two types of roll crushers: (1) single roll, and (2) {loubJe roiL Fig. 11.-McLanahan-Stone Single Roll Crusher 270 GEOLOGICAL SURVEY OJ!' GEORGIA SINGLE ROLL CRUSHERS Machines of this type are said to be used very successfully in the Florida and Tennessee phosphate fields. The principal parts of the machine are the roll and breaking plate. The roll has a shell of steel or chilled iron with lugs or teeth projecting. The breaking plate may have either a flat or concave surface and holds a position at an acute angle to the perpendicular as shown in Fig. 11. The machines are of very simple construction and require little attention, being practically self-feeding when the bin is properly constructed. The following table gives capacity, size, list price, etc.: Size) Capacity) etc.) of Single Roll Crushers (1J!IcLanahan Stone lliach,ine Comparpy) Size of roll 18 X 16 18 X 24 18 X 30 18 X 36 24 X 36 Average Weight 4,500 7,200 9,400 10,000 36,000 Price with iron gears (Approx.) $275.00 325.00 400.00 475.00 1,950.00 Capacity tons per hour to 2-in. cubes 12 20 25 30 45 H.P. required 10 to 12 12 to 15 15 to 18 18 to 20 40 to 50 The price with steel gears is about 15 per cent higher in the smaller machines. DOUBLE ROLL CRUSHERS These machines are divided into hvo types, those with corrugated and those with toothed rolls. They are both used mainly in coal washeries, but could probably be appUed successfully to the preparation of soft limestones when dry. The rolls are geared together so that when a piece of stone falls between the two it is drawn through and broken. The rolls make from 100 to 150 revolutions per minute. The corrugated rolls are used mainly when the product desired is less than three-fourths inch. They may be set so that they will grind to the consistency of meal. The toothed rolls have either inserted or cast-in teeth and are used to crush mainly to nut size. It USES AND PREPARATION OJ? LIMESTONE 271 js hardly probable that the"'e machines will find an extensive use in the limestone fields of South Georgia. GRINDERS .\XD PULVERIZERS Grinders and puherizets are necessary in the preparation of lime- stone for agricultural uses and for the manufacture of cement. They are also used to pulverize caustic lime and for other purposes. There are a number of different t ypes working on entirely different princi ples, among which are: (1) Swing hamm er puherizers (2) Ring mills (3) Roller m.ills ( -!) Tube mill s (5) Ball mills (6) Rolls. These are the t ypes most likely to be met with in the limestone and allied indn!':trie.. Fig. 12.- Jeffrey Swing Hammer Pulverizer 272 GEOLOGICAL SURVEY OF GEORGIA SWING HAMMER PULVERIZERS These machines depend upon a blow struck in space to effect the crushing or pulverization of the material fed into the machine. Different types. are built by -yarious manufacturers, but the principle is practically the same in all. They will, t4erefore, be discussed only briefly in a general way. The main features are the beaters or hammers, the breaking plate, and the bar screen. Fig. 12 shows the general construction. The hammers- are hinged to the drum or spider around the shaft usually by steel rods. There are from four to eight rows around the shaft with four to twelve or more in a row, according to the size of the machine. The space between the hammers is usually about the thickness of the hammer, 1:lj2 to 2:Y2 inches. The beaters are of various shapes and sizes, some having detachable heads which receive the wear. One manufacturer makes a machine with a long bar head which :fits over all of the hammer arms in one row. The shaft revolves at speeds varying from 1000 to 1800 revolutions per minute. As the s~one is fed into the machines it is struck by the beaters, broken and tossed against a breaker plate where it is again broken and rebounds into the path of the beaters and is again tossed against a hreaker plate and further comminuted. The breaker plates are usually of steel and set at such an angle that the stone will rebound into the path of the beaters in the direction of rotation as shown in the :figure. These plates are replaceable. When the stone reaches the last screen it is rather finely crushed and is here subjected to a grinding action. The bars are set from one-fourth. to one-eighth inch apart at the top and are so shaped that the distance between the bottom edges is greater so as to prevent packing. Owing to the high speed of the machine ball-bearings are usually used on the main shaft. The feed for a swing hammer pulverizer usually comes from a jaw or gyratory crusher in sizes varying from 1 to 31;2 inches. Larger stone is often fed, but this is not advisable. The capacity of the machine depends upon the size of the feed stone, the speed of the beaters, LIMF:STONES OF THE CO.dS1'AL PLAIN OF GEORGIA PLATE X I A. E X POS ' HE 0 1' LDJESTO:\E OF 'J'lm C LI ATTAI IOOC II EE F O IDIA'l'I OX AT STO:\Y LAKB BL I' F l'. \\'I Til LA COOC' II EF. I! I n : u . 7 ~II LF..' SOI'T llE AST OF QlTD IA:\' . BHOOK~ CO I':\T\' . U. I~ Xl' OSI ' HE OF C II A' I'TAll OOL'I IE E LL\JESTOXE IX HAXK 01' \\'l'l'l.IL ACOOC II E I~ Hl\' EH. XI-:\\' t : HII JGE (O H II O HX HHIIJl:i': ) :{ ~IlLE S BELOW THE VALI IO ''l'A SOUTHE HN RAILHOAD BaiDGE , LOWNDES COUNTY. USES AND PREPARATION OF LIMESTONE 273 and the size of the product desired. Dry stone crushes much more rapidly than moist stone. The following tables show data compiled from several catalogs of different manufacturers: Data.~ on Swing Hammer Pulverizer Oomp,ilecl frorr" Catalog Size of Diamfeed eter of mill 1" 172" 172" 2" 2" 272" I 18" 26" J 26" I 26" 40" I 40" Capacity tons per 1 hour dry stone 12 mesh I 20 mesh %-1~~ :lh-1 2-4 1-3 5-6 3-5 6-8 5-6 10-12 8-10 13-15 10-13 H.P. 10-12 15-20 20-25 30-35 50-60 65-75 I Speed, I rev.. per / Weight mm. I I 1,800 1,600 1,600 1,600 1,100 1,100 I 2,500 l 4,000 5,000 6,500 1 12,000 I 14,000 Approx. Price I $300 400-900 I 1,000 I 1,200 I 1,500 I 2,100 The minimum capacity is for hard stone and the maximum for soft. The size of the feed may be increased, but it will curtail the capacity. These machines are said to deliver a product 95 per cent of which will pass 20 mesh. Test on Hard Limestone with Swing Hammer Pulverizer Bar screen .opening. :lh" No screen Capacity in tons per hr. 8 to 10 40 to 50 Speed 1,100 1,060 Per cent passing screen indicated 10 mesh 20 mesh 40 mesh 100 mesh 99% 80% 95% 63% 85% 42% 60% 19% The stone fed was in pieces 2 to 3 inches in diameter. The :first product is finer than necessary for agricultural purposes, while the second is scarcely fine enough. The mesh of a screen is the number of openings per linear inch. Thus a 10-mesh screen has 10 openings per linear inch or 100 openings per square inch. A standard size wire is used for each mesh. No cost data could be secured on the operation of swing hammer machines. A fairly accurate estimate can be made, however, by calculating the cost of power per ton, labor. and interest on investment 274 GEOLOGICAL SURVEY OF GEORGIA and then allowing for oil, depreciation and repairs. Where automatic feeders are used no labor is necessary, provided the bins and chutes are properly built. ROLLER MILLS These mills are of several types, but all are simple, the material being fed between high-speed steel or iron wheels rolling on a steel die. Three of the better known of these machines are the Chili mill, the Huntington mill and the Griffin milL The Chili mill has two or more vertical wheels which roll on a circular die around the main shaft. The die is set in a pan "into which the ore or stone is fed directly onto the die. The sides of the pan are so made that the centrifugal thrust is consumed in grinding the material. A 6-foot mill has a capacity of about 100 tons of fairly soft ore per 24 hours, reducing the same from one-fourth-inch size to 30 or 40 mesh. The necessary :fineness of the feed and the small capacity will eliminate it from use in the limestone :fields. They are used primarily for the :fine grinding of ores. The H1mtington 1nill is very similar to the Chili mill, except that the rollers are horizontal. They are used largely in the :fine grinding of gold ores. The Griffin 1Tdll consists of a roller suspended from a vertical axis rolling upon the inside of a circular die. This machine has been used to some extent in grinding phosphate rock and limestone for Portland cement. A 30-inch mill will crush from 11j2 to 4 tons of stone per hour, from 12 inches to 40 mesh, utilizing 15 to 25 horsepower. These results compare very favorably with those of other machines, but the cost of wearing parts per ton of product is comparatively high. TUBE MILLS A T.ube mill consists of a long steel cylinder with cast iron ends. The inner lining of the mill is so grooved that the flint or quartz US!i;S AND PREPARATION OF LIMESTONE 275 pebbles with which the mill is charged will fit in the grooves and relieve the steel or iron lining of wear. Considerably more of the pebbles are placed in the tube than will :fill the grooves. These balls act as the grinders when the cylinder is revolved on the iron rollers beneath the cylinder. The tube slopes slightly to"\vards the discharge end so that as the stone is pulverized it moves toward and finally through the discharge opening. The crushing is effected by the pebbles and feed being carried up as the tube revolves and then falling to the bottom. These mills are used very extensively in grinding cement clinker and limestone. One great objection to the mill is that the feed should be comparatively :fine, 8-mesh or finer. The capacity is comparatively small. BALL MIL.LS 'The Ball mill is somewhat similar in principle to i.he Tube mill, but steel balls instead of quartz pebbles are used and the length of the cylinder is usually less than the diameter. This mi1l will take a feed up to 2lj2 inches. The machine is of small capacity compared to the swing hammer mills, but gives a finer product. The cost per ton of "Nearing parts is rather high. The Ball mill is most extensively used in the metallurgical tJ;eatment of gold ores. They are also used to some extent :in cement plants. ROLLS Fine crushing rolls consist of two steel or iron cylinders revolving upon parallel shafts t:lO placed that when a piece of stone falls between the rolls H will be drawn through and crushed to the size of the openings. Rolls are of comparatively small capacity and will :find little or no use in crushing the limestones of South Georgia. They are used mainly in the treatment of brittle ores where a minimum of :fines are desired. SCREENS Tn the preparation of crushed stone for concrete aggregate, ballast, etc., it is always necessary to size the product. This is done by 276 GEOLOGICAL SDRVEY OF GEORGIA screens. There are three general types in use, each of which has its own :field to cover- (1) grizzlies or bar screens, (2) revolvi.ng screens, and (3) shaker screens. GRIZZLIES Grizzlies or bar screens are used for separating coarse from :fine stone and are usu!lllY placed so that the discharge from the preliminary crusher feeds directly over them. They are usually built of stationary iron bars, placed a definite distance apart, according to the products desired. The material that will not pass through the openings is called the over-size and that going through the under-size. The screens are placed at such an angle that the stone will slide over them by gravity slowly enough to allow complete separation. Different materials require different angles of slope. The grizzlies are placed so that the stone will slide along rather than across the bars of which if is built. The lateral flexibility of the bars is taken care of by bolts running across the grizzley through holes in the bars with space thimbles placed on the bolts between the bars. REVOLVING SCREENS Revolving screens or trommels are usually made of a tube or cylinder of perforated sheet steel with a steel shaft running through the center. Suitable gears or pulleys by which the screen is revolved are placed at one end. The discharge end is lower than the feed end so that as the screen revolves the over-size stone will work its way to the discharge end. When several sizes of stone are desired the screen is made up in sections, the :first section having the smallest perforations and the last section the largest. The bin below the trommel is built in as many compartments as there are sizes of stone produced.. The capacity of a trommel depends upon the size of the cylinder and the speed in revolutions per minute. Where only one size perforations are used the h'ommel is usually 3 or 4 feet in diameter and 6 to 10 feet long. Where several size holes are used the screen is considerably longer, frequently 20 feet or more. There is, of course, a USES AND PREPARATION OF LIMESTONE 277 maximum speed that can be used since above this the centrifugal force would prevent the stone from moving toward the discharge end. SHAKING OR PULSATDIG SCREENS Shaking or pulsating screens are used where a product of onefourth to one-half inch is desired. The :first under-size stone from the revolving screen is fed on to the shaker screen. If the feed is all less than one-half inch and the openings in the shaker one-fourth inch the over-size product will naturally be one-fourth to one-half inch in diameter. If pulverized stone is also desired the under-size is fed to a pulverizer. The shaker screen for the <:J.bove size product is usually made of wire. The discharge end is lower than the feed end so that when the pulsating motion is imparted to the screen by a suitably arranged eccentric the stone works its way gradually down and is discharged. BUCKET ELEVATORS where a crushing or grinding plant is built on level ground it is nearly always necessary to elevate the stone from the discharge of one machine to the feed of another. This is done usually by elevator buckets. These buckets are built of sheet steel and attached to double or single chains or belting. The chains pass over sprocket wheels or pulleys at the top or discharge point of the elevator and at the bottom or loading point. The capacity is governed by the size and number of the buckets and the speed of the chain and can be readily calculated. CONVEYORS It is frequently desirable in a stone crushing plant to convey certain products from one point to another along a horizontal or slightly sloping line. This is done by two types of conveyors, (1) the belt conveyor and (2) the screw or helical con-reyor. The belt con'Ueyor is a wide, endless rubber, canvas, or leather belt driven by and running over pulleys. In order to lessen the ten- 278 GEOLOGICAL SDEVEY 011' GEORGIA sion on the belt it is supported along its course by sets of rollers at short intervals. Each set is usually made up of four rollers, two horizontal ones beneath the center of the belt and one under either edge, set at an angle so as to make a trough of the belt to prevent the stone from rolling off. These belts are frequently used for charging stor- . age bins. vVhen a number of bins are used with the belt passing across each and it is necessary to dump the load before the end of the conveyor is reached, a suitable machine for this purpose is built. The belt goes over a pulley at the top of the dumping carriage and then doubles back and passes around another pulley. The stone is dumped below from the upper pulley into a chute that feeds into the bin. A helical or scTew conveyoT is very similar in design to a common wood auger. This screw fits closely into a semi-circular trough and as it is revolved conveys the stone from the feed to the discharge end. The conveyors are fro;m 6 to 12 inches in diameter. The capacity depends upon the size of the screw and the speed. Fine material is more satisfactorily handled than coarse. DRYERS When a damp limestone is to be ground for agricultural or other uses it is frequently more economical to dry the stone before attempting to pulverize it. The damp stone is not as friable or brittle as the dry and hence is not as easily broken. Also, the moisture causes the screen to be clogged and thereby reduces the capacity. The moisture is also objectionable in the product, since it adds weight and hence freight charges per ton of actual stone. The rotary dryer is the most common in use. It consists of a steel, fire-brick lined cylinder about 4 feet inside diameter and 25 to 40 feet in length. The kiln slopes gently toward the discharge end so that as it reyolves the stone works its way to the discharge opening. A fire-box at the lower end supplies the heat. The gases from the burning coal or wood pass thro-ugh the kiln and out through a stack at the upper or feed end. USES AND PEEP.AEATION OF LIMESTONE 279 The capacity depends upon the size of the kiln, the number of revolutions per minute, the size of the fire and the amount of moisture in the stone. KILNS Kilns are used in the limestone products industries in calcining limestone for lime and in the manufacture of cements. The vertical or shaft type lime kilns are discussed briefly under the heading "The Manufacture of Lime," and will, therefore, be omitted here. Revolving kilns are used very extensively in the manufacture of Portland and other cements, and lime when it is to be sold as hydrated lime. The~e kilns are very similar in construction to the dryers described above, but are much larger. The outer shell is of sheet steel and the lining fire-brick. They are 6 or 7 feet in diameter inside and 60 to 200 feet in length. The kiln revolves on rollers, being turned 2 or 3 times per minute by power applied through gears. The_ discharge end is slightly lower than the feed end so that the cement mixture and final clinker will work its way to the discharge. The heat is supplied by coal dust usually, but also natural gas or crude petroleum. The fuel is blown in at the lower end of the kiln and burns therein. The gases go out through the feed end into a stack and hence to the air or through suitable pipes to be used in dryers. Small kilns of this type are used in calcining limestone when it is to be made into hydrated lime or ground caustic lime. The limestone before being fed in to the kiln must be crushed to a small size to insu-re thorough calcination, hence Jump lime cannot be burned in this type of kiln. PLANTS FOR CRUSHING AND GRINDING LIMESTONE The type of plant and the machines to be installed therein to work the limestone of a given deposit depends upon the character of the stone and the products desired. It, therefore, 'seems desirable to discuss briefly several plants designed to work under different conditions and for different purposes. Since the individual machines have been described on previous pages they will only be mentioned as parts of 280 GEOLOGICAL SVEVEY OJ!' GEORGIA the plants. A short discussion of three plants seems sufficient to give an idea of the methods of preparing the limestone for different purposes. The plants taken up will be as follows: (1) A plant of 11j2 to 4 tons per hour capacity of agricultural limestone from hard or soft limestones. (2) A plant of 15 tons per hour capacity of agricultural limestone from hard or soft stone. (3) A plant for preparing crushed stone for ballast, road metal and concrete aggregate and ground limestone for agricultural uses. Total capacity f)O tons per hour of all products. The above sizes and types of plants are those which are most likely to be used in developing the limestone resources of the Coastal Plain of Georgia. A Plant of 11/2 to 4 Tons per Ho~~r.-A plant of this size is for the purpose of supplying ground agricultural limestone for local or individual use. Several rp.anufacturers have on the market single machines which will reduce to an 8-mesh product in one operation, stone which will just enter a 7-inch by 9-inch opening. such a machine requires about 15 horsepower and will yield 11/2 tons per hour. V\1here this capacity is sufficient to supply the need this is the ideal plant for local farm use. Fig. 13.-' 'Allis-Chalmers Hummer'' Pulverizer-Mountecl on Steel Truck USES .AND PREP.AR.ATION OF LIMESTONE 281 When greater tapacity is desired a more elaborate plant is necessary. The same pulverizer may be used, but instead of feeding the large stone to it direct it is first run through a preliminary crusher and reduced to about 2-inch size. This increases the output of the pulverizer to 3 to 4 tons of ground limestone per hour. Flow Sheet of Plant Having Capacity of 3 to 4 Tons per Hour of -' Agricultural Limestone Quarry I t I Crusher (1) I ~ Elevator bucket (2) I l Pulverizer (3) 1 Conveyor (4) I t Storage or wagon. The crusher (1) may be either a jaw, gyratory, or other type. A Blake type jaw .crusher would probably give the best results, especially on a hard stone. The stone is delivered from the quarry to the machine in sizes that 1vill enter a 9- by 12-inch opening. After being reduced by the cru.sher it is raised by the bucket elevator (2) to the feed opening of the pulverizer (3). A swing hammer type machine is probably best suited for this work. The :final product from the . pulverizer is conveyed to storage or wagon by a screw or bucket elevator (4). This conveyor may be dispensed with, but if so a man is necessary to keep the :finished product back from the discharge of the machine, unless it is hauled away as rapidly as ground. 282 GEOLOGICAL SVBVEY OF GEORGIA Fig. 14-.A.llis-Chalmers L.B.H. Hummer Crusher and Pulverizer The single machine or crusher and pulverizer plants may be set either on permanent foundations or mounted on steel trucks so that they can be moved from place to place. Power may be obtained from steam or gasoline engines. Fifteen horsepower is necessary to oper- ate the single machine and 20 horsepower for the more elaborate plant. VSES AND PEEPARATION OF LIMESTONE 283 A Plant of 15 Tons per Hour Capacity of Agricultural Limestone from Ha1d or Soft Stone.-A plant of this capacity is designed primarily to furnish ground limestone on a more extensive scale. The :tlow sheet of such a plant is as follows: Flow Sheet ~f Agricultural Limestone Plant with Capacity of 15 Tons pet Hour Cars (1) l Bin (2) I I \[; Crusher (3) l Elevator (4) l Bin (5) l Pulverizer (6) l Conveyor ( 7) I t I t Uonvf'lyor (8) I + I Storage bins (9) I I t Conveyor (10) I t Loading bins (11) 284 GEOLOGICAL SURVEY OF GEORGIA The stone is loaded at the quarry in tram cars (1) of surface or overhead type and dumped automatically into the bin (2). 'l'his bin should have a capacity of at least several cars so that the haulage and quarry work will not be held up when the crusher is stopped for a short time or vice versa. The stone feeds from the bin 'into the crusher mouth (3). This crusher may be of the jaw, gyratory, single roll, or other types. The gyratory type is most generally used in stone-working plants. The crusher should be of about 20 tons capacity of stone to 2- or 21j2-inch size. This slight excess capacity is ad- visable in order to assure a steady feed to the pulverizer when the crusher is shut down for a few minutes occasionally for various reasons. About 15 horsepower is required to operate the machine. The crushed stone is taken from the crusher discharge by the bucket elevator (4) and delivered to the feed bin (5) of the pulverizer. The bin should be of suffi~ient size to hold enough stone to operate the pulverizer for a short period of time if it is necessary to stop the crusher for any reason. This assures a steady production. The bin feeds automatically to the pulverizer (6) . This machine may be of the swing hammer type, ring mill, ball, or tube mill, or others. This depends largely upon the type of stone and first cost of the machine. The swing hammer pulverizer would probably give very satisfactory results on the soft limestones of South Georgia. A 15-ton per hour capacity machine requires about 75 horsepower to operate it. The finished product discharges into a conveyor (8 and 10) to be carried to storage bins or loading bins (9 and 11). Since the demand for the product is largely in the fall and winter months it may be necessary to have large capacity storage bins in order to supply the demand during the "season." Although dry stone is considered in the capacities of the machines no means of drying has been put in the flow sheet. It is quite probable that drying will be necessary before the stone can be pulverized economically. In this case a mechanical dryer must be installed. USES AND PREPARATION OF LIMESTONE 285 A power plant consisting of a 100-horsepower boiler and a 100horsepower high-speed engine is sufficient to operate the plant. A Plctnt for Preparin,g Crushed Stone for Ballast) Road J."lietal) etc.) Total Capcteity 50 Tons per H onr of all Products.-This type plant would be designed to supply a comparatively large area with such materials as mentioned. A hard limestone is, of course, necessary to give good crushed stone products. The flow sheet would be as follows: Flow Sheet of Ontshed Stone Plant of 50 Tons Hourly Capacity Cars .I ~ Crusher (1) l Bucket elevator (2) I ~ 2~6'' bin I ~ Revolving screen (3) I ~ I I I I ~ ~ ~ ~ 12" %" lh" Under-size bin bin bin chute (4) I ~ Pulverizer (5) r I ~ Elevator (6) I I I \V Bin (7) 286 GEOLOGICAL SURVEY OF GEORGIA The quarry stone is dumped into a 50- to 70-ton crusher (1) and reduced to 3-inch size and smaller. Gyratory crushers have found preference in this work, but other types may be employed with practically as good results. About 30 horsepower is necessary to reduce the stone. A bucket elevator (2) receives the stone from the discharge and lifts it to the revolving screen (3), usually at the top of the mill. The screen is built up in three sections, having 2:Y2-, 11/2-, and three-quarter-inch perforations respectively. Surrounding the three-quarter-inch section there is an outer jacket having one-halfinch perforations. The stone is fed in at the upper end of the screen onto the three-quarter-inch sections. All smaller than this size fall through onto the one-half-inch screen. The under-size on this screen falls through and the over-size goes out at the lower end. The oversize from the three-quarter-inch screen goes onto 11;2-inch section and is further separated and so on to the end of the screen. Suitable bins are built beneath the revolving screen to hold the sized products. Chutes leading from these bins dump directly into cars, wagons or onto a conveyor belt which conveys the stone to larger storage bins. The under-size from the :Y2-inch screens works by gravity (4) into a pulverizer (5). The size of this pulverizer depends upon the quantity of the ground stone desired. A 10- to 15-ton machine will take care of the fine material ordinarily. If a larger capacity is desired chutes should be built so that the product from the crusher or sized-stone bins can be fed into the pulverizer. A 125-horsepower boiler and engine will produce sufficient power to operate the plant unless a large pulverizer is desired. APPENDIX A LIMESTONE QUARRIES OF NORTH GEORGIA At the present time all of the limestone, dolomite and marble quarries being operated in Georgia are in the northern part of the State. The stone is of Paleozoic age and varies in texture from granular limestone and dolomite to coarsely crystalline marble. The fol- uSES AND PEEPAEATION OF LIMESTONE 287 lowing brief descriptions are of quarries producing crushed and pulverized stone and lime during the Fall of 1915. Deal Lime 1-Vorks.-The quarries and kiln~ of the Deal Lime Works are located 2 miles south of Gainesville, Hall County, near the Southern Railway. There are three quarries on the property, only one of which (Quarry No. 2) was being operated at the time of the writer's visit. The stone is a hard, light dove colored, :finely crystalline, dolomitic limestone. All of the stone quarried is used in the manufacture of lime. There are two lime kilns on the property, one of 75 and the other 125 barrels daily capacity. The smaller kiln has not been operated in several years. A.nalyses1 of Limestones f1"0nt Deal Lime vVorlcs, ncar Gainesville, Geor-gia I Quany No.......................... , 2 3 I I Lime C?aO) ........................ 1 28.00 1 30.02 Magnes1a (MgO) .................... I1 Alumina (Al20 3 ) .... i Ferric oxide (Fe 02 3 ) I Sulphur trioxide (S03 ) ........... j Phosphorus pentoxide (P 02 5 ) I Carbon dioxide (C02 ) and organic matter ] Silica (Si02 ) . 16.06 .80 1.2;5 trace .04 39.65 14.20 r Total ........................ [ 100.00 ,17.98 .60 1 . 70 1 .02 J .06 J 42.79 J 6.83 !-- 1 100.00 I Calcium carbonate I ( CaC03 ) .. 50.00 Magnesium carbonate (MgCO,) ....... I 33.92 I 1 53.61 J 37.76 ]-]- Total carbonates .............. I 83.92 1 91.37 I I The A.rt 1J!Iarble Company's plant and quarry are located at Gartrell, Gilmer County, on the Louisville and Nashville Railroad. The stone worked is a fine grained, white marble which occurs near the 'Maynard, T. Poole, Limestone and Cement Materials of North Georgia: Bull. Ga. Geol. Survey, No. 27, 1912, pp. 112-114. 288 GEOLOGICAL SUBVEY OJ/ GEOBGIA base of th@ Murphy Marble formation. Both high-calcium and highmagnesian stones are worked. The following analyses are of the two varieties of stone : Analyses1 of Marble f'rom Art llfa1ble Company Lime (CaO) ....................... . Magnesia (MgO) ................... . AFlun:una _(dAl20(Fs) O ) } ............. . erne ox1 e e2 s I Phosphorus pentoxide CP205) ........ I Silica (Si02) .......... Undetermined ....................... . 53.00 1.54 1.44 trace 1.00 43.02 39.10 11.30 2.06 trace 4.60 42.94 Total . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 100.00 Calcium carbonate (CaCOa)............ 94.60 Magnesium carbonate (MgCOa) . . . . . . . . 3.23 69.80 23.70 Total carbonates 97.83 93.50 'l1he marble is quarried and then prepared by crushing and pulverizing for flooring material, roofing s!one, road dressing and agricultural purposes. The plant has a capacity of about 30 tons per day of agricultural limestone. The Southern States 1Vla1ble Company at Whitestone, Pickens County, quarries finely crystalline marble of the Murphy formation. The plant is equipped for preparing crushed marble for flooring, roofing and other uses and pulverized stone for road dressing and agricultural purposes. A tube mill of 30 tons daily capacity is used for pulverizing. The whitestone M cwble Company)s quarry and plant are located at Whitestone, Pickens County; on the Louisville and Nashville Railroad. The stone worked is a fine grained, white, magnesian marble. It is crushed to three sizes for flooring and roofing stone, while the under-size from the smallest screen opening is pulverized for road 1 Op. cit., p. 120. DSES AND PREPARATION OF LIMESTONE 289 dressing and agricultural uses. The plant has a capacity of 150 tons of pulverized stone per day. An average of three analyses from different strata in the mine is as follows: Average Analysis of Marble from Whitestone Marble Company Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AFlurr:ina ~dA120(3F) ) } . . . . . . . . . . . . . . . . . . . . . . . . ' erne ox1 e ' ez0 s Phosphorus pentoxide (P 02 5 ). Silica (Si02 ) ., Undetermined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.43 17.05 1.35 trace 4.29 43.88 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100.00 Calcium carbonate (CaC03) . Magnesium carbonate (MgC03 )................. Total carbonates . . . . . . . . . . . . . . . . . . . . . . . . 59.70 35.80 95.50 The Ladd Lime &: Stone Company's quarry and plant are located on Ladd Mountain, 2 miles southwest of Cartersville, Bartow Coun ty. Dolomite of the Knox formation is quarried and crushed for use as ballast, road metal, concrete aggregate and other purposes. The under-size from the screen having the smallest opening is pulverized in a Sturtevant ring mill and sold for agricultural purposes. The plant has a capacity of 300 tons per day of agricultural limestone 290 GEOLOGICAL SURVEY OF GEORGIA The following analyses are of samples of stone from the. quarry and storage bins: Analyses of Dolomite from Ladd Lime cf Stone Company) Ca1tersv-ille I Soda (Na20) . . . . . . . . . . . . . . . . . . . trace .04 .10 Potash (K20) . . . . . . . . . . . . . . . . . . . trace .06 .06 Lime (CaO) . . . . . . . . . . . . . . . . . . . . 30.00 29.04 31.96 Magnesia (1\fgO) . . . . . . . . . . . . . . . 20.00 18.16 18.70 Alumina (AI20 3 ) Ferric oxide (Fe20 3 ) 1 f 1.20 1.52 1.20 1 I Silica (Si02 ) 3.05 7.89 2.66 I Undetermined . . . . . . . . . . . . . . . . . . . 45.75 1 43.29 45.32 Total ..................... 1-10-0-.0-0 \100.00 I 1100,0Q Calcium carbonate (Ca003)....... 53.55 1 51.86 57.07 Magnesium carbonate (Mg003 ) 42.00 38.14 39.27 Total carbonates .......... \ 95.55 , 90.00 96.34 I I The :first and third analyses are of average samples from the face of the quarries while the second is of the agricultural limestone in the storage bins. The Piedr_nont Portland Cement Company)s quarry and plant are located at Portland, on the Seaboard Air Line Railroad, 5 miles north of Rockmart. The quarry was originally opened for the manufacture of lime. Some years later, howeverr a plant was installed for the manufacture of Portland cement but was operated for a short while only. At the present time crushed stone for ballast, road metal and concrete aggregate, and pulverized stone for agricultural uses is prepared. The plant has a capacity of 300 tons per day of this last mentioned product. The limestone quarried belongs to the Chicka- USES AND PREPARATION OF LIMESTONE 291 mauga formation and consists of both high-calcium and high-magnesian limestone. The following analyses are of the two types of stone: Analyses1 of Limestone from Piedmont PMtland Cement Company Soda (Na20) .... _................... Potash (K,O) .............. _........ Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . Alumina (Al20s) } Ferric oxide (Fe 0 ) 23 Phosphorus pentoxide (P 02 5 ).. Silica (Si00 ) Undetermined .... _................... .14 .17 50.12 1.81 1 92 .01 3.36 42.47 Total ......................... \100.00 Calcium carbonate (CaC03 ) Magnesium carbonate (Mg003). _ 89.52 3.80 .05 .25 33.22 12.68 2.60 1 .o2 1 8.98 1 42.2o I- I 1oo.oo I 1 59.4o 1 26.6o Total carbonates 93.32 1 86.00 1 Maynard, T. Poole, Limestone and Cement Materials of North Georgia: Bull. Ga Geol. Survey, No. 27, 1912, p. 14.7. .INDEX PAGE Abbeville, partial analysts of soil from 218 Acetic acid, lime used in manufac- ture of .................. 240 Acetone, lime used in manufacture of 240 Adams Park, limestone exposed east of ...................... 74-76 Aerial tramways for hauling lime- stone ............... 250-252 Agricultural uses of limestone and lime .................. 211-223 Literature on . . . . . . . . . . . . . . . . 222 Ainslie Station, fossils from . . . . . . . . 22 Limestone exposed near ........ 65"67 Sections near ............. 21-22, 66 Albany, limestone exposed near ... 134-137 Section south of. . . . . . . . . . . . . . 137 Allapaha River, limestone exposed along ................. 204-205 Allis-Cha~mers c'rushers and' pulver- Izer ................... 280 282 Aldrich, T. H., cited .............. .' 34 Alford property, analysis of limestone from .................... 164 Limestone exposed on ....... 164-165 Section on . . . . . . . . . . . . . . . . . . . 164 Altamaha upland . . . . . . . . . . . . . . . . . 2-3 Alum Bluff formation ............. 28-29 Ammonia, UJse of lime in manufac- ture of . . . . . . . . . . . . . . . . . . 237 Analyses for solubility of potash and phosphoric acid in limestones 216 Analyses of South Georgia soils. . . . 218 Appalachicola group .............. 25-29 Appendix A ................... 286-291 Ard property, analysis of limestone from . . . . . . . . . . . . . . . . . . . . SO Limestone deposits on ......... 80-81 Arenaceous limestone ............ 42 43 Argillaceous limestone . . . . . . . . . . . . ' 43 Arlington, analysis of limestone from near .................. 132-133 Limestone deposits near ..... 132-133 Armena, lime kiln near. . . . . . . . . . . . 253 Limestone deposits near ..... 148-151 Armstrong place, analy,sis of lime- stone from ............ 160-161 Limestone deposits on ....... 159-161 Section of bluff on .......... 159-160 Art Marble Company, analyses of limestone from .... . . . . . . . 288 Description of quarry of..... 287-288 Atwood c'annery .................. 210 Averett place, analysis of limestone from .................... 158 Limestone deposits on ....... 157-158 8 Bainbridge, Jackson exp_o,sed at.. . . . 23 Limestone d'eposits near ..... 172-173 Partial analysis of soil from near 218 Baker County, limestone exposed in .................... 169-170 Baker-Decatur county line, section near ..................... 169 P.A.Gl!l Baldwin. County, Jackson exposed in 16 Ballast, limestone used as ....... 223-224 Plant for preparation of limestone for ............... 285-286 Ball mills ......... ; . . . . . . . . . . . . . 275 B.arnwell formation . . . . . . . . . . . . . . . 8 Barrow place, limestone deposits on. 185 Bar screens . . . . . . . . . . . . . . . . . . . . . . 276 Bartow County, analyses of cement rock from . . . . . . . . . . . . . . . . 230 Analyses of limestone from... . . . 290 Limestone quarry in. . . . . . . . . . 290 Barwick, limestone deposits near .197-199 Basic open hearth furnaces, limestone for flux in ............. 242-243 Limestone used for lining of. . . 242 Bassler, R. S., determination of fos- sils by ..................10, 20 Bateman "hammock," section at .... 134 Beasley, Thomas, limestone deposits on property of. . . . . . . . . . . . 199 Beaver Dam Creek, limestone deposit!:! near ..................... 55-57 Belt conveyor, the .............. 277-2'78 Benevolence, limetstone deposits west of .................... 127-128 Berry nlace, limestone deposits on. . 100 Bibb County, Jackson exposed in.... 21 Limestone deposits in. . . . . . . . . 80 Big Indian Creek, limestone exposed on . . . . . . . . . . . . . . . . . . . . . . 97 Birmingham, d'olomite used in fur- naces at . . . . . . . . . . . . . . . . . 241 Blackshear, James, analysis of lime- stone from property of. . . . . 190 Lime,stone deposits on property of 190 Blake type stone crusher ........ 263-265 Tabulated data concerning..... 265 Blast furnace flux, use of limestone as .................... 241-242 Bleaching agents, uses of lime in manufacture of ........ 235-236 Bleckley County, description of strata in ...................... 64-69 Jackson exposed in ........... 21-22 List' of fossils from. . . . . . . . . . . . 22 Section o.f fossils from ........ 21-22 Tests on soils from. . . . . . . . . . . . 219 Blocking limestone . . . . . . . . . . . . . . . . 249 Blowing cave, analysis of limestone :from .................... 185 Limestone deposits at. . . . . . . . . 185 Blue Bluff. analysis of lime,stone from 54 Description of strata at ....... 54-55 "Blue ltuin" plantation, limestone de- posits on ..............117-118 Blue Spring, limestone deposits south of ...................... 55-57 Bonaire, analysis of limestone from near .................... 83-84 Limestone deposits near ....... 83-84 Bond postoffice, limestone dep01sit near .................... 80-81 Bond's store, fossils c'ollected near. . 20 Jackson exposed near. . . . . . . . . . 20 Limestone deposit south of. . . . . 73 INDEX 293 P!.GE Boston Phosphate works, analysis of limestone from . . . . . . . . . . 193 Limestone deposits at. . . . . . . . . 193 Brecciated limestone . . . . . . . . . . . . . . 42 Briar Creek, limestone deposits on. 56, 57 Brinsou, limestone deposits 3 miles below .................... 173 Brooks County, limestone deposits in .................... 197-201 Partial analyses of soil from. . . . 218 Browns Mill, analyses of samples from 131 Limestone deposits at ....... 130-131 Section at . . . . . . . . . . . . . . . . . . . 130 Bruce, J. I., limestone deposits on property of ........... 199-200 Brunswick, oyster cannery at. . . . . . . 20l:l Brushy creek, section on. . . . . . . . . . . 15 Bucket elevators . . . . . . . . . . . . . . . . . 277 Burchard, E. F., and Emley, W. E., cited .................... 258 Bureau of Standards, cited ......... 257 Burke County, description of lime- stone deposits in ......... 44-55 Jackson exposed in............ 15 Burke Ferry, limestone deposits north of . _.................. 140-141 Burke place, analyses of limestone from ................. 140, 141 Limestone deposits on ....... 140-141 Burning limestone .............. 257-258 Burnt Fort, lime,stone exposed near. . 208 Bynes place, limestone deposits on 150-151 Byrom, S. B., and W. H., analyses from property of. . . . . . . . . . 154 Limestone deposits on pro-perty of .................... 153-157 Sections on property of. . . . . . . . 153 Byrom well, log of ............. 156-157 c Cairo, limestone deposits south of. . . 190 Calcareous deposits, detailed descrip- tion of ................ .44-210 Calcium carbide, use of lime in manu- facture of . . . . . . . . . . . . . . . 237 Calcium cyanamide and nitrates, use of lime in manufacture of. 237 Calhoun County, description of strata in .................... 132-134 Camden County, description of strata in ....................... 208 Carswell, Dr. N. T., ,section on prop- erty of .............. 16-17, 64 Carter, J. M., analysis of limestone from property of. . . . . . . . . . 114 Limestone deposits on property of .................... 114-11"> Carter place, .Jack,son exposure on.. . 23 Cartersville, plant for preparing lime- stone at ............... 289-290 Carts for haulin.g limestone. . . . . . . . 250 Cedar Creek, analysis of limestone from mouth of. . . . . . . . . . . . 228 Ced'ar sink, section in .......... 168-169 Cement, Ga., analysis of cement rock from .................... 230 Cement materials, analyses of. . . . . . 230 Cemochechobee Creek, limestone de- posits on .............. 130-131 Century, limestone deposits near .. 145-146 Ceramics, limestone used in. . . . . . . . 239 Chalky or "rotten" limestone ...... 41-42 Charlton County, limestone deposits in .................... 206-207 Chattahoochee anticline . . . . . . . . . . . 3 PA.Gl!l Chattahoocb.ee formation .......... 25-28 Chemical action of limestone ..... 212-214 Chemical and physical action of lime .................. 214-216 Chili Mill, the .................... 274 Claiborne group . . . . . . . . . . . . . . . . . . 8-9 Classification of limestone ......... 40-43 Acc'ording to composition. . . . . . . 43 According to texture .......... 41-43 Classification of properties of limes 258-260 Classification of rocks. . . . . . . . . . . . . . 38 Clay bricks, tests .on. . . . . . . . . . . . . . . 235 Clay County, description of strata in 128-132 Clegg place, limestone deposits on 152-153 Clinch County, partial analysis of 1soil from . . . . . . . . . . . . . . . . 218 Coastal Plain, geology cif . . . . . . . . . . . 4-38 Physiography of . . . . . . . . . . . . . . 1-3 Structure of . . . . . . . . . . . . . . . . . . 3 Coastal terrace sand ............... 35 Cochran, limestone exposed north of 67-69 Coc'ke, J. F., analysis of limestone from property of. . . . . . . . . . 149 Limestone deposits on property of .................. _.149-150 "Cold" lime . . . . . . . . . . . . . . . . . . . . . . 224 Cole property, analysis of limestone from .................... 124 Limestone depo.sit on. . . . . . . . . . 124 College Creek, limestone and marl ex- posed on ................. 208 Colliers Bluff, analyses of limestone from ................. 106, 228 Limestone deposits at ....... 105-107 Section at ................... 106 Columbia formation or group....... 35 Comparison of jaw. and gyratory crusher ............... 268-269 Concrete aggregate, limestone used as ....................... 223 Coney, limestone deposits near. . . . . . 159 Congaree clay member. . . . . . . . . . . . . 8 Conveyors ..................... 277-278 Cooke, C. Wythe, cited ............ 10, 23 Quoted . . . . . . . . . . . . . . . . . . . . . . 19 l-tefe1ence to work of ........ 9-10,11 Cord'ray Mill, limestone deposits near 133-134 Cork Ferry, analysis of limestone from .................... 139 Limestone deposits at. ...... 138-140 Section at ................. 138-140 Cost of breaking limestone with gyra- tory breakers . . . . . . . . . . . . . 268 Cost of lime manufacture ........ 260-261 Cost of manufacture o.f sand-lime brick .................... 235 Cowarts Bridge, oyster shells near. . . 16 Crawford County, .Jackson exposed in 17-18 Cretaceous series, Lower. . . . . . . . . . . 4-5 Upper . . . . . . . . . . . . . . . . . . . . . . . 5 Cretaceous system, the. . . . . . . . . . . . . 4-5 Crider, A. F., cited................ 12 Crisp County, limestone deposits in 152-163 Crooked Creek, limestone exposed near 79 Crops benefited by use of limestone. . 21 7 Crushed limestone, uses of ....... 223-224 Crushed stone, plant for preparation of ... - ................ 265-286 Crusher and pulverizer, Allis-Chal- mer,s .................... 282 Crushers, Blake type of ......... 263-265 Dodge type of .............. 263-266 294 INDEX PAGE PAGE Crushing and grinding limestone, plants for ..... , ....... 279-286 Crystalline limestone ... ; . . . . . . . . . . 41 Cuthbert, limestone deposits north of 126-127, 128 D Dall, W. H., cited. . . . . . . . . . . . . . . . . 34 Dana, E. S., cited . . . . . . . . . . . . ' . . . 40 Danville, description of Jackson near 21 Daphne, limestone deposits near . 152-153, 156 Darien, oyster cannery at .......... 209 Davis house, limestone deposits north of ....................... 104 "Dead" o.yster shells, deposits of. . . 209 Deal Lime Works, analyses of lime- stone from . . . . . . . . . . . . . . . 287 Description of limestone deposits . at ....................... 287 Decatur-Baker county line, limestone deposit.s below . . . . . . . . . . . . 172 Decatur County, Jackson expo.sed in. 23 Limestone deposits in ....... 172-182 Partial analyses of soils from. . . 218 Deese, J. T., analysis of limestone from . . . . . . . . .. . . . . . . . . . . . 68 Limestone deposit on property of 67-69 Description of soils analyzed ..... 218-219 Detailed description of calcareous de- posits by counties ....... .44-210 Devils Hopper, analyses of limestone from .................... 198 Limestone exposed at ....... 197-199 Section at ................. 197-198 Dickey property, analy1sis of lime- stone from . . . . . . . . . . . . . . 109 Limestone deposit on property of 109-110 Dodge type stone crusher ........ 263-266 Tabulated data concerning. . . . . . 265 Dolomite . . . . . . . . . . . . . . . . . . . .. . . . 43 Dooly County, Jackson exposed in. . . 23 Limestone deposits in ....... 111-115 Double roll crushers, -description of 270-271 Dougherty County, limestone d'epos- its in .................134-137 Dougherty county line, secti.on above 161l Dougherty plain . . . . . . . . . . . . . . . . . . 2 Drilling and blrusting limestone ... 246-249 Dry Branch, description of -exposures at ...................... 18-1.9 Dryers ........................ 278-279 Duke, W. M., analysis of limestone from property of. . . . . . . . . . 179 Limestone deposits on property of Eckel, E. C., cited ..... 227, 231, 260, 261 Edison, limestone deposits el!Jst of. . . 134 Elevators . . . . . . . . . . . . . . . . . . . . . . . . 277 Ellaville, limestone deposit near .. 122-123 Emley, Warren E., cited ........ 256, 258 Eocene series .................... 5-24 Eocene, uridifferentia ted ........... 24-29 Evans-Miller place, analyses of lime- stone from . . . . . . . . . . . . . . 49 Description of limestone d'eposit.s on ...................... 48-49 Everhart, Edgar, analyses by ...... 36, 44 Excavating limestone, steam shovel for ...................... 252 Explosives used in blasting limestone 249 F Faceville, analysis of limestone from near .................... 175 Limestone deposits near ..... 173-175 Partial analysis of soil from near 218 Section west of ............ 173-174 Fall Line Hills . . . . . . . . . . . . . . . . . . . 2 Fall Line of Georgia. . . . . . . . . . . . . . 1-2 Fine grained limestone. . . . . . . . . . . . . 41 Fitzpatrick, Irwin, analysis of lime- stone from property of .... 76-77 Limestone exposures on property . of ...................... 76-79 Fitzpatrick place, fossils collected on 20 Jackson expo.sed on. . . . . . . . . . . . 20 Flint Hiv-er, analysis of limestone from ................. 119, 228 Jackson exposed on .... , . . . . . . . 23 Limestone exposed alo'ng ... 115; 119, 134-135, 138-142 Section on, south of Albany. . . . 137 Flintside, analyses of limestone near 121 Limestone exposed near ..... 121-122 J:Plow sheets of limestone plants 281, 283, 285 Flow sheet of plant for crushed stone 285 Fluviatile deposits . . . . . . . . . . . . . . . . 35 Flux for furnaees, limestone used as . 242-243 Folkston, limestone deposits 10 miles so.uth of . . . . . . . . . . . . . . . . . 207 Fore.st Falls, analyses of limestone from .................... 187 Description of strata at ..... 186-187 Section at ................... 186 Fort Gaines, description of strata at 131 Limestone deposits near ..... 130-131 Fossiliferous limestone . . . . . . . . . . . . 41 Fowltown Creek, limestone deposits along ................. 148-152 Limestone depo,sits near mouth of ................. -...... 146 179-180 Section near mouth of. . . . . . . . . 146 Dumesun, P., and Moyrr, J., cited ... 240 France, analyses of lime rock from_ . 228 Duncan, C. C., limestone deposits on Frieden, L., analysis of limestone from property of ............. 98-100 property of ............ 112-113 . Duncan Station, limestone deposits Limestone deposits on property of south of ................. 100 112-113 Duplin marl ..................... 31-32 Section on . . . . . . . . . . . . . . . . . . . 112 E Early "County, limestone deposits in Fungicides and insecticides. . . . . . . . . 223 G 170-172 Easterlin property, analysis of lime- stone from . . . . . . . . . . . . . . . 116 Limestone deposits on ....... 115-117 Echols County, description of strata in .................... 203-206 Gainesville, limestone deposits near. 287 Gartrell, limestone plant near .... 287-288 Gate's gyratory breaker, description of 266-269 General discussions of limestone .... 1l8-43 Geology of Georgia ............... 1, 4-38 INDEX 295 PAGE Georgia & Florida Railway tressel, analysis of limestone from near .................... 20~ Limestone deposit near .. 201,202-203 Section near . . . . . . . . . . . . . . . . . 202 Georgia-l!'lorida State line, analysis of limestone from near ..... 181-182 Limestone deposits near ..... 181-182 Georgia Kaolin Company, list of fos- sils from near. . . . . . . . . . . . 19 Section in pit of ............. 18-19 Georgia Southern & Florida ( G.S.&F.) limestone quarry, analyses of limestone from . . . . . . . . . . . 92 Description of deposits at ...... 92-95 Section at ................... 92-93 Georgia Southern & Florida Hailway. limestone deposits in cut of 83-84 Georgia Southwestern & Gulf Rail- road, lime.stone deposits on 136-137 Section on Flint River at tressel 163 Germany, Haurenbergen, analysis of lime rock from. . . . . . . . . . . . 228 Gilmer County, analysis of limestone from .................... 288 Limestone plant in ......... 287-288 Glass manufacture, use of limestone in ....................... 238 Glycerine, lime used in manufacture of ...................... 241 Glynn County, description of strata in 208-209 Oyster sheUs in. . . . . . . . . . . . . . . 209 Grady County, description of lime- stone deposits in ........ 182-191 Partial analyses of soil from. . . 218 Granular limestone . . . . . . . . . . . . . . . 41 "Green" oyster shells, analyses of. . 210 Greer Cave property, analysis of lime- >Stone from .............. 126 Limestone deposits on ....... 126-127 Greer, James, limestone deposits on property of . . . . . . . . . . . . . . 128 Griffin Landing. Jackson exposed at. . lii Griffin Mill. the. . . . . . . . . . . . . . . . . . . 274 Grimsley Mill, analysis of marl from 171 Description of strata at. ....... 171 Grinde11s and pulverizers ........ 271-275 Grinding and crushing limestone, plants for ............. 279-28fl Grizzlies . . . . . . . . . . . . . . . . . . . . . . . . . 276 Groover, Robt.. limestone deposits on property of . . . . . . . . . . . . . . 210 Gum Creek. log of well on ........ 1ii6-157 Gyratory breakers, c'ost o.f crushing with .................... 268 Comparison with jaw crushers 268-269 Description of ............. 266-269 Tabulated data concerning..... 267 H Had"dock, J. W., analysis of limestone from property of. . . . . . . . . . 200 Lime.stone deposits on property of ....................... 200 Haddock Landing, limestone de;:>osits at . . . . . . . . . . . . . . . . . . . . . . . 57 Hall, A. D.. quoted. . . . . . . . . . . . . . . . 220 Hall County, analyses of limestone from .................... 287 Limestone deposits in. . . . . . . . . . 287 PAGE Halloway, G. W., limestone on prop- erty of ............... 1\H-199 Hamilton place, limestone deposit on 113-114 Hanc-ock Landing. analyses of lime- stone from .............. 53-54 Section near . . . . . . . . . . . . . . . . . 53 Hardin, J. B., limestone deposit's on pro.perty of ............ 107-109 Harris, C. S., limestone deposit on property of ............ 127-128 John, analysis of limestone from property of . . . . . . . . . . 129 Limestone deposits on prop- erty of ........... 129-130 Hatcher Station, limestone deposits south of . . . . . . . . . . . . . . . . . 129 Hauling limestone .............. 249-252 Hawkinsville, lime>Stone deposit at 110-111 Limestone near ............ 105-111 Haygood, V. M., limestone exposure on property of. ......... 168-169 Section on property of ....... 168-169 Hayslett property, limestone depos- its on ................ 138-139 Helical conveyor . . . . . . . . . . . . . . . . . 278 High calcium limestone. . . . . . . . . . . . 43 Physical properties of ...... 224-225 High magnesian limes, physical prop- erties of .............. 224-225 Hog Crawl Creek, limestone d:epo>sits on .................... 112-113 Homerville, partial analysis of soil from .............. ~ ..... 218 "Hot" limes . . . . . . . . . . . . . . . . . . . . . 224 Hough, A. H., analysis of limestone from property of. . . . . . . . . . 196 Limestone deposits on property of .................... 196-1.97 Houston lount:v. average analyse's of limestone from southern part of . . . . . . . . . . . . . . . . . . . . . . 98 Fossils from .... , . . . . . . . . . . . . 23 Qeneralized section of ........ 84-85 Jackson exposed in ........... 22-23 Limestone deposits in ........ 81-104 Section in .................. 22-23 Hugunen Ferry, limestone deposits near ..................... 155 Huntington Mill, the. . . . . . . . . . . . . . 274 Hydrated lime ......... : . .. 225, 261-262 Manufacture of ............ 261-262 Use of with Portland cement. . . 226 Hydraulic cements ............. 226-232 Hydraulic lime ................ 227-229 Chemical composition of. . . . . . . 227 Hydraulic lime rock, analyses of. ... 228 Hydraulic limestone, analyses of. . . . 228 Ichawaynochaway Creek, limestone deposits on . . . . . . . . . . . . . . 170 Illuminating gas. use of lime in manufacture of ............... 237 Indian Cave, analysis of limestone from .................... 104 Limestone deposits at. . . . . . . . . . 104 Indian Den. lime,stone deposits at .149-150 Ind"ian Spring, limestone deposit at 149-150 Industrial chemistry, use of limestone in .................... 235-241 Ingersol-Rand .Tack]:lammer drill. de- scription of . . . . . . . . . . . . . . 248 296 INDEX PAGE PAGlll Piston drill, description of .. 246-248 Section at .................... 186 Insectic'ides and fungicides .... , . 222-223 Limesink region . . . . . . . . . . . . . . . . . . 3 Limestone, agricultural uses of ... 211-223 J Analyses of for solubility, ete.. . 216 .Jackhammer drill, description of. . . . 248 .Jacksonboro, limestone deposit near. 55-56 .Jack.son group ......... , ......... 9-23 Detailed .description of........ 14-23 .Jacksonville formation . . . . . . . . . . . . 34 ".Jacob's Well," limestone deposits at 156 .Jaw crushers, description of. .... 263-266 .Jefferson County, Jackso.n exposed in 16 Tests on soils from. . . . . . . . . . . 219 .Jeffrey swing-hammer pulverizer .. 271-274 J'ohruson County, description of depos- its in . . . . . . . . . . . . . . . . . . . 63 J'ones Landing, section at ........... 169 As soil corrective ........... 211-222 Burning of ................ 257-258 Chemical action of... , ....... 212-214 Composition of . . . . . . . . . . . . . . . 43 Crops benefited by use of. . . . . . 217 Crushed .................. 223-224 Drilling and blasting of ..... 246-249 General discussion of .... , .... 38-43 Machines for preparation of.. 262-279 Methods of applying to soil. :221-222 Origin of .................... 38-40 Physical properties of. . . . . . . . . 214 Plants for crushing and grinding . of .................... 279-286 Properties of .............. 211-213 K Quantity of to apply to soils. . . . 220 Kaolin Spring, exposure of fullers earth at ... , ........... . 21 Kathleen, fossils from near. . . . . . . . . 23" Limestone deposits east of ..... 85-91 Section near ................. 22-23 Keys Mill, oyster shells near. . . . . . . 15 Section at . . . . . . . . . . . . . . . . . . . 15 Kilns ............................ 279 Vertical 1shaft. description of. 253-257 Kinchafoonee Creek, limestone deposits along .......... 124, 142-148 King plantation, fossiliferous marl on 33-34 Limestone exposed .on. . . . . . . . . . 208 Kittrell, description of exposures near 63 Stripping of quarries for ..... 245-246 Uses and preparation of ..... 211-291 Varieties of ................ .40-43 Limestone and lime, value of for ag- ricultural purposes ..... 216-220 Limestone anef marl .............. 44-209 Limestone Bluff, analysis of lime- stone from ............... 142 Limestone exposed at ....... ,142-143 Limestone crushers, double roll ... 270-271 Single roll ................ 269-270 Limestone spring, limestone exposed at ....................... 114 Limestone quarries of North Geor- gia ................... 286-291 Limestone quarries, stripping of .. 245-246 L Limestone quarrying ........... 243-252 Lining of Basic open hearth furnaces, Ladd Lime & Stone Company, analyses of limestone from quarry of . . . . . . . . . . . . . . . . 290 Location of quarry and plant of 289-290 "Lafarge" . . . . . . . . . . . . . . . . . . . . . . . . 229 Langdon, D. W., cited ... 7, 11, 12, 25, 132 Lanier, E. C., analysis of limestone from property of. . . . . . . . . 45 Limestone exposed on property of 45-46 LeBlanc process of soda manufacture 236 Lee County, lime kiln in ........... 253 Limestone deposits in . ...... 137-152 Leesburg, limestone deposits near .144-145 Section near . . . . . . . . . . . . . . . . . 145 Leesburg-Newton road, limestone ex- posure near .............. 151 Lilly, limestone deposits .southeast of 114 Lilly-Vienna road, limestone exposure near .................... 114 Lime .......................... 213-216 Chemical and physical action of 214-216 Classification of properties of. 258-260 Hydrated, manufacture of. .. 261-262 Kilns for manufacture of .... 253-257 Literature on agricultural uses of ....................... 222 Manufacture of ............ 252-262 Lime kilns, de1scription of ....... 253-257 Lime manufacture, cost of ....... 260-261 limestone used for. . . . . . . . 242 Literature on agricultural uses of lime ..................... 222 Little Limesink, analysis of limestone from .................... 189 Desc'ription of strata at ..... 187-190 Loading limestone ............. 249-252 Location of quarries ............ 243-245 Loughridge, H. H., cited........... 132 Loutsville, Jackson exposed near. . . . 16 Lowndes County, limestone deposits iii 201-203 Partial analyses of soil from. . . 218 Lot 66, 11th dist., Houston County, analysis of limestone from. 89 Description of limestone exposure . on ...................... 88-89 Section on . . . . . . . . . . . . . . . . . . . 89 Lot 77, 15th dist., ThomUJs County, limestone denosit on. . . . . . . 201 Lot 263, 21st dist.. Decatur Co.unty, analysis of limestone from. . 178 Lot 265, 21st dist., Decatur County, analysis of limestone from. 176 Lot 286, 21st dist.. Decatur County, analysi1s of limPstone from. 175 Lot 304, 20th dist., Decatur Co.unty, analysis of limestone frcim. 178 Lot 447, 13th d'ist., Brooks Countv 197-199 Lubricants. lime used in manufacture of , ...................... 241 Lime Spring, limestone deposit at 124, 152-153 Me Limelight, use of limestone for. . . . . . 238 McBean Creek, exposure of marl on. 44 Limesink, analysis of limestone from 187 Elxposures of limestone on "' Limestone deposits at ....... 186-187 45, 46-47, 48-50 INDEX 297 PAGE McBean formation . . . . . . . . . . . . . . . . . 8 McBean Station, limestone exposed near .................... 49-50 McCallie, S. W., cited ... 27, 63, 156, 170, 197,199,200,208 McCully gyratory breaker. . . . . . . . . . 266 McGee, W .J, reference to . . . . . . . . . . 33, 35 Mcintosh County, analysis .of oyster shells from . . . . . . . . . . . . . . 210 McKenzie. W. L.. analysis of lime- stone from property of ..... 117 Limestone deposits on property of 117-118 McKinnon, M. D., analysis of lime- stone from property of. . . . . 191 Limestone deposits on property of 191-192 McLanahan-Stene single roll crusher 269-270 McRae place, limestone deposits on. . 79 M Machines for preparing limestone. 262-279 Machine for spreading limestone .. 221-222 MaC'on County, limestone exposed in 115-118 Madrea, W. T .. limestone deposits on property of .............. 195 Magnesian limestone . . . . . . . . . . . . . . 43 Malain, France, analysis of lime rock from . . . . . . . . . . . . . . . 228 Maloy, I. E., limestone deposit on property of ........... 182-185 Manufacture of lime ............ 252-262 Cost of ................... 260-261 Primitive methods of ........ 252-253 -Manufacture of ,sand-lime brick .. 234-235 Marine terrace deposits. . . . . . . . . . . . 35 Marks Head marl. . . . . . . . . . . . . . . . . 31 Marl ............................ 42-43 Matson and Clapp, cited........... 34 Maynard, T. Poole, cited'.230, 287, 288, 291 Information supplied by. . . . . . . . 133 Reference to work of. . . . . . . . . . . 1 Metallurgy, limestone used in .... 241-243 Methods of applying limestone to soils .................. 221-222 Middleton, Jefferson, cited......... 233 Midway formation . . . . . . . . . . . . . . . . 5-6 Miller place, analysis o.f limestone from .................. 151-152 Limestone deposits on property of .................... 151-152 }lfineral Spring Branch, limestone ex- posed along ............. 50-51 Miocene series ................... 31-32 Mitchell County, limestone exposed in 165-169 Mitchell-Decatur county line, analysis of limestone from near. . . . . 168 Limestone exposed near ...... 167-168 Mitchell-Dougherty county line, de- scription of strata near. . . . 166 Mitchell property, analy,sis of lime- stone 'from ............ 192-193 Limestone deposits on ....... 192-193 Mitchell, R. G., analysis of limestone from property of. . . . . . . . . . 194 Limestone deposits on property of ....................... 194 Mobley, .James, analysis of limestone from property of. . . . . . . . . . 50 Limestone deposits on property of ...................... fi0-51 Montezuma, limestone deposits north- east of ............... 113-114 PAGEl Morris, W. L.. analysis of marl from property of .............. 44-45 Exposure of marl on property o.f 44-45 "Mortar" brick, evolution of. . . . . . . . 232 Mortar, lime used' for ........ , .. 224-225 Mossy Ridge, limestone deposits near 103-104 Moyer, J., and Dumesun, P., cited .. 240 Muckafoonee Creek, analyses of lime- stone from mouth of....... 136 Limestone deposits on ....... 135-136 Section on . . . . . . . . . . . . . . . . . . . 135 MerC'ury, recovery of with lime. . . . . 238 N National Highway, limestone deposits near .............. 103-104 Natural cement, early use of........ 229 Manufacture of . . . . . . . . . . . . . . 229 Natural cement rocks, analyses of ... 230 Nettles Landing, limestone deposits at ....................... 207 Newton, sections near .... : ........ 167 Nigger Den, section at ............ 153 Norman Ferry, limestone exposure near .................... 167 North Georgia, limestone quarries of 286-291 Northington place, limestone expos- ure on . . . . . . . . . . . . . . . . . . 63 0 Oak Ridge, limestone exposure on ... 74-75 Ochlockonee IUver, limestone depos~ its on ................... 190 Ocilla Southern Railroad, limestone deposits on . . . . . . . . . . . . . . 100 Ocmulgee River, analysis of lime- stone from . . . . . . . . . . . . . . 228 Limestone deposits on ...... 105-111 Oconee, limestone exposure near. . . . 63 Okefenokee formation ............ 35-36 Okefenokee plain . . . . . . . . . . . . . . . . . 3 Okefenoke~ Sw~mp, peaty ac'cumula- twns m . . . . . . . . . . . . . . . . . 37 Old Bond oost office, Jackson exposed near . . . . . . . . . . . . . . . . . . . . . 21 Oligocene, undifferentiated ........ 24-30 Oolitic limestone . . . . . . . . . . . . . . . . . 42 Original Pond, analysis of limestone from .................... 195 Limestone deposits at ....... 195-196 . Section at ................... 195 Oyster shells ......... : . ....... 209210 Dead ........................ 209 Green, analysis of ............. 210 p Palmer, Newton. analyses of limestone from property of'. . . . 47 Description of lime.stone exposures on property of ....... 46-48 Section on property of. . . . . . . . . 46 Palmyra, limestone deposits near .146-147 Section near ................. 146 Paper manufacture, lime used in. . . . 240 Parsons Branch, analysis of lime- stone from mouth of ...... 140 Limestone deposits on ...... 140-141 Pennehatchie Creek Swamp, lime- stone exposures along. . . . . . 114 298 INDEX PAGE Peppel, S. V., cited ..... 233, 234, 235, 258 Perry-Elko road, lime.stone deposits along ................. 100-102 Perry, limestone exposed south of. 97-104 Peterson, J. I., analysis of limestone from property of. . . . . . . . . . 205 Limestone deposits on property of 205-206 Phosphoric acid, solubility of in lime- 'stone, test for. . . . . . . . . . . . 216 Physiogranhic divisions of Georgia. . 1 Physiography of Georgia. . . . . . . . . . . 1-3 Pickens County, analysis of limestone from .................... 289 Plant for preparation o.f lime- stone in .............. 288-289 Piedmont Portland Cement Company, limestone plant of. ..... 290-291 Pikes Peak Station, limestone exposed near .................... 71-72 Pisolitic limestone . . . . . . . . . . . . . . . . 42 Piston drill, description of ....... 246-248 Pitman and Wall properties, lime- stone exposed on .......... 61 Plants for crushing and grinding limestone ............. 279-286 Plant for preparing crushed stone, 50 tons per hour .......... 285-286 Flow sheet of. . . . . . . . . . . . . . . . 285 Plant of 1% to 4 tons per hour ca- pacity, details of. . . . . . . . . 280 Plant of 3 to 4 tons per hour capac- ity, details of .......... 281-282 Flow sheet of. . .. .. . . .. .. .. .. . 281 Plant of 15 tons per hour capacity, detai1s of ............. 2:::13-28!) Flow sheet of ................. 283 Plast&r ........................ 225-226 Pleistocene series ................ 34-36 Undifl'erentiated ......... : . . . . 30 Plioc'ene series .................. 33-34 Polk County, analysis of limestone from .................... 291 Plant for preparation of lime- stone in ....... J 290-291 Portland cement ......... ~ ..... 230-232 Analyses of . . . . . . . . . . . . . . . . . . 2RO Use of hydrated lime with ..... 226 Portland, analysis of lime,stone from. 291 Limestone plant at ......... 290-291 Potash, solubility of in limestones, tests for . . . . . . . . . . . . . . . . 216 Power plant near Albany, limestone exposed at ............ 135-136 Preparation of limestone, machines for ................... 262-279 Preparation of soil for application of limestone ........... 220-221 Preston, limestone deposit south of. . 124 Partial analysis of soil from. . . 2l8 Properties of limes, classification o:E 258-260 Properties of limestone .......... 211-213 Pulsating screens . . . . . . . . . . . . . . . . . 277 Pulverizers .................... 271-274 Pumpelly, H., cited................ 26 Pumpkin Creek, limestone deposit on J 27-12R Puzzolan cement . . . . . . . . . . . . . . . . . . 227 Q Quantity of Jime.stone to apply to soils . . . . . . . . . . . . . . . . . . . . . 220 Quarrying limestone ............ 243-252 Quaternary system ............... 34-38 PAGEt Quitman, partial analysis of soil from 218 R Rags used in paper manufacture .... 240 Hand Landing, limestone exposed at. 207 Handolph County, description of strata in .............. 1.25-128. Hawlings, B. T., analysts of limestone from property of.... . . . . . . 58 Limestone exposed on property of ...................... 57-6(} Rawson property, limestone deposits on .................... 146-147 Recent series .................... 36-37 Recovery, analysis of limestone from near ....... : . ......... 180-181 Limestone deposits near ..... 180-1.81 Reeovery of mercury, lllSe of lime in. 238. Hedding gin, limestone deposits near 129 Reddick, Jno., analysis of limestone from property of. . . . . . . . . . 56 Description of strata on prop- erty of ................. 55-57 Section of quarry on property of t>D Hevolving kilns . . . . . . . . . . . . . . . . . . 279> Revolving screens .............. 276-277 Richards, R. H., cited .......... 265, 268 Rich Hill, description of exposures at 17 List of fo,ssils from. . . . . . . . . . . . 18. Section at ................... 17-18 Ries, H., cited . . . . . . . . . . . . . . . . . 227, 235. Road metal, limestone used as. . . . . 223 Plant for preparation of lime- stone for ............. 285-286: Hock breakers, description of ..... 262-279 Roc'k Cave, limestone exposed at. ... 184 Rockmart, limestone plant near .. 290-291 Rocky Comfort Creek, fullers earth on 16. Holls for preparation of limestone. . 275 Roll crushers .................. 269-271 Roller n1il1s . . . . . . . . . . . . . . . . . . . . . . 278: Hoss Hill, analysis of limestone from 102 Limestone deposits on ....... 101-102' Section on . . . . . . . . . . . . . . . . . . . 101 Rossville, analyses of natural cement rock from . . . . . . . . . . . . . . . . 230, notary dryer .................. 278-279 "Rotten" limestone . . . . . . . . . . . . . . . 41 Roughton place, analysis of limestone from . . . . . . . . . . . . . . . . . . . . 90 Limestone expo,sed on .. , ...... 90-91 Section on . . . . . . . . . . . . . . . . . . . 90 "Rust" prev~nted by use of lime. . . . 217 s St. Catherine Island, oyster cannery on ....................... 209 St. Clair, section near. . . . . . . . . . . . . 15. St. Marys IUver, section on ........ 207 St. Simons Island, analysis of mud from . . . . . . . . . . . . . . . . . . . . 37 Sale City, limestone exposed north- west of ............... 168-169> Sanborn Mill Creek, analyses of lime- 'stone from ... 175, 176, 177, 178 Limestone deposits on ....... 173-182' Sections on ........... 173-174, 177 Sandersville, limestone deposits near fl7-61 Sand-lime llric'k ................ 232-235 Cost of manufacture of, . . . . . . . 235 Materials fnr manufacture of. . 2::lR Production of . . . . . . . . . . . . . . . . 233: Tests on . . . . . . . . . . . . . . . . . . . . 235. INDEX 299 PAGE Sand'y limestone . . . . . . . . . . . . . . . . . . 42 Sasser place, limestone dep01sits on.. 84 Satilla formation . . . . . . . . . . . . . . . . . 35 Savage Creek, limestone exposed on. 75-76 Savannah, oyster canneries near. . . . 20\:J Savannah !Uver, limestone exposed on ...................... 51-55 Schley County, limestone deposits in 122-123 Schoolhouse Bluff, limestone deposits at ...................... 207 Section at . . . . . . . . . . . . . . . . . . . 207 Screens ....................... 275-277 Screven County. description of lime- stone deposits in ......... 55-57 Screw conveyor .................. 278 Seidel. Atherton, cited............. 38 Senonches. France, analysis of lime rock from . . . . . . . . . . . . . . . 228 Shaking screens . . . . . . . . . . . . . . . . . 277 Shearer. H. K .. data furnished by. . . 64 Reference to work of . . . . . . . . . . 8, 12 Section furnished by .......... 16-17 Shell Bluff, analyses of limestone from . . . . . . . . . . . . . . . . . . . . 52 Description of strata at. ...... 51-53 Jac~son exposed at . . . . . . . . . . . . 15 Section of ................... 51 Shell Bluff post office, limestone ex- posed near .............. 50-51 Shellstone Creek, f.ossils from...... 22 Limestone exposed on .... 65-66, 67-69 Section on ............... 21-22, 65 Siliceous limestone . . . . . . . . . . . . . . . 43 Single roll crusher, description of. . . 270 Table of data concerning. . . . . . 270 Sloan, Earle, cited'. . . . . . . . . . . . . . . . . 10 Small, Geo. L., analyses of limestone from property of. . . . . . . . . . 87 Limestone exposed on property of ....................... 86-88 Section on ................... 86-87 Small place, fossils from. . . . . . . . . . . 23 Section on .................. 22-23 Smith, .J. R., analysis of limestone from property of. . . . . . . . . . 144 Limestone deposits on property of .................... 143-144 "Smut" prevented by use of lime. . . 217 Soap, use of lime in manufacture of 241 Soda. use of lime in manufacture of ' 236-237 Soil corrective, limestone used for. 211-222 Soils, methods of determining acid- ity of ................. 219-220 Partial analy,ses of. . . . . . . . . . . . 218 Prepnration of for application of limestone .............. 220-221 Solvay process of soda manufacture. 236 "Sour" soils .................. 211, 212 Southern States Marble Company, limestone plant of. . . . . . . . . 28R Spencer, J. W .. cited .............. 132 Spindle or gyratory breakers ..... 266-269 Spring Creek, analysis of limestone from mouth of ............ 120 Limestone exposed on ....... 132-133 Stackhouse Land Comp.any, analyses of limestone from property of ............... 119, 120, 121 Limestone deposits on property of .................... 118-122 Steam shovel for excavating lime- stone ........... , . . . . . . . . 252 Stephenson, L. W., and Veatch, Otto, abstracts from reports by. 5-7, 30 PAGE Stevens Pottery, Jackson exposed at. 16 Stewart County, description of strata in ....................... 125 Stony Creek Church, analysis of limestone from mouth of... 73 Fossils c'ollected near. . . . . . . . . . 20 Limestone deposits south of ....... 72-73 Section near .................... 20, 72 Stripping fo.r limestone quarries .. 245-246 Strouther, W. A., limestone deposits on property o.f .......... 101-102 Structure of Georgia. . . . . . . . . . . . . . 1, 3 Sugar manufacture, limestone used in 239 Sumter County, limestone deposits in 118-122 Sunhill. analysis of limesto.ne from .. 61-62 Primitive lime kiln near. . . . . . . 253 Section at . . . . . . . . . . . . . . . . . . . 61 Superficial gray sands of the upland. 37-38 "Sweet" soils ................. 211, 212 Swift Creek Station, limestone near. 80-81 Swing hammer pulverizer ........ 271-274 Tabula ted data concerning. . . . . 273 Tests on hard limestone with. . . 273 Sylvania, limestone deposit northeasi;_ __ of ...................... oo-o6 T Tanning, lime used in. . . . . . . . . . . . . . 241 Taylors Bluff, analyses of limestone from .................... 108 Limestone deposits at ....... 107-109 Section o.f . . . . . . . . . . . . . . . . . . . 107 Te'nnille, limestone deposits near .... 57-61 Partial analysis of soil from near 218 Tertiary system .................. 5-34 Thoma;s County, limestone deposits in 191-197 Partial analysis of soil from ... 218 Thomasville, partial analysis of soU from near . . . . . . . . . . . . . . . 218 Thomasville-Springhill road, lime- stone depo.sit near ......... 194 Thompsons Mill, limestone d'eposit so.uth of. . . . . . . . . . . . . . . . . . 85 Thigpin, C. D., analysi.s of limestone . from property of ......... 61-62 Description of limestone deposits on pro.perty of........... 61-63 Section on property of. . . . . . . . . 61 Thorne, C. E., quoted ........... 221-222 Thrift, W. M., marls on prooerty of. 33 Tiel, France, analysis of lime rock from .................... 228 Tivola, analyses of limestone from near . . . . . . . . . . . . . . . . . . . . 93 Limestone deposits south of ... 91-97 Sections near ............ 92-93, 97 ToQmsbo.ro, desC'ription of exposures near . . . . . . . . . . . . . . . . . . . . . 64 Sections near ............. 16-17, 64 Toy pho.sphate pits, partial analysis of soil from near. . . . . . . . . 218 Tram cars for hauling limestone. 250, 252 Trees which grow best on limestone soils . . . . . . . . . . . . . . . . . . . . 217 Trommels ..................... 276-277 Tube mills . . . . . . . . . . . . . . . . . . . 274-275 Twelve Months Landin;<, ,section at .. 169 Twiggs County, generalized section of 84-85 Jackson expo.sed in . . . . . . . . . . . J 8-21 Limestone exposed in ......... 6!1-79 Section in .................. 1819 Tests of soil from. . . . . . . . . . . . . 219 300 INDEX u PAGE PAGE Primitive lime kiln in. . . . . . . . . 253 Water Falls, analyses of limestone Undifferentiated Eocene and Oligocene . 24-29 Undifferentiated Oligocene to Pleis- ;frOI;Il ... , , . , ............. 184 Description of strata in ...... 182-185 Section at ................. .. 183 tocene, inclusive . . . . . . . . . 30 Water softening by use of lime. . . . . 238 Upper River road, limestone deposits Watsons Spring, limestone exposed in 173 on .................... 109-110 Weatherbee, Roe, limestone exposed Uses and preparation of limestone on property of. . . . . . . . . . . . 170 and lime .............. 211-291 -Weatherly place, analysis of lime- Uses of hyd'rated lime with Portland stone from .............. 65-66 cement .................. 226 Description of exposures on .... 65-67 Uses of limestone in industrial c'hem- Fossils collected from ........ -. 22 istry ................. 235-241 Section on . . . . . . . . . . . . . . . . . 21-22 Usher, M. H., limestone deposits on Webster County, limestone deposits in property of .............. 49-50 123-124 Utley Point Bluff, analysis of lime- Partial analysis of soil from. . . 218 stone from .............. 53-54 West Lake, limestone exposed north- Description of 1strata at ....... 53-54 east of .................. 76-79 Section at . . . . . . . . . . . . . . . . . . 53 Wheelbarrows for hauling limestone. 249 v Whigham, limestone deposits near 182-185, 187-190 Valdosta, partial analyses of soil from Partial analysis of soil from near 218 near ..................... 218 White Oak Creek, limestone exposures Valona, oyster cannery at .......... 210 along .................... 208 Value of limestone and lime for ag- Whitestone Marble Company, analyses ricultural purposes ..... 216-220 of limestone from. . . . . . . . . 289 Varieties of limestone ............. 40-43 Plant for preparation of lime- Vaughan, T. Wayland, cited . . . . . . . . 15, 26 JStone at .............. 288-289 Fossils identified by .......... 18, 19 Wilcox County, partial analysis of Heference to ............. 10, 51, 56 soil from . . . . . . . . . . . . . . . . 218 'Quoted . . . . . . . . . . . . . . . . . . . . . . 39 . Wilcox formation .. . . . . . . . . . . . . . . . 6-7 Veatch, Otto, and Stephenson, L. W., Wilkinson C_oun~y, description of de- abstracts from reports by posits 1n . . . . . . . . . . . . . . . . . 64 4-5, 17-18, 25-29, 33-38 .Jackson exposed in. . . . . . . . . . . . 16 Cited .8, 11, 12, 15, 18, 24, 25,55,132 Williams, I., analyses of limestone Veatch, Otto, quoted ........... 132, 134 from property of ........... 162 Vertical shaft kilns, description of. 253-257 Limestone exposed on property of w 161-163 Section of bluff on property of. . 161 Wade, J. W., limestone deposits on Wimberly, Minter, analysios of lime- property of ............ 126-127 Wade property, limestone deposits on 194 stone from property of. . . . 74 Limestone exposed on property of Walker County, analysis of natural 74-76 cement rock from. . . . . . . . . 230 Wall and Pitman propertLes, lime- stone deposits on.... . . . . . . 61 Wall, Lowe, analy,sis of limestone from property of. . . . . . . . . . 71 Fossils collected on property of.19-20 Limestone exposed on property of Withlacoochee anticline . . . . . . . . . . . 3 Withlacoochee River, analysis of lime- stone from . . . . . . . . . . . . . . . 203 Limestone deposits along .... 201, 202 Section on . . . . . . . . . . . . . . . . . . . 202 Wood alcohol, lime used in manufac- ture of ........ , ......... 240 71-72 Jackson exposed on property of.19-20 Wood, lime used in distillation of ... 240 Wood pulp for paper manufacture. . . 240 Walls Crossing, limestone deposits Workings, limestone, types of ..... 242-245 near .............. , ..... 123 Worth County, limestone exposed in Section near . . . . . . . . . . . . . . . . . 123 163-165 Washington County, description of Wring Jaw Landing, description of limestone deposit in ....... 57-63 strata at . . . . . . . . . . . . . . . . 63 Partial analysis of soil from. . . 218 Section at . . . . . . . . . . . . . . . . . . . 63