B A UXJ'l'E A.-D FU LLER S E :IH'l'H Oli' 'l'HE GOASTrLL PLAIN Oli' GEORGIA Ji'RO N'l'JS PUJOE-PL!l'l'E 1 FULLERS EAHTH MINE OF 'THE GENERAL HEDUCTION COMPANY. PIKES PEAK, TWIGGS COUNTY. Plloto by S. I.V. JllcCalb'e GEOLOGICAL SURVEY OF GEORGIA S. W. McCALLIE, State Geologist BULLETIN NO. 31 A REPORT ON THE BAUXITE AND FULLERS EARTH OF THE COASTAL PLAIN OF GEORGIA BY H. K. ~HEARER, Assistant State Geologist Atlanta, Ga. THE INDEX PRINTING COMPANY State Printers ' 1917 THE ADVISORY BOARD OF THE Geological Survey of Georgia IN THE YEAR 1917 (Ex-Officio) His ExcELLENCY, NAT. E. HARRIS .......... Governor of Georgia PRESIDENT OF THE BOARD HoN. PHILIP COOK .......................... Secretary of State HoN. W. J. SPEER .............................. State Treasurer HoN. W. A. WRIGHT ........................ Comptroller-General HoN. CLIFFORD WALKER .......~............. Attorney-General HoN. J. J. BROWN . . . . . . . . . . . . . . . . . . Commissioner of Agriculture HoN. M. L. BRITTAIN ............ Commissioner of Public Schools LETTER OF TRANSMITTAL GEOLOGICAL SuRVEY OF GEORGIA, ATI,ANTA, JUNE 14, 1917. To His Excellency, NAT. E. HARRIS, Governor and President of the Advisory Board of the Geological Survey of Georgia. Sm: I have the honor to transmit herewith the report of Mr. H. K. Shearer, Assistant State Geologist, on the Bauxite and Fullers Earth of the Coastal Plain of Georgia, to be published as Bulletin No. 31, of this Survey. Very respectfully, S. W. McCALLIE, State Geologist. PREFACE AND ACKNOWLEDGEMENTS The accompanying report on the Bauxite and Fullers Earth Deposits of the Coastal Plain of Georgia is the result of field work during the summers of 1914, 1915 and 1916, and includes such tests of fullers earth as could be made with the laboratory facilities available. The tests were made by the writer in the laboratory of the Geological Survey, following methods commercially employed in testing fullers earth. While there is a large field for research work on the properties of fullers earth, it was found to be impracticable to do much along that line with the time and materials available. The writer wishes to express his thanks to Mr. K. R. Slocum of the General Reduction Company, Mr. W. L. MacGowan of the Floridin Company, Mr. J. T. Mitchell of the Lester Clay Company, and Mr. Thos. C. Law and Mr. Wm. Kelley of the Picard-Law Laboratories, for advice and assistance in the work on the fullers earth; also to the managers and superintendents of all the bauxite mines visited for their courtesies and interest in the work. All of the analyses, unless otherwise stated, were made by Dr. Edgar Everhart, Chemist for the Geological Survey of Georgia. Mr. J. P. D. Hull, Assistant State Geologist of Georgia, has rendered assistance in making tests of fullers earth and in preparation of illustrations. HAROLD K. SHEARER. June, 1917. TABLE OF CONTENTS ADvisoRY BoARD ... . .. . . . . . . . . . . . . . . . . . . LETTER OF TRANSMITTAL ........... .......................... PREFACE AND ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . TABLE OF CoNTENTS .............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LJST OF ILLUSTRATIONS PAGE ii iii iv v-xri xiii-xv INTRODUCTION TOPOGRAPHIC AND GEOLOGIC FEATURES OF THE COASTAL PLAIN ......... Physiography ................................................... . Topography .................................................. . Drainage ..................................................... . Elevations .................................................... . Structure ....................................................... . Geology ........................................................ . Pre-Cambrian rocks ............................................ Lower Cretaceous ............................................. . Upper Cretaceous ....................................... , ..... . Eutaw formation ........................................... . Ripley formation ........................................... . Midway formation ............................................ . Wilcox formation ............................................ . Claiborne age ................................................ McBean formation .......................................... . Undifferentiated Claiborne ................................... . Jackson age ................................................. . Ocala limestone ............................................ . Twiggs clay member ........................................ . Barnwell formation ......................................... . Vicksburg formation .......................................... . Apalachicola group ........................................... . Chattahoochee formation .................................... . Alum Bluff formation ....................................... . Miocene series ................................................ . Pliocene series ............................................... . Pleistocene and recent series 1-18 1-6 1-2 2-3 3-6 6-7 7-8 8-9 9 9-11 9-10 10-11 11 11-1:? 12-14 13 13-14 14-16 14-1fi 15 15-16 16-17 17 17 17 18 18 18 PART I BAUXITE DEPOSITS 19-140 Definition ...................................................... . 19 Occurrence and distribution ...................................... . 19-25 General distribution .......................................... . 19-20 T PAGE Foreign localities ............................................. . 20-22" France ..................................................... . 20 Germany ................................................... . 21 Austria ............. ." ...................................... . 21 Hungary ................................................... . 21 Ireland ...................................................... 21 India ...................................................... . Jl2 Italy ....................................................... . 22 Guiana ..................................................... . 22 American localities ........................................... . 22-25 North Georgia-Alabama-Tennessee ............................ . 22-24 Arkansas .................................................. . 24-25 New Mexico ............................................... . 25 Bauxite deposits of the Coastal Plain of Georgia ................... . 25-91 History ............ . . 25-26 Lower Cretaceous bauxite deposits .............................. . 26-60 Geology of the Lower Cretaceous ............................ . 26-32 Conditions of deposition in eastern United States .......... . 26-28 Areal distribution in Georgia .............................. . 28 Stratigraphie position ..................................... . 28-29 Lithologie characters ...................................... . 29-30 Strike, dip and thickness .................................. . 30-31 Physiographic expression .................................. . 31-33 Paleontologic characters .................................. . 32 Location of bauxite deposits ............................... . 32 Description of individual deposits ........................... . 32-60 Wilkinson County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ." .. . 32-5!! Parker-Honeycutt-Daniel group of properties (Mcintyre mine) 32-39 General Bauxite Corporation property ..................... . 39-45 Canon property ........................................ . 45-46 Cason property ......................................... . 47-48 Holleman property ...................................... . 48 J. U. Parker property ................................... . 48-49 Underwood property .................................... . 49-51 Fountain property ............................. : . ....... . 51-52 Dupree property ........................................ . 52-54 Jones property ......................................... . 55 MeNeal property ....................................... . 55-56 Butler property ......................................... . 56 Sheppard property ..................................... . 56-57 Columbia Kaolin and Aluminum Company ................. . 57-59 R. L. Stubbs property ................................... . 59 Baldwin County ......................................... . 59~60 Ethridge property ...................................... . 59-60 Twiggs County ........................................... 60 Washington County ....................................... . 60 vi .. PAGE :Midway bauxite deposits ................................... 61-91 Geology of the Midway and Wilcox formations ................. 61-66 Areal distribution ........................................ . 61 Stratigraphic relations .................................... . 61-62 Lithologic characters .................................... 62-63 Thickness .... : . .......................................... . 63-64 Physiographic expression .................................. . 64 Paleontologic characters ................................... 64 Location and age of the bauxite deposits .................... . 64-66 Descriptions of individual deposits ........................... 66-91 Sumter County ........................................... . 66-78 Sweetwater mine ................................... 66-73 Thigpen lot .......................................... 73-74 Easterlin mine ...................................... 74-78 Hodges property ................................. 78 Macon County .......................................... 79-89 Kalbfleisch Corporation property ......................... 79-80 English property ................................... 81 Kleckley property ........................ : . ......... . 81-85 Robinson property ...................................... . 85-86 Park property ........................................ 86-88 Morton property ................................... 88 Ideal localities . ........................................ , 88-89 Schley County ............................................ . 89-91 Stewart property ....................................... 89-90 Holloway property ....................................... 90-91 Stewart County ......................................... 91 Physical and chemical characteristics ............................ . 91-110 Physical characteristics ...................................... 91-94 Classification . . . . . . . . . . . . . . . . ...................... 91-93 Pebble ore .......................................... 91-92 Pisolitic and oolitic ore ................................ 92-93 Vesicular ore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Amorphous ore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Hardness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93-94 Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 :Microscopic structure ......................................... 94-103 Chemical and mineralogical composition . . . . . . . . . . . . . . . . . . . . . . . . . 103-110 Genesis of deposits ......................................... 111-132 Origin of kaolin .......................................111-113 Relation of bauxite to kaolin ................................ 113-123 "Middle Mine, " Edgar Brothers Clay Company............... 113-117 Claymont mine .................................. 117-119 Dupree property ..................................120-121 Adkins property .......................................121-123 vH PAGE Origin of bauxite ........................................... 123-132 Conditions to be explained .................................... 123-125 Source of solutions ......................................... 125-126 Chemical reactions and mode of deposition ................. 126-128 Minor reactions and forms of deposits ....................... 128-131 Solubility of kaolin in dilute sulphuric acid ................. 131-132 Methods ....................................................... 132-135 Mining ...................................................... 132-1:!3 Preparation ........................... , ...................... 133-134 Transportation ......... ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Exploration .................................................. 134-135 Uses .......................................................... 135-139 Production of bauxite and aluminum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139-140 PART II J<'ULLERS EARTH DEPOSITS ................... , 141-318 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Historical ....................................................... 141-144 Occurrence and distribution ....................................... 144-150 Foreign localities ........................................... 144-145 England .................................................... 144-145 American localities outside Georgia .................... , ...... 145-150 Arkansas .............. .................................... 145-147 California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 Florida ................................................... 147-148 Massachusetts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Mississippi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 New York ................................................. 148-149 South Carolina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 South Dakota .............................................. 149-150 Texas . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Virginia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 ' Tests for fullers earth ........................................ 150-158 Preparation of samples ..................................... 150-151 Bleach ..................................................... 151-155 The Lovibond color scale ............................... 153-154 After-bleach ........................................... 154-155 Absorption of oil ........................................... 155-156 Specific volume ........................................ 156-157 Apparent acidity ......................................... 157-158 Fullers earth deposits of Georgia ................................. 158-318 Fullers earth of Jackson age ................................. 158-259 Geology of the Twiggs clay member . . . . . . . . . . . . . . . . . . . . . . . . . . . 158-163 Areal distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 Stratigraphic relations .................................... 158-159 viii .. PAGE Lithologic characters ....................................... 159-161 Strike, dip and thickness ................................... 161-162 Physiographic expression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 l:'aleontological characters .................................. 162-163 Description of individual deposits .............................. 163-259 Twiggs County .......................................... , .163-217 Pikes Peak localities ..................................... 165-183 General Reduction Company property .................... 165-183 Localities north of Pikes Peak ............................ 183-193 Atlanta Mining and Clay Company ...................... 183-184 American Clay Company ............................... 184-185 Mrs. F. M. Tharpe property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185-188 Georgia Kaolin Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188-19(! Savage property ....................................... 190 -1V3 Localities west and south of Pikes Peak .................... 19::-~0~ Crump property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194-1:J6 Dorsey property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 Abandoned railroad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1!16-198 Wall property ......................................... 198-199 Delzel ................................................. 199-200 John Tharpe estate ..................................... 200-202 Localities near Fitzpatrick ................................ 202-205 Solomon property ...................................... 202-205 Kennington property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20ti Localities between Fitzpatrick and Jeffersonville ............ 200-~09 Sixteen-milepost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 Eighteen-milepost ...................................... 20G-207 Nineteen-milepost ...................................... 207-20<2 Localities near Jeffersonville .............................. 209-211 Four miles northeast of Jeffersonville.................... 20P-2ll Localities near Danville .................................. 211-21 r, Hill property ......................................... 211-212 Porter property ........................................ 213-214 Hughes property ...................................... 21,!-216 Localities south and west of Danville ....................... 2H>217 Bleckley County ........................................... ~17 220 Deese property .......................................... 211-220 Ainslie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Houston County ........................................... 220-222 Ross Hill .............................................. 221-222 Crawford County .......................................... 222-224 Rich Hill .............................................. 222-224 Wilkinson County ......................................... 224-230 Localities near Gordon .............................. 225-226 Dupree property ......................................... 226-227 Hall and Toler properties ...................... , ......... 227-22\i ix PAGE Stephensville ............................................ 229230 Toomsboro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 Jones County ............................................ 230-231 Roberts ................................................. 230-231 Baldwin County ............................................ 231-233 Hall' property ............................................ 231-233 Washington County ......................................... 233-240 Buffalo Creek ............................................ 234-236 Irwin property ........................................... 237-238 Chalker .................................................. 238-240 Glascock County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 J,efferson County ...........................,.............. 240-245 Wrens .................................................. 241-243 Hatcher's Mill ......................................... 243-244 Louisville .............,.................................. 244-245 Burke County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 Richmond County .......................................... 245-247 Mount Enon ............................................. 246-247 Columbia County ........................................... 247-259 Phinizy Gully ............................................ 248-251 Grovetown .... ........................................... 251-254 Fiske estate ............................................ 254-258 Harlem ................................................. 258-259 Fullers earth of the Alum Bluff formation . . . . . . . . . . . . . . . . . . . . . . . 259-28!) Geology of the Alum Bluff formation .......................... 259-265 Areal distribution ........................................ 259-260 Stratigraphic relations .................................... 260-261 Lithologic characters ....................................... 261-264 Strike, dip and thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Physiographic expression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264-2G5 Paleontological characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Descriptions of individual deposits ........................ 265-2811 Fullers earth mines of Gadsden County, Florida............. 265-270 Decatur County ....................................... 270-279 Lester Clay Company .................................. 270-275 Gibson property ......................................... 275-276 Smith property ........................................ 277-278 Amsterdam and Wataga . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Grady County ............................... 278-280 Whigham .......................................... 279-280 Thomas County .............................. 280281 Brooks County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 Lowndes County ................................... 281-::?84 Withlacoochee River ................................ 282-28-1 Old Troupville ....... : . . . . . . . . . . . . . . . . . . . . 284 Echols County ....................................... 284287 X PAGE Allapaha River . . . . . . . . . . . . . . . . . . . . . .................... 384 ~87 Appling and Toombs counties ....... , ....................... 287-28H Grays Landing Bluff ..................................... 287 i:S9 Screven County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .:?89 Fullers earth of the Wilcox and Clairborne formations ............. 289-290 Physical and chemical characteristics ............................... 290-309 Physical properties . .......................................... 290-303 Bleaching power ........................................... .'. 291-~~6 Theories as to bleaching power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291-2!)2 Adsorption ................................................ 29:!-:!93 Forms of colloids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 Action of fullers earth ..................................... 283-29!3 After-bleach and reversion of color . . . . . . . . . . . . . . . . . . . . . . . . . . . 296-297 Plasticity .................................................... 297-298 Hardness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 Porosity and density ......................................... 298-299 Absorption of oil ............................................ 299-300 Spontaneous combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Apparent acidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301-302 Fractionation of petroleum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302-303 Microscopic structure ......................................... 303-306 Chemical and mineralogical composition .......................... 306-309 Gen~sis of deposits .............................................. 309-311 Methods ........................................................ 311-312 Mining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 Preparation ................................................... 311-312 Uses ........................................................... 312-316 Petroleum .refining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312-313 Bleaching of cotton oil . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . 313-315 Manufacture of pigments ............................. ; . . . . . . . . . 315 Detecting coloring matter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 Talcum powder .............................................. 315-316 Medical uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316-318 APPENDIX A .......................... 319-324 Bauxite deposits of Meriwether County ............................ 319-324 Geologic relations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 The deposits .............................................. 319-321 The ore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321-322 Origin ....................................................... 322-324 APPENDIX B ...................................................... 325-329 Notes on the bauxite deposits of north Georgia ..................... 325-329 Mining operations in 1917 ................................ 325-327 Hermitage mines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 Merrimac mine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 Booger Hollow mine ................ 326-327 PAGE Comparison of the Paleozoic and Coastal Plain bauxite deposits .... 327-329 APPENDIX C . , . , .. , . , ... , . , , , . , .. , ..... , , , .. , , , , , , , , , , , , , .._, .. , , , 330-332 Notes on halloysite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330-332 The North American Chemical Company . . . . . . . . . . . . . . . . . . . . . . . . . 330-332 Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331-332 INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' .. 333-340 xii ILLUSTRATIONS PLATE FACING PAGE 1. Frontispiece. Fullers earth mine of the General Reduction Company, Pikes Peak, Twiggs County ........................ Frontispiece. A. Bauxite drier, Republic Mining & Manufacturing Company, Mc- Intyre mine, Wilkinson County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 B. Working face in the Mcintyre mine, Wilkinson County. . . . . . . . . 32 III. A. Working face in the Mcintyre bauxite mine of the Republic Min- ing & :Manufacturing Company, showing bedded bauxite with an unconformity above .................... , . . . . . . . . . . . . . . . 34 B. Mcintyre mine. Upper surface of the bauxite stripped prepara- tory to mining, showing ''pot holes '' and irregularities. . . . . . . . 34 IV. A. & B. Working face in the Sweetwater bauxite mine of the Re- public :Mining & Manufacturing Company, Sumter County, November, 1914 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 v. A. Sweetwater bauxite mine and drier of the Republic Mining & Manufacturing Company, Sumter County . . . . . . . . . . . . . . . . . . . . . 72 B. Close view of bauxite drier and storage oin, Sweetwater mine, , Sumter County . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 VI. A. & B. Easterlin bauxite mine, Sumter County. July, 1916...... 76 VII. A. Bauxite exploration pit on the Kleckley property, Macon county.. 82 B. Bauxite explorations on the English property, Macon County. . . . 82 VIII. A. SeYer Cretaceous series were never deposited in the Southeastern States, or were removed by erosion before the Upper Cretaceous beds were laid down. The Potomac group and the Lower Cretaceous strata of the South Atlantic and Gulf States belong to the terrestrial rather than the marine type of deposits. The whole eastern mountain and plateau region seems to have suffered peneplanation during the Jurassic period, attended inevitably by the deep decay of the underlying crystalline and other rocks, and the consequent accumulation of a heavy mantle of residuary earth and insoluble rock. The warping which inaugurated the Lower Cretaceous period seems to have involved a rise of the axis of the Appalachian tract, and a consequent rejuvenation of the drainage from it, while the coastward tract was left relatively fiat, or perhaps bowed downward, making it a zone of lodgment for the sediments brought down from the north and west. The quickened drainage of the axial tract, acting on material prepared for easy removal, loaded itself with a burden it could not carry across the low coastal tract, and deposition resulted. :Th1:arshes, lakes, and lagoons were probably features of the area, and the perfect separation of the sand from the clay at many places points to the existence of local conditions which allowed of the differentiation of sediments to an un- 1 Stephenson, L. W., Cretaceous deposits of the eastern Gulf Region: U. S. Geol. Survey Prof. Paper 81, pp. 10, 11, 1914. 28 GEOLOGICAL SURVEY OF GEORGIA usual degree. The presence of feldspar in the sand, and of pieces of schist in the gravel beds, shows that erosion sometimes exceeded chemical decay. This betokens high land to the north and west from whence the sediments were derived, and is one of the reasons for the belief that the region west of the site of deposition was tilted upward at this time. Areal distribution in Georgia.1-The Lower Cretaceous strata present in Georgia are believed to represent a part of the Potomac group of the Middle .Atlantic States. This terrane appears as outcrops in Georgia in an extremely irregular belt 2 to 30 miles in width, extending entirely across the State from Chattahoochee River in the vicinity of Columbus, northeastward to Savannah River in the vicinity of }_. ugusta. The irregularities of the belt are due partly to the unevenness of the surface of the basement rocks upon which the formation rests, partly to overlaps of younger formations, and partly to the deep erosion valleys that the streams have developed along the Fall Line region. The last named condition causes the underlying basement rocks to appear much farther southward in the bottoms of the valleys than would otherwise be the case, and likewise causes the Lower Cretaceous beds themselves to appear still farther down these valleys beneath the underlying younger formations. The area in which the beds appear includes parts of the following counties: Muscogee, Chattahoochee, Talbot, Marion, Taylor, Macon, Crawford, Bibb, Twiggs, Jones, Wilkinson, Baldwin, Washington, Hancock, Warren, Glascock, Jefferson, McDuffie, Columbia, and Richmond. Stratigraphic position.-The Lower Cretaceous beds in Georgia rest upon a basement of ancient crystalline rocks, all of which are believed to be of pre-Cambrian age. The surface of the crystalline rocks is very uneven in detail, but in general slopes to the south and southeast. Calculations from well borings at several places have bhown that the amount of this general slope in the region of the Fall Line varies from 25 to over 50 feet per mile. In Jefferson County, it maintains a slope of between 35 and '40 feet to the mile for a distance of nearly 40 miles from the Piedmont border. t Abstracted from Geol. Survey of Ga. Bull. 26, pp. 73-77, 1911. BAfJXITE DEPOSITS OF THE COASTAL PLAIN 29 Between Chattahoochee and Ocmulgee rivers the formation is overlain unconformably by Upper Cretaceous strata belonging to the Eutaw and Ripley formations, and to a very limited extent, where both of these formations are absent, by Eocene strata. Between Ocmulgee and Savannah rivers it is overlain unconformably by the Claiborne and Jackson stages of the Eocene. Lithologic characters.-The Lower Cretaceous materials consist dominantly of arkosic sand, with, however, a considerable percentage of clay in the form of interbedded lenses. The sands are usually coarse to very coarse in texture, and generally cross-bedded. They are composed largely of angular to subangular quartz grains, with an important percentage of mica flakes and disseminated grains and particles of kaolin. In addition, there are subordinate amounts of undecomposed feldspar and various other minerals derived from the crystalline rocks of the adjacent Piedmont region. Locally the sand beds have been indurated, forming friable sandstones. The clay lenses vary in lithologic character, shape, and extent. In thickness they range from an inch or less to a maximum of 30 or 40 feet, and in horizontal extent from, a few square yards to many acres. In general, the clays are light drab or gray in color, and are more or less sandy. Locally, however, there are commercially important clay lenses of remarkable whiteness and purity, approaching kaolin in composition. Lamination is rare, the beds being as a rule massive and breaking with a hackly or conchoidal fracture. For the most part the formation displays great irregularity of bedding, but in places a distinct banding of the clay and sand layers is apparent, individual beds being traceable for considerable distances. Locally, coarse gravel lenses and layers occur in the formation, this being especially true of the basal portions. Unconformities of little or no time significance occur locally within the formation. As a result of the shifting of the channels which produced these unconformities clay beds within the formation have been torn to pieces and redeposited, as evidenced by the large number of rolled clay balls and boulders which in many places occur scattered through the sands. 30 GEOLOGICAL SURVEY OF GEORGIA The better grades of commercially important clays, so far as know:n, occur in the region between Ocmulgee and Savannah rivers. Beds of very fine quality are especially abundant in Twiggs and Wilkinson counties where mining operations have been carried on more extensively than elsewhere. Strike, dip, and thickness.-The strike of the Lower Cretaceous beds in Georgia is in general northeast and southwest, with the dip a little south of southeast. On account of irregularity of bedding and of the limited extent of the exposures, the exact amount of the dip can not readily be determined. It is greate:~, however, than the gradients of the larger streams and probably averages 25 or 30 feet to the mile. Data are available for a fairly accurate determination of the thickness of the formation in the Chattahoochee Valley below Columbus. The point on Chattahoochee River adjacent to Columbus, where the surface of the basement rocks passes beneath water level, has an elevation of about 195 feet above sea level. Data furnished by well borings near the mouth of Bull Creek show that this surface dips southward at an average rate of between 50 and 60 feet per mile. The top of the Lower Cretaceous terrane passes below water level at Broken Arrow bend 7 miles south of Columbus, in an air line, and about 180 feet above sea level. If the dip of the surface of the basement rocks is 50 feet to the mile, 7 miles south of Columbus it would be 350 feet lower, or 155 feet below sea level. The thickness of the formation at Broken Arrow Bend would therefore be 155 plus 180, or 335 feet. If the dip of the basement rock surface is 60 feet, the thickness is 405 feet. The average of these amounts, 370 feet, is believed to be a close approximation to the total thickness at this point. Calculations based on well data have shown that the probable general dip of the unconformity separating the Lower Cretaceous and the overlying Eutaw beds in this region varies from 48 to 50 feet per mile. If the upper and lower planes of unconformity maintain their apparent angles of dip they diverge and the Lower Cretaceous formation thickens southward, but it is not likely that the crystalline . BAUXITE DEPOSITS OF THE COASTAL PLAIK 31 surface maintains so great a degree of slope for any great distance from the Fall Line. A well at Reynolds, Taylor County, is said to have penetrated 600 feet of strata before encountering the underlying crystalline rock. As the well starts in Lower Cretaceous strata, the whole- thickness should be referred to this formation. Three and a half miles southwest of Louisville, Jefferson County, a well 1,143 feet deep is believed to have penetrated about 790 feet of Cretaceous strata between the overlying Eocene beds and the basement rock. None but Lower Cretaceous strata outcrop from beneath the Eocene beds along the Fall Line to the northwest of Louisville, but it is not at all certain that all of the Cretaceous beds penetrated in the Louisville well should be referred to that division. In fact it seems highly probable that buried Upper Cretaceous strata exist between the Eocene and Lower Cretaceous beds. The thickness of the Lower Cretaceous at this point is therefore believed to be considerably less than 790 feet. From well data and other considerations, it may be shown that in general along the line where the formation passes beneath the Upper Cretaceous or Eocene formations, as the case may be, its thickness ranges from 350 to 600 feet. Physiographic expression.-The belt in which this Lower Ore' taceous terrane outcrops constitutes part of a dissected plain which is characterized by a broken, hilly topography, the area presenting in fact the roughest surface of any portion of the Coastal Plain of Georgia. The elevation of the upland surface ranges from 400 to 600 feet above sea level. The major streams crossing the area have elevations at the fall line ranging from 100 to 250 feet. The surface relief therefore reaches a maximum of at least 400 feet. This hilly topography is the result of active stream erosion caused by the relatively high elevation of the area and favored by the unconsolidated, sandy character of the materials of which the formation is predominantly composed. The surface soil throughout the greater part of the area is com- 32 GEOLOGICAL SURVEY OF GEORGIA posed of loose gray or yellowish sands, the product of the weathering and leaching of the underlying sand beds of the formation. These surface sands have been shifted more or less by winds and torrents ~o that in places they have been entirely removed, and elsewhere have been heaped up to abnormal thicknesses. The area forms a part of the so-called ''sand hill'' region of the northern part of the Georgia Coastal Plain. Paleontologic characters.-A few faint, indeterminable leaf impressions have been observed in white, sandy clay in a cut of the Georgia Railroad at Carr's Station, Hancock County. With this exception no fossil remains have been discovered in the beds of this formation in Georgia. Location of bauxite deposits.-Although the outcrop of the Lower Cretaceous beds extends in an unbroken belt across the State from the Chattahoochee to the Savannah, bauxite has been found only in a limited district near the central part. The greater number, and also the richer of the deposits are in Wilkinson County, but the area of bauxitic clays with some smaller deposits is known to extend into Twiggs, Washington, and Baldwin counties. DESCRIPTIONS OF INDIVIDUAL DEPOSITS WILKINSON COUNTY The Lower Cretaceous strata are exposed m the valley of the Oconee River in the eastern part of Wilkinson County, and in the valleys of Commissioners and Big Sandy creeks almost to the southern boundary. Deposits of bauxite are known in all parts of the county, and are likely to be found throughout the area of outcrop of the formation. All known deposits are at or near the contact of th.Cretaceous with the unconformably overlying Eocene beds. PARKER-HONEYCUTT-DANIEL GROUP OF PROPERTIES (MCINTYRE MINE) (Map locality W-1) Location.-Bauxite occurs on the property of Mrs. W. R. Parker, J. R. Honeycutt, W. E. Honeycutt, and James Daniel, located 3 BAUXITE OF THE COASTAl, PLAIN OF. GEORGIA PLATE II A. BAUXITE DRIER, REPUBLIC MINING & MANUFACTURING CO., MciNTYRE MINE, WILKINSON COUNTY. B. WORKING FACE IN THE MciNTYRE MINE, WILKINSON COUNTY. BAUXITE DEPOSITS OF THE COASTAL PLAIN 33 miles northeast of Mcintyre imd 11/2 miles north of the 159 milepost on the Central of Georgia Railway. The mining rights on all of the properties are held by the Republic Mining and l\i(anufacturing Company. H. M. Skelt?n, of Irwinton, is the superintendent of the mine which is commonly known as the Mcintyre mine. The ore is found along both sides of a small branch of Commissioners Creek; the best bauxite, and the only part which has been worked, being on the Parker and Daniel tracts, west of the branch. The topography, location of the bauxite outcrops, and workings up to November, 1916, are shown in the accompanying sketch and section (fig. 1). ~0 ~0 N r ~0 DANIEL 0 300 600 9QO SCALE IN FEET. _Fig. I.-Topographic sketch map and section of the .Mcintyre bauxite mine of the Republic Mining & Manufacturing Co., Wilkinson County. 34 GEOLOGICAL SURVEY OF GEORGIA Geologic relations.-The bauxite has the form of a lens at the top of the Cretaceous beds. It grades down into white or stained and mottled plastic kaolin, and is overlain unconformably by Eocene sands and clays. .Although the character of the ore varies greatly, it is evident that all exposures belong to the same lens, which has been partly eroded by the branch. The character of the underlying beds is plainly shown in the well at the drier. The well is 17 feet deep, starting several feet below the base of the bauxite bed, and when examined contained only 5 feet of water. .At the surface is yellowish clay with occasional large soft nodules, which grades down into smooth, plastic kaolin. Several feet above the wat~r line the kaolin is splotched and mottled with red, while the material from the bottom is tough, plastic, maroon colored clay. The upper surface of the bauxite is a distinct unconformity, approximately plane and level, but very irregular in detail. .Along the face northwest of the drier there are circular cavities like pot holes filled with Eocene clay, some of which penetrate the entire thickness of the ore bed (see Pl. III, B). The material overlying the bauxite in the mine consist of 3 to 4 feet of tough sandy blue clay; peculiarly stained and mottled with red and yellow, and several feet of loose gray sand forming soil and subsoil. There is no marked bed of basal conglomerate, but the blue clay contains occasional boulders of bauxite up to one foot in diameter, and rounded quartz pebbles up to 2 inches. In the slope of the hill to the west, which rises about 50 feet, small gullies and washes show typical red and yellow argillaceous sands of the Eocene. The deposits.-The exposures west of the branch are the working face of the mine and exploration pits to the north. The length of the face northwest of the drier is 200 yards, and exploration work has shown up ore continuing around the slope 20 yards to the fence line and about 100 yards in the cultivated field beyond. The base of the workable bauxite is about 15 feet above the level of the branch. The thickness of ore is said to have been as much as 9 feet in the worked- BAUXITE OF THE COASTAL PLAFN OF GEO&GlA PLATE Ill A. WORKI~G FACE IN THE MciNTYRE BAUXITE MINE OF THE REPUBLI.C MINING & MANUFACTURING CO., SHOWING BEDDED BAUXITE \VITH AN U CONFORMITY A B0VE. B . MciNTYRE MINE. UPPER SURFACE OF THE BAUXITE STRIPPED PREPARATORY TO MINING, SHOWING "POT HOLES" AND IRREGULARITIES. Photo by S. W. Jlf cCallie .., . BAUXITE DEPOSITS OF THE COASTAL PLAIN 35 out portion on the Daniel property, but the greatest thickness exposed at the time of examination was little over 6 feet. The ore along the face northwest of the drier, which was being worked in November, 1916, had a maximum thickness of 6 feet, with average hardly 5 feet, and was thinning rapidly toward the west. Where the working face swings around at the south end of the pit the ore not only thins but changes in character, becoming softer, with larger and more scattered nodules. It is evidently grading into kaolin along the strike as well as in depth. On the Honeycutt property, which lies east of the branch, no mining or exploration work has been done since Veatch's examination. Red, highly ferruginous bauxite, in a bed ::tt least 4 feet thick, outcrops in the slope east of the branch, about 150 yards from the mine and at the same level. Lower on the slope is an outcrop of dark red, plastic clay. Another small outcrop of red bauxite occurs in the public road near the Honeycutt house. The bauxite outcrops are 500 feet apart, on opposite sides of a small knoll, which rises only 5 feet above the exposures. If the bed is continuous in the intervening dis- . tance the area underlain is about 4 acres, with overburden nowhere exceeding 5 feet. The ore.-The upper 3 feet (more or less) of the bauxite bed in the mine is hard, white, finely pisolitic ore. This charges in depth into softer, iorn-stained ore of similar texture, which in turn grades into soft kaolin with scattered nodules. The nodules in the best portion of the ore average less than one-fourth inch in diameter, but there are scattered complex pebbles with a maximum diameter of 6 inches. The complex pebbles consist of a number of small, soft pisolites in a gray or brown, dense, flinty matrix, but most of the bauxite has a white, porous and chalky, instead of a flint-like matrix, and is therefore softer than the high-grade ore from other occurrences in the vicinity. As a rule the pisolites have a thin hard shell with softer or powdery center, and are the same color or a little darker than the matrix. At the angle of the face nearest the drier the ore is only 3 feet 36 GEOLOGICAL SURVEY OF GEORGIA thick, and is ferruginous and dark yellow in color. .Along the face to the southwest, several hundred feet from the drier, the bauxite becomes horizontally banded, with thin white and thick red layers, apparently due to variations in iron content during deposition (see Pl. III, .A). The bauxite of the red bands has light colored pisolites in a red matrix. On the contrary, the low grade red bauxite of the Honeycutt property, a part of the same lens, is made up of dark red, pebblelike nodules in a white, sandy matrix. The ore in the face northwest of the drier is also, in part, distinctly stratified, with layers of bluish plastic clay up to 2 inches in thickness, while some beds are more ferruginous than others. Perpendicular "veins" a few inches thick and occasional larger irregular masses of soft, white, kaolinic material, with the same pisolitic texture as the bauxite, but of very different composition, cut across the bedding. When exposed to the weather, the bau~ite becomes lighter in color, harder, and apparently higher in alumina. The lightening of color and enrichment are probably due to removal of clay and iron oxide while the hardening is caused by repeated solution and recrystallizat~on of very minute quantities of silica and alumina. Veatch collected surface samples from these properties before mining was started, the analyses of which gave the following results: Analyses of surface samples1 Constituents 1. 2. I I S1hca (S Alumina i02 (A ) l20 .. 8) . .. .. . . . . .. .. . . . . .. .. . . . . .. .. . . . . . . 9.41 57.80 10.20 53.11 Ferri Ignit c io oxide n ... . ( . F..e.20. . .8 ) ..... . . ....... .96 29.21 7.66 26.55 Titanium dioxide (Ti02) 2.77 -- 2.30 -- 100.15 99.82 Moisture ........................ .35 .35 1. Surface sample from Parker property. 2. Surface sample from Honeycutt property. 3. Surface sample from Honeycutt property. 4. Red clay underlying bauxite, Honeycutt property. 3. 8.48 50.94 9.50 27.80 2.02 -- 98.74 1.94 1 Veatch, Otto, Geol. Survey of Ga. Bull. 18, pp. 440-442, 1909. 4. 38.14 30.26 17.54 12.12 1.57 -- 99.63 .55 BAUXITE DEPOSITS OF THE COASTAL PLAIN 37 To show the gradation of bauxite into kaolin with depth, a series of samples was taken by the writer from the best part of the face, 100 feet southwest of the drier. The first sample was from the Eocene sandy clay overburden 6 inches above the unconformity, the second was .bauxite 6 inches below the unconformity, and the remdinder were taken at one foot intervals, giving a total section of 101/z feet below the contact. Average samples were taken, but the large ferruginous concretions scattered through the lower part of the bed were avoided. A thickness of 51/z feet of the section below the unconformity may be called bauxite, as that is the portion mined and shipped. A pit was dug 5;~ feet below the floor of the mine for the purpose of getting these samples. The lower part of th~ bauxite in the face, and the clay to a depth of 7 feet below the unconformity, are stained yellow, and the clay carries large, soft nodules to a depth of 8 feet. From 8 to 10 feet the white kaolin is mealy, while below 10 feet it is soft and plastic. Through the material from 5 to 10 feet are scattered large, irregular, hard, ferruginous concretions, with maximum dimensions up to one foot. The concretions seem to have been affected by weather, as they lack the soft centers of pyrite, sulphur, and soluble salts found at other localities. An auger boring 8 feet deep in the bottom of the pit penetrated some red-stained clay, and was in gray-blue plastic kaolin at the bottom. Analyses of ore from Republic Mine, showing gradation into kaolin Constituents I I I S-63 S-64 S-65 I SiO, .............. 50.57 23.72 10.63 A~o. ............. 30.45 50.15 57.91 Fe,o. ............. 3.22 1.13 .96 FeO MgO .................... .00 .03 .00 .04 .00 .03 CaO .............. .08 .00 .02 Na,O K.O .................. .21 .51 .02 .05 .04 .03 Ignition .......... 13.28 23.10 28.70 I I S-66 S-67 S-68 I 14.12 54.15 1.61 .00 .02 .00 .01 .02 27.50 18.84 52.03 2.25 .00 .00 .00 .02 .02 25.26 22.40 51.56 2.89 .00 .03 .00 .01 .02 21.34 38 GEOLOGICAL SURVEY OF GEORGIA TiO, ............. I 1.81 P,O, .............. .00 s ................ .00 MnO .11 .............. ZrO, 0 BaO .............. .00 I I 100.27 Moisture ........ I .69 I 2.18 .00 .09 .00 .003 .00 100.483 .73 1.44 .00 .09 .00 .007 .00 99.857 .38 2.27 .00 .12 .00 .00 99.82 .63 1.74 .00 .05 .00 .00 100.21 .53 2.01 .00 .01 .00 .00 100.27 .45 Constituents I S-69 870 S-.71 S-72 S-73 S-74 I SiO, .............. 23.73 28.89 Al.Oa ............. 50.75 47.16 Fe,o. FeO .................. 2.73 .00 1.77 .00 MgO ;~ 0 0 0 0 .00 .00 CaO .... .00 .00 Na,O .00 .03 K,O ........... .00 .06 Ignition ........... 21.33 20.09 TiO, .............. 2.31 2.17 P,O, .............. .00 .00 s .... .00 .00 I MnO .............. 1 ZrO, BaO ............... .00 . . .. .00 I -- 100.85 .00 ---- I .00 -- 100.17 I Moisture ........ II I .37 .42 I 27.38 46.81 2.41 .00 .00 .00 .05 .04 20.43 1.99 .00 .02 .00 .... .00' -- 99.13 .48 31.79 44.21 1.12 .00 .00 .00 .32 .18 20.10 1.81 .00 .03 .00 . .. . .00 -- 99.56 .48 36.35 44.06 1.13 .00 .00 .00 .08 .10 16.83 1.99 .00 .00 .00 .... .00 -- 100.54 .50 42.40 39.08 .96 .00 .02 .00 .12 .24 14.74 2.35 .00 .02 .00 0 .0\i -- 99.93 .38 The dried ore as shipped is said to average 55 per cent alumina, and weighs 3,300 pounds per cubic yard. Development.-The ore on the Daniel property has been entirely worked out, having graded into kaolin to the west. The area origmally underlain by bauxite on that property seems to have been about S,OOQ square yards. The unworked area remaining on the Parker property is probably somewhat larger. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 39 The maximum overburden being moved (November, 1916) was 11 feet, 25 feet back of the working face northwest of the drier. The overburden will not increase much more, as this is about the limit of the extent of the ore bed to westward. Stripping and mining have been carried on entirely by hand labor. As the overburden in the area likely to be underlain by bauxite does not exceed 10 or 15 feet, with average less than 10 feet, it has not been considered profitable to use steam shovels. The ore is dried in a rotary kiln, and hauled in wagons 11/2 miles to the railroad siding at Wriley station. Production and ttses.-The mine was opened in 1912, and during 1913 produced about a carload per day. Work was stopped for several periods when the demand for bauxite was not great, but in 1916 the mine was being actively worked and was producing about two cars per day. The greater part of the ore shipped has been low in iron, and has been used principally in the manufacture of alum. All of the ore known on the Honeycutt property, and a part of that remaining on the Parker property contains considerably more than two per cent of ferric oxide, and will probably therefore be used for aluminum manufacture. GEKERAL BAUXITE CORPORATION PROPERTY (Map locality W2) The bauxite property formerly owned by Dr. N. T. Carswell was purchased in 1916 by the General Bauxite Corporation, 52 Broadway, New York, of whl.ch 1\Ir. A. Rust-Oppenheim is president. It is situated just south of the Central of Georgia Railway, 3 miles west of Toomsboro. This property is one of the first on which bauxite was. discovered, in fact, Dr. Carswell claims to have known of the occurrence before Veatch announced the discoverey near Mcintyre. A considerable amount of prospecting has been done in the valley of a small branch wh'ich flows nbrtheast into Commissioners' Creek. 40 GEOLOGICAL SURVEY OF GEORGIA The location of the pits described is shown on the accompanying sketch map (fig. 2). N s . 0 SjlO 1'!00 100 S Cf\LE IN FEET Fig. 2.-Sketch map of bauxite explorations on the property of the General Bauxite Corporation, Wilkinson County. The numbers refer to pits described in the text. Geologic relations.-The bauxite is found in the Lower Cretaceous kaolin beds at or near the unconformable contact with the overlying Eocene sands and clays. The unconformity was observed at the junction of the two small branches, altitude 250 feet, near pits Nos. 7 and 8. A basal conglomerate consisting of fragments of bauxite and . BAUXITE DEPOSITS OF THE COASTAL PLAIN 41 indurated clay in a matrix of mottled clayey sand overlies the Cretaceous indurated bauxitic clay. The upper surface of the Cretaceous is irregular, as kaolin is found up to an altitude of 280 feet at pit No. 1. The Eocene beds overlying the bauxite and kaolin belong to the Barnwell formation of the Jackson group. No continuous section of the Eocene beds is exposed, but there is apparently about 40 feet of red sandy clay or argillaceous sand immediately above the Cretaceous. Calcareous, pale yellow clay of the character of fullers earth, is exposed in gullies near the tops of the hills to the east and west of the valley, at an altitude of about 300 feet, and one mile southwest of the Lauxite locality is a bed of bryozoan limestone, typical of the Jackson group, at approximately the same horizon as the fullers earth. The Lower Cretaceous strata consist of white, plastic kaolin; indurated and bauxitic white kaolin; red kaolin, both plastic and indurated; white kaolinic sand; and bauxite, all of which is rather siliceous. The character of the material shows great local variation, and none of the beds are continuous for any great distance along the ~trike. The ore.-All possible gradations between kaolin and high grade bauxite may be found on the property. The following table includes all analyses of kaolin and bauxite made by Dr. Edgar Everhart for the Geological Survey of Georgia. The samples marked "S" were collected by the writer, others were collected by Otto Veatch and H. C. Parker. These analyses are arranged in order of alumi:r;ta content, to show the gradation between kaolin and bauxite. 42 GEOLOGICAL SURVEY OF GEORGIA Analyses of samples from the property of the General Bauxite Oorpor!ftion l;onstituents I I 1 I ~I (S-88) I 3 14(s-s7B)I 5 SiO, .............. \ Al,03 Fe,03 .................. MgO ............ CaO. .... .... ... .. Na,O 0 IKg,nOitio.n........... TiO, .............. s 0 MnO .............. 40.12 34.56 11.80 .00 .00 tr. tr. 12.49 1.49 100.46 Moisture 0 .58 45.24 36.04 1.61 13.91 1.71 -- 98.51 .66 44.63 38.75 1.73 tr. tr. tr. .28 13.59 1.50 tr. tr. 100.48 .90 39.73 39.47 1.09 15.97 1.82 43.96 39.69 .73 .10 .00 .05 .10 14.23 1.62 tr. 98.08 10o.48 .78 .89 6 35.14 41.09 1.29 20.66 2.01 100.19 .42 I I I Constituents ..... -1 7 8 9(8-89) 10(8-182) ll(S-231) I I SiO, ........... II 27.88 I 30.98 28.36 12.35 9.79 Al,03 ............. 42.91 46.37 48.29 56.70. 57.00 Fe,o. ............ MgO 0 0 0 0 0 ~ 0 1.61 . .. . 1.29 . ... .1..9. 2. 1.61 0 .1..6..1 CaO .............. -. 0 ... . .... . .. . 0 Na,O ............. 00. ... . . .. . . .. . .... K,O .............. .... 0 0 . .. . . .. . 1 Ignition 0 TiO, ......... s ................ ~1:n0 ........... 25.46 1.81 ........ 19.58 1.81 .... . ... ..........I Moisture -- 99.67 .70 -- 100.03 .52 I I 20.05 .......90.. -- 99.52 .25 27.55 ..1...6....3 -- 99.84 .39 30.30 . ..9..0 . ... -- 99.60 .54 12 1.18 61.52 1.70 . ... 0 . ... .... 32.70 ..2...7....6 -9.9..8..6 1. Red kaolin. Veatch, Otto, Geol. Survey of Ga. Bull. 18, p. 166, 1909. 2. S-88. Claystone exposed at junction of branches, just below the Ecocene contact. 3. Plastic white kaolin. Veatch, Otto, Geol. Survey of Ga. BulL 18, p. 164, 1909. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 43 4. S-87B. Average sample of soft, nodular clay from 8 feet of beds in pit No. 5. 5. Indurated nodular clay or ''chimney rock.'' Veatch, Otto, Geol. Survey of Ga. Bull. 18, p. 165, 1909. 6. Average sample from top to bottom of pit No. 11. Collected by H. C. Parker. 7. Average sample from bottom and walls of pit No. 10. Collected by H. C. Parker. 8. Bauxitic clay from bottom of pit No. 11. Collected by H. C. Parker. 9. S-89. Bauxitic clay, average sample from 8 feet of beds exposed in pit No. 9. 10. S-182. Bauxitic clay, average sample of 6-foot bed of bauxite in pit No. 11, on site of the mine. 11. S-231. Average sample of 5-foot beds of bauxite in a cut on the slope above pit No. 3, on the site of the mine. 12. Hard nodules of high-grade bauxite. Veatch, Otto, Geol. Survey of Ga. Bull. 18, p. 444, 1909. Pits Nos. 1, 2, and 3 cut only indurated white clay, with scattered clayey nodules. The material is only slightly bauxitic, and has no value at present except as a fire clay. Pit No. 4 shows 6 feet of indurated, nodular, maroon-colored clay. The material is the same as that in the preceding pits, except that it contains a higher percentage of ferric oxide. Pit No. 5 cuts 5 feet of indurated white clay, underlain by 8 feet of softer, light-colored clay with soft pisolites. According to Dr. Carswell, the pit penetrated 27 feet of the latter material, which appears to be bauxitic, but the analysis (S-87B) shows it to run very little higher in alumina than an ordinary kaolin. Pit No. 6 is said to hitve cut 14 feet of clay similar to that in the bottom of pit No. 5. Pits Nos. 7 and 8 are in the branch, and were filled with water when examined. As may be seen from the material excavated, they cut some clay with nodules one inch in diameter of hard, high-grade bauxite. It was from this locality that the sample (analysis No. 12) was taken. The rock in the branch immediately beneath the unconformity, which is well exposed, is a very hard white claystone w1th irregular flinty concretions (analysis S-88). Along the slope northwest of the branch are several pits. Nl lle of these show good bauxite, but they cut more or less indurated kaolin, massive or nodular, and one reaches plastic kaolin. Pit No. 9, directly opposite pit No. 4, is the best looking prospect, showing 8 feet of mealy, very unplastic clay containing a few hard pisolites. Analysis 44 GEOLOGICAL SURVEY OF GEORGIA of an average sample (S-89) shows it to be a low grade bauxite, but the percentage of alumina is higher than the appearance of the material would lead one to believe. The pits above described are the earlier explorations. During the summer of 1915 two more pits, Nos. 10 and 11, were dug in the slope above Nos. 2 and 3. These pits disclosed a lens of bauxite of considerable extent and of much better quality than any previously discovered on the property. Pit No. 10 just reached the bauxite, while No. 11 penetrated the bed, showing the following section: Section in pit No. 11 Feet 3. Sandy soil containing fragments of bauxite. . . . . . . . 1 2. White bauxite, of medium hardness, containing hard pisolites up to one inch in diameter. . . . . . . . . . . . . 6 1. Somewhat plastic white kaolin..................... 1 Samples 6, 7, and 8 in the preceding table of analyses were taken from these pits by H. C. Parker, artd sample 10 (S-182) is an average of the 6-foot bed of bauxite in pit No. 11. Sample 11 (S-231) is from the same bed, exposed in a cut in the slope a few feet below pit No. 11. Mining operations were started on this property by the General Bauxite Corporation in 1916. The mine was opened on the slope between pits Nos. 3 and 11. When visited, in November, 1916, the opening was small and only six carloads of ore had been shipped. The working face was 50 feet long, and the maximum thickness of the ore was 5 feet at the south end of the workings, but the bed is known to become thicker farther south in the hill. The ore occurs in small and irregular lenses, cut by masses of ''chimney rock.'' The relations of ore to indurated clay are shown in the accompanying sketch (fig. 3), which shows the working face in November, 1916. s Fig. 3.-Section in mine of the General Bauxite Corporation, showing distri bution of bauxite and chimney rock. BAUXITE DEPOSITS OF THE COASTAL PLAIN 45 All of the ore shipped is of good quality for alum manufacture, contining less than tw6 per cent of ferric oxide, but the silica content is too high for use in the manufacture of aluminum. The alumina content of shipments is kept above 52 per cent, while the best car. load analysis received was 58 per cent. No high-grade, low-silica bauxite has been found except the hard pisolites from the pits at the junction of the branches. The material containing these nodules was not visible at the time of the writer's visits, and it can not be stated whether or not the nodules are in &ufficient abundance to make a washable ore. Besides the lens of 52 to 58 per cent alumina bauxite now being worked, there is a large quantity of clayey bauxite which would carry over 50 per cent of alumina after drying. The low grade bauxite mixed with plastic kaolin would undoubtedly produce a fire brick of ~superior quality. Conditions affecting mining.-The deposit is very favorably located in regard to transportation, as the principal prospects are within half a mile of the Central of Georgia Railway. The bauxite lens is so far above water level that drainage will cause no trouble. The principal mining problem will be the handling of the overburden, which will become heavy if the deposit is extensive. Development, methods, and tonnage.-A tramway about three quarters of a mile long has been built from the mine to Nadine Station on the Central of Georgia Railway. l\Iining is done by manual labor. The ore body is well drained, and the ore as mined contains only 3 or 4 per cent of moisture, so it is shipped without preliminary drying. About 500 tons had been shipped up to March, 1917. Dr. T. Poole Maynard, of Maynard and Simmons, who have conducted the recent exploration work, states that the reserve of bauxite in sight is 25,000 tons, with a possibility of discovering more. CANNON PROPERTY (Map locality W-3) A deposit on the property formerly belonging to Mrs. Cannon, 1% 46 GEOLOGICAL SURVEY OF GEORGIA miles north of Toomsboro, was worked by the ~ational Bauxite Company, but has been abandoned for some years. The pit is at the top of a small knoll, and has a working face about 250 feet long and 5 feet high. The best ore, which was of very high grade, seems to have occurred as one or more small lenses in indurated white clay in the northern part of the mine. The overburden amounts to only 1 or 2 feet of soil, so the unconformity separating the Cretaceous from the Eocene is not observable. A drainage ditch running off to the southwest shows the material underlying the ore to be mealy, nodular clay, gradin'g down into more or less stained, plastic kaolin without nodules. The high grade ore, now exhausted, was hard, with olive-gray flinty matrix, making up a larger part of the mass than the pisolites. 'rhe latter are one-fourth to one inch in diameter, with thick hard shells and softer white centers. In the southeast end of the pit 10 feet lower than the north workings, some washable ore still remains. The bed is several feet thick, but its extent could not be determined. The ore consists of hard pisolites, mostly an inch or more in diameter, in a mealy, slightly in.durated, clayey matrix which could be removed by washing, without difficulty. Samples of the matrix and nodules were taken separately, and analyses gave the following results: Analyses of bauxite from the Gannon mine Silica (SiO,) .............. Alumina (AI,03 ) Ferric oxide (Fe,03 ) Ferrous oxide (FeO) ...... Magnesia (MgO) .......... Lime (CaO) .............. Sodium oxide (Na,O): ..... Potash (K,O) ............ Ignition ... .. .. .. .... .. .. . Titanium dioxide (TiO,) ... S-91 28.98 47.07 1.12 .16 .03 .00 .04 tr 20.87 1.62 ............. 0 0 ............. ............. . ............ ............. 0 ............. ............. S-92 2.78 61.16 1.28 .16 tr .00 . .06" .08 32.63 1.62 Moisture ................ . S-91 Matrix. S-92 Pisolites. 99.89 .32 ............ 99.77 .25 BAUXITE DEPOSITS OF THE COASTAL PLAIN 47 CASON PROPERTY (Map ZocaZity W-4) This deposit is located three-tenths of a mile east of Toomsboro station, about 60 yards north of the railroad and 40 yards south of Commissioners Creek, just on the edge of the creek swamp. Work }Vas started June 1, 1915, by the National Bauxite Company. The area known to be underlain by bauxite measures 35 by 75 yards, and the thickness of workable ore is 7 feet. The overburden consists of 1 to 3 feet of superficial loose sand. As is usual, the bauxite grades downward into white kaolin. The ore shipped during 1915 is said to have contained nearly 60 per cent alumina when air dried, with average iron oxide content of less than two per cent. An average sample of about a carload of ore in the drying shed in March, 1916, has the following composition: Analysis of bau.rite from the Cason mine Silica (SiO,)....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,03) Ferric oxide (Fe 02 3 ). Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,).......... . . . . . . . . . . . . . . . S-232 4.30 61.06 1.61 30.89 1.63 99.49 JVIoisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 The ore is coarsely pisolitic, with hard nodules in a matrix varying from hard to soft. On account of the lack of impervious overburden the ore is considerably iron stained, but the stains are only on the surface of the nodules, so the iron content is not nearly so high as it appears. A part of the ore is stained black by carbonaceous matter washed down through the sandy soil, but this stain does not materially affect the quality. As the quantity of ore is known to be small, it has not been con~;idered advisable to install a drier. The ore is shipped after drying in sheds or in the sun for several days. About 6 inches of the ore at the top of the bed is mixed with 48 GEOLOGICAL SFRVEY OF GEORGIA sand, and must therefore be screened, for which a trammel is used. The base of the bauxite bed is below the level of Commissioners Creek, so it is necessary to pump out the surface water which flows into the pit. Up to the latter part of November, 1916, an area 180 feet long and 100 feet wide has been worked out, and 125 carloads (about 4,000 tons) had been shipped. The estimated amount remaining at that time was only about 1,000 tons: There is no probability of finding bauxite farther south than this property, because the upper surface of the Cretaceous beds dips below the grade of the larger streams. IIOLLEMAX PROPER'l'Y (Jiap locality W-5) No recent work has been done on this property, so the following description is taken from Veatch 's1 report: "Scattered boulders of bauxite have been found on the Holleman property, 3 miles west of Mcintyre. A white clay, semi-indurated, which has been quarried out for building purposes, occurs here, and the bauxite fragments lie in the slope beneath this clay bed. It seems probable that they are erosion remnants of a bed which existed above the clay bed. The ore here shows 60 per cent of alumina. "On the same property on the s,outh side of the Central of Georgia Railway track, fragments of a highly ferruginous, pebbly bauxite were observed in the soiL Search in the ridge, above the fragments, failed to reveal any bauxite bed.'' J. U. PARKER PROPERTY (Map locality W-6) This property is situated 5 miles north of Mcintyre, on lot 172, 4th district, Wilkinson County. This bauxite occurrence is in a valley one mile north of the Parker residence. In a small gully in the hillside is an outcrop of slightly indurated 1 Veatch, Otto, Geol. Survey of Ga. Bull. 18, p. 443, 1909. BAUXITE DEPOSITS OF THE COASTAL PLAIN 49 nodular clay overlying soft, white kaolin. A few feet farther down the slope fragments of high grade bauxite are found in the soil. Sandy soil with bauxite boulders is found for a distance of half a mile down the valley, and covers an area of many acres. By aneroid readings, the nadular clay outcrop is at an altitude of 370 feet and the bauxite area from 310 to 350 feet. A number of test pits in the bottom show that the soil contains bauxite to a depth of only about 18 inches, below which is yellow-stained kaolin. The boulders vary in size from one foot down, and are of very high grade ore, as shown by the following analysis: Analysis of J. U. Parker bauxite1 Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,)................................ Ferric oxide (Fe,03) Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (Ti02)......................... 2.12 60.55 1.89 32.97 1.96 99.49 The bauxite is light drab in color, hard and flinty, with scattered pisolites, few of which are over half an inch in diameter. In a thin section the matrix is also seen to be made up almost entirely of small nodules. No bauxite in place has ever been found, although two carloads of float ore were shipped some years ago. It seems probable, judging from the topography, that the original bauxite lens was at about the horizon of the present bauxitic clay outcrop, overlying the kaolin bed; but it has been entirely eroded, leaving only detrital material scattered through the soil of the bottom. UNDERWOOD PROPERTY (Map locality W-7) The property of Andrew Underwood (colored) is situated 1% miles southeast of Irwinton. Fragments of bauxite are found in the soil on a small knoll, 1 Veatch, Otto, Geol. Survey of Ga. Bull. 18, p. 442, 1909. 50 GEOLOGICAL SURVEY OF GEORGIA which has been thoroughly explored by 23 pits from 3 to 10 feet deep. The area prospected is about two acres. The hill rises only 15 feet above the public road, which passes to the south. The pits near the base of the hill cut soft, plastic kaolin; while those at the summit show massive or nodular indurated clays .or low grade bapxite. Hard bauxite, in the form of boulders and pebbles, is found only in a limited area, about 100 feet square, on the middle and lower slope of the southeast side of the knoll. The exploration work indicates that the original lens of hard ore was very small, and it has all been eroded except for the fragmental material. The :float ore is light brown, very hard and of :flinty texture, with small, hard, scattered pisolites. It is of exceptionally high grade, as shown by the following analysis : Analysis of hard bauxite from the Underwood property Silica (SiO,).................................... Alumina ( Al 02 8 ) Ferric oxide (Fe20,) . . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,)............... . . . . . . . . . . 4.72 62.46 .81 31.03 .23 99.25 One of the test pits near the top of the hill shows the following section: Section in test pit on the Underwood property Feet 4. Black sandy soil containing bauxite pebbles....... 1.5 3. Reddish bauxite, moderately hard, with irregularly distributed pisolites about one inch in diameter. . 2 2. Clayey bauxite, similar to the overlying bed in tex- ture, but softer and lighter in color. . . . . . . . . . . . 2 1. White kaolin with scattered soft nodules, showing only slight evidence of bauxitization..... . . . . . 1.5 Bed No. 3 is bauxite of good quality for alum manufacture, as shown by the following analysis, but the amount in sight is very small. 1 Veatch, Otto, Geol. Survey of Ga. Bull 18, p. 445, 1909. BAUXITE DEPOSITS OF THE COASTAL PLAIN 51 Analysis of bauxite from 2-foot bed, Underwood property Silica ( SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe,03 ) Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,)......................... S-42 12.51 56.11 1.93 27.81 1.72 100.08 Moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Where the public road crosses a small branch, one-eighth of a mile east of the bauxite deposit, the unconformity between the Cretaceous and Eocene beds is exposed. The basal beds of the Eocene contain pebbles of kaolin, but no bauxite. FOUNTAIN PROPERTY (Map locality W-8) The Fountain property is situated about half a mile south of the Underwood property, or 2 miles southwest of Irwinton. The bauxite prospects are in a spur running west from a flattopped hill. A pit at the end of the spur, just above a plantation road, shows a thickness of 5 feet of bauxite, overlain by 2 feet of red argillaceous sand containing pebbles and boulders of bauxite. An average sample was taken from the 5-foot bauxite bed in this pit. The bauxite is stained yellow by limonite, but analysis shows that the iron content is not excessive, and it is probable that where the overburden is a little heavier the percentage of ferric oxide will be less. Analysis of bauxite from 5-foot bed, Fountain property Silica (SiO,)................... . . . . . . . . . . . . . . . . . Alumina (Al,O,). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe,03 ) . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,) . . . . . . . . . . . . . . . . . . . . . . . S-288 14.32 55.67 2.10 25.39 2.36 99.84 Moisture ........... , , . , , .55 52 GEOLOGICAL SURVEY OF GEORGIA The property has not been thoroughly explored, but the indications are that an area of about one acre is underlain by a bed of bauxite of this quality and at least 5 feet in thickness. Dr. Heinl"ich Ries made an examination of the property, and he estimated 15,000 tons of "high-grade bauxite." However, all of the ore in sight is siliceous, containing nearly 15 per cent silica, so it can not be considered suitable for the production of metallic aluminum. Another spur of the hill, to the north of the bauxite deposit, shows only indurated kaolin, or "chimney rock." The deposit is at the same elevation as that on the Underwood property, and is of very similar character. DUPREE PROPERTY (Map locality W-9) The property of J. T. Dupree consists of lots 44, 45, and 46, 4th district, 41;2 miles in a straight line northwest of Irwinton, and 2 miles south of Claymont station on the Central of Georgia Railway. Although all bauxite known on the property is of low grade, it is of special interest from a geologic viewpoint because the relations of kaolin, bauxite, and fullers earth are exposed in a single section. About 70 feet below the level of the Dupree residence is the top of the Cretaceous beds. The upper portion of the Cretaceous is ma:de up of kaolin, varying from pure, white, plastic clay to various stained, nodular, and more or less indurated varieties. The indurated clay beds or lenses outcrop at numerous localities throughout the area of the property. The material is usually a little harder than chalk, and contains fine to coarse clayey pisolites, no harder than thematrix. Some fragments of good bauxite have been found in the soil over or near these indurated clay beds, but the small amount of prospecting done has failed to disclose any deposits of importanc~. The best exposures are along the course of a small branch in the fouthern part of the property, where the following section is shown: BAUXITE DEPOSITS OF THE COASTAL PLAIN 53 Section along branch, Dupree property Eocene Jackson group Barnwell formation Feet 8. Yellow clayey sand, in head of the gully......... 10 7. Yellow-gray, sticky, plastic clay ................. 6. Occasional outcrops of fullers earth, mostly of good quality, but contains some sandy layers. Possible thickness .. .. .. .. .. .. .. . .. .. .. .. .. . .. . .. .. 45 5. Redandblue mottled sandy clay with a thin basal conglomerate containing small pieces of kaolin and bauxite and small, well-rounded quartz pebbles. ( Unconformity ) Lower Cretaceous 4. White, massive, slightly indurated kaolin on one side of the branch; on the other side, ~oft, finely nod ular, light colored, sandy bauxite. 3. Soft red bauxite, consisting of red pisolites or pebbles in a white, sandy matrix. The bed has a maxi- mum thickness of at least 10 feet, and grades up- ward into light colored, slightly indurated clay with scattered soft nodules. 2. White kaolin, plastic and free from grit. Between 2 and 3 feet exposed, but the thickness is prob- ably considerably greater. 1. Light colored kaolinic sand, with interbedded layers of white clay breccia. The relations of the beds are shown in figure 4. ~----------At>oui J4 ,Mule---------~ Fig. 4.-Section along branch, Dupree property, Wilkinson County, showing relation of bauxite, kaolin, and fullers earth. Numbers in the section refer to beds described in the text. The bauxite of bed No. 3 is of an unusual type. It is both ferruginous and siliceous, as shown by the following analysis of an average sample from a pit beside the branch: 54 GEOLOGICAL SURVEY OF GEORGIA Analysis of red bauxite from Dupree property Silica (Si02 ) Alumina (Al20,) . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe,03 )............................. Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (Ti02)......................... S-49 22.10 45.96 7.77 22.05 1.37 99.25 Moisture . . . . . . . . . . . . . . . . . . . . . . . 1.14 The '' pisolites'' are dark red. Many are perfectly round and about the size of buckshot, others are irregular in shape and an inch or more in diameter. The outside of these nodules or pebbles shows traces of botryoidal structure, but the interior structure is not concretionary. They appear to be water worn pebbles around which a thin shell of limonitic material has been deposited. The interior of the pebbles is usually made of angular grains of soft white material, easily cut with a knife, and of bauxitic or halloysitic nature, surrounded by red bauxite which has the appearance of limonite, the whole being cut by later veinlets of a white, translucent mineral. The matrix is almost white, and is made up largely of grains of quartz sand, with a little white mica, cemented by bauxitic material. Although quartz is so abundant in the matrix, sand grains within the pebbles are rare, which suggests that the two materials were transported and deposited together by the action of water. The distance of transportation, however, may have been very small. A pit in the bank of the stream shows 5 feet of this material. Another pit, about 4 feet deep is at the top of the bank, 10 feet above the level of the stream. This pit shows that the red bauxite grades upward into a white, slightly indurated clay with large scattered nodules. The base of the bauxite bed can not be seen, as the unconformity cuts down below the level of the branch. The next exposure of the Cretaceous, 7 feet lower, is very pure, white, plastic kaolin. BAUXITE DEPOSITS OF THE COASTAL PLAIN 55 JONES PROPERTY The property of W. A. Jones, of Gordon, adjoins the Dupree property on the southeast. A deposit of hard red bauxite occupies the top of a small knoll, and probably underlies an area of 10 acres. The thickness of the bed apparently does not exceed 2 or 3 feet. The one test pit which penetrates the bed shows only 8 inches of hard red bauxite, underlain by 3 feet of light colored bauxitic clay. At lower points on the property are exposures of plastic, non-bauxitic kaolin. The red bauxite is similar to that on the Dupree property, previously described, but it is much harder. Fragments found on the ~urface are harder than the bauxite in the pit. The hardening is probably due to weathering effects at or near the surface, at depth the material may become soft. A great deal of the superficial rock has been used locally for chimneys and foundations. Analyses of red banxite from the Jones property Constituents I 1 2 S-52 I Silica ( SiO,) .......... .. II Alumina (Al,Os) .. .. Ferric oxi(\e (Fe,OJ) ......... 1 Ignition ................... Titanium dioxiae (TiO,) ...... . 12.50 49.60 15.40 19.83 2.35 20.25 40.43 17.06 19.77 1.49 25.35 38.20 16.71 17.73 1.83 I 99.68 Moisture .................. I 99.00 1.25 99.82 1.40 1. Hara lump bauxite, analyzed for Pennsylvania Salt Manufacturing Company, at Natrona, Pennsylvania. 2. Veatch, Otto, Geol. Survey of Ga. Bull. 18, p. 446, 1909. S52. Sample from 8-inch bed of hard red bauxite in test pit. MCNEAL PROPERTY The bauxite deposit on the property of J. R. McNeal is situated west of that on the Jones property, across a small valley. The occurrence is similar to that just described. An area of a 56 GEOLOGICAL SURVEY OF GEORGIA number of acres is strewn with fragments of hard red bauxite, some of which must have been derived from a bed at least 3 feet thick. .Analyses show a composition very similar to the Dupree and Jones deposits .. Anaylsis of red battxite from the MeNeal property1 Silica (SiO,) .................. Alumina (Al10 3) ....................... Ferric oxide (Fe,03) Ignition Titanium dioxide (TiO,) ...... 17.97 43.12 18.73 17.30 2.72 ........ ........ 0 0 . ....... - 0 16.02 43.98 15.43 20.89 1.89 Moisture 99.84 2.65 98.21 2.79 Occasional fragments of hard, flinty, high grade bauxite are found, but none has been discovered in place. .A pit 16 feet in depth, below the level of the main bauxite bed, was filled with water when visited, but the dump shows that the material penetrated was mostly porous, chalky, mealy or indurated clay, with at least one bed of red bauxite. BUTLER PROPERTY .A small tract of land north of the McNeal deposit is owned by Judge Butler, of Irwinton. Several shallow pits have been sunk, ~;~howing only yellowish, slightly bauxitic clay, with occasional soft, light colored nodules. SHEPPARD PROPERTY The property of J. M. and J. J. Sheppard adjoins the Jones and Dupree places on the southeast. The deposit differs from the others of the vicinity, as the bauxite is light colored. .An area of a number of acres in the valley bottom is strewn with fragments of indurated clay and bauxite, some of the latter being of the high-grade pisolitic variety with flinty matrix. There is one pit from which a carload of ore was shipped by 1 Veatch, Otto, Geol. Survey of Ga. Bull. 18, p. 446, 1909. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 57 Hatfield Brothers, of Irwinton. An average sample of the bed exposed in the pit, 4 feet in thickness, gave the following analysis: Analysis of bauxite from the Sheppard property S-87A Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.06 Alumina (Al 02 3 ) . Ferric oxide ( Fe,03 ) Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49.33 2.09 21.30 Titanium dioxide (TiO,)......................... 2.00 Moisture 99.78 .29 This bauxite is not nodular, but consists of irregular or shelllike, white, flinty concretions in a soft, granular, gray matrix. There is a little iron stain along fractures. The pit is at the foot of a gentle slope, so the overburden will not increase rapidly. There is another pit, 150 feet east of the preceding, which shows 5 feet of very similar material. There are small lenses, usually about one foot thick and a few feet in extent, of high-grade bauxite, but the indications are that it would be difficult to mine ore containing over 50 per cent of alumina. The Sheppard, Jones and Dupree properties have been prospected by Maynard and Simmons, engineers, of Atlanta. COLUMBIA KAOLIN AND ALUMINUM COMPANY (Map locality W-10) The property formerly owned by Mrs. Z. T. Miller has been purchased by the Columbia Kaolin and Aluminum Company, Walter Swindell, of Washington, D. C., being president. The location is 3 miles south of Gordon, and a tramway from Gordon was under con1\truction during the summer of 19'16. The intention is to mine both bauxite and kaolin. A large area, at least half a mile in length, is strewn with fragments of indurated kaolin, and numerous small outcrops occur. Several shallow pits cut more or less indurated clay with scattered nodules. 58 GEOLOGICAL SURVEY OF GEORGIA Half a mile south of the public road is a hill 50 feet high, the south and west sides of which are strewn ''lith fragments of hard, high grade, flinty bauxite, resembling that of the Adkins and J. U. Parker properties. A trench 120 feet long, with a maximum depth of 20 feet has been dug in the southwest slope of the hill. The relations of the beds exposed in the cut is shown in the accompanying sketch (fig 5) . sw NE ~~~~~~91 ~-=-=-=_',:,:-:~:~.:~.:,':-':::C:::U::T:::Q:J~;~5~BMi- :~A~:~- :~SSN=OIDM=UVA=LSEAS=RIKV=EKAA:KOOA:LOLIN:LIIN:N::::::::::::::::::;~ut. Fig. 5.-Section on property of the Columbia Kaolin & Aluminum Co., Wilkinson County, showing relation of bauxite to kaolin. The knoll seems to be due to the influence of the lens of resistant bauxite. The following is the analysis of an average sample from the 8-foot bed of bauxite exposed in the trench. Analysis of bauxite from the Columbia Kaolin and Aluminum Company property Silica (SiO,). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,)................................ Ferric oxide (Fe,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,).... . . . . . . . . . . . . . . . . . S-98 10.92 57.29 1.13 28.69 1.99 Moisture 100.02 .68 This analysis shows an ore of good quality for the manufacture of alum. The quantity is not large, as the bed, 8 feet thick, underlies a possible area of only an acre or two. The overburden consists chiefly of argillaceous red sand, and will not exceed a thickness of 10 feet at any point. Indurated and nodular clay is found on the property of J. W. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 59 Batchelor, Jr., and at other places in the vicinity of the Columbia Kaolin and Aluminum Company's property. R. L. STUBBS PROPERTY (Map locality W-11) Bauxite occurs on the property of R. L. Stubbs, near Oconee River, about 9 miles north of Toomsboro. The occurrence has been examined by H. C. Parker, who states that bauxite boulders are found on the surface, but no bedded deposit has been discovered. The ore is :finely pisolitic and of good quality, as shown by the following analysis of a sample taken from loose boulders: Analys1:s of bauxite from R. L. Stubbs property Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,03)............... Ferric oxide (Fe,03 ). Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,). . . . . . . . . . . . . . . . . . . . . . . . S-249 13.52 57.19 .48 27.00 2.07 Moisture BALDWIN COUNTY 100.26 .09 ETHRIDGE PROPERTY (Map locality Ba-1) On the property of J. I. Ethridge, 2 miles northeast of Stevens Pottery, is an occurrence of bauxite. An area of several acres on the north slope of a hill is strewn with float ore. A shallow pit at an altitude of 410 feet (aneroid reading), cuts only Tertiary sand. A second pit, 10 feet lower, cuts a foot of bauxite, with hard nodules predominating over the softer matrix, and grading down into iron stained kaolin. A third pit, 10 feet below the second, cuts a foot of clayey bauxite with hard nodules, also grading down into stained kaolin. The ore found on the surface is hard, white, and apparently of good quality. The structure is coarsely pisolitic, with simple nod- 60 GEOLOGICAL SURVEY OF GEORGIA ules over half an inch in diameter. The quantity in sight is too small to be of commercial value, but the quality is good, and it is not impossible that a workable bed might be found by more careful prospecting. TWIGGS COUNTY The Lower Cretaceous strata are exposed in all valleys in the northern part of rwiggs County, but up to the present no bauxjte likely to be of commercial value seems to have been discovered. At Myrick Mill on Big Sandy Creek, in the northesatern part of the county, is a bed of indurated, nodular clay which has superficial appearance very much like bauxite, but low alumina content. A part of the kaolin in the mine of the Georgia Kaolin Company is very slightly bauxitic. Southwest from Twiggs County to Chattahoochee River the kaolin beds become less extensive, and no trace of bauxite is known. WASHINGTON COUNTY The area of bauxitization of the Cretaceous kaolin extends from Wilkinson County across the Oconee River into Washington County near Oconee station. On the property of Dr. L. A. Grable and on the Elkins estate ~Map locality Wa-1), 1 to 2 miles southwest of Sheppards Bridge over Buffalo Creek, are a number of exposures of more or less bauxitic, nodular and indurated clays. A few test pits have been dug, but no bauxite of workable grade has been found. Nevertheless, the area between Buffalo Creek and the Oconee River is worthy of careful examination. Northeast from this point to Augusta there are abundant exposures of Cretaceous kaolin, but traces of bauxitization were noted at only one point. In the lower portion of the kaolin bed at the plant of the Albion Kaolin Company, near Hephzibah, Richmond County, are a few scattered, hard nodules of bauxitic material. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 61 MIDWAY BAUXITE DEPOSI'J'S GEOLOGY OF THE MIDWAY AND WILCOX FORMATIONS1 Areal distribution.-'l'he Midway occurs in a narrow belt, extending from Fort Gaines on Chattahoochee River to J\Iontezuma on Flint River, and thence a short distance into Houston County. The average width of the belt is 8 to 10 miles. It is the surface formation over portions of Clay, Quitman, Stewart, Randolph, Marion, Schley, Webster, and Macon counties. The Wilcox formation extends from the vicinity of Fort Gaines to Flint River in the northeastern part of Sumter County. The width of the belt of outcrop is on the average perhaps not more than 5 or 6 miles. Stratigraphic relations.-The Midway formation rests unconformably upon the Upper Cretaceous. No conclusive physical evidence of an unconformity representing a considerable time interval between the Cretaceous and Midway has yet been discovered in Georgia, but there is paleontologic evidence that this interval is as great as in adjoining States. Irregular contacts that appear to represent erosion unconformities between the two divisions were noted, especially in the gullies north and west of Lumpkin, Stewart County. The strata of the basal Midway and the Upper Cretaceous seem to be lithologically similar and on account of the inadequate exposures considerable difficulty is experienced in determining the exact location and nature of the contact. The Wilcox formation includes the strata lying between the Midway and the Claiborne. At Fort Gaines the Wilcox and the Midway are separated by a remarkable erosion unconformity, represented by holes in the white limestone of the J\iidway formation filled by black sandy clay of the overlying formation. Paleontologic and lithologic differences and the erosion unconformity furnish a sufficient basis for the separation of the formations at Fort Gaines. East of this locality, however, the paucity of the fossils, the fact that no unconformity could be discovered, and the unsatisfactory character of the 1 Abstracted from Geol. Survey of Ga. Bull. 26, pp. 216-235, 1911. 62 GEOLOGICAL SURVEY OF GEORGIA evidence furnished by the lithologic composition of the strata, has rendered the discrimination of the two formations very difficult; therefore, the boundary line as mapped is necessarily tenta~ive. Lithologic characters.-The Midway is mainly a marine formation and consists of sands, clays, marls, and limestones. Much of the sand, however, has a fresh-water aspect. The lower part of the formation consists principally of sands and clays and the upper part consists of marls, clays, and limestones, but there is such variety in the character of the sediments that sharp lines of division based upon lithology can not be drawn. Thin layers of flint interbedded with sands and clays were noted in the lower part. The sands are vari-colored, generally friable, and in several places contain lenticular, massive layers of white clay. In the lower part of the formation limonite is rather widely distributed in the sands in the form of thin crusts and as hollow concretions having. black, polished, and botryoidal interiors. The limestones are fossiliferous, usually very hard and generally highly arenaceous. Friable marl, made up of glauconite, quartz sand, clay, and shells occurs, and also laminated, black clay, and fullers earth. The limestones are conspicuous at several localities and are more abundantly fossiliferous than other parts of the formation. Individual beds of limestone in natural exposures are thin, from 2 or 3 to 25 feet in thickness, and are interbedded with clays, marls, and sands. Sands and clays make up by far the greater part of the beds. The lithologic character and the character of the fossils indicate a very shallow water deposition for the whole formation. The Wilcox formation on Chattahoochee River is made up of sandy, glauconitic shell marl, dark colored, laminated, often lignitic, sandy clay, in places consolidated into mudstone, and usually dark or gray glauconitic and lignitic sand. The laminated clay exposed in the bluff at Fort Gaines can be traced northeastward, having in Randolph County north and west of Cuthbert the nature of fullers earth, which is locally glauconitic. Farther eastward in Schley and Macon counties and in the vicinity of Andersonville, the strata which BAUXITE DEPOSITS OF THE COASTAL PLAIN 63 might be referred to this formation on the basis of geographic position are mainly red and vari-colored sands with massive beds of white clay, very pure and in the nature of sedimentary kaolin, bearing little resemblance to the strata on Chattahoochee River. As a result of later investigations, these kaolin-bearing beds are believed to belong to the Midway formation, while the carbonaceous and pyritiferous beds of Copperas Bluff represent the Wilcox. Thickness.-The thickness of the Midway on Chattahoochee River was estimated by Langdon1 at 218 feet. The width of the outcrop on Chattahoochee River is about 8 miles and it is believed that Langdon's estimate is nearly correct, but it is probably excessive rather than too small. The thickness of the whole Midway northeastward is probably greater, and >Yhile it can not be accurately estimated, is about 300 to 400 feet. The width of the outcrop on Flint River is about 15 miles and it is not believed that an estimate of 400 feet is excessive. As recorded dips of the strata are variable, individual beds not continuous, and only a few well data available, no accurate estimate is possible. It seems very probable that Langdon's estimate of 402 feet for the thickness of the Wilcox is excessive, in view of the small thickness of the form~;~,tion at Fort Gaines, and from the fact that Vaughan has determined Exogyra costata from the Blakely well at a depth of 500 to 510 feet. The thickness of strata between the Claiborne and the Midway formations at Fort Gaines does not exceed 75 feet. It is difficult to form an accurate estimate of the thickness of the Wilcox formation as is true also of the Midway formation, for east of Chattahoochee River neither the base nor the top of the formation has been accurately established. There is a natural exposure of the formation revealing an estimated thickness of 100 feet of strata at Peterson Hill, 41j2 miles northwest of Cuthbert. The maximum thickness at any place over the area of outcrop probably does not exceed 150 or 200 feet. There is no positive proof of strata of Wilcox age on Flint River. They may be entirely overlapped by the Langdon, D. W., Geology of the Coastal Plain of Alabama: Geo. Survey of Ala., p. 369 1894. 64 GEOLOGICAL SURVEY OF GEORGIA Claiborne, but assuming that the strata lying between the Midway formation at Dripping Bluff and the Claiborne or Jackson formations is Wilcox, the thickness is perhaps 100 feet. Considering the kaolin-bearing beds to be Midway, the thickness remaining for the Wilcox formation is even less than this estimate. Both the Midway and Wilcox formations have a gentle dip to southeast, amounting to only a few feet per mile. On account of the slight inclination and the inconstancy of individual beds, it is not possible to make direct measurements of the strike and dip. Physiographic expression.-The topography of the area underlain by these formations is rather broken and hilly, somewhat similar to the Cretaceous area to the northward, and in contrast with the level topography of the areas to the southward underlain by Upper Eocene and Oligocene strata. A few limesinks occur in the vicinity of Fort Gaines and north of Cuthbert. Paleontologic characters.-Both formations are poorly fossililerous. Thirteen invertebrate forms and one vertebrate (a turtle) have been reported from the Midway. Thirteen invertebrates make up the entire known fauna of the Wilcox. 'fhese fossils are found only in the limestone and chert beds, and are therefore of little value in correlating the kaolin and bauxite deposits. Location and age of the bauxite depo.sits.-The bauxite deposits of the Lower Eocene are associated with a horizon of plastic to indurated and nodular, white, sedimentary kaolin and white kaolinic and micaceous sand which extends from Flint River in northern Sumter County through Macon County and the eastern part of Schley County. The kaolin beds of this horizon cap the hills near Ideal, Macon C 00 Ci":l l;lj 0 t-< 0 ~ ~ t-< 1"r.> ~ "'1 l;lj '1 0 "';j ~ 0 1::>:1 Nl o 100 zoo 300400 soo r;:Ci":l SCALE IN FEE.T CONTOUR INTERVAL lOfT. Fig. 7.-Sweetwater mine and Thigpen lot, Sumter County, showing distribution of bauxite deposits. Map by L. M. Richard. BAUXITE DEPOSITS OF THE COASTAL PLAIN 69 The accompanying map, figure 7 (after Richard), shows the extent of outcrop of the bauxite lens and its relation to the topography. Actual outcrops of the bedded ore are uncommon, but pits and borings together with the bauxite fragments in the soil show that the bed is continuous around the slope, the distance between the most widely separated exposures being 1300 feet. In 1916 the working face, 200 yards long, cut across the end of the hill in a northeast-southwest direction. The average overburden was at least 30 feet, and the ore bed varied between 5 and 6 feet in thickness, except at the edge where it had been partly cut away by the unconformity. At pit No. 2 a little stripping had been in preparation for starting mining. There is here from 3 to 4 feet of workable ore, overlain by plastic kaolin and grading downward into bauxitic clay. At pit No. 3 the bauxite is also overlain by kaolin. Only 1 foot of ore is in sight; this, however, does not represent the entire thickness of the bed. Pit No. 4 shows 4 four feet of workable ore, which is apparently not the entire thickness. The bauxite is overlain by kaolin. Drill hole No. 2 is said to have penetrated bauxite 8 feet thick at a depth of 45 feet. The bed of ere is horizontal and shows only slight variations in thickness. The greatest thickness in the portion of the mine already worked out was 7 feet, while the maximum reported in borings is 8 feet. The thickness in the working face when last visited was a little less than formerly, the average being about 5 feet and the maximum only 6 feet. Near the center of the face the ore thins to 4 feet on account of a rise in the underlying clay, the upper surface remaining horizontal. The mass of clay forming the rise is finely nodular and iron stained. Above it the ore shows banding, produced by iron stains, at various angles, but the red bands do not enter the nodules. This banding appears to be original, and formed by the currents which deposited the ore. The rise in the base of the ore is circular and about 100 feet in diameter. This may mark the inlet 70 GEOLOGICAL SURVEY OF GEORGIA of the original source of the mineralizing solutions (hot or acid spring), but unfortunately the structure of the underlying clay can not be seen. The ore.-The best portion of the ore makes up a bed 3 or 4 feet thick. It is hard and conglomeratic in appearance, consisting of nodules of rather irregular shape, varying in size up to 1% inches, in a softer matrix which is locally iron~ stained. The volume of the nodules or pebbles is considerably greater than that of the matrix. When broken the nodules are seen to be compound, made up of hard, light gray, flinty material containing lighter colored and softer pisolites. The bauxite grades into white kaolin both upward and downward. The upper gradational phase is thin, and the distance separating hard bauxite and plastic kaolin without nodules is only 1 to 2 feet. The lower gradational clay is more coarsely nodular and extends through a much greater distance, the clay being bauxitic for some feet below the floor of the mine. The following series of analyses shows the gradation, from the overlying kaolin down to the base of the workable portion of the bed .. Ana~yses of bauxite from Sweetwater mine . I I donstitutents I I I I I S-1091 S-110 S-111 S-112 S-1131 S-114 S-115 S-1161 S-117 Si02 AI.O, . ..................... Fe.o. ............. FeO .............. 34.31 44.18 .81 .29 I 23.18 16.18 49.55 54.58 2.28 .99 .14 .29 9.08 57.13 2.42 .29 5.46 58.82 2.72 .14 6.00 58.06 2.73 .14 8.84 58.38 1.30 .14 14.28122.79 55.641 51.48 1.32 1.14 .28 .14 MgO ............ CaO .............. Na.o ........ ..... K.o ...... ... ..... .00 .00 .06 .08 .02 .00 tr. tr. .00 .00 .00 .00 .04 .00 tr. tr. .00 .oo .oo .oo .00 .00 .00 .00 .06 .00 tr. tr. .00 .00 .00 .00 .03 .00 tr tr. Ignition ........... 18.16 23.28 25.58 27.75 30.26 30.21 29.25 26.84 22.58 Ti02 1.82 1.81 2.74 3.08 2.72 3.07 1.80 1.81 1.81 -- -- -- -- -- -- -- -- Total ............. 1 99. 71 100.26 100.36 99.79 100.12 100.21 99.77 100.17 99.97 Moisture . .. I .77 .72 .73 .67 .91 .40 .06 .44 .39 I I B.AUXITE DEPOSITS OF THE COASTAL PLAIN 71 These samples were taken from a vertical working face at one foot intervals. Sample S-111 is from the top of the hard ore bed; S-110, from the soft but nodular clay one foot above S-111 ; S-109, one foot higher thap. S-110, is white plastic kaolin, shown by analysis to be slightly bauxitic, although it shows no trace of nodular structqre. Samples S-111 to S-117 are from the face of ore as worked. The average of these samples from the ore bed is as follows: Average analysis of seven samples from working face Sweetwater m~ne Silica ( SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,03 ) Ferric oxide (Fe,08). Ferrous oxide (FeO). . . . . . . . . . . . . . . . . . . . . . . Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Soda (Na,O) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potash (K,O) ......... :. . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,)........................ 11.80 56.30 1.80 .20 .02 .00 tr. tr. 27.50 2.42 Moisture 100.04 .51 Near the edges of the deposit, where the overlying impervious bed of kaolin has been cut away by the unconformity, the ore is badly stained by iron deposited from water percolating through the red sand. In the central part of the lens, however, the bauxite shows no sign of alteration by weathering. In the southwest end of the pit a mass of bauxite containing con~iderable pyrite was encountered. The pyrite occurs principally within the nodules, sometimes in crystals visible to the naked eye, but mostly so finely divided as to appear only as a gray stain. Microscopic examination shows that the pyrite occurs as small cubes and octahedra forming the nuclei of the smaller oolites, as veinlets filling .fractures in the pisolites, and as very fine, disseminated grains. (See detailed description, p. 101 and Pl. X, A, B and 0.) The quantity of pyrite is sufficient in some places to give deter- 72 GEOLOGICAL SURVEY OF GEORGIA minations of over four per cent ferric oxide, or more than is contained in the red-stained bauxite around the edges of the deposit. The ore in the southwest part of the face is becoming more clayey, and appears to be grading into kaolin. On this account the average grade of ore is not quite so high as in the earlier part of the work. Development and methods.-The mine and other pits have been previously described. Two trestles lead from the mine and pit No. 2 across the valley of Big Branch to the drier. All work, both mining and stripping, is done by manual labor, filthough this is apparently not the most economical means of handling an overburden which averages 30 feet of soft material over a large area. A little blasting is done to loosen the overlaying kaolin, but this would probably not be necessary if steam shovels were used. The overburden is dumped into the valley of Big Branch and into the worked-out part of the pit. A small amount of ore around the edge of the pit is mixed with the superficial sand and clay. This portion is passed over a screen of one-fourth inch mesh, that passing through the screen being rejected. Some bauxite is lost by this method, but the quantity of such ore is so small that it would not pay to install a washer. Most of the ore goes to the drier without any preliminary treatment. All of the ore is put through a rotary drier, 30 feet long and 3 feet in diameter, which is heated by a wood fire. This removes all of the hygroscopic and a part of the combined water, bringing the percentage of alumina up to between 58 and 60 per cent. The dried ore is hauled to the railroad with a four-ton motor truck, which is able to make, in dry weather, one round trip per hour, or ten trips a day. Most of the ore contains less than two per cent 9f ferric oxide, and is used principally in the manufacture of alum and. other aluminum salts. The ore carrying more than two per cent of ferric oxide is used in making aluminum. Tonnage estimate.-The outcrop of ore has a length of 1300 feet, so the deposit may safely be assumed to have the form of a half cir- "' B.!DXJTE OF THE COASTAL PLAIN OF' GEORG I A PuATE V A. SWEETWATER BAUXITE MINE AND DRIER OF THE REPUBLIC MINING & MANUFACTURING CO. , SUMTER COUNTY. - - -- --- B. CLOSE VIEW OF BAUXITE DRIER AND STORAGE BIN, SWEETWATER MINE. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 73 cular lens of that diameter. Assuming an average thickness of four feet and 15 cubic feet of ore per ton, the tonnage would be 175,000. This is a reasonable estimate of the amount of ore in the deposit, but it may not all be available, because the overburden reaches a thickness of 60 feet over a part of the assumed area. The production of the mine recently has been about 1,000 tons per month. THIGPEN LOT (Map locality S-2) Lot 214, known as the Thigpen lot, lies west of lot 186. Sweetwater Creek crosses the northeastern corner of the lot, but all of the bauxite is on the south, or Sumter County, side of the creek. The Republic Mining and Manufacturing Company has the refusal of the deposit, but no mining has yet been done. The bauxite deposit lies across the valley of Big Branch from the Sweetwater mine, and at the same altitude. There is a possibility that the two deposits may have been continuous before the valley was cut. Outcrops or indications of bauxite in the form of nodules and boulders in the soil are found for a distance of 3,000 feet around the contour of the hill, while a straight line joining the ends of the exposures measures 1,750 feet. Pit No.1 (See map, fig. 7) is at the summit of a small knoll, which is covered with blocks of hard bauxite. The pit exposes 5 feet of bauxite, overlain by only a few inches of sandy soil. The ore is hard at the top, becoming softer and more clayey, with small and scattered, but hard, nodules toward the bottom. It appears to be rather badly iron-stained, on account of the lack of impervious overburden, although the iron content is reaHy low. An average sample of the 5-foot bed was taken for analysis. Analysis of bauxite, pit No. 1, Thigpen lot Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,03) S-118 8.30 57.45 - 74 GEOLOGICAL SURVEY OF GEORGIA Ferric oxide (Fe.O,)............................ 1.77 Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.01 Titanium dioxide (TiO,)........................ 2.72 Moisture 100.25 .58 Pit No. 2 is across the old plantation road, 800 feet southeast of Pit. No.1. Section in pit No. 2 Thigpen lot Feet 3. Yellow clay soil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Finely nodular white clay, like that overlying the bauxite in Sweetwater mine.................... 1 1. Bauxite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 The bottom of the pit was filled with water at the time of examination, so the bauxite may be thicker than indicated by the section. Pit No. 3 is :1 cut in the hillside northeast of No. 1, showing 4 feet of bauxite. Although the ore body has not been very thoroughly explored, the ore seems to be of approximately the same grade as that on lot 187. The location is more favorable for working than at the Sweetwater mine, as the maximum overburden is less than its increase on working back from the outcrop will be more gradual. The outcrop is more extensive than at the mine, but the bed seems to be thinner, and its continuity throughout the area between outcrops is somewhat doubtful. EASTERLIN MINE (Map locality 83) The property of B. F. Easterlin of Andersonville comprises nine land lots, but bauxite is known to occur only on lot 277, on the south side of Sweetwater Creek, 3% miles from Flint River and 3.8 miles, by road, east of Andersonville, the shipping point. The deposit has been known since 1912, but continuous mining was not started until March, 1916. The mine is operated independently by Mr. Easterlin. The bauxite outcrop is 30 feet above the level of Sweetwater BAUXITE DEPOSITS OF THE COASTAL PLAIN 75 Creek, and is a little higher than the deposits on lots 187 and 214. The geologic relations are similar, the deposit being a lens of bauxite in a bed of kaolin. On account of the hardness of the ore and lack of overburden over a considerable area, the deposit makes a great surface showing. Bauxite caps a small knoll and outcrops around the slope of a hill, as shown on the map (fig. 8), and section (fig. 9). 1 0 :;; 0 I00 200 300 400 SCALE IN FEET CONTOUR INTERVAL 5 FT Fig. 8.-Easterlin property, Sumter County, showing distribution of bauxite deposits. Numbered pits are described in the text. Map by L. M. Richard. :0 "c ' ."0..'. ~ A ro ~ B ... :._: t~ ?&@hik~Bauxite ~.: ~ Ba~ uxite ~-------~ - - - - - - - - - =---= 1 ==::Kaolin-- ~-=-----==----===-.-==-----=-==- -----------IOOOFt--------------;. Fig. 9.-Section on Easterlin property, along line A-B, fig. 8. 76 GEOLOGICAL SURVEY OF GEORGIA Pit No. 1, from which 150 tons of ore was shipped some years ago, shows the following section : Section in pit No.1, Easterlin property Feet 3. Sandy soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Hard, finely nodular bauxite with gray, flinty matrix 1% 1. Coarsely nodular bauxite with softer matrix, becom ing clayey toward the bottom.................. 2 Analyses of bauxite from pit No. 1, Easterliu property Silica ( Si02 ) Alumina (Al20 8 ) _ . . . . . . . . . . . . . . Ferric oxide (Fe 02 3 ) Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (Ti02). S119 7.63 57.67 2.89 28.97 2.80 S-120 19.54 49.52 4.66 23.72 2.71 Moisture ............ - ........................ S-119-Average of bed No. 2 in above section. S-120-Average of bed No. 1 in above section. 99.96 .22 100.15 ........ .46 Pit No. 2 is 4 feet deep, cutting 2 feet of stained, coarsely nodu- lar bauxite, which grades downward into stained, nodular clay. Pit No. 3 exposes 2 feet of bauxite consisting of hard nodules in a soft, stained, clayey matrix. This ore would probably require wash- ing. Pit No. 4 shows 1 foot of material similar to that in No. 3. Pit No. 5 is below the bauxite horizon, and cuts only mottled, I sandy clay. Pit No. 6 on the edge of the bauxite knoll, cuts 2 feet of hard red bauxite, underlain by mealy clay of a bright maroon color. Samples were taken from the bauxite and red clay, 6 inches apart. Analyses of bauxite from pit No. 6, Easterlin property Silica ( Si02 ) Alumina (Al 02 3 ) , Ferric oxide (Fe 02 3 ) Ferrous oxide (FeO) ......... , ................. . Magnesia (MgO) ............................. . S-121 18.29 47.88 7.39. .32 .08 ........... S-122 32.28 38.42 9.34 .32 .08 BJ UIJ'l'l!J Oft' T il E 00dS7'AL PLAI N OF' GEOTWU PL A TEri A. EASTERLJ N BAUXITE MI NE , SUMT ER COUNTY. JULY, 1916. B. EASTERLIN BAUXITE MINE, SUMTER COUNTY. JULY, 1916. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 77 Lime (CaO) ................................. . Sodium oxide (Na20) ................ , ......... . Potassium oxide (K20) ........................ . Ignition ..................................... . Titanium dioxide (Ti02 ) .00 .06 .04 23.65 2.08 0 ......... 0 ..... .. .. 0 . ........ 00 0 ... .. ....... .00 .14 .12 16.95 2.22 99.79 99.87 Moisture ..................................... . .42 0 0 0 0 0 00 0 0 0 .64 Pit No. 7 is also at the edge of the bauxite, showing 1 foot of ore in place, underlain by indurated, maroon colored clay. Pit No. 8 is at the summit of the knoll, and cuts 41j2 feet of workable bauxite, which grades downward into mealy, yellow clay. As in pit No. 1, the upper part of the ore is hard and finely nodular, while the lower part is coarsely nodular, with hard pisolites in a softer rnatrix. A boring 200 feet southeast of pit No. 1 penetrated 40 feet of sand and clay, without cutting any b~uxite, showing that the extent of the ore lens into the larger hill is small. The overburden on the knoll is almost nothing, and on the larger hill it will not exceed 12 feet. On account of the light overburden all of the bauxite in the knoll and a large proportion of that around the slope is badly stained by iron carried down by surface water, and a part of the bed had originally high iron content, as shown in pit No. 6. There is little "alum ore," containing less than two per cent of ferric oxide in sight, and it is doubtful if any considerable amount will be found. Besides the high iron content, roots have opened up crevices in the hard ore, which have become filled with sand. This will necessitate washing or screening a large part of the ore. Up to July 10, 1916, about 1,000 tons of ore had been mined and shipped, all of which was taken from the knoll. There was no real working face in the mine, but the difference in elevation between the highest and lowest exposures of good bauxite was 8 feet. This is greater than the thickness shown in the pit at the top of the knoll, the greater thickness around the edges being apparently due to the creep of masses of ore down the slope. Most of the ore shipped 78 GEOLOGICAL SURVEY OF GEORGIA has consisted of boulders and hard nodules obtained by screening the sandy soil. It is shipped without drying or other preliminary treatment except the screening of the sandy portion. The bauxite exposed in the workings from which the soil has been stripped is coarsely nodular or gravel ore, similar to that of the Sweetwater mine, except that its color tends more to red or yellow. An average sample of bedded ore was taken from a shallow cut in the top of the knoll, and represents approximately the grade being shipped. This ore is high grade with respect to alumina, and the iron content is by no means excessive. . Analysis of bauxite from the Easterlin mine Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe 02 3 ) :. Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,)........................ S-237 5.65 60.22 2.42 29.50 1.91 Moisture , HODGES PROPERTY (Map locality S-4) 99.70 .90 Bauxite is reported on the property of A. F. Hodges, near the Dixie Highway bridge over Sweetwater Creek, one mile south of Andersonville. A sample, consisting principally of hard pisolites, was sent to the Survey by Mr. Hodges. The analysis is as follows: Analysis of bauxite nodules from Hodges property Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe,03 ) Magnesia (MgO) . . . . .. . . . . . . . . .. . . . . . . . . . . . .. . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,) . . . . . . . . . . . . . . . . . . . . . . . 4.34 60.49 1.13 .00 .00 31.12 2.73 Moisture 99.81 .85 BAUXITE DEPOSITS OF THE COASTAL PLAIN 79 MACON COUNTY There are two groups of bauxite deposits in Macon County. One group is in the southern part of the county very close to the Sumter County line, along Boggy Branch, a tributary of Camper Creek, and the other is in the central part of the county in the valley of Buck Creek. KALBFLEISCH CORPORATION PROPERTY (Map locality M-1) Two small properties purchased in 1915 by the National Bauxite Company and later transferred to the Kalbfleisch Corporation, of Chattanooga, Tenn., are situated on the south slope of Boggy Branch, 21;2 miles north of Andersonville and 11;2 miles from the closest point on the Central of Georgia Railway. The bauxite exposures are found in two spurs of a hill, running north toward Boggy Branch, with a slight valley between. The altitude of the bauxite bed is 360 feet above sea level by aneroid measurement, and from 10 to 15 feet above the surface of the branch. On the first, or northeast, spur of the hill loose nodules and large blocks of hard bauxite are found in the soil covering a part of the slope. Six test pits have been dug in a cleared field, but these are below the horizon of the bedded bauxite and cut only mealy, stained kaolin. One pit a little higher penetrates the bed of bauxite in place, showing 3 feet of ore which consists of very hard nodules or pebbles, averaging an inch in diameter, in a softer, rather clayey matrix. The composition of an average sample is as follows: Analysis of bauxite from the National property Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,)........................ S-123 14.47 54.57 1.93 26.93 1.63 Moisture 99.53 .60 80 GEOLOGICAL SURVEY OF GEORGIA The second spur is located about 200 yards southwest. Exploration work shows that the bauxite bed extends for a distance of 200 yards around the slope. .l\Iost of the work has been done by boring, but one pit penetrates the thickness of the deposit. The ore resembles that in the Sweetwater mine, consisting of very hard, compound nodules an inch or more in diameter, in a softer matrix, and grades into mealey kaolin both upward and downward. The layer containing hard pebbles is 3 feet thick bu~ the entire workable thickness may be as much as 4 or 5 feet. An average sample taken from 3 feet of the bed showing the best ore gave the following analysis: Analysis of bauxite from the National propmty Silica ( SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (AI,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,)............. . . . . . . . . . . . S-236 18.08 52.24 1.62 25.73 1.64 Moisture 99.31 1.10 Both exposures of bauxite here described may belong to one large lens, or they may represent two smaller lenses, as the development work does not prove the continuity of the ore in. the intervening depression. In any case, an area of 3 or 4 acres in the southwest deposit, and probably a little less ,in the other, is underlain by bauxite, whose thickness is not known to be anywhere more than 4 feet. All of the ore is low in iron but has rather high silica content. The slope of both spurs is steep, the overburden in each reaching a thiclmess of 40 feet about 100 yards back from the outcrop, and if the deposit is sufficiently extensive, the overburden will increase to 60 feet. The deposit was opened by the Kalbfleisch Corporation in the !!pring of 1916, and about 1,000 or 1,200 tons of ore shipped. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 81 ENGLISH PROPERTY (Map locality M-2) The property of Charles and Albert English lies on the north slope of Boggy Branch, just opposite the National Bauxite Company's prospects previously described. The deposit is small, but of fair quality and favorably located with respect to transportation. Exploration work has been principally by borings, so that not much of the deposit is visible, but workable ore 4 to 6 feet thick is said to underlie an area of an acre. The following is an analysis of a sample taken from a pit near the branch, where a 2-foot bed of the best looking bauxite is exposed: Analysis of bauxite j1om the English property Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric. oxide (Fe,O,).... . . . . . . . . . . . . . . . . . . . . . . . . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium cUoxide (TiO,)......................... S-140 16.70 53.12 1.33 26.41 1.80 99.36 This ore is similar to that across the branch, consisting of hard pebbles in a clayey matrix. The slope of the hill to north is gentle, and the overburden of the area likely to be underlain by bauxite is light, probably not exceeding 5 feet on the average. KLECKLEY PROPERTY (Map locality M-3) The property of J. L. Kleckley is situated on the south slope of the valley of Buck Creek in the western part of l\Iacon County, 81;2 miles west of Oglethorpe and 9lj2 miles east of Ellaville. The exposures of bauxite are on lots 24 and 37, 29th district. The lower slopes on these lots consist of more or less pure kaolin and fire clay, prevailingly white and containing lenses of indurated nodular clay and bauxite, mantled by a few feet of gray or red 82 GEOLOGICAL SURVEY OF GEORGIA sand. The hills are capped by red sand of' the Wilcox formation, which overlies the white clays u,nconformably. //;;.-------~~o t~ ?i~ ff!I !lS ~-1 10 5 . 0 Fig. 10.-Sketch map showing bauxite exploration work on the Kleckley property, Lot 37, Macon County. Numbered pits and borings are described in the text, The prospect on lot 37 1s on a hillside sloping south, half a mile northwest of Kleckley's residence. The accompanying sketch shows the location of the exploration work and probable extent of the deposit (fig. 10). A detailed description of the openings is as follows : Prospect No, 1 is a trench 80 feet in length and 9Yz feet deep at the head, showing the following , section in the head of the cut. Section of prospect No. 1 Feet 4. Sandy soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Light-colored clayey bauxite with scattered nodules, not quite so hard as the Cretaceous ''chimney rock" of Wilkinson County, which it resembles, in texture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Yellow, finely nodular, clayey bauxite, having about the same texture as the underlying pink material, which appears to weather to yellow bauxite as it approaches the surface along the strike.......... llh 1. Pink or pale maroon, :finely nodular bauxitic clay. The nodules are almost white and slightly harder than the matrix............................... 3 Prospect No. 2 is a pit 4 feet deep, cutting indurated clay which contains large, hard, ferruginous concretions surrounded by maroon stains. Prospect No. 4 is a pit 2 feet deep, in sandy soil containing small pebbles and loose nodules of hard bauxite. Prospect No. 5 is a pit 2 feet deep, in soil containing large blocks of indurated clay with scattered nodules. "' BAUXI'l'E OF THE COASTAL PLAIN OF GEORGIA PLATE Vll A. BAUXITE EXPL ORATION PIT ON THE KLECKLEY PROPERTY, MACON COUNTY. B. BAUXITE EXPLORATIONS ON THE ENGLISH PROPERTY, MACON COUNTY. . BAUXITE DEPOSITS OF THE COASTAL PLAIN 83 Prospect No. 6 is a pit 10 feet deep, showing the following sec- tion: Section in Pit No. 6 Feet. 2. Clayey sand, lower part bright red, upper 3 feet bleached to yellow-gray ... _. __ ..... _.......... 6% ( Unconformity ) 1. BaU:Xite, consisting of very hard nodules, mostly over one inch in diameter, in a softer matrix, with very little iron stain. In the bottom the material becomes softer and more stained so the entire workable thickness is probably penetrated. As shown by the analysis, this is the best bauxite exposed on the property_..................... 3% Prospect No. 7 is a pit 8 fe.et deep, 25 feet south of No. 6. It penetrates 2 feet of sandy ~lay soil overlying 2 feet of bauxite similar to that of No. 6, grading downward into 2 feet of stained kaolin. Prospect No. 8 is a pit 23 feet deep. The section is as follows: Section in pit No. 8 Feet 4. Clayey sand, yellow-gray at top, grading down into red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 ( Unconformity ) 1 3. Red-stained, plastic kaolin....................... 2 2. Bauxitic clay containing scattered hard nodules one inch in diameter. The nodules are most abundant near the bottom,' at the top the material is a white plastic kaolin. . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1. Bottom of pit filled with water at time of visit. . . . 3 The best looking material is the 6 feet just above the water level but even this contains only 44 per cent alumina. Prospect No. 10 is a pit 7 feet deep, cutting 3 feet of sandy soil with a basal conglomerate of small pebbles of indurated clay and hard bauxite, overlying unconformably 4 feet of nodular kaolin. The nodules in the kaolin are small, hard, and ferruginous, with maroon stains in the white clay surrounding individual nodules and groups of nodules. 84 GEOLOGICAL SURVEY OF GEORGIA Prospect No. 11 is a boring which struck bauxitic material at 5% feet. Prospect No. 12 is a boring showing bauxitic material at 121/2 feet. Prospect No. 13 is a boring which reached white kaolin, not apparently bauxitic, at 28 feet. Prospect No. 14 is a boring showing pink bauxitic clay at 25 feet. Prospect No. 15 is a boring with hard bauxitic material at 18 feet. Prospect No. 16 is a boring which struck hard material at 9 feet. The analyses of samples from this locality are as follows: Analyses of bauxite from lot 37, Kleckley property Constituents Silica (SiO,) .................... Alumina (Al,03) 0 Ferric oxide (Fe,O.) .............. Ignition 0 'ritanium dioxide (TiO,) .......... I I I I S-135 S-136 S-137 S-139 14.56 55.47 1.20 26.17 2.40 23.70 49.08 2.00 22.38 2.87 I 99.80 100.03 43.41 35.99 2.33 14.00 2.10 97.83 33.12 43.62 .66 18.12 2.40 97.92 S-135-Average sample from 31;2-foot bed of bauxite in the bottom of pros pect No. 6. S-136-Average sample of beds Nos. 2 and 3, prospect No. 1. S-137-Average sample of bed No. 1, prospect No. 1. S-139-Average sample of the lower 6 feet of bed No. 2, prospect No. 8. The exploration work covers an area of about 4 acres, and shows that this area is underlain by a large deposit of clayey bauxite carrying 40 to 50 per cent alumina with average content of ferric oxide less than two per cent. There is apparently only a small amount of bauxite of better than 50 per cent grade, and a very little above 55 per cent. All is probably too siliceous for use as aluminum ore. On account of the rather low grade of the ore, the heavy overburden, and the haul of at least 8 miles to the nearest railroad, this deposit is hardly worth working at the present price of bauxite; but it is almost certain to be worked in the future. . BAUXI1'E DEP0811'8 OF 1'HE COAS1'AL PLAIN 85 The exposure of bauxite on lot 24, known as the "Stone Spring" locality, is a mile northwest of Kleckley's residence. A trench in the hillside 50 feet from "Stone Spring" exposes a thickness of 10 feet of rather soft, finely pisolitic bauxite, with nodules averaging one-sixteenth of an inch in diameter. The composition of an average sample is as follows: Analysis of bauxite from lot 24 Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe,O,). . . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition .................... . . . . . . . . . . . . . . . . . . . 'l'itanium dioxide ( Ti02) S-134 14.77 53.70 2.10 23.13 1.65 95.35 The hill slopes to north, and 200 feet south of the pit is a gully exposing 20 feet of sandy, micaceous, iron-stained kaolin above the level of the bauxite. This is overlain u~conformably by 30 feet of red sand. However, the slope is gentle, so the overburden will not increase rapidly. Several borings on the slope above the bauxite exposure passed through the kaolin and struck a water-bearing sand stratum, which could not be penetrated by the auger, at about the level of the top of the bauxite bed. As bauxite is exposed at only one point, it is i~possible to make any estimate of the quantity; but the bed is much thicker and apparently more uniform in composition than that on lot 37. The aluminum content could easily be brought up to over 55 per cent by drying. The iron content is a little high for an alum ore, but it is likely that the percentage will decrease on working back into the bed. If this deposit is found to have any considerable extent along the strike it should be of more value than the apparently larger deposit on lot 37. ROBINSON PROPERTY The property of Mrs. Mary Robinson adjoins the Kleckley propBrty on the south. There are indications of a small deposit of baux- 86 GEOLOGICAL SURVEY OF GEORGIA it on the boundary between the two properties, the greater part of the bed lying under a hill on the Robinson property. A pit a few feet south of the boundary line cut 4 feet of sandy soil, underlain by 2 feet of stained kaolin which grades downward into 3 feet of low grade bauxite, consisting of scattered hard nodules in a matrix of kaolin. As nothing of possible commercial value is exposed no samples were taken; the locality, however, is worthy oE further prospecting. PARK PROPERTY (Map locality M-4) There is an occurrence of bauxite on the estate of l\Trs. Josephine Park, 2lj2 miles southwest of the Kleckley property and 7 miles east of Ellaville, the nearest railroad station. The bauxite occurs near a small branch on the west side of lot 83, 29th district. LAND LOT UN~ The property has been thorough- ly explored by Maynard and Sim- mons, of Atlanta, by means of 11 pits and trenches and 18 drill holes. The prospects extend for a distance of about 800 feet along the slope southwest of the branch, 200 300 400 ~00 600 SCALE !N rm. which flows southeast. The relations of bauxite to bauxitic clay Fig. ll. Map of the Park estate, Macon County, by Maynard and Simmons, showing locat10n of bauxite prospects. are shown on the accompanying map (fig. 11). 1.'he best bauxite is exposed in a pit near the bottom of the hill at the southeast end of the prospected area. This pit cuts 5 feet of bauxite, and a boring in the bottom showed 2ljz feet additional. The material is pale yellow, with pisolites abundant but rather soft, averaging half an inch in diameter. The following is an analys'is of an average sample from the 5 feet exposed: BAUXITE DEPOSITS OF THE COASTAL 1-'LAIN 87 Analysis of bauxite from Park estate Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,O,.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide (Fe 02 3 ) . . Ignition . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . Titanium dioxide ( Ti02) . S-138 19.34 51.73 1.80 25.02 1.40 99.29 Four hundred feet northwest of the pit above described the kaolin comes within a foot of the surface. Several pits show indurated kaolin, with or without pisolites. One pit cuts 5 feet of hard material without pisolites, but with irregular crust-like concretions. This bed appears bauxitic, but the following analysis shows it to have the composition of an ordinary kaolin, indurated by deposition of silica. Analysis of indurated kaolin from Park estate Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al 02 3 ) Ferric oxide (Fe,08 ) . Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,). . . . . . . . . . . . . . . . . . . . . . . . S-144 41.54 37.21 1.07 15.03 2.35 97.20 Maynard states that the bauxite discovered consists of two very small lenses at the ends of the area of indurated kaolin. The slope of the hill is .steep, so the overburden will increase rapidly. The estimated quantity of bauxite containing 50 to 52 per cent alumina is 1,000 tons, while there is a considerable amount of bauxitic clay with 40 to 50 per cent alumina. Analyses of the two best samples collected by ::\Iaynard and Simmons from this property are as follows: Analyses of best battxite from Park estate Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . Alumina (Al 02 3 )" Ferric oxide (Fe,O,). . . . . . . . . . . . . . . 16.40 51.90 2.00 19.25 50.13 1.60 88 GEOLOGICAL SURVEY OF GEORGIA Ignition .. . . . . . . . . . . . . . . . . . . . . . . 29.94 Titanium dioxide (Ti02)............ 1.00 27.29 1.50 101.24 99.77 MORTON PROPERTY Bauxite has been discovered on the property of J. S. Morton, of Byromville, Georgia. The property is lot 119, 29th district, Macon County, situated in the extreme southern part of the county, and the deposit belongs to the Camper Creek group. Samples of nodular clay and bauxite were sent to the Survey by Mr. Morton. Analyses of these samples are given below. The bauxite resembles in texture that from other deposits along Camper and Sweetwater creeks. It consists of hard, compound pisolites up to one inch in di_ameter in a softer matrix. The samples appear to have been taken from surface boulders, and the extent of the deposit is not known. Analyses of clay and ba1txite from Morton property Silica ( SiO,) . oo. oo.. o.. :. o . . . . Alumina (Al,03 ) oo. . . . 0. 0 0 0 0 0. 0.. Ferric oxide (Fe,03 ) o. . . . . . . . . . Magnesia (MgO) 0 o... o. . . . . . Lime (CaO) .. oo.... 0 o.. o......... Ignition . . . . . . o. 0 0 0 0 Titanium dioxide (TiO,) .. o......... 43o22 38.05 1.23 .08 .04 13.82 2.73 10.53 56.45 1.23 .08 .06 29.21 2.34 Moisture 99.17 .44 IDEAL LOCALITIES (Map locality M-5) 99.90 .72 On the north side of Whitewater Creek, 2 miles northeast of Ideal, are exposures of both soft and indurated nodular kaolin, which is only slightly bauxitic. Exploration work has been done on the W. A. Aldrich and Chapman-Hardison properties. The bauxite lenses near the top of the Midway formation here cap the hills, while in the southern part of the county they are only a little above the level of the creeks. BAUXITE DEPOSITS OF THE COASTAL PLAIN 89 So far nothing of economic importance has been discovered, but the indications gre good, as deposits of bauxite are likely to be associated with the indurated kaolin. SCHLEY COUNTY STEWART PROPERTY (Map locality Sc-1) Bauxite is found south of Buck Creek on the property of J. T. Stewart, lot 50, 29th district, half a mile north of the Ellaville-Oglethorpe public road and 5% miles east of Ellaville. .A plantation road crosses the bauxite area. One thousand feet west of the road an area of several acres is covered with bouders with maximum diameters of 5 or 6 feet of light red, hard, finely nodular bauxite. .A test pit within the boulder area penetrated 4 feet of white, sandy clay and struck a ledge of hard, ferruginous sandstone, showing that the boulders were derived from a higher horizon. South of the boulder area is a slight rise, and a pit cuts 3 feet of sandy soil overlying 3% feet of bauxite. The bauxite is of medium hardness, consisting of small white nodules, (average size, one-fourth inch) in a harder red matrix. .Although much softer than the boulders, the latter were eviaently derived from this stratum by surface hardening. The overburden increases very gently to southward, and will not exceed 10 feet over an area of several acres. East of the plantation road a number of pits at higher level than the preceding cut only slightly bauxitic clay. One pit, 500 feet east of the road and about level with the boulder exposure cuts light yellow finely nodular bauxite. The pit was partly filled, so the thickness could not be measured, and the sample had to be taken from the material on the dump. The following analyses indicate the grade of ore which may be expected: 90 GEOLOGICAL SURVEY OF GEORGIA I Constituents I S-141 I I Silica ( SiO,) ............ 12.42 Alumina (Al,O,) .......... 53.32 1 Ferric oxide (Fe,O,) ...... 4.93 Ignition .................. 25.66 Titanium dioxide (TiO,) .... 2.25 I I 98.58 S-142 19.59 50.64 3.10 24.10 2.26 99.69 S-143 13.80 51.05 2.70 26.80 2.40 96.75 S-141-Average sample from surface boulders of hard bauxite. S-142-Average sample from 3% feet of bauxite in pit south of the boulder a,rea. S-143-Light-colored bauxite from pit 500 feet east of the plantation road. All of the ore is siliceous and ferruginous, but there is a considerable amount containing between 50 and 55 per cent of alumina in its natural state. Bauxite is shown up at two points, 1,500 feet apart, and there is a possibility that it is continuous throughout the intervening area. Even if not continuous, there are two lenses which may be expected to yield a considerable ton:uage, while the overburden is light as compared with deposits which are being worked. The haul to Ellaville, the nearest point on the railroad, is 5.7 miles, over a good road without heavy grades, which would not be prohibitive for a good grade of ore. HOLLOWAY PROPERTY (Map locality Sc-2) On the property of G. W. Holloway, situated in the southern part of Schley County, between LaCrosse and Andersonville, is an exposure of bauxitic material of unusual character. It is hard and nodular. The color is yellow, showing that the large percentage of iron occurs as yellow limonite. The bed is 4 or 5 feet in thickness, and the outcrop extends for about 100 feet around the slope of a hill. Analysis of bauxite from Holloway property S-235 Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.18 BAUXITE DEPOSITS OF THE COASTAL PLAIN 91 Alumina (AI,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ferric oxide ( 3 ~'e,0 ) Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium Jioxide (TiOJ........................ 34.00 34.48 22.32 2.20 l\foisturc STEWART COUNTY (JJ ap locality St-1) 100.18 2.13 Bauxite has been reported on a property held under option by G. W. Dozier, of Dawson, Georgia. The location is 1% miles west of Troutman's siding, in the southeastern corner of Stewart County. The prospeet has not been explored, and no analyses are avail- ahie, hut the oecurrence indicates that bauxite may be expected in the area of outl'rop of the l\fidway formation west of the l\Tacon and Schley County area. PHYSICAL AND CHEMICALICHARACTERISTICS PHYSICAij CHARACTERISTICS CLA SSH'ICATION 'l'he bauxiteH of' the Coastal Plain vary grea11y in eolor and texture. With eei"t11in modifications, the classifieation of the north Georgia h;w~itre was broken up and the pebbles rounded by attrition. 6. The mixture of amorphous aluminum hydrate and kaolin forming the clayey matrix to the pebbles was deposited. Specimen S-232.-This is a high grade, coarsely pisolitic ore from the Cason mine of the National Bauxite Company at Toomsboro, Wilkinson County: The ore is irregularly nodular, most of the nodules appearing simple to the naked eye. (See analysis, p. 47.) The section was cut from a sample taken near the surface, and contains more iron than the average analysis, but otherwise has about the same composition. It cuts two nodules, the larger of which is B. t UXJ'J'EJ Oft' '!' li E CO .t 8 'l' .Jf, PTuJ ZN OF' GEOROU PL A'I'EJ .1' ~ R A. SEC. S-1 96. BAUXITE PISOL ITE CUT BY VElNLETS OF PYHlT E. THANSMITTED LIGHT. MAGN I.FIED 37 D IAMETEHS . B. SEC. S-196. BAUXITE PISOLT'J'E OF OOLITIC MATERIAL. \\' ITH VE [NLE TS OF PYI.{lTE BETWEEN T HE OOLITE S. T RANSMITTED LIGH.T. MAGNIFIED 37 DIAMETERS. c. D. C. S!!:C. S-196. BAUXITE OOLlT.I!: \V ITH A M ASS O F FINE PYHI'J'E C RYSTALS FOR A NU 'LEUS. T HANSMITTED LIGHT. MAGNIF IED llO D IAME TEH S . lJ. Si!:C. S-2. FULLEHS EAR TH, SHO\YJ NG GRANULAR AND POHOUS STHUCT UHE AND THACES OF FOSSILS. THANSMlTTED. LIGHT. MAGNIFIED 110 D l AMETEHS. BAUXITE DEPOSITS OF THE COASTAL PLAIN -103 oval in shape and 1 em. long. The interior structure of the nodules shows concentric banding, but the bands consist of finely oolitic ore, with oolites up to 0.3 mm. in diameter. Only the outer shell of the large pisolite, 0.1 mm. thick, is really amorphous. The pisolites are not cut by shrinkage cracks or gibbsite veinlets, as is the case in most ore. The only crystalline gibbsite present is a few scattered crystals 0.03 to 0.04 mm. long. The matrix is more coarsely oolitic than the material of the pisoIites. It is much stained by iron carried in by surface waters, solutions which did not penetrate the larger nodules. There are no gibbsite veinlets, but a few small cavities are filled by crystals of a translucent red mineral, probably iron-stained gibbsite. CHEMICAL AND MINERALOGICAL COMPOSITION There are three generally recognized hydrates of alumina, with the following compositions: Constituents Diaspore Bauxite Gibbsite Al,03 H,O AI.08 2H.o AI.o,. sH.o I Alumina (Al20 8 ) ............... , Water (H20) .................. I 85.01 14.99 -- 100.00 73.93 26.07 -- 100.00 65.41 34.59 -- 100.00 I have found no analyses which correspond very closely to the formula given for bauxite, and the existence of such a mineral is denied or considered doubtful by many writers who have made a careful E.tudy of bauxite deposits. Clarke1 says of it: "Although many writers have regarded bauxite as a distinct mineral species, having the empirical formula Al20 3, 2H20, few samples of it have exactly that composition.. It is usually intermediate be- tw~n diaspore and gibbsite; but is sometimes near one and sometimes near the other. It seems, in fact, to be a mixture of the two hydrates, but in an amorphous condition. When solutions of sodium aluminate s Clarke, F. W., U. S. Geol. Survey Buii. 491, p. 475, 1911. 104 GEOLOGICAL SURVEY OF GEORGIA are decomposed by carbon dioxide, only the trihydrate is thrown down, at least so far as crystalline products have been observed. The ordinary, precipitated, gelatinous hydroxide has the same composition, according to E. T. Allen1 ; but at 100 it loses water and becomes a dihydrate. The latter, in moist air, regains water readily-an order of change which renders its occurrence on a large scale as a natural a mineral highly improbable. Even if dihydrate were formed it would speedily be altered into something more nearly resembling gibbsite." In this connection it is notable that all of the deposits formed in comparatively recent time by alteration of igneous rocks, or found in undisturbed btratified material, approach gibbsite very closely in composition; while those in folded beds which have undergone dynamometamorphism to a greater or less degree, such as the Baux deposits, contain a lower proportion of water. In a tabulation of all the analyses of north Georgia bauxites available at the time of publication of his report, Watson2 shows that all of the ore is very close to the trihydrate in composition. Wysor3 has published analyses showing the presence of diaspore in the oolites, but not in the matrix, of the Arkansas bauxite. Some of the oolites have almost the composition of diaspore, and others are intermediate between that mineral and gibbsite, but the existence of the dihydrate as a separate mineral is not demonstrated. Leith and Mead,4 in describing th~ same deposits, call the amorphous form of the trihydrate bauxite and the crystalline mineral of the same composition gibbsite. This is a variation from the older and more commonly used terminology of Dana,5 who defines the trihydrate of alumina as gibbsite, with a crystalline variety, hydratgillite. Laur6 states that "the bauxites" constitute a mineralogical family, having as a basis the dihydrate of alumina (H4Al20 5 or Al20(0H) 4 ) which acts as an acid in combining with iron and as a base in com- ' Chern. News, vol 82, p. 75, 1900. 2 Bauxite deposits of Georgia, Geol. Survey of Ga. Bull. 11, p. 42, 1904. 3 Wysor, D. C., Aluminum hydrates in the Arkansas bauxite deposits, Econ. Geol., vol. 11, p. 42, 1916. Leith, C. K. and Mead, W. J., Metamm-ph!c geology, p. 27, 1915. Dana, J. D., A system of mineralogy, 6th ed., p. 254, 1893. 6 Laur, Francis, The bauxites-A study of a new mineralogical family, Trans. Am. Inst. Min. Eng. vol. 24, p. 234, 1894. BAUXITE DEPOSITS OF THE COASTAL PLAIN 105 bining with silica. In other words, the mineral always contains about 69 per cent Al20 3 , 4 per cent accessories such as titanium oxide, and 27 per cent of H 20, Si0 2, and Fe 20 3 combined; and these latter subFtances may replace each other in widely varying proportions. He calls the dihydrate hydrargillite, but also refers to the trihydrate as gibbsite, which he says grades into clay and iron ore and is of little importance. He says of the Georgia-Alabama bauxite, "It is nothing tlse than amorphous hydrargillite, nearly pure, with 3 to 4; per cent of accessory conatit11ents and 27 per cent of water.'' This statement is t.>ntirely erroneous, according to his usage of the word hydrargillite, yet these deposits afford his only example of the basic mineral, or "hyaline bauxite." as the French deposits are all of "mixed" types. His conclusions are not substantiated by analyses, in fact, the only analysis quoted in his paper is a monohydrate. Phillips and Hancock1 investigated the solubility of the GeorgiaAlabama bauxite in sulphuric acid of different concentrations. They divide the alumina of bauxite into three portions: ''free,'' which is soluble in acid of 50 B. at a temperature of 1000. in one hour; ''combined," which is soluble in_ concentrated acid when evaporated until fumes of SO, are given off; and "insoluble," which is the small amount (one or two per cent) remaining in the residue after the latter treatment. The ''free'' alumina is shown to exist almost entirely as trihydrate, although that of the kaolin is also slightly attacked by the weaker acid; and the ''combined'' comprises most of the alumina combined as kaolin. This work does not prove that the lower hydrates of alumina are absent, but it shows that if present at all they are in very small amounts. The authors conclude that the titanium oxide is in the hydrated form (leucoxene), and is almost insoluble in the 50 acid, although the concentrated acid dissolves a large proportion. The Ferguson method, now used for the determination of available . alumina in alum ores, is based on this ~ork. In this method 50 acid 1 Phillips, W. B. and Hancock. David, The commercial analysis of bauxite. Jour. Am. Chern. Soc. vol. 20, p, 209, 1898. 106 GEOLOGICAL SURVEY OF GEORGIA 1s used, and boiled for three hours with a reflex condenser to keep the volume constant. The results agree very closely with the extraction obtained in commercial practice. In all of the analyses given in this report the total alumina has been determined. In the usual type of bauxite, which has very little free silica or sand, but practically all combined in kaolin, the amount of soluble alumina available for the manufacture of alum by the acid process is approximately the total percentage of alumina minus the percentage of silica. In the Coastal Plain deposits the alumina seems to occur almost exclusively as the trihydrate. All gradations are found from almost pure trihydrate of alumina to almost pure kaolin, the limiting analyses being as follows : Constituents I Gibbsite Al,O,. 3H,O Kaolinite Al,O. 2Si0,. 2H,O Alumin~ (AI,O,) ........... .. ... 1 I Silica (SiO,) ..................... 1 Water (H,O) ...................... 65.41 .00 34.59 39.48 46.60 13.92 100.00 100.00 Of course, there are always present oxides of iron and titanium, with small amounts of other elements. These impurities usually make up three to five per cent in the white bauxites and kaolins. In the analyses made for this report Ti02 varies from 0.90 to 3.26 per cent; Na20, 0.00 to 0.32; K 20, 0.00 to 0.24; CaO, 0.00 to 1.13 (the latter analysis is a kaolin, and is the only one showing more than a trace) ; MgO, 0.00 to 0.40; S, 0.00 to 0.36; Zr02, 0.003 to 0.007; BaO always 0.00; and P 20 5, always 0.00. To show the gradation in individual deposits, the analyses of series of samples taken at one-foot intervals from the working faces in the Mcintyre and Sweetwater mines have been plotted on triangular diagrams (figs. 12 and 13). In these diagrams each of the small triangles represents a single analysis : its area shows the percentage of Fe20 3 and miscellaneous elements: its position in the large triangle, BAUXITE DEPOSITS OF THE COASTAL PLAIN 107 the percentages of the three principal oxides. The distance from the base of the large triangle represents the percentage of Al20 3 ; from the left-hand side, H 20; and from the right-hand side, Si02 All simple mixtures of kaolin and gibbsite would fall as points along the line connecting the two points representing the composition of those minerals. Fig. 12.-Analyses of bauxite from the Mcintyre mine plotted on a triangular diagram to show gradation from gibbsite to kaolinite. In figure 12, analysis No. 1 is the sandy, sedimentary clay of Eocene age which forms the overburden; the other analyses are all bauxite and kaolin, showing well the gradation. However, such gradation does not in this case indicate that the bauxite is a weathering product of the kaolin. Its significance will be discussed later. The recalculated mineral compositions of the bauxites of this series are as follows: (See complete analyses, p. 37.) 108 GEOLOGICAL SURVEY OF GEORGIA Mineral composition of bauxite from the Mcintyre mine Minerals IS-1091 S-110 S-111 S-112 S-113 S-114 S-115 8-116 S-117 Gibbsite ~ 0 0 0 22.97 45.62 62.46 75.58 82.88 80.96 77.82 66.56 49.14 ......... Kaolinite 73.78 49.78 34.77 19.51 11.72 12.92 18.97 3o.68 48.95 ......... Limonite .93 2.65 1.16 2.84 3.18 3.19 1.53 1.54 1.35 ......... TiO, etc. 2.25 1.97 3.03 3.41 2.86 3.21 2.00 2.09 1.98 H,O-excess 0 .24 ... H,O-deficiency .22 1.06 1.55 .52 .07 .55 .70 1.45 These compositions were computed by the following method: 1. All ferric oxide was computed as limonite. 2. All silica was computed as kaolinite. 3. The remaining alumina was computed as gibbsite. This sometimes requires more water than the amount available, sometimes less. The difference is stated as excess or dificiency of H 20. 4. Titanium dioxide and small amounts of soda, potash, etc., are not computed as definite minerals. These figures show a very close approximation to a mixture of gibbsite and kaolinite. Excess of water may be due to hydration of Ti02 ; to iron replacing aluminum in gibbsite, in which case it would take up more water than in limonite; or to a higher hydrate of alumina than gibbsite, which seems to occur occasionally.1 It is also a known fact that some of the silica exists as sand grains, while all has been computed as kaolinite. If a correction could be made for the free silica, the alumina used in computing kaolinite would be free to combine with a higher ratio of water, as gibbsite. A deficiency of water may be explained not only by the presence of lower hydrates of alumina, but some of the alumina may be, and usually is, in the form of feldspar, mica, or other anhydrous or only slightly hydrous silicates. The mineral composition of the samples from the Sweetwater mine (for complete analyses, see p. 70) is as follows: 1 Wysor, D. C., Econ. Geol. vol. 11, p. 49, 1916. BAUXITE DEPOSITS OF THE COASTAL PLAIN 109 Fig. 13.-Analyses of bauxite from the Sweetwater mine plotted on a triangular diagram to show gradation from gibbsite to kaolinite. Mineral composition of bauxite from the Sweetwater mine Minerals I I I I I I I I I I I I S-64 S-651 S-661 S-67 S-681 S-69 S-70 S-71 S-72 S-73 S-74 . I I! I I I I 1_1_1_1_ G1bbsite ........ I45.88174.75164.48J55.10149.73146.80I34.57136.01 26.30,20.1414.66 Kaolinite ........ I50.99J22.85 30.35140.;30148.19 .51.00162.12 58.87 68.35 78.15 91.15 L~monite ........ I 1.311 1.121 1.871 2.621 3.37,3.181 2.06 2.80 1.30 1.31 1.12 I T10,, etc........ I 2.381 1.651 2.441 1.831 2.08 2.311 2.2612.10j 2.34 2.17 2,75 H,O-excess ..... I 1 1 .681 .161 1 1.27 .25 H,O-deficiency .. I .081 .5~1 1 1 3.10j 2.44 .841 .65 1.231 Several of the richest bauxites and purest kaolins from the Coastal Plain deposits have mineral compositions as follows: 110 GEOLOGICAL SURVEY OF GEORGIA Mineral composition of Georgia bauxite and kaolin I Minerals 1 2 3 4 5 6 7 Gibbsite ............... I 89.48 94.19 Kaolinite Limonite ................ 10.15 .93 1.96 1.98 TiO, etc. ...... .... .... .23 2.28 SiO, ................... Sand 0 H,O-excess ............ H,O-deficiency . .. 1.54 1.09 92.80 1.57 2.28 2.67 .41 89.92 5.97 1.50 1.92 .46 .91 96.85 .69 1.53 .33 .05 1.22 97.00 1.01 1.46 .00 .10 95.37 1.01 1.88 1.35 .31 .06 1. Hard bauxite from the Underwood property, Wilkinson County, Veatch, Otto, Second report on the clay deposits of Georgia, Geol. Survey of Ga. Bull. 18, p. 436, analysis 10, 1909. 2. Hard bauxite from Wilkinson County. Veatch, op. cit., p. 436, analysis 6. 3. Hard bauxite from Wilkinson County. Veatch, op. cit., p. 436, analysis 8. 4. Bauxite nodules from Cannon mine, Wilkinson County. See p. 46 of this report. 5. Kaolin from Atlanta Mining and Clay Company pit. Veatch, op. cit. p. 133. 6. Kaolin from American Clay Company pit. Veatch, op. cit., p. 140. 7. Kaolin from L. Mandie pit. Veatch, op. cit., p. 143. These analyses were all recalculated without moisture before com- puting the min&ral composition. In case of the kaolins ''sand'' is mechanically determined, "SiO/' in No. 7 is excess silica in the clay substance, and probably exists in hydrated form. These analyses show that even the purest of the plastic, sedimentary kaolins of the Coastal Plain frequently have an excess of alumina over that com- binable with the silica as kaolin, which excess must be in the form of aluminum hydrate. Edwards1 has shown that a large number of Georgia clays contain free hydrates of aluminum, using the fact as an argument that these hydrates are produced by weathering, but he has chosen his examples largely from sedimentary kaolins of the Lower Cretacious and from those associated with the north Georgia bauxite deposits. These clays are clearly related to the deposits of bauxite in origin, and it is evident that neither clay nor bauxite is due to ordi- nary weathering processes. 1 Edwards, M. G., The occurrence of aluminum hydrates in clays. Econ. Geo!., vol. 9, p. 112, 1914. BAUXITE DEPOSITS OF THE COASTAL PLAIN 111 GENESIS OF DEPOS.TS ORIGIN OF KAOLIN The bauxite deposits of the Coastal Plain are so closely related to the larger beds of kaolin, that the origin of the latter, and of the Lower Cretaceous beds as a whole, must first be considered. The best discussion of the theory of origin and deposition of the kaolin is that of Veatch/ from which the following paragraphs are largely abstracted. The greater part of the area of the Piedmont Plateau, from which the material of the Lo-..ver Cretaceous sediments was derived, is composed of granites, gneisses, and feldspathic schists, with subordinate amounts of basic intrusives. On the whole the rocks of the region are highly feldspathic. The greater part of the Piedmont was a land surface from the close of the Cambrian period to the beginning of the Cretaceous. During this enormous time interval the region was approximately base-levelled, and was mantled by a great thickness of decomposed and kaolinized rock. Just before the beginning of the Cretaceous period the Piedmont was greatly uplifted and tilted to the southeast, forming a shore line near the present location of the Fall Line. The streams were rejuvenated, and rapidly set to work carrying the great mass of weathered rock down to the sea. On account of the steep gradient of the streams and the soft material on which they worked, the result was a rapid deposition of a great mass of sand, gravel, and clay along the f,oast. The streams formed deltas, which overlapped, resulting in the formation of sand fiats and fresh-water delta lakes, and areas of sea water were enclosed by sand barriers, to be quickly freshened by the inflow from the land. In the quiet waters of the lakes and ponds thus formed the fine clay particles were deposited as lens-like masses of pure white kaolin; whil~ in shallower waters and amid shifting currents the masses of cross-bedded sands and pebbles 1 Veatch, Otto, Geol. Survey of Ga., Bull. 18, p. 97, 1909. 112 GEOLOGICAL SURVEY OF GEORGIA were laid down. Conditions did not long remain uniform, as one set of barrier lakes would fill up while another set was forming farther out. Some of the beds of sand and clay first formed were reworked by a shifting of drainage channels, forming numerous local unconformities and clay conglomerates, which have no time significance. Marine conditions of deposition were entirely absent. No shells nor animal remains have been found in the Lower Cretaceous beds of Georgia, and for some reason plant remains are also absent except jn one locality. There are no calcareous beds, nor even lime nodules, which is natural in such a formation, as the regolith of the Piedmont rocks was thoroughly decomposed and leached and the most of the rocks were only slightly calcic in the first place. Gypsum, which might indicate brackish water deposits, is absent ; and the small amounts of pyrite and sulphates present are closely related to the bauxite deposits in origin. The remarkable pu.rity of the kaolin depm;its indicates that nature operated a very efficient clay washing plant on a great scale. The separation of clay and sand particles depended on specific gravity and fineness of grain. The weathered rock of the crystalline area consisted essentially of quartz, kaolin, mica, and limonite, as the feldspars and ferro-magnesian minerals were almost entirely decomposed. The quartz and remnants of feldspar and ferro-magnesian minerals were dropped in the deltas and close to the shore line, on account of their coarseness of grain; most of the limonite was also deposi~d with the sand, on account of its high specific gravity and because a considerable part adhered as coatings around the sand grains. The kaolin, although it has about the same specific gravity as quartz, was so much more finely divided that it remained in suspent.ion and was deposited in the quieter and deeper waters of the barrier lakes, forming lenses which sometimes have an extent of many acres and a thickness of 30 or 40 feet. On account of their fineness of grain, a considerable proportion of the white mica and titanium in the form of leucoxene went with the kaolin, as well as extremely fine grains of BAUXITE DEPOSITS OF THE COASTAL PLAIN 113 . all other minerals and even of the heavy accessory minerals such as .zircon. Judging from the red soils which now cover the greater part of the Piedmont area, the whiteness of the kaolin and the prevailing light color of the sand beds of the Lower Cretaceous seems remarkable. But these red soils are only superficial, grading down into gray or white material; and their percentage of iron is much less than would be expected from a cursory examination. Forty-eight analyses of Georgia granites and gneisses by W atson1 show a range in content of ferric oxide content from 0.71 to 3.05 per cent, with an average of only 1.45 per cent; while seventeen weathered rocks show a range from 1.22 to 6.33 per cent, with an average of 2.47 per cent. So all except the best deposits of kaolin and bauxite actually contain as large a per- centage of iron as the original rocks from which they were derived. In brief, the kaolin is a sediment derived from deeply weathered, acid igneous rocks, and deposited in shallow, fresh-water lagoons; the conditions being unusual only in that a very complete separation of sand from clay substance was attained. The depositional conditions during that portion of ~Iidway time in which kaolin and bauxite were formed were essentially similar to those of the Lower Cretaceous. RELATION OF BAUXITE TO KAOLIN There are several localities showing gradational phases between kaolin and bauxite which afford important evidence as to the origin of the bauxite; but as they can not be classed as bauxite deposits, detailed descriptions and analyses are given here rather than under the descriptions of the deposits. ''MIDDLE MINE,'' EDGAR BROTHERS CLAY COMPANY (Map locality W-12) This is a small, abandoned pit near the clay-washing plant of the Company, about one mile west of Mcintyre, Wilkinson County. The pit is about 100 feet in diameter, and when visited there was 15 feet 1 Watson, Thomas L., Geol. Survey of Ga. Bull. 9, p. 354, 1902. , 114 GEOLOGICAL SURVEY 'oF GEORGIA of kaolin exposed above the level of the water which filled the bottom. The contact of the kaolin with the red and yellow sand of Eocene age which overlies it is not marked by a distinct clay conglomerate. There is rather a gradational phase of a few inches, where the white clay seems to have been softened and stained before redeposition started. There are scattered rounded clay pebbles for a number of feet above the contact, and on the south side of the pit, 6 feet above the unconformity, is a distinct conglomerate layer of kaolin boulders and fine quartz gravel. Most of the kaolin pebbles in the red sand are less sandy than the kaolin in the pit, and their well-rounded condition indicates that they were transported some distance. The kaolin is all more or less sandy, especially the middle portion of the bed. The quartz grains contained in it are mostly angular, up to one-eighth of an inch in size; and there are a number of specks of dark minerals, among which were recognized hematite flakes and cleavage fragments of green hornblende. The kaolin is white and massive, and no bedding planes can be distinguished. On the south side of the pit the upper 18 inches of the kaolin is stained by iron along dendritic channels, but it shows no sign of change to bauxite. On the east side, where the road entered, is a mass of nodular clay of the form shown in the sketch (fig. 14). When freshly broken, the nodules may be distinguished from the matrix only by their slightly darker color, as both matrix and nodules are of the same hardness. The nodules consist of light gray, very plastic, putty-like clay, which shrinks away from the matrix on drying, and are thus easily eroded out, producing superficial honeycomb structure. They contain more ferrous iron than the matrix, and become ''rusty'' on weathering. The angular quartz grains and dark mineral fragments found in the massive kaolin persist in the nodular clay, and &re found in both matrix and pisolites. The upper contact of the nodular clay with the massive is marked by a band of large, soft, iron-stained clay concretions about 6 inches in diameter, while the pisolites in the mass of nodular clay average 1 inch. BAUXITE DEPOSITS OJ!' THE COASTAL PLAIN 115 L4nd Surfa.ce . _ Fig. 14.-Section in Edgar Bros. Kaolin Co. Middle mine, wilkinson County, showing relations of massive and nodular kaolin and geodes. A and B are places where samples \Yere taken. Along the lower contact are scattered large, irregular shaped geodes, with maximum dimensions of a foot or more. These consist of a limonitic shell about half an inch thick, with the interior partly filled with soft, dark colored material. When freshly broken the material contained in the geodes gives off for a few seconds a fetid odor resembling that of carbon bisulphide, afterwards an empyromatic odor persists for some time. The material from the geodes consists of an unusual assemblage of minerals. The analysis is as follows: Analysis of geode material-S-59 Constituents Carbon bisulphide solution Hydrowater chloric solution acid solu- tion Aqua Insoluble regia residue solution Loss on heating I I S,O, ......... I Al,O, ......... I Fe,O, ......... FeO ........... 1 MgO .......... 1 CaO ......... I I Na,O .......... KH,,O0(100)....II I H,0(150) .... I TiO, .......... s .............. 1 so............. 1 FeS, .......... I I Total 95.72 I I 1.60 I .60 I I 10.28 I I I I I I 2.31 I 22.55 I 2.31 35.03 .59 .70 .00 .00 .00 .00 .00 .78 2.07 .12 4.57 .08 .03 .00 36.37 31.17 9.38 ~.59 .20 .04 tr. 4.65 7.38 .90 13.11 12.03 ~--~ 116 GEOLOGICAL SURVEY OJt' GEORGIA Cursory examination of the material shows that it contains crystalline sulphur; a transparent, soluble mineral, crystallized in fibrous forms and having a strongly astringent taste; and marcasite, so finely crystallized that it appears black. The heavy residue after washing with water consists principally of quartz in subangular grains and microscopic crystals of marcasite. Under the microscope the latter crystals show orthorhombic forms, with crystal faces of a very pale bronze yellow color. No pyrite crystals are present. Only the crystalline sulphur is soluble in carbon bisulphide. It occurs in bunches of crystals and incrustations around other minerals, so that it appears to make up a larger proportion than is actually the case. The water-soluble mineral consists principally of ferrous sulphate (melanterite) with an admixture of ferric sulphate (coquimbite) and aluminum sulphate (alunogen). The water solution has a strongly acid reaction, and it may be seen that the sulphate radical is present in a quantity far in excess of that necessary to combine with the bases. The hydrochloric acid treatment dissolved only an unimportant quantity of material, and the insoluble residue consisted principally of quartz and kaolin. The marcasite, which is, after melanterite, the most abundant mineral, all went into the aqua regia &olution. The discrepancy between the total and 100 per cent is probably due to water not lost at 150 C. The geodes were formed contemporaneously with the surrounding clay, and have been altered little if at all by surface waters. The limonitic shells form impervious envelopes; in cases where the shell has been fractured, allowing surface water to enter, the interior material has been altered to a mass of limonite. Samples of nodular and massive clay were taken at the points marked A and B on the sketch, at the same level and one foot on either side of the contract. The analyses are as follows: Analyses of kaol!in, from Edgar Brothers mine .S-57 Silica (SiO,) . . . . . . . . . . . . . . . . . . . . . . 45.64 Alumina (Al,O,) . . . . . . . . . . . . . . . . . . 37.54 S-58 45.55 38.07 /J.I U .\'l 'f'R 011' 'l'HFJ OO.L8'l'JL PLJ 1 ~' 071' GFJOHGIA ..\.. CLAYMONT KAOLIN MINE , \ V ILKINSON COUN TY. THE PRO.J ECTI NG BED IS A L ENS OF NODULAR SLIGHTLY INDURAT ED CLAY. B.,. :1\ILD DLE M I NE" O F ' l'l'LE EDGAR BH OS. CLAY CO ., M ciNTYRE , W ILKl NSON COUN'Y. IHE HAMMER MARKS THE CONT ACT BET WEEN MASSIVE AND NODULAR KOLIN. BAUXITE DEPOSITS OF THE COASTAL PLAIN 117 Ferric oxide (Fe,03 ). Ferrous oxide (FeO)....... . . . . . . . . Magnesia (Mgo) . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . Soda (Na,O) . . . . . . . . . . . . . . . . . . . . . . Potash (K,O) ................... - Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide ( TiO,) . . . . . . . . . . . . 1.45 .00 .30 .00 .00 .00 13.92 1.45 1.12 .00 .19 .00 .08 .00 13.85 1.44 Moisture 100.30 .40 100.30 .30 The mineral compositions are computed as follows: Mineral composition of kaolin from Edgar Brothers mine Gibbsite . . . . . . . . . . . . . . . . . . . . . . . . . . Kaolinite . . . . . . . . . . . . . . . . . . . . . . . . . Limonite . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium dioxide (TiO,)............ Quartz ....... :. . . . . . . . . . . . . . . . . . . . Water (H,O), excess. . . . . . . . . . . . . . . . S-57 .00 94.96 1.68 1.75 1.48 .43 S-58 00 96.30 1.31 1.71 .76 .22 It is possible that both of these samples contain a little gibbsite, which does not show up in the recalculated analyses on account of the presence of quartz sand, which is computed as combined with ~lumina in kaolinite. The two analyses are almost identical, showing that kaolin may assume a distinctly bauxitic texture without any sensible variation from the massive material in composition. CLAYMONT MINE (Map locality W-13) The Claymont kaolin mine of the Kaolin Mining Company is situated near the Central of Georgia Railway, 4 miles west of McIntyre.' The section in the working face in November, 1914, is shown in the sketch (see fig. 15 and Pl. XI, A). The section was as follows: 118 GEOLOGICAL SDRVEY OF GEORGIA Section in Claymont mine Eocene Feet 7. Overburden, consisting of red sand at top, grad- ing down into yellow sand and this into greenish yellow, clayey and glauconitic sand. The lower portion contains clay pebbles, hard, weathered-out clay nodules, and boulders of indurated clay, harder than any found in place in the pit .......................... 1 to 10 ( Unconformity ) Lower Cretaceous 6. Kaolin containing a little sand ...............' 9 5. White, micaceous, clayey sand. . . . . . . . . . . . . . . . 2 4. Brittle, gritless, jointed kaolin. . . . . . . . . . . . . . . 7 3. Nodular kaolin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 to 6 2. Firm, brittle, jointed kaolin, containing a little sand, and stained along joints by oxides of iron and manganese . . . . . . . . . . . . . . . . . . . . . 4 1. White, clayey sand ......................... ? N !- ~~~~~~~~~~~~~~~~~~ ~ .".., Fig. 15.-Section in the Claymont kaolin mine, Wilkinson County, showing relation of the massive and nodular kaolin. The nodular bed, No. 3, has concretions varying m size from pisolites to over one foot in diameter. All of the material is soft and plastic enough to be worked, washed, and used as paper clay. The nodules can scarcely be distinguished from the matrix when freshly broken; but on drying the nodular material shrinks, becomes harder and darker in color than the matrix, and breaks with an intricate system of conchoidal fractures. There is a gradation downward into stratum No. 2, but the upper surface of the nodular layer is sharp. The following are analyses of samples from the mine : BAUXITE DEPOSITS OF THE COASTAL PLAIN 119 Analyses of kaolin from the Claymont mine Constituents I I Silica ( SiO,) ... I Alumina (Al.Oa) I Ferric oxide (Fe,Oa) ...... I Ferrous oxide (FeO) ...... I Magnesia (MgO) ........ Lime (CaO) ............ 1 Soda (Na,O) ............ . Potash (K.O) ........... . I Ignition ................. Titanium dioxide (TiO,) .... , S-81 45.62 39.39 .49 .00 .22 .00 .03 .02 13.19 .92 S-82 49.54 33.80 .92 .11 .36 1.13 tr tr 13.21 .96 S-83 45.19 39.15 .48 .00 .07 tr .04 .02 13.87 1.54 II Moisture ................ 99.88 2.21 100.03 6.50 100.36 .45 Mineral composition computed Minerals 1 I Gibbsite ................. I Kaolinite ................ I Limonite ................ I Titanium dioxide ( TiO,) .. I Silica (SiO,) ............ I Water (H,O)-excess ..... I Water (H,O)-deficiency .. S-81 .93 98.00 .56 1.19 .80 S-82 85.48 1.08 2.56 9.77 1.14 S-83 1.13 97.15 .56 1.67 .15 Sample S-81 is an average sample from the nodular layer; S-82 is from the center of one of the larger nodules, about one foot in diameter; and S-83 is a massive kaolin taken 6 inches above the nodular layer. The nodular material is in such physical condition that it retains a great deal more hygroscopic water than the massive kaolin, as all of the samples were taken at the same time and had the same opportunity to dry before the analyses were made. S-82 is the only sample of Lower Cretaceous material analyzed which contains any appreciable amount of lime. The excess of silica in this sample is probably in colloidal form, as no sand grains could be detected. The nodular material contains ferrous iron, which is not found in the massive kaolin, and a little less of the alkalies and titanium. 120 GEOLOGICAL SURVEY OF GEORGIA DUPREE PROPERTY (Map locality W-9 On the Dupree property, Wilkinson County, (see p. 52) the white, indurated clay bed which overlies the red bauxite also contains a mass of nodular clay. The irregu- lar form of the contact between the nodular and massive clays is shown in the sketch (fig. 16). Along the contact and running off into fissures Fig. 16.-Detail of contact of mas- in the white, massive-clay is a band sive and nodular kaolin, Dupree property, Wilkinson County. of. dark, greenish, non-plastic clay an inch or two in thickness. Analyses of the massive and nodular clays from Dupree property S-85 (massive) Silica (SiO,) ..................... . 45.75 Alumirvt (Al,03 ) _ Ferric oxide (Fe,03) Ferrous oxide (FeO) ......... _.... . 36.85 2.14 .28 Magnesia (MgO) ................. . .04 Lime (CaO) ..................... .. .00 Soda (Na,O) .................. _.. . .00 Potash (K,O) ........... _.. __ .... . .00 Ignition ......................... . 13.10 Titanium dioxide (TiO,) .......... _. 2.00 Manganese (NnO) ................ . .06 S-84 (nodular) 41.19 34.82 5.14 .15 .88 .00 .00 .00 16.65 .98 .16 Moisture 100.22 .78 99.97 7.78 The massive clay is mealy, but contains very little sand and no nodules. The bauxitic clay consists of nodules about the size of peas in a sandy matrix. Both matrix and nodules have a pale greenish color. The nodules are soft enough that they may easily be cut with 8. knife, and some of them show distinctly concretionary interior r>tructure. The massive clay contains more alumina than the bauxitic material, but the higher water content of the latter indicates that it is r. mixture of gibbsite and silica, while the other is a normal kaolin. BAUXITE DEPOSITS OF THE COASTAL PLAIN 121 As in the Claymont mine the bauxitic clay retains a great deal of hygroscopic moisture. ADKINS PROPERTY (Map locality W-14) The bauxite deposit described by Veatch as the R. W. Adkins property was bought by George Carswell, of Irwinton, and worked by the National Bauxite Company. It is situated just south of the Central of Georgia Railway, 3 miles east of Mcintyre. The mine seems to be entirely exhausted, but it is of interest because it shows well the structure of the deposit and affords clues as to the origin. The structural relations are shown in the accompanying sketch (fig. 17). On the north side of the pit Eocene red-and-blue mottled clayey sand overlies unconformably, but without basal conglomerate, a bed of indurated white clay. The claystone, which is locally known as ''chimney rock,'' is hard and massive, but without distinct nodules. It contains slightly more combined water than most of the plasti.. white kaolins, but its alumina content does not indicate bauxitization. (See analysis S-76.) The bed has a maximum thickness of 2 feet and tapers out to eastward. It is underlain by a bed of less indurated clay, with indi"cations of bedding and containing scattered pisolites one inch in diameter. This bed is more bauxitic than the preceding. (See analysis S-77.) It grades downward into roughly stratified red, yellow, blue, and white, mealy, non-plastic clay. In this bed occurred the lens of high grade bauxite, of which only small remnants are left. The bauxite was some of the best ore ever found in Fig. 17.-Section in Adkins bauxite mine, Wilkinson County. 122 GEOLOGICAL SURVEY OF GEORGIA this district, as it all contained over 60 per cent of alumina in its natural state. It has a light gray-brown, flinty matrix predominating over the pisolites, which are of softer white material and average a quarter of an inch in diameter. On the east side of the pit the chimney rock bed is cut away by a pre-Eocene gully. The Eocene sand here has a basal conglomerate several feet thick, with pebbles of chimney rock, bauxite, and quartz. The quartz pebbles are well rounded and average less than half an inch, the largest found being about 3 inches; showing long distance transportation. The bauxite and chimney rock fragments vary greatly in size and shape and are mostly angular, showing local erosion and redeposition. At one point a mass or pipe of clay with pisolitic structure cuts vertically across the banded clay. The bedding of the clay runs into the nodular mass and disappears. The pisolites are white, soft, and clayey, with average diameter of 1 inch; and in volume are about equal to the softer red matrix. Although this pisolitic clay (S-78) has the bauxite texture better developed than the associated bedded clay (S-79), its alumina content is less. In the soft, pisolitic clay are found occasional very small lenses, about half an inch thick by 3 or 4 inches in diameter, of hard, flinty, light colored bauxite. In another place- a mass of indurated clay with scattered pisolites crosses the bedding in a manner similar to the soft, pisolitic clay. The underlying material, that is, the lowest exposure in the pit, is a bluish, mealy clay with occasional sand grains, and partly with pisolitic structure. Its analysis (S-80) shows it to be still bauxitic. A test pit south of the mine cut only soft clay,. and several hundred feet east is a valley cut down to 20 feet below the level of the mine, but no bauxite nor claystone is seen on the slope. There are no indications that more high grade bauxite will be found in the vicinity, but there is available a large amount of clayey bauxite which will contain over 50 per cent of alumina after drying, and' will undoubtedly come into demand some time in the future. BA U.YJ'l'E OF 'I'HFJ GOA S'L'A L PLAIN OF' GEORGIA PLA'l'E X ll A. NORTJJ FACE OF THE ADKINS MINE OF THE NATIONAL BAUXITE CO., WILKINSON COUNTY, SHOWING "CHIMNEY ROCK" ovgRLYING CLAY AND BAUXITE. B. EAST FACE OF THE ADKINS MINE OF TI-lE NATI ONAL . BAUXITE CO., '\'<' ILKINSON COUNTY, SBOWING THE EOCENE BASAL CONGLOMATE ABOVE CLAY AND BAUXITE. BAUXITE DEPOSITS OF THE COASTAL PLAIN 123 Analyses of clay and bauxite from the Adkins property I Constituents I I I I I S-76 S-77 S-78 S-79 S-80 I I I I I Silica ( SiO,) .. 1 43.02 31.30 41.92 23.47 31.57 Alumina (Al,O,) I Ferric oxide (FeO) ...... I Ferrous oxide (FeO( ..... 37.70 1.85 .14 46.37 1.84 .14 39.16 1.83 .10 48.90 2.04 .14 43.54 3.38 .14 I Magnesia (MgO) tr .05 tr .18 .40 LSPIgoiomndtaiaetsiho((nCN(aaK.O,.O,).O).)...............................................III! .00 tr tr 14.80 .00 .00 .00 17.85 .00 .00 .00 13.98 .00 .02 tr 24.04 .00 tr tr 18.30 I Titanium dioxide ( TiO,) .. 2.72 ~.72 3.26 1.45 2.54 I I 1 Moisture _.... _........ __ 100:~~ I 100.27 .86 100.25 .78 100.24 1.02 99.87 .74 A 2.37 62.39 1.37 31.45 2.0G 99.64 2.79 S-76. Massive claystone. S-77. Bauxitic clay from bed just below the claystone. S-78. Nodular clay from mass which cuts bedded clay. S-79. Bedded clay. S-80. Bauxitic clay from lowest exposure in pit. A. Han1, high grade bauxite. Geol. Survey of Ga. Bull. 18, p. 443, 1909. Mineral composition Minerals I I I Gibbsite ................ 'II Kaolinite .............. "II I Limonite ............... Titanium dioxide ( Ti02 ) 1 Water (H,O)-exress ...... I Water (H,O)-deficiency .. j I S-7G I 1.73 92.50 2.16 2.86 .98 0 I S-77 30.24 67.30 2.13 2.91 0 2.31 I S-78 5.39 90.15 2.12 3.36 . .. . .77 I S-79 I 44.27 50.46 2.39 1.79 1.33 .... I S-80 I 25.57 67.88 3.92 3.08 . ... .58 A 92.34 5.08 1.61 2.06 .... 1.45 ORIGIN OF BAUXITE Conditions to be explained.-The brief summary given in the first part of this report indicates the diversity of form and mode of genesis of the various bauxite deposits of the earth. It is evident from the distribution, composition, and structural relations that the bauxite 124 GEOLOGICAL SURVEY OF GEORGIA of the Coastal Plain of Georgia had an origin different in many re spects from that of any other known deposits. The following are the conditions which must be explained by any satisfactory hypothesis of origin: 1. The depusits are horizontal, lens-like bodies, seldom if ever more than 10 feet thick and a few acres in horizontal extent. 2. The lenses are invariably underlain by sedimentary kaolin. The upper surface of the bauxite is frequently an unconformity, but in some known deposits, and probably originally in all, the bauxite is or was entirely surrounded by kaolin, having the form of a small lens of bauxite within a much larger lens of kaolin. 3. The bauxite was completely formed and indurated to almost its present condition before the end of Cretaceous time, as boulders and pebbles are found in the basal conglomerate of the overlying earliest Eocene beds. 4. There is no limestone nor any calcareous material either in or under the bauxite-bearing beds, which could have served as a reagent in precipitating the alumina. 5. The bauxite consists essentially of a mixture of gibbsite and kaolin, and contains iron and titanium in about the same proportion as the associated kaolin. Percentages of soda, potash, lime, and magnesia are lower in '.-he bauxite than in the kaolin. 6. Nodular structure is always present in the ores, in fact, it is developed in some kaolins which contain only a minute amount of aluminum hydrate. 7. The nature of the solutions present during the formation of the bauxite was such that they were able, locally, to deposit pyrite, and to form geodes containing marcasite, sulphur, melanterite, coquimbite, alunogen and sulphuric acid. It is obvious from conditions here stated that two unrelated phenomena were necessary for the production of bauxite deposits: first, the normal deposition of kaolin in a fresh-water lake or pond must be going on; and second, some solution having the power to form and deposit hydrate of alumina must be introduced. If any general or BAUXITE DEPOSITS OF THE COASTAL PLAIN 125 climatic factors were capable of producing bauxite, the large deposits would consist of bauxite instead of kaolin, so it is necessary to explain not only how the bauxite was formed, but why there is so little of it. Only a solution containing hydrogen sulphide could have deposited pyrite and the assemblage of minerals found in geodes. The hypothesis here offered is that the bauxite is due to the action of hydrogen sulphide introduced into the lagoons in which kaolin was being deposited. This theory requires an explanation of the source of the hydrogen sulphide solution and the chemical reactions resulting in the deposition of aluminum hydrate. Source of soltttions.-During and at the close of the Triassic period occurred a period of deformation-faulting and warping, attended by igneous intrusions-in the rocks of Southeastern United States. The Jurassic was a period of erosion, but additional warping at the beginning of the Lower Cretaceous period was necessary to c6nvert parts of the land area into localities of sedimentation. The disturbance of the rocks was great along the coast line, now the Fall Line. These movements opened up fissures and channels by which surface water could circulate through the igneous and crystalline rocks and the freshly deposited Cretaceous sediments. Apparently all of the bauxite deposits in the Cretaceous formation are in the middle and upper portions. The lower beds near the contact with the crystalline rocks, contain considerable amounts of finely divided pyrite, which was evidently the source of hydrogen sulphide solutions. The liberation of hydrogen sulphide from the pyrite took place by two reaction,;. First, descending water containing dissolved oxygen acted on the pyrite, producing ferrous and ferric sulphates and oxidizing the remaining sulphur to sulphuric acid. On penetrating below the zone of oxidation this free sulphuric acid attacked other &ulphides, liberating hydrogen sulphide.1 The hydrogen sulphide ' Emmons, W. H., The enrichment of sulphide ores: U. S. Geol. Survey Bull. 529, p, 91, 1913. 126 GEOLOGICAL SURVEY OF GEORGIA solutions then found outlets, forming groups of sulphur springs which were possibly, but not necessarily, thermal. In the Lower Cretaceous period a group of such springs apparently found outlets in the Wilkinson County area and during the Midway deposition a similar group existed in Sumter and Macon counties. The distribution of the bauxite deposits indicates such an origin, as they occur in groups, with areas of barren kaolin between the individual deposits, and great areas along the strike of the beds in which no bauxitization has taken place. There is plenty of present-day evidence that hydrogen sulphide soolutions have been active, as the water of man;y wells and some springs throughout the Coastal Plain, and especially in the bauxite areas, is rather highly charged 'with hydrogen sulphide. A flowing well at Irwinton is said to have been abandoned on account of the offensive odor and unpleasant taste of the water, due to the presence of hydrogen sulphide and iron salts.1 The water of the Toomsboro artesian wells has a decided taste and odor of hydrogen sulphide. These wells are in ~he center of the Wilkinson County bauxite district, and they penetrate very nearly to the crystalline basement rocks. 'rhere is a group of seven springs, known as Miona Mineral Springs, situated in Macon County a few miles north of the bauxite area. Two of the springs give water containing hydrogen sulphide.2 Sulphureted water may also be formed from the disseminated sulphides of the crystalline rocks, as at White Sulphur Springs in Meriwether County. In that county sulphur springs and a hot spring are found within a few miles of the only deposit of bauxite known to occur in the crystalline area. Chemical reactions and mode of deposition.-Suppose deposition of kaolin to be going on in a barrier lake (fig. 18). The streams flowing in had a steep gradient, and were rapidly cutting away the kaolinized rock which covered the slopes of the hills. The coarse sand and minerals of high density were dumped as crossbedded strata near the 1 McCallie, S. W., Underground waters of Georgia: Geol. Survey of Ga. Bull. 15, p. 19_4J 1908. .oo.cCallle, S. W . Mineral springs of Georgia: Geol. Survey of Ga. Bull. 20, p. 114, 1913. BAUXITE DEPOSITS OF THE COASTAL PLAIN 127 mouths of the streams. Kaolin, mica, and other very finely divided minerals were carried out into the quiet waters of the lake, forming a bed of pure white kaolin at the deepest part. At all times the water of the lake was turbid with the considerable amount of kaolin which remained long in suspension. Then a hydrogen sulphide spring found its outlet in the bed of the lake. When the hydrogen sulphide solution entered the aerated water of the lake the following reactions took place: + + 2H2S -j- 0 2 = 2H20 -j- 2S 2H2S 302 = 2H20 2S02 If the supply of oxygen was limited, the former reaction occurred, with deposition of free sulphur; but in general oxygen was abundant, and the latter predominated. The sulphur dioxide united with water and oxygen by two stages, forming first sulphurous, then sulphuric acid, thus: + S0 2 H 20 = H 2S0 3 + H 2S03 0 = H 2S04 Sulphuric acid was the active agent in decomposing the kaolin. The reaction is: + + + H 4 Al2 Si 2 09 3H2S0 4 = Al2 (S04 ) 3 2Si0 2 5H20 The aluminum sulphate was carried by circulation or diffusion to a position near the vent of the spring, where hydrogen sulphide was present and the water neutral or alkaline. Here it was hydrolized and precipitated as aluminum hydrate by the following simultaneous reactions: Al2 (SO 4 ) 3-j-3H2S=Al2S3-j-3H2SO4 Al2S3-j-6H20 =2Al(OH) 3-j-3H2S The hydrogen sulphide and sulphuric acid were thus regenerated and were able to act on more kaolin, so no large initial supply was necessary. The aluminum hydrate formed in the above reaction at once accumulated into impervious, gelatinous balls and sank to the bottom, 128 GEOLOGICAL SURVEY OF GEORGIA Fig. lB.-Hypothetical sketches illustrating formation f bauxite. where it was removed from the sphere of action of the sulphuric acid, which was thus left free to attack the more stable, but finely divided, kaolin. The silica liberated was in hydrous form and remained in solution. A little was carried down with the aluminum hydrate, forming an opaline cement between the granules, but most of it was finally carried off at the outlet to the lake. Solution of alumina and deposition of the hydrate depended on the distribution of solutions by currents and on the local active mass of sulphuric acid and hydrog~n sulphide. Conditions for the decomposition of kaolin might be effective at one point, while dep.osition of aluminum hydrate was taking place an inch away. Finally, the outlet to the sulphur spring became clogged or diverted to another locality, cutting off the supply of hydrogen sulphide, and deposition of kaolin continued until the lake was filled. Usually the spring seems to have died out gradually, producing a gradational phase of bauxitic clay between the pure bauxite and the kaolin. Minor reactions and form of deposits.-Feldspar and mica fragments carried into the lake were more readily attacked by sulphuric acid than the kaolin, and the alkalies went off in solution. This explains the very minute amount of soda and potash found in the purer bauxites. Iron went through the same cycle of solution and BAUXITE DEPOSITS OF THE COASTAL PLAIN 129 redeposition as the aluminum, and titanium in the form of leucoxene was not affected by the solutions, so these two elements retain the same ratio to alumina in the bauxite as in the kaolin. Aluminum sulphate may have been carried in by the water of the springs, and, if so, it was precipitated. But this hypothesis does not require the transferrence of aluminum in solution for any considerable distance, as its source is to be found in the kaolin which was constantly being supplied. Carbonates carrie~ into the lakes would have assisted in precipitating the alumina, but their presence was not essential. The inflowing streams were cutting into decomposed rocks, from which calcium and the alkalies had already been very thoroughly leached, and it is likely that in the early part of the Lower Cretaceous period erosion was so rapid that little soil could form and the steep slopes were almost bare of vegetation. On this account plant fossils are absent from the greater part of the formation. With the dearth of humus and lack of elements soluble as carbonates in the soil, the amount of carbonates carried down must have been negligible. Locally, conditions were right for the deposition of the iron sulphides. In geodes the solution became concentrated and strongly acid, so marcasite was deposited; but in the dilute, neutral solution permeating the mass of freshly deposited aluminum .hydroxide deposition in the form of pyrite cubes took place. Allen1 proved experimentally that the concentration of free acid in solutions determines the precipitation of marcasite instead of pyrites on reduction of ferric salts by hydrogen sulphide. Whitman2 produced pyrite synthetically under conditions very similar to those which must have existed during the deposition of bauxite. It would take too much space to describe the apparatus used and reactions obtained, but he concludes3 "that pyrite can be precipitated from dilute (neutral or slightly alkaline) cold water solutions under practically atmospheric ~ WhAllen, E. T., The mineral sulphides of iron, Am. Jour. Sci., 4th Ser. No. 33, 1912. itman, A. R., The vadose synthesis of pyrites, Econ. Geol. vol. 8. p. 455, 1913; 1 0 p. cit., p. 468. 130 GEOLOGICAL SURVEY OF GEORGIA pressure, and that the precipitation is favored or induced by alumminous material, or by fine slimes in a reducing environment.'' The richness and form of the bauxite bodies depended on the supply of materials, both kaolin and hydrogen sulphide, and on local conditions, such as the relative positions of inlet, outlet, and spring vent, and rapidity of change of water. For the deposition of a bed of pure aluminum hydrate a nice adjustment of these various factors was necessary. The water must be very quiet, the kaolin must be fine and supplied very slowly, and sulphuric and hydrosulphuric acids must be present in sufficient amounts to attack all the kaolin and precipitate a large part of the alumina. Naturally, under such conditions the alumina was deposited in a flat-lying lens. In case the supply of kaolin was too abundant, only a small part of it was altered, and a bed of nodular clay was the result. Disturbance of the water by strong inflow from the springs or from feeding streams produced bauxitic masses of irregular shape, but in such cases there was no opportunity for complete alteration, so the irregular deposits never consist of high grade ore. The inlets of the springs are inconspicuous and have not been certainly located in any case. In the Sweetwater mine a rise in the surface of the clay underlying the bauxite probably marks the position of the inlet, and in the Adkins mine a vertical mass or pipe of nodular clay cutting bedded clay was evidently a water channel. The sulphide water must have entered the lakes by numerous shifting channels through the freshly deposited kaolin, and, as the water had no power to alter kaolin until after it had come in contact with oxygen, with formation of sulphuric acid, the entrance channels can not easily be found and recognized. The occurrence of pebble ures is also easily explainable. During periods of quiet deposition and siow introduction of kaolin, beds of very pure aluminum hydrate were formed, and lay as soft, gelatinous coatings on the bottoms of the lakes. Then the springs changed their points of entrance, or the waters were disturbed by storms or floods, and the amount of kaolin carried in increased for a time. The BAUXITE DEPOSITS OF THE COASTAL PLAIN soft precipitate was broken up and rolled into pebbles by slight disturbflnces or shifting currents. The pebbles sometimes received fresh accretions of aluminum hydrate, in concentric layers around the older portion. Thus were formed beds of complex pebbles of very pure ore in a kaolinic matrix. Solubility of kaolin in dilute sulphuric acid.-An experiment was made to determine the solubility of kaolin in dilute sulphuric acid. The kaolin sample used was a washed white plastic clay from the mine of the Savannah Kaolin Company near Gordon, -Wilkinson County. A quantity of ten grams was placed in 500 cubic centimeters of a one per cent solution of sulphuric acid, and allowed to stand at room temperature (average 70 1_1~) for seven days. 'l'he flask was shaken once or twice a day. It was found that even in the presence of the sulphuric acid, which, like other electrolites, has a tendency to cause kaolin to settle rapidly from suspension, the liquid did not become entirely clear in 24 hours. Half of the solution (250 c.c.) was then filtered off and the dissolved alumina and iron precipitated with ammonia, ignited, weighed, fused with potassium bisulphate, reduced with zinc, and the iron titrated with potassium permanganate. A blank test was also made, using the same quantities of reagents, but without any kaolin, for which a correction of 0.0003 gm. had to be deducted. The amounts taken in solution by 250 c.c. of acid acting on 5 gm. of clay, after deducting for the weight of the filter ash and the blank test on the reagents, were : Alumina (Al 02 3 ) _ Ferric oxide (Fe,O,) . . . . . . . . . . . . . . . . . . . . . . . . . . gm. .0108 .0029 .0137 The original sample contained: Per cent Alumina (Al,03).......... . . . . . . . . . .. .. . . . . 44.28 Ferric oxide (Fe 02 8) .93 132 GEOLOGICAL SURVEY OF GEORGIA Therefore the percentage of the total quantity of these oxides dissolved was: Per cent Alumina (Al 02 3 ) .55 Ferric oxide (Fe.O,) ......................... . 6.23 This experiment shows that kaolin is soluble to a certain extent in cold dilute sulphuric acid, but it also indicates that a long time and very unusual conditions would be necessary for the production of bauxite deposits by any strength of acid likely to be produced by nature. However, bauxite is known to be produced by the much weaker carbonic and humic acids during rock weathering, and sulphuric is certainly a more efficient reagent than those acids. The preceding hypothesis is presented as the best explanation of the possible origin of the deposits from materials known to have been available. It may require considerable modification if other factors favorable or unfavorable to bauxite deposition are discovered in the future. METHODS Mining.-The methods used in mining bauxite in the Coastal Plain are the simplest possible. Every deposit worked up to the present time has had an outcrop at some point on the slope of a hill, and mining consists simply in removing the overburden and working out the ore. The maximum known thickness of ore is about 10 feet, while overburden as I:eavy as 40 feet has been moved in places to get 5 or 6 feet of ore. All mining is done by manual labor, the ore and overburden being trammed to the dumps by hand or mule power. Steam shovels and drags have not been employed in any of the bauxite mines, but they are used extensively in kaolin and fullers earth ~ines in the vicinity. Their use in bauxite mining would certainly be economical in the larger deposits with heavy overburden. Both ore and overburden are so soft that blasting is rarely necessary. As a rule, the upper surface of the bauxite forms a fairly sharp BAUXITE DEPOSITS OF THE COASTAL PLAIN 133 contact. In cases where an unconformity cuts off the top, the upper surface of the ore is rendered very irregular by pot holes and gullies, but there is no difficulty in distinguishing the place where the ore commences. The lower limit of workable ore, however, is not so easily determined, because there is usually a gradual change from bauxite to kaolin extending through a number of feet. Most of the ore is used in the manufacture of alum by treatment with sulphuric acid or 50B., in which the alumina combined in silicates, such as kaolin, is not readily soluble. The only means of finding out just how much of the clayey material may be mined and used as ore is by keeping a check on the shipments, especially at first, by chemical analyses. The usual practice is to work far enough into the clayey bauxite so that the mixed material, when dried, will contain about 50 per cent of soluble alumina, as the alum manufacturers do not desire ore of lower grade than that. Preparation.-The only treatment given the bauxite of the Coastal Plain previous to shipment consists in drying and, occasionally, screening. There are small quantities of bauxite which could be enriched by washing with a log washer, such as is used in the treatment of iron and manganese ores and bauxite in north Georgia, but no such washer has yet been installed. The ore as mined contains a variable, but large, percentage of uncombined water, which adds greatly to the freight charges. It is customary, therefore, at all of the larger mines to dry the ore artificially before shipment, although that from several small deposits of high grade bauxite is simply air-dried in sheds or on board floors in the sun. The driers used are slightly inclined, rotary-cylinder kilns, about 30 feet long by 3 or 4 feet in diameter. They are usually heated by wood fires, the wet ore passing downward toward the flame. The dried ore is mechanically elevated to overhead bins, from which it is loaded on wagons or trucks by gravity. The drier at the Sweetwater mine is said to reduce the weight of the ore 10 per cent. It is not advisable to heat the ore so highly as to drive off a large 134 GEOLOGICAL SURVE"Y VF GEORGIA part of the combined water. Phillips and Hancock1 carried on experiments which show that calcining reduces the solubility of the alumina in sulphuric acid of the strength used, although the effect is not great until about 80 per cent of the total combined water is removed. In the type of kiln used it is wt likely that more than a very small percentage of the combined water is expelled. A small amount of the pebble ore is screened to remove admixed sand and clay. The screens used are fiat, inclined screens or revolving trommels of about three-eighths inch mesh. Transportation.-The bauxite districts are well supplied with railroads. All of the deposits are within 10 miles of railroad connections, but none of the deposits so far worked are more than 4 miles from loading points. The ore is usually hauled to the railroad station in wagons, but one company has recently put a motor truck into serv ice. The truck has a capacity of 4 tons, and carries 10 loads per day 3lj2 miles to the station. In the Sumter and the Macon county district good sand-clay roads have been built, wltile in Wilkinso~ County the materials for constructing such roads are available but so far they are only partially improved. Sand clay roads are badly damaged by heavy hauling with wagons in very dry or very wet weather, so the use of motor trucks will render the maintenance of the roads much less expensive. Exploration.-The known lenses of bauxite cover only a minute fraction of the area of the outcrop of the formations in which they are known to occur. There are almost certainly buried deposits which give no surface evidence of their existence, but the chances of finding them by random test holes are very small even in the most promising localities. Therefore, boring where there are no surface indications of bauxite is not advisable. When fragments of bauxite or indurated, nodular clay are found on a slope, pits or trenches should be sunk near the highest point at which such fragmental material is found. It is best to first dig pits around the edge of the ore body, in order that the workable thickness may be determined 1 Jour. Am. Chern. Soc., pp. 220-221, 1898. BAUXITE DEPOSITS uF THE COASTAL PLAIN 135 and representative samples obtained, after which a common clay auger, two or three inches in diameter, may be used to investigate the extent of the body where the overburden is heavier. USES The chief uses of bauxite as given by Phalen are1 : (1) in the production of metallic aluminum; (2) in the manufacture of aluminum salts; (3) in the manufacture of bauxite brick; (4) in the manufacture of alundum (fused alumina) for use as an abrasive; (5) in the manufacture of calcium aluminate, used to give a quick set to plaster compositions. 1. The most important use of bauxite is in the production of metallic aluminum. The :first step necessary is the treatment of the bauxite to obtain pure aluminum oxide. The method most commonly used is Bayer's process.2 The bauxite is fused with sodium carbonate or sodium sulphate and lixivated; or is calcined and pulverized, mixed with a little lime and treated with sodium hydroxide under pressure. Sodium aluminate soluble in water is thus obtained. It is :filtered hot, washed, and pure gelatinous aluminum hydroxide is added to the solution. The whole is then stirred continuously until the sodium aluminate is dissociated and the alumina precipitated as hydroxide. It has been discovered3 that the alumina is precipitated :first, and the silica mainly near the end of the reaction, so the process is stopped at a suitable point, before too much silica has been precipitated, the precipitated aluminum hydroxide is :filtered off, and the solution containing sodium hydroxide or carbonate and some alumina is re-utilized in treating more bauxite. The hydroxide obtained by the Bayer process contains 40 per cent of water, and is easily soluble in acids. After drying it forms a white powder consisting of almost pure Al20 3, and is almost insoluble. Sodium hydroxide or carbonate does not attack the iron oxides in 1 Phalen, W. C., Bauxite and aluminum: U. S. Geol. Survey Mineral Resources (or 1909, 1910, 1911, 1912, 1913, 1914, 1915. p. 257M1,ol1i9n1a2r.i, Dr. Ettore, General and industrial chemistry, translation of 3d. ed. 3 McCulloch process, U. S. Geol. Survey Mineral Resources for 1914, p. 189, 1915: 136 GEOLOGICAL SURVEY OF GEORGIA the bauxite, which remain in the insoluble residue. Iron is therefore not objectionable in this process, except that it increases the bulk of material to be treated. Silica, however, goes into solution, and it is difficult to prevent its precipitation with the alumina. Silicon is reduced along with aluminum in the electric furnace, and its presence in the latter metal is very objectionable. Therefore, the principal requirement for aluminum ore is a low silica content, and iron may be considered a neutral impurity. Aluminum is extracted from the pure aluminum oxide by the Hall or Heroult process. The two processes are essentially similar, but were developed simultaneously and independently by the two inventors. In both processes the alumina is reduced by an electric current in a bath of fused cryolite, the double. fluoride of aluminum and sodium, using carbon electrodes. The cryolite is fused and powdered aluminum oxide introduced. The alumina dissolves and is electrolized, the metallic aluminum sinking to the bottom of the bath. The uses of aluminum have become too numerous to be discussed in detail here. The new uses developed each year for the metal are described in the annual reports of the United States Geological Survey on Mineral resources. The use of aluminum is being curtailed at the present time (1916) on account of the high price, and it ls reported that aluminum in actual use for electrical transmission is being replaced by copper. But when prices again reach a normal level, of something like twenty cents per pound, the former rapid increase in the demand for the metal for non-military purposes may be expected to continue. 2. The use of bauxite in the manufacture of alums and aluminum salts ranks second to its use in the production of aluminum. The base of most aluminum chemicals is the sulphate. For making ironfree alumin~m sulphate, used for high grade chemicals, the aluminum hydroxide is first purified by Bayer's process; but in the manufacture of commercial grades of alum and aluminum sulphate the purification by solution as sodium aluminate is eliminated. The bauxite is pulverized and treated with sulphuric acid of 50 B. (1.53 BAUXITE DEPOSITS OF THE COASTAL PLAIN 137 specific gravity), which dissolves all of the aluminum trihydrate, and also slightly attacks kaolin and any lower hydrates which may be present. The solution is filtered or decanted into lead pans, where aluminum sulphate (Al2 (S04 ) 3+18 H 20) crystallizes out. If common alum is desired the necessary amount of potassium sulphate must be added to the solution, and the double salt (Al2 (S04 ) 3 .K2S04+24 H 20) crystallizes. Alum was first prepared from the natural mineral alunite, found near Rome, Italy, which contains both aluminum and potassium in the proper ratio; but since most alum has come to be made from bauxite it has been found that the normal aluminum sulphate will serve for most purposes as well as the more expensive potassium alum. The latter has therefore been almost entirely supplanted by aluminum sulphate. By the acid treatment any iron oxide which may be present in the bauxite goes into solution with the aluminum; therefore only bauxites containing less than two per cent of ferric oxide are considered suitable for the manufacture of alum by this process. Silica is not dissolved, a~d its presence is not chemically objectionable. It must be remembered, however, that the silica in bauxite is mostly in the form of kaolin, and not only is it insoluble, but it holds in combination an approximately equal amount of alumina, which is rendered unavailable. The principal use of aluminum sulphate is for the coagulation of impurities in water, especially for municipal supplies. It is also used as a mordant in dyeing, in tanning, etc. 3. Pure alumina melts at 2050 C, as against 1830 C for pure kaolin, so it was early suggested as a refractory material for furnace linings, but there were certain difficulties to be overcome before bauxite brick came into successful use. Brick made of pure kaolinite would contain 46 per cent of alumina, and any addition of aluminum oxide renders the brick more refractory. Two kinds of bauxite brick are in common use, containing respectively 56 and 77 per cent of alumina, which represent the ex- 138 GEOLOGICAL SURVEY OF GEORGIA treme proportions of alumina of value.1 The brick containing 56 per cent of alumina is used in place of fire-clay brick, but is more refractory. The brick containing 77 per cent alumina is used as a substitute for magnesia brick for open-hearth furnaces, etc. Bauxite brick for use in basic open-hearth steel furnaces should contain less than 12 per cent silica.2 Such bauxite brick has given good results, but normally is probably more expensive than magnesia brick. In making the brick, the bauxite is first calcined at about 1400 C. (2500 F.). It is necessary to calcine at this great heat because the greatest shrinkage takes place between 2390 and 2500 F. The calcined mineral may be bonded with either fire-clay, sodium silicate, or lime. The brick must be carefully dried and burned at a high temperature. The brick are very hard and tough, but have a tendency to spall if suddenly cooled or heated. 4. Bauxite is used at Niagara Falls in the manufacture of the artificial abrasive, alundum. This is made by fusing calcined bauxite in an electric furnace. High grade bauxite produces alundum which is practically artificial corundum, and the ferruginous varieties give products corresponding to various grades of emery. Low silica content is required in the bauxite, but even highly ferruginous varieties are used. Alundum has a hardness of about -nine in Moh's scale, and is particularly efficient in the grinding of steel. Ground alundum, mixed with a binder and burned, makes a very refractory material for small articles such as muffles and crucibles, but it is too costly for extensive use in larger shapes. 5. Lastly, bauxite is used in the manufacture of hydraulic calcium aluminate, which is incorporated in plaster compositions to give them a quick set. This use is described in detail in the United States Geological Survey report on Mineral Resources for 191]. The bauxite of the Coastal Plain, being prevailingly low in iron, but rather high in silica, is best fitted for use in the manufacture of alum and chemicals, and most of it is used for that purpose. Ores low enough in iron for use in the manufacture of alum by the acid 1 Seaver, Kenneth, Bull. Am. Inst. Min. Eng., pp. 2505-2506, Dec. 1915. 'U. S. Geol. Survey Mineral Resources for 1913, p. 15, 1914. BAUXITE DEPOSITS OF THE COASTAL PLAIN 139 process bring a higher price than aluminum ores, even thought the silica may be too high for the latter purpose. PRODUCTION OF BAUXITE AND ALUMINUM 1 Bauxite produced, imported, and consumed in the United States, 1889-1915, in long tons. PRODUCTION IMPORTS CONSUMPTION Year 1889 . 1890 1891 1892 1893 1894 1895 1896 1897 I Quantity I I 728 1,844 3,593 10,518 9,179 11,066 17,609 18,364 20,590 Value 2,366 6,012 11,675 34,183 29,507 35,818 44,000 47,338 57,652 I Quantity Value . . . .. .. . I 0 ........ 0 ... .. .. . ........ ... .. .. . 0 0 0 0 ........ . .. .. ... ........ . .. ..... 0 . ....... ..... .. . 0 I Quantity Value I ........ I 0 ........ ........ 0 ........ 0 ........ . ....... 0 ........ ........ 0 ........ . ....... 0 0 . ....... 00 0 1898 25,149 75,437 1,201 4,238 25,350 '77,675 1899 35,280 125,598 6,666 23,768 39,916 '144,799 1900 23,184 89,676 8,656 32,697 30,840 '119,643 1901 1902 1903 18,905 27,322 48,087 79,914 120,3661 171,306 18,313 15,790 14,889 I 67,107 1 54,410 49,684 36,218 43,112 62,976 1144,021 175,875 220,990 1904 47,661 235,704 15,374 49,257 63,035 285,961 1905 48,129 240,292 11,726 46,517 1 59,855 286,809 1906 75,332 368,311 17,809 63,221 93,141 431,532 1907 97,7'7(} 480,330 25,066 93,208 122,84~ 573,538 1908 52,167 263,968 21,679 87,823 73,846 351,791 1909 1910 129,101 148,932 679,447 716,258 18,688 15,669 83,956 65,743 147,789 164,601 763,403 782,001 1911 155,681 1 750,649 43,222 164,301 198,840 914,950 1912 1913 1914 1915 I 158,865 1 768,932 210,241 997,698 219,318 1,069,194 297,041 1 1,514,834 26,214 21,456 24,844 3,420 95,431 85,746 96,500 17,107 186,079 231,697 244,162 300,461 864,363 1,083,444 1,165,694 1,531,941 I 'Exports deducted. 1 Statistics taken from U. S. Geol. Survey reports on Mineral Resources. 140 GEOLOGICAL SURVEY OF GEORGIA World's production of bauxite, 1900-1914, in long tons I . Year 1 Umted States 1900 23,184 1901 18,905 1902 27,322 1903 48,087 1904 47,661 1905 48,129 1906 75,332 1907 97,776 1908 52,167 1909 129,101 1910 148,932 1911 155,618 1912 159,865 1913 210,241 I 1914 219,318 'Metric tons. France 158,530 '76,620 '96,900 131,781 74,449 101,378 115,926 155,512 167,9fll 128,099 192,913 250,818 254,851 304,407 ...... United Kingdom '5,873 '10,357 '9,192 6,128 8,700 7,300 6,654 7,480 11,716 9,500 3,792 6,007 5,790 6,055 8,286 Italy . ..... .................. ............ ... .. . 3,445 6,890 3,881 4,524 5,600 6,596 6,843 3,844 India ...... ...... ...... ...... ...... ...... . 32 32 66 12 950 1,184 514 Prices.-The total production of bauxite in the United States to the end of 1915 was 1,912,122 long tons, valued at $9,016,465 at the mines; an average value of $4.72 per ton. The price has had an upward tendency during the past few years, being $4.81 in 1912, $4.75 in 1913, $4.87 in 1914, and $5.10 in 1915. The United States now leads the nations in the production of metallic aluminum, and the rapid increase is shown in the accom- panying table. These figures give production to 1900 and consump- tion since that year. Al:umimtm produced or consumed in the United States, 1885-1915, in pounds Year Production 1885 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 1890 ............................. --- ....... . 61,281 1895 ...................................... 920,000 1900 ...................................... . 7,150,000 1905 ...................................... 11,347,000 1910 .................................... 47,734,000 1911 .................................... 46,125,000 1912 ................................... 65,607,000 1913 ............................... 72,379,000 1914 .................................. 79,129,000 1915 .................................... 99,806,000 FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 141 PART II FULLERS EARTH DEPOSITS DEFINITION Fullers earth is a variety of clay which has a high capacity for absorbing oil and grease, and also for adsorbing organic and mineral bases, including basic coloring matter, from solution in animal, vegetable or mineral oils, as well as from some other liquids, especially water. It is of commercial value when its adsorptive power is strong, and the balance between its other desirable and undesirable properties is such as to enable it to compete actively with other earths already accepted as of standard quality for refining oils. Like other clays, fullers earth is made up essentially of hydrous silicates of aluminum; but analyses vary so greatly that the chemical composition is now known to be of almost no value in determining the efficiency of a fullers earth, or even in deciding whether a particular clay is to be classified as a fullers earth at all. However, all of the better grades of fullers earth are alike in that they show a ratio of silica to aluminum considerably higher than the ratio for the mineral kaolinite, which is supposed to form the base of common clays; and they always contain a large percentage of hygroscopic moisture which is not lost by air drying at ordinary temperatures. Some fullers earths also carry a higher percentage of combined water than ordinary clays, but this characteristic is by no means universal, and in some cases the bleaching power is not destroyed by driving off the water of composition. The bleaching efficiency of an earth is due principally to its physical characteristics, of which a high degree of porosity is most important. HISTORICAL The original use of fullers earth, from which it derives its name, wa~ for removing grease and fat from woolen cloth during the proc- 142 GEOLOGICAL SURVEY OF GEORGIA ess of fulling. The earliest reference to this process is by Pliny/ who, speaking of the "mysterie of the fuller's craft,,. says, "first they wash -and scour a piece of cloth with the earth of Sardinia." The use of earth in fulling cloth was practiced in England during the Middle Ages, and the exportation of wool and f~:1.llers earth was prohibited in order that foreigners might not learn the secrets of the craft of woolen manufacture. The importance of this industry is evidenced by the commonness of the family name "Fuller." Fullers earth for cleansing cloth has been almost entirely supplanted by soap and alkalies, so that use is at present of very minor importance. Its use for bleaching edible oils in the United States started about 1880.. N. K. Fairbanks & Company, of Chicago, learned that in the Orient the color. of olive oil is improved by agitating it with clay. A series of experiments were undertaken with cotton oil, which showed that the clay used in England for fulling cloth gave better results than any other clay then available.2 The first attempt to work fullers earth in the United States was made in 1890. A bed of Teritary clay marl near Alexander, Arkansas,3 was opened and tested, but the material did not prove entirely satisfactory. The deposits near Quincy, Florida, were discovered in 1893, and the earth was soon found to be especially applicable in the refining of petroleum lubricating oils. The discovery was made accidentally.4 An attempt was made to burn bricks from a clay found on the property of the Owl Cigar Company. The clay proved unsuitable for brick, but its resemblance to a German fullers earth was noted. The property is now held by the Floridin Company, and is one of the largest producers in the country. Other companies which have been active in Florida in recent years are the Atlantic Refining Company and the Manatee Fullers Earth Company, at Ellenton, Manatee County; and the Fullers Earth Company, at Midway, Gadsden County. 1 Holland, tr. of Pliny, XXXV, 17. 2 Wesson, David, The bleaching of oils with fullers earth: Min. & vol. 37, p. 667, 1912. 3 Miser, H. D., Developed deposits of fullers earth in Arkansas: Survey Bull. 530, p. 208, 1911. U. S. Geol. Survey Mineral Resources for 1914, p. 36, 1915. Eng. World U. S. Geol. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 143 The most important of the Arkansas deposits, those near Benton, were discovered in 1897 by John' Olsen, but that State was not added to the list of commercial producers until 1901, while Florida had been producing since 1895 and Colorado and New York since 1897. J\Ir. Olsen's mine and mill at Klondike, Arkansas, was still in operation in 1915, but seyeral other mines in the vicinity, which had been operated for a time, were closed down. The fullers earth deposits of Decatur and Grady counties, Georgia, were discovered soon after the F'lorida deposits, but Georgia did not become a producer until 1907, ~when it ranked as the third largest producing state, and since 1909 it has held second place. Almost the whole production of Georgia has come from tvvo mines; one near Attapulgaus, Decatur County, operated by the Lester Clay Company; the other at Pikes Peak, T\Yiggs County, operated by the General Reduction Company. Fullers earth is known to occur m 17 States, namely, Alabama, Arizona, Arkansas, California, Florida, Georgia, ::\iassachusetts, Minnesota, Mississippi, Nebraska, New York, South Caro.lina, South Dakota, Texas, Utah and Virginia; but it was mined and marketed in 1915 in only six, Arkansas, California, Florida, Georgia, ::\Iassachusetts, and Texas. On account of the small number of producers, the figures on production by States are not given out by the United States Geological Survey, but some comparative statements have been made. Since the beginning of fullers earth mining Florida has produced two-thirds or more of the total each year. In 1915 Florida reported nearly 75 per cent of the total quantity and value, and Georgia about 20 per cent. The industry in these two states has shown a slow but healthy growth, but in all other states production has been small and intermittent. The average price per ton has shown an upward trend. The lowest reported average was $5.72, in 1904; the highest was $10.21, in 1915, the latter year being the first time the price rose above $10.00. The total annual production is now in the neighborhood of 50,000 tons, with a value of about half a million dollars. The 144 GEOLOGICAL SURVEY OF GEORGIA quantity imported is normally about half the domestic production, but the value per ton of the imported earth is less than for the domestic. OCCURENCE AND DISTRIBUTION FOREIGN LOCALITIES England.-Fullers earth is found in beds of Jurassic and Cretaceous age in England. The principal deposits occur in the Fullers Earth or Fullonian group of the Lower Oolites.1 Geilrie says ''The Fuller's Earth is an argillaceous deposit which, extending from Dorsetshire to the neighborhood of Bath and Cheltenham, attains a maximum depth of nearly 150 feet, but dies out in Oxfordshire, and is absent in the eastern and northeastern counties.'' Searle2 says of this formation: ''Much of what the geologists term the Fuller's Earth or Fullonian series consists of limestone rocks or brown, blue, and yellow clays at the base of the Great Oolite. These are of insignificant industrial value and must not be confused with the true 'fuller's earth.' " The series is large and thick, but the valuable portions are small and scattered. Fullers earth from this formation is mined at Midford and Wellow in Somerset, near Bath. Fullers earth is also obtained from the Greensand formation of Upper Cretaceous age at Nutfield, Surrey, near Oxford, and at Woburn (Bedfordshire) ; also at Bletchingley, Reigate, and at Debtling near 1\iaidstone. It is found occasionally in Silurian rocks, as in the Wenlock shales and Lower Ludlow beds in Shropshire. "Fullers earth rock" occurs at Thornton, Dorset, but can only be used to a limited extent, as it is deficient in some of the properties of true fullers earth. In parts of central Gloucestershire ''fullers . clays'' lie over the solid strata of white limestone.3 1 Geik!e, Archibald, Text Book of Geology, 3d ed. p. 898, 1893. 2 Searle, Alfred B., An introduction to British clays, shales, and sands, p. 190, 1912. Searle, A. B., op. cit., pp. 73 and 190. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 145 Fullers earth mining has been most actively carried on m the region around Woburn Sands, on the border of Bedfordshire and Buckinghamshire. The fullers earth beds are found in the Lower Greensand formation. 1 The formation is 220 feet thick, but the fullers earth bed has a thickness of only 12 feet, and only about half of this is mined. The work is all underground, with timbered slopes and drifts. The earth is dried on iron shelves heated by flues. After drying the earth is ground in a cyclone pulverizer, and the fine ma terial is separated by a current of air. There are two varieties of earth, blue and yellow, the latter being considered more valuable commercially. A similar variation in color has been noted in the Georgia earths, where it is due to oxidation and leaching out of carbonaceous and calcareous material. The product of these mines is exported for use in oil refining. The earth from the Pullers Earth formation, mined at .l\Iidford, near Bath, was used (1898) only for fulling cloth. This earth is washed in a form of wet pan, passed into settling tanks, where it is allowed to settle for 30 days, then dried. At present (1916) most of the earth imported from England appears to have been washed, and perhaps subjected to some other treatment. Little has been published regarding the English mines; and the details of preparation are, to a large extent, guarded as trade secrets. AMERICAN LOCALITIES OUTSIDE GEORGIA Arkansas. 2-The developed fullers earth deposits of Arkansas occur in an area about 3 miles square which lies between Hot Springs and Benton. These deposits differ from all others in the United States, as the earth does not occur in sedimentary beds, but is derived from the weathering of an igneous rock in place. The country rock of the 1 Ries, Heinrich, The kaolins and fire clays of Europe, U. S. Geol. Survey, Nineteenth Ann. Rept., pt. 6 (cont.), pp. 408-411, 1898. 2 Miser, Hugh D., Developed deposits of fullers earth in Arkansas: U. S. Geol. Survey Bull. 530, pp. 207-220, 1913. 146 GEOLOGICAL SURVEY OF GEORGIA area is the Ouachita shale, a black graphitic clay shale possessing slaty cleavage. The E;hale is cut by dikes of ouachitite, biotite monchiquite, and syenite, which are later than the period of metamorphism which produced the slaty cleavage. The time of intrusion is believed to have been late Cretaceous. The basic dikes are weathered to a depth varying from 60 to 200 feet, according to permeability and local conditions, and the resulting clay has the properties of fullers earth. The fresher portions of the ouachitite and biotite monchiquite consist of augite, hornblende, hiotite and magnetite with abundant secondary serpentine and calcite, besides limonite, chlorite, analcite, and zeolites. The weathered portion forms a decidedly plastic clay, yellowish to reddish brown near the surface and light gray to light olive-green at greater depth, which still retains the texture of the unaltered dike. If the original rock contained biotite, that mineral is present in the clay, but clays containing much biotite are not considered suitable for use as fullers earth. The fullers earth is a decomposition product of hornblendes and augites, rather than of feldspars, as are ordinary clays. The basic dikes, which yield fullers earth, contain much augite and a large amount of hornblende, but practically no feldspar. A syenite dike in the area produces a residual clay of kaolinic character, which is not suitable for use as fullers earth, and intrusive masses of nepheline syenite a few miles east of the fullers earth district have been altered to high grade bauxite. The basic dikes dip at steep angles, usually to the southeast, and vary from a fraction of an inch to 4lj2 feet in width. The mining is all underground work. A shaft is sunk and the earth is worked out in 30-foot stopes until hard rock is reached, but the upper 30 feet is not generally used. The clay is dried in cylindrical driers, ground, and bolted or airseparated to pass 80 to 120 mesh. All is used for bleaching edible oils, as the product is not suitable for refining petroleum. The production was 2,563 short tons in 1910, but it has since FTJLLERS EARTH DEPOSITS OF THE COASTAL PLAIN 147 declined. In 1915 the combined production of Arkansas, California and Texas was less than 2000 tons. On account of the expensive methods necessary in mining, the Arkansa;;; earth, even if of equally good quality, can not well compete with that of the thick beddeil deposits of Georgia and Florida. California1.-Fullers earth is reported at several localities in California. The most important deposit is that operated by the Cali fornia Fuller's Earth Company. The earth is a bedded deposit of Tertiary age, situated 18 miles north of Bakersfield. The bed is said to vary from 15 to 50 feet in thickness, with an extent of many acres, with only a thin layer of soil as overburden. The deposit was first opened in 1898, but its production has been small, and the product is used exclusively for refining animal and vegetable oils. The earth is said to compare favorably with English earth in bleaching power, but a feature of disadvantage is the wagon haul of 18 miles to the railroad. Florida2.-The extensive fullers earth deposits of Florida belong to the Alum Bluff formation, which forms the upper part of the Appalachicola group of late Oligocene age. The earth seems to form a continuous bed, underlying all of the upland area of Gadsden County, and outcropping on the slopes of the larger streams, near the bottoms of the valleys. The fullers earth bed also extends into the adjoining counties, Liberty and Leon, and across the State line into Decatur and Grady counties, Georgia. Fullers earth beds, apparently of the same age, are also found in Alachua and :\Ial'ion counties, m central Florida, and in Manatee County, along the Gulf coast in southern Florida. The most extensive mining operations have been carried on m 1 Cal. State Mining Bureau Bull. 38, pp. 273-275. 1906. 2 Vaughan. '1'. W., Fullers earth of southwestern Georgia and western Florida: U. S. Geol. Survey Mineral Hesources for 1901, pp. 922-934, 1902. 392: 399; ig~~Ilers earth of Florida and Georgia: U. S. Geol. Survey Bull. 213, pp. Sellards, H. E., Fullers earth: Fla. Geol. Survey First Ann. Rept., pp. 33-35, 1908. F ourth . , Production Ann. Rept. pp. of fullers 167-168, earth 1912. in Florida during 1910-1911: Fla. Geol. Survey ., Fullers earth, Fla. Geol. Survey Sixth Ann. Rept., pp. 28-36, 1914. :;n~ Gunter, H. Fullers earth deposits of Gadsden County, Florida, with Anontne.s on Similar deposits found Rept., pp. 257-291, 1909. elsewhere in the State: Fla. Geol. Survey Second 148 GEOLOGICAL SURVEY OF GEORGIA Gadsden County, at Quincy, Midway and Jamieson, near the Georgia line. The fullers earth bed seems to be a little thicker and more persistent in Gadsden County thah in Georgia, but the composition, structure, and geological relations are exactly the same. These deposits will be discussed in detail in connection with the description of the Alum Bluff earth of Georgia. An important guide rock associated with the fullers earth in both States is a white to greenish or yellowish gray, soft, argillaceous and locally calcareous sandstone, locally called ''sand rock.'' This rock is more resistant to erosion than the fullers earth, and often outcrops where the clay beds are entirely concealed. Massachusetts. 1-0n the property of E. and R. M. Farnsworth, one mile north or Lancaster, Massachusetts, is a deposit of clay which has been mined for use as a fullers earth. This is a glacial silt, deposited in the Glacial Lake Nashua, and it is the only reported fullers earth of glacial origin. The bed has a thickness, at one point, of at least 26 feet. Analysis shows that the clay resembles other fullers earths in its high content of silica and alkalies, but the percentage of combined water is very low (3.03 per cent). It is reported that all of the earth is used in fulling cloth, and its qualities as a bleaching agent for organic or mineral oils is not known. Mississippi. 2-Fullers earth is reported from Smith and Yalobusha counties, Mississippi, but it has never been worked on a commercial scale. That from Smith County probably comes from the Jackson formation, and it is said to have bleaching power equal to the English earth. New York.3-A bed of clay at l\IcConnellsville, 12 miles north of Rome, was worked several years ago by the New York Fullers Earth Company. It is a fine grained, dense Quartenary clay, occurring in 1 Alden, W. C., Fullers earth and brick clays near Clinton, Mass.: U. S. Geol. Survey Bull. 430, pp. 402-404, 1910. 2 Lowe, E. N., Soils and mineral resources of Mississippi, Miss. State Geol. Survey, Bull. 12, p. 143, 1915. 1 Ries, Heinrich, Fullers earth, New York State Museum, Bull. 35, pp. 848-851, 1900. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 149 layers 2 to 8 inches thick, interbedded with sand layers of equal thickness. The clay was used only for cleansing woolen goods. South Carolina.1-Clays having the properties of fullers earth are widely distributed in South Carolina, occurring, according to Sloan, in the Black Mingo a~d Congaree phases of the Eocene, the Parachucla shales of the Oligocene, and the Hampton clays of the Lafayette formation. The fullers earth found in the vicinity of Augusta and Aiken, classed by Sloan as the Congaree phase, belongs, at least in part, to the Barnwell formation, and is areally continuous with the important deposits of Barnwell age in Georgia. This earth seems to lie at a higher horizon than the type Congaree of the Congaree River area. Sloan publishes 14 analyses/ showing that the clays resemble the Georgia earths in composition. In spite of the large quantities of fullers earth present in South Carolina, mining operations have been of small importance. No production is reported since 1913. South Dakota. 3-The fullers earth deposits of South Dakota are fluviatile and fresh water clays, porous and lacking in plasticity, and said to be almost exact duplicates of the English earth in composition and properties. The age is Oligocene. The earth makes up a large part of the Chadron or '' Titanotherium'' beds at the base of the White River formation. The fullers earth formation extends from the high slopes of the Black Hills west of Fairburn and Hermosa far eastward into the Bad Lands, covering thousa\lds of square miles. 1 Sloan, Earle, Preliminary report on clays of South Carolina: S. C. Geol. Sur- vey, pp. 54-61, 1904. . . . . Fullers earth, S. C. Geol. Survey, Bull. 2, 4th ser., pp. 339-361, 1908. Op. Cit., pp. 392-395. 8 Ries, Heinrich, Fullers earth of South Dakota: Am. Inst. Min. Eng. Trans., vol. 27, pp. 333-335, 1898. Darton, N. H., Preliminary description of the geology and water resources of the southern half of the Black Hills: U. S. Geol. Survey, Twenty-first Ann. Rept. part 4, pp. 588-589, 1901. Fullers earth: U. S. Geol. Survey, Twenty-first Ann. Rept. part 6 (Cont.) p. 591, 1901. ' Todd, James E., Mineral Resources of South Dakota, S. D. Geol. Survey, Bull. ,3, pp. 107-108, 19020 - Darton, N. H., Geology and underground water resources of the Great Central Plains: U. S. Geol. Survey Prof. paper 32, pp. 43, 44, 175, 185, 398, 1905. O'Harra, C. C., The Badland formations of the Black Hills region: S. D. School ot Mines, Dept. of Geol., Bull. 9, pp. 65-66, 1910. Perlsho, E. C., The geography, geology, and biology of Melletto, Washabaugh, B ennett and Todd counties, south-central South Dakota: S. D. Geol. Survey Bull. 5, p. 60, 1912. 150 GEOLOGICAL SDRT"EY OF GEORGIA Test shipments have been made from localities near Fairburn and near Argyle, but no mining on a large scale has been done. Small samples are said to have given good results in bleaching vegetable and animal oils, but the larger test lots were not so good, owing to lack of care in selection of the material. Texas. 1-The fullers earth beds of Texas occur in the upper portion of the Jackson formation, of Eocene age, and in the Corrigan formation, probably Oligocene. The earth in the Jackson formation is a brmYn clay, occurring in beds up to 12 feet thick. Its bleaching power is greater than that of the standard English earths, and filtering properties are good.~ Two expensive grinding plants ~were erected about 1909, near Somerville (Summerville), Burleson County and near Burton, ~Washington County, but the production has remained very small, as the sale of the earth is severely handicapped by the cost of transportation. Virginia. 3-The so-called fullers earth of Virginia and Maryland consists of beds of infusorial or diatomaceous remains near the base of the Chesapeake formation of Pliocene age. The best exposures are in bluffs along the Potomac. At one time the deposits near the mouth of Pope Creek, ~Iaryland, were worked for shipment, but no production has been reported in recent years. TESTS FOR FULLERS EARTH As the chemical analysis does not indicate the commercial value of a fullers earth, it is necessary to make tests of the bleaching power and other physical properties. The earths described in this report have been tested for bleaching power on cotton oil only. No tests 1 Duessen, Alexander, Notes on some clays from Texas: U. S. Geol. Survey Bull. 470, pp. 337-343, 1910. Phillips, Wm. B., Mineral Resources of Texas: University of Texas, Scientific Series Bull. 29, pp. 81, 97, 121, 216, 241, 1914. Udden, Baker, Bose, Review of the geology of Texas: University of Texas, Bull. 44, p. 147' 1916. 2 Parsons, Charles L., Fullers earth: Bureau of Mines Bull. 71, 1913. 3 Darton, N. H., Geologic atlas of the United States, Nomini folio, No. 23, U. S. Geol. Survey, 1896. Watson, T. L., Mineral Resources of Virginia, The Virginia Jamestown Exposition Commission, pp. 296, 297, 1907. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 151 were made with mineral oils. In commercial practice in bleaching mineral oils percolators containing as much as 25 tons of fullers earth are used and several hun:dred barrels of oil are bleached in a run, making the conditions difficult to duplicate on a laboratory scale, and no standard method for comparing tests has been devised. In the case of animal and vegetable oils, however, in which the oil is agitated with a definite proportion of earth and filtered, the laboratory tests indicate accurately the results which may be expected in commercial practice, and by the use of the Lovibond color scale quantitative results may be obtained. It is probable that the bleaching power of the various earths when applied to other animal and vegetable oils will be of the same order as with cotton oil. In bleaching mineral oils the actual bleaching efficiency should also rank about the same as for cotton oil, but for this use the physical character of the earth is of as much importance as the bleaching power. Coarsely granular earth is used, and it must have such hardness and strength that not much will be lost as dust during repeated use and revivifying. The following methods of testing were used for all earths described in this report. PREPARATION OF SAMPLES Samples of 2 or 3 pounds of earth were taken, usually representing an average of all the beds in an exposure. The samples were broken down to a maximum size of half an inch, and a small sample for analysis taken out by quartering. The remain:der was dried in an electric oven for 24 hours, at a temperature maintained between 100 and 110 C. The dried material was then ground in a coffeemill until all passed through 20 mesh, and put through a small bolting machine, grading it into 20 to 40, 40 to 60, 60 to 100, and through 100 mesh sizes. A few samples were put through 200 mesh. The bolter used was equipped with silk cloth. The average size 152 GEOLOGICAL SURVEY OF GEORGIA of the openings, measured with the optical micrometer, was as fol lows: Mesh Distance between \ centers of cords of cloth \ Average Opening Inches Inches 20 0.05 40 0.025 60 0.0167 100 0.01 200 0.005 0.0384 0.0192 0.0115 0.0062 0.0025 BLEACH The method used in making bleaching tests is that employed at the Picard-Law Laboratories, Atlanta, Ga. The oil used for tests is a ''prime summer yellow'' cotton oil, preferably one of moderate color and capable of bleaching well. Fullers earth has no power to bleach crude cotton oil; the oil must first be refined by the usual alkali treatment, which removes free fatty acids and converts the coloring matter into basic forms. Oil from the same lot should be used for all tests of a series, as different refined oils, even if they have the same original color, differ greatly in their capability of being bleached. Two hundred grams of oil is weighed in a beaker, and heated to 120 C. Twelve grams of earth is added, the beaker removed from the burner, and the oil is stirred for five minutes, then filtered immediately. The preliminary heating is for the purpose of driving out any trace of water which the oil may contain, and also to drive out the hygroscopic moisture from the earth added. A small amount of extent. water in either oil or earth prevents the bleaching action to a great In standard tests the amount of earth used is 6 per cent of l!'ULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 153 the weight of the oil; and unless otherwise stated, this proportion is always used. If only a bleaching test is to be made a large folded filter paper may be used, but if it is desired at the same time to measure the speed of filtration and the proportion of oil remaining in the earth, in order to form an idea of the action of the earth in filter press, the filtration is made with a Buchner funnel, using suction. The filtered oil is placed in a standard sample bottle and the color determined as soon as possible, and without exposing to light any more than absolutely necessary. The standard sample bottles have a capacity of 4 ounces, and are exactly 51,4 inches in height, from the in:side of the bottom to the base of the neck. The bottoms are ground plane and polished, as the refraction of light by an ordinary rough or curved glass surface would effect the apparent color of the oil. Some forms of color comparators have horizontal rectangular cells, but the essential feature is to have a column of oil exactly 51;! inches in length. The Lovibond color scale.-The Lovibond scale consists of glass plates tinted with graduated shades of the primary colors. By the use of the red, yellow, and blue series of glasses almost any color can be duplicated. As cotton oil contains no blue coloring matter, its shades can be matched with color glasses of the yellow and red series. It is found in practice that a colum of 514 inches of prime yellow oil, refined but unbleached, can be best matched by using the 35 units yellow glass, then adding enough red glasses to match the tint. The number of units of red needed is more than one tenth the number of yellow units, commonly between 5 and 6. If more than 7.6 units of red are necessary to match, the oil is considered off-color. Fullers earth has a stronger affinity for the red than for the yellow coloring matter of cotton oil; so after bleaching, it is found that a normal oil can be most accurately matched by using red and yellow glasses in the ratio of 1 to 10. This color ratio applies in all cases where the earth used is of fair efficiency; if an earth or clay 154 GEOLOGICAL SURVEY OF GEORGIA with only slight bleaching power is used the red may remain more than one tenth the yellow after bleaching. As oils vary so much in bleachability, the best results that can be secured are only comparative. The same oil used for the bleaching test on an earth of unknmvn value must also be bleached with a standard earth of known quality, and the results compared. The earths generally adopted as standard are the IXL brand of English earth and the Pikes Peak brand of Georgia earth. Of these the Pikes Peak brand gives a bleach several units lighter in yellow and several tenths lighter in red than the English earth. After-bleach.-An oil bleached by fullers earth is further bleached by exposure to light. A number of the bleached samples of oil were allowed to stand for two weeks in a well-lighted room, but in a position where direct sunlight did not fall upon them, then readings were taken again. The results indicate that the bleaching effect of light is stronger after some earths have been used than after others, but sufficient data have not been collected to show on what property of the earth the efficiency of the after-bleach depends. The bleaching by light affects principally the yellow coloring matter of the oil. The oils after exposure to light contained only a few tenths less red than immediately after treatment with the earth, but the yellow was bleached as much as 10 units in a number of cases. This means that while exposure to light gives the oil a lighter color, the tint becomes redder. Exposure to light has also some bleaching effect on the oil untreated with fullers earth, but when untreated the light-bleach affects principally the red coloring, as the oil can still be matcher with the 35 yellow glass and a smaller amount of red than before exposure. The bleach produced by light is only temporary. The samples after exposure to light were placed in a dark room for two weeks. In all cases the oil was darker than when the preceding reading was made, but the tests indicate that the reversion of color is very slow, FULLERS EARTII DEPO?:!ITS OF TilE COASTAL PLAIN 155 and no attempt was made to find out how long and to what extent the process would continue. ABSORPTION OF OIL Absorption was in most cases determined in the fullers earth residue from the bleaching tests. Filtration vvas made through a small Buchner funnel, using an aspirator with a gage. The maximum vacuum attained was equivalent to 25 inches of mercury, but it generally dropped to about 20 inches near the end of the suction, as the cake became more pervious to air. Suction was continued in all cases until the oil came through ate the rate of one drop per minute. This, in some cases, required several hours of suction, and it would have required an unreasonably long time to have sucked the cakes entirely dry. The entire funnel containing the oil and earth cake was weighed to 0.1 gram, then the earth was removed from the funnel and filter paper and the funnel weighed again. A hard filter paper was used, fastened around the edges with a little glue, so the earth could be easily cleaned out. The amount of oil remaining in the paper and in the bottom of the funnel was the same for both weighings, and the difference in weight represents the original 12 grams of earth plus the oil absorbed by it. The absorption is stated as the percentage of oil remaining in the cake after filtering. The results obtained by this method are not highly accurate, the greatest source of error being the uncertainty as to the exact time at which suction should be stopped. The percentage of oil remaining in the earth after suction is about twice that left in commercial practice with the filter press, but the results are valuable as a basis for comparing the various samples. No attempt was made to measure the time required for filtration, except to note those cases in which filtration was exceptionally rapid or exceptionally slow. In general, the very light and porous earths with high absorption filtered more slowly than denser earths, but little can be learned by laboratory tests as to the action of the earth 156 GEOLOGICAL SURVEY OF GEORGIA in a filter press, because so mu~h depends on the method of grinding and the proportion of very fine material. The earths containing calcium carbonate also filter very slowly. It seems that calcium carbonate is sufficiently alkaline to saponify a small amount of the oil, and the minute quantity of soap so formed clogs the pores in the filter paper. SPECIFIC VOLUME The true mineral specific gravity of all samples of fullers earth runs about the same, not differing greatly from that of ordinary clays, and varying from 1.75 to 2.50. The weight of a given volume of the dried and ground earth, however, varies greatly. The relation between weight and volume depends to some extent upon the shape of the grains, the relative proportions of coarse and fine grains, and the method of grinding, but it is principally a function of the porosity of the earth. Most of the Georgia earth of good bleaching power is extremely light and porous, weighing approximately half as much as the English earth, and therefore requiring twice as many sacks per ton and necessitating the opening of the filter press a greater number of times in filtering a given quantity of oil, if the same proportionate weight of earth is used. On account of this great variation the quantity of earth used in large scale filtering tests should always be weighed, not measured. The weight of equal volumes of different earths was determined under as nearly identical conditions as possible. The method consisted in taking a small Erlenmeyer flask of known weight and capacity, and filling it with the dried and ground earth, at the same time tapping the flask gently on some soft surface; until it would hold no more. The weight of the contents was then determined. The results are comparative rather than absolute, but they are of much more value than exact determinations of specific gravity, because the latter gives no indication of the porosity and the space occupied by the ground material. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 157 It was found that, allowing for errors in the rather rough methods used, the absorption of oil by an earth varies inversely as the density. The English earth has a density as determined by the above method, of a little over 1.0, and weighs 66 pounds per cubic foot; almost the same as a pure kaolin. The Georgia earths are all lighter, several having a density as low as 0.44, weighing 28 pounds per cubic foot. Provided the particles are of about uniform size, the fineness of grinding has little effect on the weight of a given volume of earth. Normally the portion of the earth passing through 100 mesh is a little heavier than the 20 to 40, 40 to 60, and 60 to 100 mesh grades, because the smaller particles are more irregular and have a greater relative variation in size, therefore packing closer; but in some cases the earth through 100 mesh is so light and fluffy that it cannot be packed by the same amount of tamping as the coarser grades, and is therefore a little lighter. As a check on these determinations, the density of pure granular vein quartz, which has an actual specific gravity of 2.60, was determined by the same method. The 20 to 40 mesh size had a density of 1.41, weighing 88.5 pounds per cubic foot; and the 40 to 60 mesh, a density of 1.39, weighing 86.6 pounds per cubic foot. The density of the Georgia earths in mass is very nearly equal to that of water. As taken from the mine the earth contains about 50 per cent of hygroscopic moisture, but after air drying it will float in water until the pores become filled. This provides an easy test for fullers earth, as a dry clay which will float is almost certain to have good bleaching power. APPARENT ACIDITY Fullers earth possesses the power of adsorbing inorganic bases as well as basic colors, and this affinity for basic ions causes neutral solutions to give an acid reaction on addition of fullers earth, although there is actually no free acid present in the earth. To test an earth for apparent acidity, a two gram sample of the finely ground earth was placed in 100 c.c. of distilled water, which 151) GEOLOGICAL SURVEY OF GEORGIA was then boiled to expel carbon dioxide and to thoroughly saturate N the earth, and titrated with a standard - solution of potassium 10 hydroxide, using phenolphthalein as indicator. The results are stated as the number of cubic centimeters of tenth-normal alkali required to neutralize 100 grams of the earth. Some of the earths contain pyrite, which becomes partly oxidized during drying. When placed in water these earths actually liberate sulphurous acid, and they also contain soluble sulphates of iron and aluminum, which must be precipitated by the base before an alkaline reaction can be obtained. Such earths, therefore, require a very large amount of alkali for neutralization. In the case of earths which contain no free acid nor soluble salts the bleaching power is not directly proportional to the apparent acidity, but in general those having a high power of absorbing inorganic bases are good bleaching earths. FULLERS EARTH DEPOSITS OF GEORGIA FULLERS EARTH OF JACKSON AGE GEOLOGY OF THE TWIGGS CLAY MEMBER Areal distribution.-Outcrops of fullers earth and similar clays belonging to the Twiggs clay member of the Barnwell formation occur in a narrow belt extending more than half way across the State. The westernmost exposures are in Dooly County, and the belt continues northeastward to Savannah River near Augusta, wi~h exposures in Houston, Crawford, Twiggs, Bibb, Bleckley, Wilkinson, Jones, Baldwin, Washington, Glascock, Jefferson, Burke, Richmond and Columbia counties. Throughout most of the area underlain by the Twiggs clay the underlying Ocala limestone and the earlier Eocene formations are absent, so the location of the outcrops is just south of the belt in which the Cretaceous strata come to the surface. Stratigraphic relations.-The Twiggs clay member occupies a position at the base and near the northern margin of the Barnwell forma- FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 159 tion, which consists principally of glauconitic sand and marl. The clay grades downward and southward into the Ocala limestone, or into the marl and oyster shell beds of the Barnwell formation. Along the northern margin of the outcrops it is overlain with a slight unconformity by red sands of the Barnwell formation. This unconformity is exposed at Pikes Peak and Grovetown, but it evidently represents .a withdrawal of the sea for only a short distance and for a short period of time, because farther south the clay member is conformable with the remainder of the Barnwell formation. Northeast of Wilkinson County the Ocala limestone is absent, and the clay rests directly on the surface of the Lower Cretaceous, or is separated from it only by a thin bed of sand, and locally tongue~ of the clay member overlap the, Cretaceous beds entirely and rest upon the crystalline rocks of the Piedmont area. The most notable of these overlaps are at Roberts and Grovetown. Lithologic characters.-As indicated by the name, the member consists chiefly of clay, most of which presents some characteristics of fullers earth. The earth of commercial value is a laminated to moderately thick bedded, jointed clay, which is chiefly characterized by its extreme lightness and porosity. When thoroughly air-dried it will float on water. It is brittle and lacking in plasticity, so that when a fragment of the wet clay is struck with a hammer it shatters, instead of being deformed. Such plasticity as the earth possesses is developed only by fine grinding and mixing with a large proportion of water. The earth does not slake in water, but remains firm, and pebbles are often rolled in streams for considerable distances from the outcropping beds. The layers of fullers earth are soft and unctuous to the touch, and almost free from grit, but the stratum generally contains more or less sand in lenses and pockets and has thin partings of micaceous sand between the layers or laminae. In color the dry earth is white, drab, gray, or yellow, varying in tint from pale cream color to ocher-yellow, according to the percentage of ferric oxide. When wet the color is darker than when dry, and is characteristically gray or olive green of varying shades. 160 GEOLOGICAL SURVEY OF GEORGIA Locally in the northeastern counties of the fullers earth belt, the clay is indurated by the deposition of silica in the pores, forming a clay-stone or flint clay with approximately the hardness of an average limestone. Such clay is massive in the ground, but on exposure it breaks down in a peculiar manner into small fragments with angular and conchoidal fracture. It i~> distinguishable from indurated kaolins of the Lower Cretaceous, which it resembles in appearance, by its method of fracturing and by its high content of silica. Earth of good quality seems to have been deposited only in estuaries and several miles from the shore line. On this account the deposits, while large, are discontinuous and .Jf lens-like character. The clay along the extreme northern margin of the area of deposition is denser and more plastic than the good fullers earth, and approaches common clay in composition and characteristics. The formation has this character at Stevens Pottery and at Roberts, some of the northernmost extensions. Locally the clay deposited near the shore line is highly carbonaceous, grading into lignite, as the Chapman Lignite mine near Grovetown and at the Harbison and Walker fire clay mine near Gibson. Where carbonaceous, the clay generally contains also a considerable percentage of pyrite, which sometimes occurs in crystals visible to the naked eye. Southward, as the water during the period of deposition became deeper, the "Twiggs clay becomes more ralcareous, and gradually merges into the Ocala limestone in the west and into marl and oyster shell beds in the east. As the percentage of calcium carbonate increases the clay becomes harder, until some varieties are best described as argillaceous limestones. Most of the calcareous clay varies in color from slate-blue to very dark gray when fresh and wet, but at the surface it becomes cream-colored by oxidation of the iron and leaching out of carbonaceous and calcareous matter. At localities where the fullers earth was not deposited, and north of the limit of clay deposition, beds of yellowish-green glauconitic sand extend to the base of the Barnwell formation. Locally near the base of the formation are beds of shaly aluminous sandstone, quartzite, FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 161 and completely silicified sandy limestone. These beds and the local deposits consisting largely of oyster shells represent depositional phases during the time of formation of the fullers earth member. At a few localities the basal beds of the Barnwell consist of reworked Lower Cretaceous sands and therefore resemble the latter formation, but in general the two formations may be readily distinguished by color and presence of fossils in the Barnwell. Strike, dip and thickness.-The line of strike of the Twiggs clay member extends approximately northeast, from the vicinity of Perry, Houston County, to Grovetown, Columbia County. Exposures along the Macon-Perry road (National and Dixie Highway) in Houston County afford data for estimating the slope of the Cretaceous surface. At 5.1 miles from Perry the unconformity between the Cretaceous and Eocene (Jackson) beds is exposed at an altitude of 360 feet, and at 13.1 miles is another exposure at an altitude of 450 feet. There are several other exposures in the intervening distance, which show that the Cretaceous surface is almost plane and has a uniform slope. The unconformity dips 90 feet in 8 miles, or 11 feet per mile, in the direction of the road, but the road is not perefectly straight, and it makes an angle of about 30 degrees with the line of dip of tlie beds, so the dip is steeper than indicated, and may be estimated as exceeding 12 feet, but not exceeding 20 feet, per mile. 'l'he dip of the Jackson beds is a little less than that of the unconformity, and is probably about 10 feet per mile, in a direction a little south of southeast. In Twiggs County the slope of the upland areas, remnants of the original plain, is 9 feet per mile in the direction of the Macon, Dublin, & Savannah Railroad from Pikes Peak to Danville. No data have been secured for accurately measuring the dip of the Jackson beds, but it is a little steeper than the slope of the plain, and is probably between 10 and 15 feet per mile. In the eastern part of the State the upper surface of the Lower Cretaceous bedsis very irregular, and the angle of dip of the unconformities can not be stated with any degree of certainty. At Grove- 162 GEOLOGICAL SURVEY OF GEORGIA town the fullers earth beds lie directly upon the Lower Cretaceous at an altitude of 500 feet. At Griffin Landing on Savannah River, Burke County, a bed of Ostrea georgiana shells in a matrix of calcareous clay of the fullers earth type rests unconformably upon blue marl of the Claiborne (McBean formation) near low water level, altitude 80 feet. The distance between these points in an air line is 36 miles, in a direction S 52 E, or almost parallel to the dip. Therefore the clay beds at the base of the Barnwell formation dip slightly more than 10 feet per mile to the southeast. The Twiggs clay attains its maximum thickness near Pikes Peak, Twiggs County, where there are two fullers earth horizons separated by a bed of greenish, fossiliferous sand, the whole having a thickness of 100 feet. In Houston County also there are beds of fullers earth, calcareous clay and sand having a thickness of about 100 feet which may be considered as making up the Twiggs clay member. To northward the clay grades into sand, and to southward it becomes thinner as the underlying limestone thickens. Northeastward along the strike the member also becomes thinner, and in Jefferson and Columbia counties the beds of fullers earth rarely reach a thickness of 20 feet. Physiographic expression.-The clays have no marked influence on the topography, as the outcrops are mainly in ravines, gullies and stream bluffs and on the lower slopes in valleys ; localities where the overlying red sand of the Barnwell formation has been eroded. In the few localities where the fullers earth outcrops over any considerable area it forms exceedingly sticky, black clay soil. Paleontological characters.-The Twiggs clay member is not paleontologically distinct from the rest of the Barnwell formation. The most characteristic fossil of the fullers earth horizon is Ostrea georgiana, which forms beds many feet in thickness, and is at some places accompanied by Bryozoa of the Rich Hill (Ocala) fauna. The westernmost of the oyster beds is near Danville, Twiggs County, and they become increasingly thick and abundant eastward, reaching their greatest development at Keys Mill, Shell Bluff and Griffin Landing, Burke County. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 163 The fullers earth, especially the calcareous varieties, contains abundant fossil remains at some places. The animal remains are mainly molluscan casts, with the material of the shells sometimes changed to a soft, chalky material. Such fossils are very fragile and are difficult to collect and identify, but the forms are apparently. the same as in the harder, silicified beds. At certain localities, plant fossils are abundant in the more or less carbonaceous varieties of clay, consisting principally of leaves and stems deposited along bedding planes, and splendidly preserved. Vertebrate remains consist of sharks teeth, which are abundant at a few localities, and bones of the Zeuglodon, Basilosarurus cetoides (Owen), are found in sand beds just below fullers earth near Dry Branch. For a more extensive list of the fossils see Bulletin 26, Geological Survey of Georgia. DESCRIPTIONS OF INDIVIDUAL DEPOSITS TWIGGS COUNTY As previously stated, the important clay member of the Jackson group reaches it maximum thickness and is best exposed in Twiggs County, from which the name '"l'wiggs clay member" is derived. Ocmulgee River forms the western boundary of the county, and its valley is cut down into the Lower Cretaceous beds and the sand members of the Upper Cretaceous Ripley formation as far south as a point between Adams Park and \Vestlake. Big Sandy Creek, which crosses the northeastern corner of the county, has also cut through the Tertiary beds and into the Lower Cretaceous, while the Upper Cretaceous strata are not exposed in Big Sandy Valley nor at any place farther east within the State of Georgia. The upland area forming the central and southern portions of the county is underlain by red sand, fullers earth, and limestone of Jackson age. In the extreme southern part chert bearing fossils of Vicksburg (Oligocene) age is found in the red sand, and although there is no paleontological evidence farther north, it is possible that the red sand capping the hills and locally overlying the clay member unconformably as far north as Pikes Peak also belongs to the Vicksburg formation. 164 GEOLOGICAL SURVEY OF GEORGIA Topographically the county forms a part of the Fall Line Hills belt. Only Ocmulgee River and Big Sandy Creek have formed broad valleys with well-developed river swamps or flood plains, while the remainder of the county is a plateau dissected by deep narrow valleys with precipitous sides. The steep valley slopes are cut by many deep gullies, largely formed since the deforestation of the land, in which may be observed geologic sections often totaling over 100 feet of freshly exposed strata. The Lower Cretaceous beds consist of light-colored arkosic and kaolinic sands with prominent lenses of sedimentary kaolin, which is extensively mined in the vicinity of Dry Branch. The Upper Cretaceous, of which only the Cusseta and Providence sand members of the Ripley formation are exposed in the county, consists dominantly of light-colored kaolinic sand. Fossils, calcareous materials, a;nd clays of ordinary composition are lacking in all the Cretaceous formations, and the character of the beds is so different from the Eocene deposits that there is never any possibility of mistaking the Cretaceous or Eocene age of the strata. The Ocala limestone, which underlies the fullers earth beds throughout the greater part of the area of Twiggs County, has the same character as in other counties to the southwest. It consists al most en~irely of bryozoan fossils, and Pecten perplanus and Periarchus pileus-sinesis are very abundant. The maximum thickness is 45 to 50 feet in the southwestern part of the county, but it becomes thinner to the north and east. The Twiggs clay member changes considerably in character from north to south within the county. In the northern part, near Pikes Peak, there are two well defined beds of fullers earth in a horizon having a total thickness of 100 feet. The lower bed is about 45 feet thick, the upper over 20 feet, and the two are separated by a bed of greenish-yellow fossiliferous sand which reaches a thickness of 50 feet. The earth in this vicinity is not calcareous except near the base, where it grades into limestone. Where leached and oxidized by surface water it has a pale yellow to cream color, and is extremely light and FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 165 porous; but below the zone of oxidation it is usually dark gray, and contains organic matter and pyrite. Farther south, for instance, in :the vicinity of Danville and Westlake, the fullers earth bed becomes thinner as the underlying limestone thickens, and the clay becomes more and more calcareous. The calcareous earth is blue or gray where unoxidized, but becomes cream or yellow at the surface. It is much less pervious than the non-calcareous variety, so the zone of leaching and oxidation frequently extends less than an inch from the surface, while in the northern part of the county the material is usually oxidized to a depth of many feet. The structure is simple, as the beds are almost in their original position, and dip slightly to the southeast. The only evidence of folding is seen in the railroad cut at Pikes Peak station, where there is a local anticline with limbs dipping 4 degrees southeast and 3 degrees northwest. The slope of the upland areas, remnants of the original plain, is 9 feet per mile, as the altitude decreases from 625 feet on the hill tops near Pikes Peak to 460 feet at Danville, a distance of 18 miles. The dip of the beds is a little steeper than the slope of the plain, and is probably between 10 and 15 feet per mile. PIKES PEAK LOCALITIES GE)!ERAL REDUCTIOX COMPANY PROPERTY (Map locality T-1) The General Reduction Company was incorporated m 1908, and mining operations were commenced by 1\fr. James E. Carlton about that time. A great deal of experimental work was done before finding a satisfactory method of drying and grinding the earth, but the difficulties have been overcome and the plant is now operating steadily and profitably. At present Mrs. L. H. Carlton is president of the company and Mr. K. R. Slocum is manager. The post-office address is Dry Branch, Georgia. Location.-The General Reduction Company owns about 1300 acres of land in the vicinity of Pikes Peak station on the Macon, Dub- 166 GEOLOGICAL SURVEY OF GEORGIA lin & Savannah Railroad. The mine is 12 miles from Macon, and half a mile northeast of Pikes Peak station. The locations of the exposures described are shown on the topographic sketch map, figure 19. Geologic relations.-The following section IS exposed in and near the fullers earth mine (Map locality A). Section in fullers earth mine of the General Reduction Company Oligocene or Eocene Vicksburg formation or Jackson group Barnwell formation? Feet 8. Massive, dark red, argillaceous sand............... 17 7. Quartz sand and fine gravel, indistinctly bedded.... 10 6. Varicolored sands with laminae and lenses of tough, plastic clay, locally called ' 'gumbo.' ' Some layers of the sand are slightly indurated.... . . . . . . . . . . . 8 ( Unconformity ) Eocene Jackson group Barnwell formation (Twiggs clay member) 5. Light cream-colored fullers earth, almost white when dry. The lower portiov is thin-bedded, with fine sandy partings. Toward the top the earth becomes more massive, and the beds are several feet thick between partings. The material along the partings consists of fine quartz sand and flakes of mica ( damourite or partly weathered mu~covite) stained yellow by oxides of iron. The whole mass of fullers earth is cut by numerous joints in all directions, and along the joints, as well as the sand partings, iron-and manganese-bearing solutions have penetrated, locally depositing oxides of man- ganese in dendritic forms. Some of the joints and partings are slickensided, showing that slight movements, probably caused by shrinkage, have occurred. This unit is uniform in texture and composition, and is very light anvalnut size. ] 1 rom the storage bin the earth is fed to a four-roll Raymond pulverizer, and when ground sufficiently fine the earth is carried up by a current of air, from which it is precipitated by a Cyclone sep- arator. The air separation is so adjusted that 95 per cent of the finished product passes through a 100 mesh screen. A screen analy- sis of the dry commercial earth, made with a small flour bolting machine, is given below, with an analysis Jf the IXL brand of English earth for comparison. (The IXL sample from the Picard-Law Company is specially ground and prepared for laboratory tests, and is finer than the commercial product.) Screen analyses of fullers earth Screen used I I 1 Pikes Peak (S-1) 1 I I On 21J mesh ............... . I On 40 mesh .................. I On 60 mesh ................. I On 80 mesh ............... I On 100 mesh ................. ... I On 150 mesh ................ I .00 .00 .56 1.49 2.43 14.68 On 200 mesh .......................... I 1 Tlmmgh 200 '"""" .................. 13.96 66.88 IXL English .00 .12 .05 .04 .04 .14 2.29 97.32 100.00 100.00 The plant has an annual capacity of 10,000 tons of prepared earth. " FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 183 Uses.-The Pikes Peak earth sold in the United States is used almost entirely in the refining of vegetable vnd animal oils, especially cotton oil and linseed oil. Before the European war a large quantity of the earth was exported to Germany. The exact uses made of the exported earth are not known, except that a part was used in refining edible oils. Parsons1 makes the following statement, which probably refers to earth from this deposit: ''Certain finely ground and nearly white clays of high adsorptive power have been imported from Germany to be used in the production of clay pigments as a basis for color printing on wall papers. While these samples of imported clay can not be positively identified, certain brands strongly resemble samples from one or two American deposits of fuller's earth, and there is every reason to believe that the material was exported and after specially fine grinding was reimported into this country." No serious attempt has been made to introduce this earth for refining of mineral oils. The dried earth from the Pikes Peak deposits is softer than that from the Alum Bluff formation of south Georgia and Florida and offers less resistance to crushing and attrition, so it would probably not prove so satisfactory as the latter for this purpose. LOCALITIES NORTH OF PIKES PEAK North and northwest of the General Reduction Company property, along the Macon, Dublin & Savannah Railroad between Pikes Peak and Dry Branch, are the kaolin mines of the Georgia Kaolin Company, American Clay Company, John Sant Clay Company, and "the abandoned mine of the Atlanta Mining and Clay Company. All of the clay pits, as well as numerous gullies, expose fullers earth of varying grade and thickness. ATLANTA MINING AND CLAY COMPANY The kaolinmine of the Atlanta Mining nnd Clay Company is half a mile east of Winthrop and 2 miles north of Pikes Peak. 1 Parsons,. Charles L., op. cit. p. 33. 184 GEOLOGICAL SURVEY OF GEORGIA Section at south end of Atlanta Mining and Clay Company pit Eocene Jackson group Barnwell formation 7. Sand and soil containing quartz pebbles. . . . . . . ( Unconformity ) Feet 7-10 6. Yellow and red-and-gray-mottled plastic clay. . . . 2-5 5. Bedded red and black sand. . . . . . . . . . . . . . . . 1.5 4. Yellow sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 3. Yellow clay and- sand, interbedded......... . . . . . 1 2. Yellowish-gray sand ......................... 10 ( Unconformity ) Lower Cretaceous 1. White kaolin, varying from very pure to sandy and micaceous ........................... 12+ The clay of bed No. 3 is non-plastic and resembles fullers earth in appearance, so this thin bed must represent the fullers earth horizon. Its altitude is 465 feet. AMERICAN CLAY COMPANY PROPERTY The kaolin mine of the American Clay Company is situated about half a mile northeast of Winthrop and a mile south of Dry Branch. Section on north side of American Clay Company pit Eocene Jackson group Barnwell formation Feet 7. Slightly indurated red and yellow sand........ 10 6. Plastic clay, red-and-gray-mottled, containing some sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5. Red, yellow and black bedded sand............... 4 4. Fullers earth horizon. The earth exposed is very impure. It is sandy, iron-stained, and more plastic than earth of good quality. . . . . . . . . . 2 3. Yellow argillaceous sand......................... 10 ( UnconformityT ) Lower Cretaceous 2. White kaolin, almost free from grit.............. 12 1. Sandy white kaolin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 The altitude of the top of the Cretaceous beds is about 430 feet. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 185 .At the west end of the kaolin pit the fullers earth bed pinches out, but in a well 100 yards north of the pit fullers earth of considerably greater thickness and better quality than shown in the preceding section was cut. On the same property, south of the mine, is a gully which heads near ihe store on the public road. In this gully a good section is exposed. Section in gully south of the American Clay Company mine Eocene! Feet 6. Greenish argillaceous sand, weathering to bright red. Overlies the fullers earth bed with a slightly irreg- - ular contact, which is marked by an inch or two of carbonaceous clay .......... _. . . . . . . . . . . . . . . . . . 20 ( Unconformity~ ) Eocene Jackson group Barnwell formation (Twiggs clay member) 5. Fullers earth horizon. About 10 feet from the base is a sand stratum some feet in thickness, and there . are other rather sandy beds, but as a whole the formation is light-colored and apparently of good quality. A few feet of earth at the top of the bed is fossiliferous and slightly indurated............ 45 4. Fossiliferous sandstone. . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 3. Yellow argillaceous sand........................ 1. 2. Argillaceous limestone. . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 1. Yellow sand............. . . . . . . . . . . . . . . . . . . . . . . . PROPERTY OF MRS. F. M. THARPE (Map locality T-2) The property of Mrs. F. M. Tharpe, on which the kaolin mine of the John Sant Clay Company is located, adjoins the property of the .American Clay Company on the west. Geologic relations.-A section of the lower beds of the Jackson formation is exposed as overburden in the pit of the John Sant Clay Company. 186 GEOLOGICAL SURVEY OF GEORGIA Section in John Sant Clay Company pit Eocene Jackson group Barnwell formation Feet 5. Soil and clayey sand. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Massive red and yellow sand...................... 4 3. Fullers earth horizon, here represented by olive-gray clay, iron-stained and more plastic than good fullers earth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 2. Light colored sand, partly argillaceous............. 10 ( Unconformity ) Lower Cretaceous 1. White kaolin................... . . . . . . . . . . . . . . . . . 15 The Tharpe residence is situated on a ridge about half a mile west of the clay pit, and 50 feet above the surface of the kaolin in the pit. A well near the house is said to have struck fullers earth with 18 feet overburden. It passed through one bed of fullers earth, then through a sand bed, and ended in fullers earth at a depth of 60 feet. Other wells along the ridge have also encountered fullers earth. In gullies on both sides of the public road, which follows the ridge south of the Tharpe house, fullers earth is exposed. In a gully west of the road are discontinuous exposures of fullers earth through a vertical range of over 30 feet, with a thin bed of hard limestone about the middle of the section. In a gully east of the road light-colored, thick-bedded fullers earth outcrops altnost continuously for a thickness of 30 feet. An average sample (S-16) was taken from the exposure. The overburden above this deposit apparently consists entirely of red argil laceous sand, and has a thickness of 40 feet to the top of the ridge followed by the road. Between the house and the kaolin mine is another gully in which a considerable thickness of fullers earth is exposed, but this earth as contains sandy fossiliferous beds, and is not of as good quality that where the sample was taken. The earth.-This occurrence is near the northern limit of the area FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 187 of deposition of the fullers earth beds, and therefore the earth has more of the characteristics of ordinary clay than the Pikes Peak deposits. As shown by the tests, the Tharpe earth is denser and absorbs less oil than the Pikes Peak earth, approaching the English earth in these characteristics. Its original bleaching power is not especially high, but after standing in the light the oil bleached with this earth becomes as light in color as that bleached with the standard earths. It is more plastic than the Pikes Peak earth, and when dried is harder and appears finer in grain. Tests.-All tests of sample S-16 were made on earth ground in a coffee-mill to pass through a 100 mesh screen. As usual, the tests on IXL and Pikes Peak commercial earths are stated for compari;;on. Sample useit at "C" cut a thickness of 18 feet of fullers earth overlain by 8 feet of sandy plastic clay and soil. This pit was :filled with water when examined, but the earth taken from it was stored in the drying shed, and an average sample (S-197) was taken from there. In gullies at "D" above the drying shed are exposures of fullers earth. The beds are a few inches to several feet thick, with much sand interbedded. The better part of the fullers earth deposit seems to fill an erosion depression in the Lower Cretaceous surface, because in the surrounding hills kaolin and kaolinic sands are found at higher elevation than the base of the fullers earth beds. There is undoubtedly plenty of fullers earth on the property for working on a commercial scale, but the distribution is irregular, and much of the earth is unsuitable, so it would be desirable to do considerable exploration work before mining is started. The earth.-The earth on the Savage property is almost identical in composition and properties with that on the adjoining property of the Georgia Kaolin Company. It has considerably higher specific gravity, with correspondingly lower oil absorption, than the Pikes Peak earth. The following analysis shows no unusual characteristics, except that this earth contains slightly more alumina and slightly less silica than most of the lighter 'varieties. Analysis of fullers earth from Savage property S-197 Silica (SiO,)..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67.72 Alumina (Al,O,)................................ 17.86 Ferric oxide (Fe,O,). . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.69 Ferrous oxide (FeO)......... . . . . . . . . . . . . . . . . . . . .15 Lime (CaO).................................... .68 Magnesia (MgO)............................... 1.14 Soda (Na,O).... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57 Poatsh (K,O).................................. .57 Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.43 FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 193 Carbon dioxide (CO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . .00 Titanium dioxide (Ti02 ). .79 Phosphorus pentoxide (P20J. . . . . . . . . . . . . . . . . . . . . .33 Sulphur (S).................................... .00 99.93 Moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.91 Tests.-Al1 tests of sample S-197 were made on earth ground in a coffee-mill to pass a 100 mesh screen. These tests show very good bleaching power and high apparent acidity for an earth of so great density. The absorption of oil by this sa"31ple was not determined. Tests on commercial earths are stated for r:omparison. Bleach Yellow Red Oil used. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 6.1 IXL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.5 Pikes Peak. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2.3 S-197 ... '... . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.2 Specific volume Specific gravity IXL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.05 Pikes Peak. . . . . . . . . . . . . . . . . . . . . . .61 S-197 . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Apparent acidity Lb. per cu ft. 66.0 38.2 44.4 N -alkali per 100 gm. earth 10 IXL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.6 c.c. Pikes Peak..................................... 163.0 S-197 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131. LOCALITIES WEST AND SOUTH OF PIKES PEAK East of the Macon, Dublin & Savannah Railroad in the vicinity of Pikes Peak the valley of Big Sandy Creek is cut down below the fullers earth horizon, but west and south of the railroad is a large I . upland area underlain by the beds of the Barnwell formation. Ful- lers earth is to be found on almost every property within 5 miles 194 GEOLOGICAL SURVEY OF GEORGIA west and south of Pikes Peak station, but only a few of the best exposures are he 'e described in detail. CRUMP PROPERTY (Map locality T-E) The property of J. D. Crump, of :Jfacon, adjoins the American Clay Company and General Reduction Company properties on the west, and comprises an area of 380 acres north of Stone Creek Church. Geologic relations.-The best exposures of fullers earth on the property is in a deep gully at Stone Creek Church. Section in gully on Crump property, at Stone Creek Church Eocenef Feet 4. Red sand with thin beds of plastic clay, forming overburden on the fullers earth. Maximum thickness, to the level of the church ...... _. . . . . . . . 45 Eocene Jac'kson group Barnwell formation (Twiggs clay member) 3. Fullers earth, light-colored and thick-bedded, but contains occasional sand partings over an inch in thickness ........................ _. . . . . . . . . . . 13 2. Hard sandstone bed, forming a small waterfall... 0.5 1. Yellow sand and fullers earth interbedded, in about equal quantities .......................... _. . 6.5 In another gully a quarter of a mile northwest of the church the fullers earth horizon is represented by rather plastic yellow and purple-stained clay interbedded with an equal volume of sand. This exposure and that at the church show that the formation can change in a short distance from a thick-bedded stratum of good fullers earth to a mixture of impure sands and clays. Near a house in the valley, half a mile north of Stone Creek Church, and 100 feet below the level of the church, is a pit 3 feet deep, cutting yellow fossiliferous marl containing nodules of pure white chalk, thin beds of hard limestone, and laminae of pale yellow calcareous clay resembling fullers earth in appearance. The marl represents the gradation between the fullers earth and the un- FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 195 derlying Ocala limestone. Several pits and borings on the slopes 15 to 20 feet above the house have shown fullers earth, but the thickness and quantity are not known. The earth.-An average sample (S-56) was taken from the bed, 13 feet thick, in the gully near Stone Creek Church. The earth is not calcareous and is very light and porous, resembling the lightcolored earth in the General Reduction Company mine. It absorbs a large percentage of oil, and while the original bleach is not especially good, the after-bleach by action of light makes the oil very light in color. Earth from other exposures on the property varies greatly in composition and physical properties. Tests.-All tests of sample S-56 were made on earth ground in a coffee-mill to pass through a 100 mesh screen. Tests on commercial earths are stated for comparison. Bleach Sample useoint on th& Macon, Dublin & Savannah Railroad is little more than a mile. DELZEL (Map locality T-7) Fullers earth is exposed near the old Delzel post-office ill a gully parallel to the road to Bond's Mill, which is situated a mile northwest of Delzel. In the bottom of the gully is an exposure of 13 feet of bryozoan limestone of Ocala age, the elevation of the top of the limestone bed being 445 feet. The limestone bed is immediately overlain by yellowish fullers earth. The exposure shows 55 feet of thick-bedded earth, calcareous near the base,. where it grades into the limestone. The massive earth bed is overlain by 45 feet of fullers earth interbedded with sand, and 25 feet of red argillaceous sand caps the hill. Other gullies in the vicinity show varying thicknesses of limestone and fullers earth. At Bond's Mill both limestone and fullers earth are absent, and kaolin of Lower Cretaceous age is overlain by red sand with beds of plastic clay. The Delzel fullers earth is denser than that from Pikes Peak, with correspondingly lower bleaching power and lower oil absorption. Although the bed is very thick, its economic importance is small, on account of the very heavy overburden and distance of at least 5 miles to either the Southern or the Macon, Dublin & Savannah Railroad. Tests.-Sample S-17 represents an average from a thickness of about 50 feet of the best beds of the fullers earth horizon in the Delzel gully. All tests of this sample were made on earth ground in a coffee-mill to pass through a 100 mesh screen. Tests of commercial earths are stated for comparison. 200 GEOLOGICAL SL~RVEY OF GEORGIA Sample useYeen light and dark earth is sharp, but does not seem to be a bedding plane. The lower part of the bed of dark-colored earth is dark at the surface, but above, where weathering has had more chance to act, it has been bleached to a depth of a few in<.:hes. At this locality the light earth lies below the dark, a relation which may be explained by the fact that the former was leached and oxidized by water circulating through the underlying sand bed. Tests.-The dark earth from this locality, while stained by organic matter, docs not seem to contain any pyrite. Both samples were 208 GEOLOGICAL SURVEY OF GEORGIA taken from natural exposures and were somewhat weathered. Neither shows especially good bleaching power. All tests of samples S-27 and S-28 were made on earth ground in a coffee-mill to pass through a 100 mesh screen. Tests on commercial earths are stated for comparison. Bleach Sample used After two weeks After two weeks Original bleach in light in dark Yellow Red Yellow Red Yellow Red I Oil used........... IXL ................ 1 Pik;s Peak ........... S-21 ................. 35 21 19 22 I I 4.8 35 2.1 15 1.9 15 I 2.2 13 4.0 1.9 1.9 1.9 35 16 17 14 4.4 2.0 2.1 2.0 S-28 . . . . . . . . . . . . . . . . . 1 23 I 2.3 16 2.0 18 2.2 I I I .Absorption of oil IXL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pikes Peak...................................... 827 .............. '. . . . . . . . . . . . . . . . . . . . . . . . . . . . S-28 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2% 38.4 35.8 35.8 Specific v~me Specific gravity IXL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.05 Pikes Pleak.................... .61 S-27 .. .. .. . .. ... .. .. . .. . .... . . .. .76 S-28 .79 Apparent acidity Lb. per cu. ft. 66.0 38~2 47.4 49.4 N -alkali per 100 gm. earth 10 IXL 19.6 c.c. Pikes Peak.................................... 163.0 S-27 .......................................... . 14.8 S-28 ....................................... 2.5 FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 209 LOCALITIES NEAR JEFFERSONVILLE . The town of Jeffersonville is situated on an upland plain capped by red sand, at an altitude of 52'6 feet. There are no exposures of the underlying formations in the immediate vicinity, but to east and west, where erosion has proceeded farther, good sections are exposed. Toward the west, the road to Bullards descends from the upland 4 miles from Jeffersonville. On the slope a fullers earth horizon 60 feet thick is encountered, 65 feet by aneroid reading below J effer. sonville station. The earth is thin-bedded and badly iron stained; and contains many laminae and beds of sand. The deposit is probably too impure to have any commercial value, even if means of trans'portation were available. Farther west, in the vicinity of Bullards and .Adams Park, the land surface is cut down below the 400-foot level, so no fullers earth is to be expected. There are a number of gullies within 2 or 3 miles north, south, and east of Jeffersonville, where good sections of the strata of the fullers earth horizon are shown, but none of the deposits are likely to have commercial value, as the fullers earth beds are usually very thin and interbedded with a great amount of sand. FOUR MILES NORTHEAST OF JEFFERSONVILLE (Map locality 1'-10) Four miles northeast of Jeffersonville is a deep gully parallel to the public road. .An excellent section is exposed. Section in gttlly four miles northeast of Jeffersonville Eocene' Feet 11. Red sand capping hill.......................... 45 Eocene Jackson group Barnwell formation (Twiggs clay member) 10. Tough, plastic yellow and white clay interbedded, partly sandy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 9. Olive-yellow clay, resembling fullers earth, but rather plastic................................ 4 210 GEOLOGICAL SURVEY OF GEORGIA 8. Black-mottled sandy clay containing well rounded quartz grains up to an eighth of an inch in diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7. Clay of fullers earth character, light yellow, thinbedded, and containing much sand along partings 7 6. Thick-bedded greenish fullers earth, of high specific gravity ............... .'. . . . . . . . . . . . . . . . . . . . . 3 5. Bluish and yellow sandy fullers earth....... . . . . 10 4. Hard, fine-grained limestone. . . . . . . . . . . . . . . . . . . . 1 3. Interval concealed except for a small outcrop of pale blue argillaceous sand................ . . . . 20 2. Hard, fine grained limestone, maximum. . . . . . . . . 1 1. Soft, argillaceous, fossiliferous marl. . . . . . . . . . . . ' The earth of bed No. 6 is denser than any other Georgia earth discovered, and resembles the English earth very much in most physical properties: For this reason a sample (S-33) was taken for testing, but its bleaching power was found to be unsatisfactory. Tests.-All tests of sample S-33 were made on earth ground m a coffee-mill to pass through a 100 mesh screen. Tests of commercial earths are stated for comparison. Bleach Sample userl After two weeks After two weeks Original bleach in light in dark Yellow Red Yellow Red Yellow Red Oil used .............. 35 4.8 35 4.0 35 4.4 IXL ................. 21 2.1 15 1.9 16 2.0 Pikes Peak ............ 19 1.9 15 1.9 17 2.1 S-33 ....... .. 26 2.6 17 2.1 19 2.3 Absorption of oil IXL 21.2% Pikes Peak..................................... . 38.4 S-33 .......................................... . 23.6 FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 211 Specific volume Specific gravity !XL . . . . . . . . . . . . . . . . . . . . . . . . . . 1.05 Pikes Peak...................... .61 833 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.04 Lb. per cu. ft. 66.0 38.2 65.3 Apparent acidity N - alkali per 100 gm. earth 10 !XL 19.6 c.c. Pikes Peak .................................... . 163.0 S-33 ....................................... 42.0 LOCALITIES NEAR DANVILLE Danville has an altitude of 460 feet and is situated on the upland plain capped by sand and chert of Vicksburg age, but there are exposures of the beds of the Barnwell formation along the valley of Turkey Creek. These localities are far south of the northern limit of fullers earth deposition and the earth shows signs of a gradation into limestone, being mostly calcareous and interbedded with impure, fossiliferous marls. HILL PROPERTY (Map locality T-11) Fullers earth is exposed on the property of Robert Hill (colored), just south of the Macon, Dublin & Savannah Railroad bridge over Turkey Creek, l:fh miles northwest of Danville. The elevation of the creek at this point is 365 feet, and the following section starts about 5 feet above creek level. Section on Hill property Eocene Jackson group Barnwell formation (Twiggs clay member) Feet 4. No outcrops, but the slope is eovered with boulders of hard argillaceous limestone.................. f 212 GEOLOGICAL SURVEY OF GEORGIA 3. Light yellow, slightly calcareous fullers earth, exposed in a wash............................... 4 2. Sandy and indurated fullers earth................ 1 1. Light yellow, indurated calcareous fullers earth or argillaceous limestone.......................... 2 Tests.-Sample S-37 was taken from bed No. 3 of the preceding section. In spite of the content of lime, this earth bleaches fairly well, but filtration is slow. All tests were made on earth ground in a coffee-mill to pass through a 100 mesh screen. Tests on commercial earths are stated for comparison. Bleach Sample used After two weeks After two weeks Original bleach in light in dark Yellow Reel Yellow Red Yellow Red Oil used............. 35 4.8 35 4.0 35 4.4 IXL ................. 21 2.1 15 1.9 16 2.0 Pikes Peak ............ 19 1.9 15 1.9 17 2.1 . S-37 ............ 21 2.1 14 2.0 15 2.1 Absorption of oil IXL 21.2% Pikes Peak .................................... 38.4 S-37 ...................................... 38.5 Specific volume Specific gravity IXL .......... '................ 1.05 Pikes Peak . . . . . . . . . . . . . . . . . . . . .61 S-37 . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Lb. per cu. ft. 66.0 38.2 44.2 Apparent acidity N - alkali per 100 gm. earth 10 IXL 19.6 c.c. Pikes Peak.................................. 163.0 S-37 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0.0 FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 213 PORTER PROPERTY (Map locality T-12) On the property of J. F. Porter, about a mile downstream from the Macon, Dublin & Savannah Railroad bridge over Turkey Creek, is an exposure locally known as "Kaolin Spring." The exposure consists of 5 feet of calcareous fullers earth, above which is several feet of hard argillaceous limestone. Both hard and soft varieties are dark slate-blue when fresh, but have weathered to a 'light olive-gray color to a depth of an inch or more from the surface. The earth.-The earth at this locality is highly calcareous. A sample (S-36) was taken from the beds below the hard limestone ledge, principally for the purpose of determining the effect of a large percentage of lime on the bleaching power and other properties, but the results show that it has not very strong bleaching power. The analysis is as foll9ws: Analysis of earth from Porter property Silica (SiO,). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alumina (Al,03 ). Ferric oxide (Fe,03 ) .'. Ferrous oxide (FeO)............................ Magnesia (MgO)............................... Lime (CaO).................................... Soda (Na,O)................................... Potash (K,O).................................. Ignition (Less CO,) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carbon dioxide (CO,)........................... Titanium dioxide (TiO,). . . . . . . . . . . . . . . . . . . . . . . . . Phosphorus pentoxide (P,05)..................... Sulphur ( S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-36 25.93 6.94 .87 .45 .34 34.94 .37 .12 3.51 25.50 .28 .10 .44 Moisture 99.79 3.08 Tests.-All tests of sample S-36 were made on earth ground in a coffee-mill to pass through a 100 mesh screen. Tests on commercial earths are stated for comparison. 214 GEOLOGICAL SURVEY OF GEORGIA Bleach Sample used After two weeks After two weeks Original bleach in light in dark Yellow Red I Oil used ............. -~ 35 I 4.8 !XL ................ . 21 2.1 Pikes Peak .......... 19 1.9 S-36 .............. l 23 2.3 l I Yellow Red Yellow Red I 35 4.0 35 4.4 15 1.9 16 2.0 15 1.9 17 2.1 16 2.2 17 2.3 I Absorption of oil lXL 21.2% Pikes Peak .................................. . 38.4 S-36 ...................................... 33.3 Specific volume Specific gravity IXL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.05 Pikes Peak . . . . . . . . . . . . . . . . . . . . . .61 S-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 Apparent acidity Lb. per cu. ft. 66.0 38.2 50.7 N - alkali per 100 gm. earth 10 !XL 19.6 e.c. Pikes Peak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.0 S-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0 HUGHES PROPERTY (Map locality T-19) Two and a p.alf miles west of Danville, on the property of Dudley Hughes, a good section is exposed in a small branch which :flows north into Turkey Creek. FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 215 Section along branch on Hughes property Eocene' Feet 7. Apparently all red argillaceous sand to road level.. 60 Eocene Jackson group Barnwell formation (Twiggs clay member) 6. Chert ledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 2 5. Hard limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4. Pale yellow fullers earth, resembling the Pikes Peak earth in appearance, although slightly calcareous 10+ 3. Hard to soft, fossiliferous, blue, clayey and sandy marl. Analysis shows only about 25 per cent of calcium carbonate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2. Calcareous, blue fullers earth-like clay resembling that at ''Kaolin Spring'' on the Porter property 5 f 1. Blue dayey and calcareous sand. . . . . . . . . . . . . . . . . . 5 f The earth.-An average sample (S-38) was taken from the goodlooking earth of bed No. 4 of the preceding section. In spite of several per cent of calcium carbonate which it contains, this is a good bleaching earth, but its oil absorption is very high and it filters with difficulty. The analysis is as follows: Analysis of earth from Hughes property Silica ( Si02 ) Alumina (Al 02 8 ) Ferric oxide (Fe 02 3 ). Ferrous oxide (FeO)............................ Magnesia (MgO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lime (CaO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Soda (Na20) . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . Potash (K20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ignition (less C02 ). Carbon dioxide (C02)......... Titanium dioxide (Ti02 )......... Phosphorus pentoxide (P20,)..................... Sulphur (S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-38 71.60 10.62 5.13 .47 .04 2.47 .25 .70 4.67 1.37 .59 1.75 .12 99.78 Moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.95 Tests.-All tests of Sample S-38 were made on earth ground in 216 GEOLOGICAL SURVEY OF GEORGIA a coffee-mill to pass through a 100 mesh screen. Tests on commercial earths are stated for comparison. Sample userl After two weeks After two weeks Original bleach in light in dark Yellow Reel Yellow Red Yellow Red Oil used ............. 35 IXL ................. 21 4.8 2.1 35 15 I 4.0 35 1.9 I 16 4.4 2.0 Pikes Peak ........... 19 1.9 15 1.9 17 2.1 S-38 ................. 19 1.9 12 1.8 13 1.9 Absorption of oil IXL 21.2% Pikes Peak .................................... . 38.4 S-38 .......................................... 49.0 Specific volume Specific gravity IXL . . . . . . . . . . . . . . . . . . . . . . . . . 1.05 Pikes Peak . . . . . . . . . . . . . . . . . . . . .61 S-38 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 Apparent acidity Lb. per cu. ft. 66.0 38.2 32.2 N - alkali per 100 gm. earth 10 IXL 10.6 c.c. Pikes Peak ................................... 163.0 S-38 ........................................ 9.9 LOCALITIES SOUTH AND WEST OF DANVILLE South of Danville the fullers earth beds dip below the Vicksburg and younger formations. West and southwest of Danville, in the vicinity of old Marion and Tarversville, and between Tarversville FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 217 and Westlake, numerous sections of the Twiggs clay member are exposed. None of the fullers earth deposits of southwestern Twiggs County are likely to be of commercial importance, as most of them are several miles from any railroad, and the beds of earth of sufficient thickness and extent for "\vorking are sandy and calcareous. One of the best exposures is at the locality known as "Chalk Hill" on the Burton property, 3 miles west of Tarversville, where a 30-foot bed of cream-colored, highly calcareous fullers earth overlies bryozoan limestone, while 60 feet of calcareous earth is shown in gullies near by. Other exposures of more or less calcareous fullers earth were noted on the Bradberry property near Richlands Church; on the Marchman place, 3% miles southwest of Tarversville; on the Minter Wimberly place, 1% miles north of Tarversville; on the Irwin Fitzpatrick place, 2% miles northeast of Westlake; and on the Carter place, 1% miles northeast of Westlake. BLECKLEY COUNTY As the outcrops of the Jackson beds in Bibb and northern Twiggs counties are typical of the shoreward phase of deposition, those of northern Bleckley County are typical of the deeper water deposits now found near the southern limit of exposure of the Jackson group. The Jackson beds in this county are almost entirely calcareous, consisting of blue clay of the fullers earth type, sandy marl, and bryozoan limestone, overlain by red sand which belongs largely to the Vicksburg formation. The fullers earth exposures are confined to a narrow belt along the northern boundary of the county. DEESE PROPERTY (Map locality B-1) Calcareous fullers earth is well exposed on the property of J. T. Deese, situated on the southeast side of Shellstone Creek, 10 miles north of Cochran. Geologic relations.-The beds of the Twiggs clay member are exposed in a number of gullies, and the exposures show local variations, 218 GEOLOGICAL SURVEY OF GEORGIA but the following section, measured in a gully near the Deese residence, is typical. Section on the Deese property, near Shellstone Creek Probably Oligocene 9. Red sand with chert ledges, to the flat summit of the hill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Eocene Jackson group Barnwell formation (Twiggs clay member) 8. Blue calcareous fullers earth, thin-bedded, fossiliferous, and more sandy than the underlying beds 3 7. Thin bed of hard impure fossiliferous limestone, probably . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6. Blue calcareous fullers earth. . . . . . . . . . . . . . . . . . . . . 20 5. Blue calcareous fullers earth, containing harder and more calcareous layers............. _........... 10 4. Blue calcareous fullers earth, almost free from grit 20 3. Concealed interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. Interbedded massive blue argillaceous limestone and blue calcareous fullers earth. (These are varying phases of the same formation, the hard~tess depending on the percentage of carcium carbonate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Rotten fossiliferous limestone. . . . . . . . . . . . . . . . . . . . 5 This section is above the horizon of the typical Ocala bryozoan limestone, but the latter formation is exposed in the Shellstone Creek escarpment, 1Y2 miles northwest of the section just described. The earth.-The exposures on the property indicate a thickness of at least 50 feet of fullers earth, but all is calcareous and contains interbedded layers of limestone and marl. Most of the exposures are in recently eroded gullies, so the earth is comparatively fresh and unweathered. At the surface and for a depth varying from an inch to several feet the earth is altered by leaching out of the calcium carbonate and oxidation of the iron. After this alteration it is pale yellow or cream colored and very light and porous, resembling the Pikes Peak earth. Sample S-l83 represents an average of bed No. 4 of the section described, a 20-foot exposure of fresh, blue, calcareous earth. The FULLERS EARTH DEPOSITS OF THE COASTAL PLAIN 219 analyses of this sample and of two others sent to the State Geological Survey by lVIr. Deese in 1912 are as follows: Analyses of earth from the Deese property Constituents S-183 No.1 No.2 Silica (SiO,) ............................. . Alumina (AI,03) Ferric oxide (Fe,03) Ferrous oxide (FeO) ...................... Magnesia (MgO) ......................... . Lime (CaO) .............................. . Soda (Na,O) ............................. Potash (K,O) ............................ . Ignition .................................. . Carbon dioxide (CO,) ...................... . Titanium dioxide ( Ti02) Phosphorus pentoxide (P,O,) ................ . Sulphur (S) .............................. . Manganous oxide (MnO) .................... , 43.88 10.55 2.00 .61 1.58 18.56 .75 .24 5.76* 13.75 .69 .108 .81 .00 56.50 10.90 2.12 .30 .22 12.58 .91 1.89 13.65 .58 .15 .17 .13 52.87 11.21 1.79 .27 .16 13.19 .so 1.97 16.38 .64 .13 .15 .11 Moisture ........................ .. ' I 100.288 5.32 *Loss on ignition less CO,. 100.10 7.64 99.67 5.94 Tests.-All tests of sample S-183 were made on earth ground in a coffee-mill to pass through a 100 mesh screen. In spite of the high content of calcium carbonate, the earth is equal to the English in bleaching power. The absorption of oil was not determined. Tests on commercial earth& are stated for comparison. Bleach Yellow Red Oil used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 6.1 IXL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.5 Pikes Peak . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2.3 S-183 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2.4 220 GEOLOGICAL SURVEY OF GEORGIA Specific volume Specific gravity !XL . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.05 Pikes Peak . . . . . . . . . . . . . . . . . . . . . .61 S-183 . . . . . . . . . . . . . . . . . . . . . . .72 Apparent acidity Lb. per cu. ft. 66.0 38.2 44.6 N - alkali per 100 gm. earth 10 IXL 19.6 c.c. Pikes Peak ................................... 163.0 S-183 ..................................... 25. AINSLIE Beds of calcareous fullers earth at least 20 feet in thickness are exposed at Ainslie, on the Southern Railway, and on the Weatherly place, 12 miies east of Ainslie, in the escarpment on the east side of Shellstone Creek. The earth at both these localities overlies the Ocala bryozoan limestone.1 The earth exposed is cream-colored but highly calcareous. It has eviden~ly undergone weathering to a sufficient extent to oxidize the iron, but not enough to remove the calcium carbonate, and may be expected to become blue and more calcareous in depth. HOUSTON COUNTY The greater part of the area of Houston County is underlain by beds of Jackson age. The ;fullers earth member, however, outcrops only in a belt across the county south of Perry, passing between Tivola and Grovania and swinging southwestward into Dooly County, tohfetbheestvaelxlpeoysuorfesInbdeiianng in the Creek steep escarpment along the south side and its tributaries. North of Perry the upland areas are underlain by red sand of the Barnwell forma- tion, while the larger streams have cut their valleys down into the light-colored sand and clay of the Upper Cretaceous formations, but it is evident that the fullers earth beds have been removed from this ' Brantly, J. E., Geol. Survey of Ga. Bull. 21, pp. 65-67, 1916. FULLERS EARTH DEPOSITS OF THE COAS1'AL PLAIN 221 area by erosion, since .an erosional outlier of limestone and fullers earth is found farther north, at Rich Hill, Crawford County. In the belt south of Indian Creek the Ocala limestone is exposed on the lower slopes of the hills, and is overlain by almost 100 feet of beds referable to the Twiggs clay member of the Barnwell formation, while the hills are capped by red sand of late Eocene or early Oligocene age. The clay member consists of fullers earth interbedded with much limestone and marl. The earth is almost entirely calcareous, but is always light yellow at the surface, due either to weathering or to original deposition without the carbonaceous matter which characterizes the calcareous earth of Bleckley and Twiggs counties. ROSS HILL (Map locality H-1) The most complete and typical section of the Twiggs clay member in Houston County is that exposed at Ross Hill on the Perry-Elko public road, 3 miles south of Perry. The following section was measured in an old limestone quarry and gullies west of the road. Section west of the Perry-Elko public road, Ross Hill, 3 miles south of Perry Feet Oligocene or Eocene Vicksburg or Barnwell 15. Residual red sand with flint fragments to the top of the hill. . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Eocene Jackson group Barnwell formation (Twiggs clay membar) 14. Fullers earth and glauconitic clay, apparently in- terbedded, poorly exposed. The earth is yellow- ish-green, rather coarse grained, and is stained by iron, manganese and organic matter, but it is only slightly or not at all calcareous........ 15 13. Glauconitic clay-marl, yellow-green in color, con- taining poorly preserved fossils............... 2.5 12. Fullers earth, with pockets or masses of glauconitic clay in the upper 2 feet. The lower part is almost white, thick-bedded, fine-grained, and not calcareous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 222 GEOLOGICAL SURVEY OF GEORGIA 11. Bed or lens of limestone. The rock is hard and dense, and contains abundant but poorly preserved molluscs, no Bryozoa. . . . . . . . . . . . . . . . . . 1 10. Fullers earth, more or l