FRONTISPIECE. PLATE J. DEATON (COUPER) IRON ORE PITS, Polk County, into which lime tone "horses" rise. GEOLOGICAL SURVEY OF GEORGIA .. THE PA.LEOZOIC GROUP: The Geology of Ten Counties of Northwestern Georgia BY J. w. SPENCER, A.M., PH. D., F. G. s. (L. AND A. ), STATE GEOLOQISl'. PUBLISHED BY AUTHORITY. ATLANTA, GA.: GEO. W. HARRISON, State Printer. 1893. ADVISORY BOARD OF THE GEOLOGICAL SURVEY. (EX Ol''FICIO.) His ExcELLENCY, W. J. NonTHEN, GovERNOR oF GEORGIA, PRESIDENT OF BOARD. RoN. RoBERT T. NESBITT_ _ Commissioner of Agricultute. RoN. S.D. BRADWELL. --_ _ . . Commissioner of Schools. RoN. RoBERT U. HAnDE:tiiA:S _ . ___ _ _. __. _.. _~ _- . _Treasurer. RoN. Wl\L A. WRIGH'r ___ ~ _ . . . . . - - -. Comptroller General . RoN. J. M. TERRELL - __ _________ _. __ __ . _ Attorney General. n (2) HIS EXCELLENCY, W. J. NoRTHEK, GovERNOR O.F GEORGIA: DEAR SIR-I have the honor of transmitti11g to you herewith my report upon the Paleozoic Group, which constitutes one of the \ natural great belts of geological formations in Georgia. In this report I have treated Northwestern Georgia from the scientific, economic and agricultural standpoints. Yours respectfully, Atlanta, March 22d, 1893. J. "' SPENCER, State Geologist. (::) GENERAL CONTENTS OF 'l'HE REPORT UPON THE PALEOZOIC GROUP OF GEORGIA I. GEOLOGICAL AND PHYSICAL CHARACTERISTICS .. II. EcoNoMIC GEOLOGY. III. THE SOILS. IV. v. AcKNOWLEDGMENTs AND PROGREss oF SuRVEY_ SPECIAL CONfl'ENTS OF CHAP'l'EBS. VI. INDEX. (4) PART I. GEOLOGICAL AND PHYSICAL CHARACTERISTICS OF THE PALEOZOIC GROUP OF GEORGIA, IN YOLK, FLOYD, BARTOW, GORDON, :MURRAY, WH1TFIELD, CATOOSA, CHA'fTOOGA, WALKER AND DADE COUNTIES. }IY J. W. SPENCER. (5) Geology of the Paleozoic Group. CHAPTER I. S KETCH OF THE GENERAL GEOLOGICAL STRUCTURE OF NORTHWEST GEORGIA. CONTENTS. NoTE. LITHOLOGY: Igneous Ro'"ks, Sedimentary Rocks, Limestones, Metamorphic Rocks. ll'oRMA'l'ION AND DEs'l'RUC'l'ION OF RocKs: Cause of Rock Decay, ]'ormatio~ of New Beds of Rocks. EFFECTS QF TERRES'l'RIAI~ l'rloVEMEN'fS ON GROWTH 0~' Sl'RA'l'A : Oscillation, Unconfmmity, Succession of like and unlike Materials, Fossils, Position of Strata. GREAT GEOLOGICAL BELTS OF GEORGIA. INCOMPLE'l'EN.ESS OF THE GEOLOGICAl. FoR~fA'l'IONS AND MoDE OF REGIONAL GROWTH. DISTURBANCES AND DrsLOCA'l'IONS OF THE ORIGINAL BEDS: Elevation ancl Folding of Beds, Faults, Effects of Folding upon the Materials of th!l Bed~, Effects of Atmosphel'ic Action upon the Folds. DEcAY oF SurER~'ICIAL l'l.ocKs IN NoRTHWEST GEORGIA. ORIGIN OF VALLEYS. l1ECEN'l' GRAVELS AND LoA~Is. NOTE . .Note.-The topographic features, the soils, and the resources of the State are all the outgrowth of the geological structure. The facilities for geological investigations are dependent upon the physical features of the country. Owing to this reciprocal relationship of topography and structure, an intelligent view of the geology of a limited region requires a general survey of the whole. The foundation rocks, which are exposed in any locality, are only some of the many series which go to make up the state or even continent; so that (7) GEOLOGY OF 'l'HE PALEOZOIC GROUP. "'ome knowledge of the general geological laws and classification becomes necessary for understanding the problems presented in these :investigations. The object of the geological survey is principally for the bene- nt of the citizens of Georgia; and particularly those who are not familiar with geological . science, rather than for the specialist. As the present report co\-ers a territory which comes in contact with rocks not yet scientifically studied, but with striking boundaries, owing, in part, to great dislocations and repetitions of strata, it is advisable to give some general explanations of geological structures as related to the country in question. without constant attention to the general characteristics described, it would be impossibfe to get any order out of the complex structu~e of the State. vVhilst over the vastly greater area of the continent, only rocks of ,-;edimentary or organic origin are found, here in Georgia igneous :and metamorphic rocks occupy a large area of the State. LITHOLOGY. I,gneol8 Rocks.-The igneous rocks have resulted from fusion processes, and belong, on some portion of the globe or another, to all geological periods. But as the globe .has passed through various stages of consolidation from the gaseous condition, it appears that the oldest rocks of the earth's crust are igneous, and from them all the forms have ultimately been derived. Of younger igneous rocks none are found in Georgia; and of the older, granite may be taken as a type; but igneous rocks do not occur in the belt :-:nrveved. Sedimentcwy Rocks.- Whilst tbe sedimentary formations have been primarily derived from older igneous rocks, the newer have often resulted from the destruction of older stratified rocks; tbe most common forms of these materials are gravel, sandstones, shaleil or hardened clays, ancl limestones. Lime.~tone.~.-Limestones are of sedimentary origin, but mostly LITHOLOGY . :accumulated through the agencies of marine animal life, from cal-careous matters dissolved in the waters. Metamorphic Rocks are commonly sedimentary deposits (ot occasionally igneous rocks), rendered crystalline and compact through agency of heat, in presence of moisture, acting upon unaltered rocks. There are various degrees of rock metamorphism. The metamorphic forma hom; of Georgia a1e of very wide extent. They are also represented in different geological epochs, but the altered rocks, in the State, have tnt yet been scientifically investigated. To these group~> belong such rocks as gneiss, mica schist, hydromica schist, etc. 'The eastern or southeastern edge of the country, now reported upon, is bordered by crystalline strata, which will be referred to in this report by their structure, and not by their scientific relation.ships, as such characteristics are easily distinguishable, even to the most casual observet, especially as the topographic features are also marked. l'ORMA.TION AND DE'Jl'Rl'CTION OF ROCKS OCC:L'R IN CYCLES. AR has been stated, the sedimentary rocks are derived from the -older crystalline formations; and these newer strata may again be :altered into crystalline rocks. Cau8e of Boek Destnwtion.-The great destructive agents in \Vearing down the olrler rocks are the rains, rills, rivers and, along .coast lines, waye actioiL The chemical action of rain water washes .out alkalies, lime, etc., from the crystalline and calcareous rocks, thus leaving them porous and easily washed a\va~' by the rains, rills and rivers. Every observer in middle Georgia is familiar with the decayed rocks. It was notal ways tb us-once the rocks were as compact as tlw hardest granite. On the northern part of the co_ntinent, the compact rock~ are seen. Their upper layers arc not decayed, but are uudecomposed and hard, becau:;e, in recent times, a geological broom swept from those region~; such decayed rocks and soils as 10 GEOLOGY OF' THE PALEOZOIC OROtJl' . now cover middle Georgia, lea.-ing, great, barren, desolate regions. But from our southern uplands, the rills anrl rivers are carrying off the remains of decaying rock, almost as fast as they fonn. The degree and amount of the rock decay varies, ranging from theincipient decay of some superficial granites, to depths of 95 feet near Atlanta. In northwestern Georgia, the decayed remains of limestones reach a thickness of 200 feet, whilst" the maximum depth ,of residual earth is not known. In this case, the calcareous matter is dissolved away, leaving a great accumulation of residual siliceous impurities, covering the irregularly weathered surfaces of the limestones (as in figure 1, see also plate III.) Jr. . FwuRE 1.-At lime quarry two miles east of Kingston-Hesidual clays coveringthe unequally weathered aurfaces of limestone. The Forrnations of New Beds of Rock8.-The washi1ig~"" uf tlll' land are carried down to the sea; some portions, f.luch afi soluble alkalies, lime, etc., are borne off in solution. The muds are carried off to be assorted and laid down beneath the sea as the foundation of new lands; the sand and pebbles formv shore depo;;its and th(~ fine clays and muds cover the more distant sea bottoms, in near!: horizontal sheets. . For the conditions of the deposition of iron, manganese, alumina, see the Economic Report. 'l'ERRI~S'l'IUAL :'.IOYE~U~NTS. 11 Thus the destruction of the land by atmospheric agents onl~' :;upplies materials for the constructiou of new lands by the sea. Upon the mud and clay plains, formed on the neighboring sea bottom, marine organisms, as shells, corals, etc., grow and extract from the sea water dissolved calcareous matter; and from their remains the accumulating muds or sands become calcateow;, or are succeeded by beds of limestones of varying rlegrees of purity and thickness. El'Fl!:CT OF TERRESTRIAL MOVEMENTa ON GHOWTH OF STRATA. Oscillation.s.-The greater portion of the land wastes are accumulated neat the shore, with the beds becoming thinner, 011 extending sea wards-the sea bottoms remaining nearly stationary. The margins may be characterized hy swamps or lagoons, which are being gradually filled by the detritus brought down by the ri VeL'S or carried along by thP coastal currents. These deposits grow outward and haYe only the thickness of the depth of the sea. But the sandstones, shales and limestones have often a development of thousands of feet, and also alternatP. with each other. This great thickness results from accumulations of the various muds upon a sinking sea bottom. In some portionR of mountainous regions, this subsiding of the land has permitted of accumulations of rock to a thickneRI:\ of many mileR upon the original sea floor, although in 110 place is the sea nearly so deep, but the floor has yielded to the great weight of the forming beds. This great thickness diminishes to a mile or less in the interior of the continent. The subsiding is not continuous, and in many regions, it is replaC'ed by moYements of elevation. The amount of uplift ha~ again become sufficient to bting the newly formed beds above the sea level, whereupon, the atmospheric agents begin to grind them down or carve them out into prominent features. Unconj'o1mity.-Upon imbsequent :mhsidence, these recent lands again become covered with sheets of new sediments, but they do not lie flat upon the underlyi ug disturbed i;urfilCes, and here then is 12 GEOLOG-Y 01" THE l'ALEOZOJC GROUP. produced a most important structure which geologists call nncon.fonnity. Sometimes unconformity represents only short. intervals of time elapsing betweeu the production of the succeeding strata, or it may indicate long eras-that is to say, long breaks in the geological succession. But the structure is always most important in making geological surveys. Thus, if formations, belonging to horizons above, let. us say the Coal .Measures, are discovered, reating directly above others which belong beneath them, it would indicate the absence of coal and would be useless to search for coal in localities showing such gaps. This enormous unconformity may be represented by weathered surfaces and water channels as shown between d and c in figure 2, or b~ disturbances in position of beds as between b and c, or by both disturbances of beds and surface .erosions as between aa and the other strata. FmuRE 2. - Showing unconformities. 8-ucces.~iori of Unlike Jlfate'f'ial8.-when the crust movements do not bring the sea bottom abo\e its surface, but only produce vary; ug conditions of depth or uhanges of currents, as from muddy to .dea,r water, or vica versa, alternating beds of sandstones, .~hales or limestones, in varying degrees of purity, may be formed. Under ,-.;uch circumstances different materials may all belong to the same or to different geological hori:wns, extending over wide areas, as the conditions obtaining throughout the geological periods, or their formations, may have varied. vVheu the same conditions extended nver wide regions, the lithological characters of the strata, as now seen, are of primary value in the surveys. But the uniformity tly to the Cenozoic (new life) group. Thus it appears that in most ancient times Georgia was a portion of a great island, commencing in Alabama, broadening in Georgia, even far coaRtward of prer;ent surface exposures, of crystalline formations, and extending towards the northeast. On tbe one side there are very old and disturbed strata; on the other side the fo1mations are comparatively young. I~C01IPLETENESS OF THE GEOLOGICAL FORMATIONS AND MODE OF REGIONAL GROWTH. The physical revolutions of the early geological times left the formations west ofGeorgia above the sea line, for there is a general absence of the succeeding formations toward the southeast. Yet these may have once been local!:; deposited, and since washed away by the enormous denudation whieh occurred. But except the western portion of the metamorphic zone, Georgia formed part of an islaml in the earlie1; geological periods. The eastern side of the ancient land extended far eastwat'd of the present surface limit of metamorphic belt, even perhaps far seaward, as the continental margin, now submerged, extends 200 miles oceanward of the coast of Georgia. Central and northwestern Georgia long remained abo\'e the tirle, during the time that the Paleor.nie formations were aecnmnlati ng upon its western side. Indeed, the southeasterit lands squeezing passes, in places, into fracture, producing a con vex structure FIGURE 4.-Bending and fracture of strata along the Ocoee river; a a a represent quartzose beds; b b b, are slates. which eventually overturns some of the strata. In the movement,. the slaty beds (shaded portions of figure) have more or less adjusted themselves by being squeezed into position, but' the quartzose layers are those which have been bent and broken. The folded structure is carried farther and is well shown along a section near the iron bridge over the Etowah river, southeast of Cartersville (figure 5). The section has a length of about 400 feet. Here two synclinals and three anticlinals occur, in which the beds upon the northwestern side dip the more steeply and are somewhat overthrown. Erosion has denuded the crests, and if the surface of the section were lev~!, only a number of strata dipping in different directions would be visible; but these would be sufficient for recog- 18 GEOLOGY OF '.rHE PALEOZOIC GROUP. nizing the position of the beds. However, washes in the road havP. give n more perfect exposures, and thus a fine study may be seen. FIGURE 5.-SAction at Iron bridge, south of Cartersville; n n a represent unti_ clinal folds; s s, synclinal folds. T he undulation on a grand scale may be SE en in figure 6. Scale 3 Mile.s 1/i>rkcal 10 9rt>et FIGURE 6.-Sections across Sand, Lookout and Pigeon n1ountnins, showing undulations of strata. When the thrusts are continued after p,assing the limit of folding, the strata mnst be faulted (as at F, figure 7). A beautiful example on a Rmall scale, in a section ahout 200 feet long, is seen at the cut of the Western and Atlantic Railway, on the northwestern bank of the Etowah river. Fwu RE 7.-F represents fault line, c, decayed r ock . Here, th en, is an anticlinal with axis trending northeastward, the thrust coming from the southeast. The upper beds, along the fault line are completely cut in two and slidden over those FAULTS. 19 upon one side of the fault. Lower down in the section, the fracture and slip has been less perfect, with the beds forced into an anticlinal and carried to the point of fracture, with only a slight slipping and a tendency to invert the strata. By the position of the layers other complex movements are indicated, but not exposed in the cut. On the large scale, we find all the above conditions tepeated, and great beds are often inverted. These complex features add to the difficulty of determining the thickness of formations, and location of special layers, when the lithological characteristics and the fossil contents do not readily explain the conditions. Faults.-Tbe further thrusts not only produce breaks, but often carry the beds over upon other strata,. In some casee, these slip~;, technically called faults, will simply lift the rocks upon one side of the break or produce a downthro'w, so that the same beds are no longer continuous (F, figure 7). Very often, when the strata are pushed over the others, the movement becomes a thntst fault, in which case the beds upon the side of the fracture, from which the movement com8s, are forced over those upon the opposite side, or, in northwestern Georgia~ those on the southeastern ;;ide slide over towards the north west. This is a nmmal thrustjmtlt. An illustration of thrust faults is seen west of FrouRr; B.-Illustrating a thrust fault (adapted Irom Hayes). F F F F, line of fautt; Ca, Cambrian shales forced over Silurian (R ) nncl Sub-Carboniferous (Cf) strata. Rome, where a narrow trough of Cambrian strata has been carried at least four miles to the westward, over Sub-Carboniferous strata, as shown in figure 8. Tbi~ thrust fault represents a vertical dislocation of from 7,000 to 10,000 feet. Erosion has caused the remoYal of the shales between the trough and the Cambrian belt to the east- 20 GEOLOGY OF THE PALEOZOIC GROUP. ward over what is now known as Horseleg mountain, which wasforced up during or aftet tbefaulting movement. This will be again desetibed in the local geology. Thus, although the. whole series of beds may dip to the southeast, yet the newer are those towards the northwest, and appear to underlie the others, which would be the case if the faults did uot exist. Such faults are common ou large scales in northwestern Georgia, bringing into contact widely separated geological horizons. StiII more frequently the same series of beds are repeated in parallel ridges; also small faults are very common, repeating the same adjacent strata; and others which do not amount to more than a few feet. Often the structure is very complex, atising ftom a combination of folds and faultfl, as shown in faults at Cave Spring and at Erwin. FIGURE 9 -Faults F F F F, one mile we't of Cave Spring. Strata Cl'U8bed at a, nnd decu)ed at e f rl and h. It is by one of these great thrust faults that the metamOI'ph ie rocks are brought into contact, and indeed overlie the Paleozoic rocks all the way along the southeastern margin of the belt und~r exploration. This overthrust of the crystalline rocks above Cambrian limefltone is well shown along the creek at Erwin's Milh; on the southern border of Gordon county. Sometim<.Js the troughs of the folds are thrust under their arches, when the effect is the converi;e of the above, as if the movement came from the opposite direction; such are called revused thnu:; ]mdts. In normal faulting, the overlying strata are much nearer the horizontal than the more steeply inclined and overridden beds, EFFECTS OF FOLDING UPON STRATA. 21 these last occurring on the northwestern side of the folds. The {)pposite is true in reversed faults. In normal faulting, the lower beds are sometimes dragged over, ptoducing subordinate and local reversed folds. The effects pf the faulting and repetition of the same beds have not been merely to make simple ridges and valleys. These folds and faults are coincident with both the great and small valleys crossing not only the State, but extending from Alabama across Georgia to :fennessee and northward. In the northwestern part of the belt reported on, the same strata are brought to view in narrow belts rising from beneath upper Paleozoic strata, which are wanting to the east. Accordingly, the same sheets of lower Paleozoic beds, Once nearly horizontal, still occur everywhere beneath all the various series of the overlying series. E;tl'ect8 of Folding ttpon the JYiateria.ls of the Strata. are primarily to hmdeu them, and often to produce metamorphism of various degrees. Thus, the original textures become more or lrss obliterated, .as also the organic remains; and then the fossils are rare or very obscure. Such rocks are apt to be more or less traversed by veins. Y ery often the internal slipping in the rocks results in polished joints or surfaces (which structure is called slickenside). Tbejoints'are not a! ways visible, but form lines of easy fracture or decay. Ef/'t, which has produced warping and ridges of upturned beds of rock. However, such movements haYe been slower than the carving of the valleys out of the more easily degraded rock beds. In the old Coosa basin, the origin of the valleys may not appear so simple as those of the newer formations of the Chickamauga and Lookout valleys, from the stmcture of which the key to the ex. planation of the older valleys to the east is obtained. Let the Lookout yaJley be taken as an example. That valley is bounded on either side by plateaus from a few bund~ed to as much as fifteen hundred feet above the floor. The plateaus, which were formerly one plain, is capped by hard durable sandstones, lying at low angles, dipping from the valley on both sides. This plateau has been incised by Lookout creek and its branches, until the stream reached the base level of erosion, deeper than which the valleys could not be cut. The streams then began to btoaden th0 valley, which is now two. to four miles in width. This widening could not have been done by Lookout creek alone, but by the tributary streams, rills and rains undermining the mountain side~. Upon Lookout mountain, there are still many streams cutting down to the base level of erosion, and the various stages of valley making ORIGIN OF VALLEYS. 25 are in progress. where the streams are flowing in opposite directions, there the heads of the valleys gradually unite and often appear as one continuous valley, with walls hundreds of feet high . and miles in width, as may be seen at the union of Lookout and Big wills' creek valleys. Fw u m: 11 .-Map showing form o f the brond, deep vnl)ey, cut into the forme rly nne plateau of Lovkout- Sand mountain table-lnnd, nt the heads of Lookout and vVills' creeks. FrcwaE 12.-Section across Lookout valley, near Sulphur Springs, showing Cllm bined erosive effects of small streams in making a broad valley. The Yalleys just described were once filled with the Carboniferous rocb> containing valuable beds of coal, which have been swept :away and carried into the sea. From narrow ravines this proces:,; nf degradation of the rocks may be traced through various developments to twenty miles or more in width. Here and there remnants of degraded formations are left, showing that even the Caeboniferous rocks extended much further into Georgia than the valHable beds of to-day; thus it becomes apparent that 1,500 feet of 26: GEOLOGY. 01!' THE PALEOZOIC OROUP. Carboniferous rocks alone, and elsewhere 2,.000 feet or more or limestones, belonging to the earlier Paleozoic periods3 have been removed from what a,re now t.he valleys of northwest Georgia. RECENT GRAVELS AND LOAMS. Often coarse quartz gravel and other stones, as well as asRociated lmims, are foun(l in the valleys up to elevations,from 80 feet to 150> feet. The>~e are not everywhere met with, but are very common;. and represent bar or other shore deposits in the great, broad streams, at a late period, wheu the lower parts of Geurgia weresubmerged to a depth of 700 or 800 feet. Locally the soils arethus made to vary from that of the residual clays. GEOLOGICAL GROUPS. 27 CHAPTER II. GEOLOGICAL GROUPS OF NORTHWEST GEORGIA. CONTENTS. TABLE OF GEOLOGICAL GROUPS. GNOLOGICAL SYSTEMS O.F NoRTHWES1'ERN GEORGIA-Eustern Border Rnnge of Unaltered Formations. PALEOZOIC FoRMATIONS OF GEORGIA-Table, Value of Fossils. THICKSESS OF THE LOWER PALEOZOIC FoRMATIONS; OF THE UPPER PAL~;ozou ROCK!>. J.<'AULTS. TABLE.OF GEOLOGICAL GRO UPS. In order to give a clear idea of the order of superposition of the different formations which geologists recognize, and the relations of the strata occurring in Georgia, the following table is given: GROUPS, SYSTEMS. LOCATION JN GEORGIA. I ~1od ern ..... . .. .'. . Ri ver deposits. il1 Pleistocene . . . . . . . . (South Georgia.) CENOZOIC. , !:l.iocene . . . .. . } Neocene { southh GGeorg!R. ~uJOcen e . . .. , , . 8 out eurgJR. Eocene , . . . . . . . . South Georgia Cretaceou~< . ...... . MESOZOIC. . { Jurassic.. Triassic . . . . . , .. .... . . South Georgia. Not known. Not known. !' Permian .... , Carbonifsrou!' . , Devonian . . l'ALEOZOIC Silurian . . . ... lOrdovician . . , . , Cambrian . . ... . ARCH~ AN . {Metamorphic Roeks Not known. "N ottillwe ~ :GeorgiA . 1'w'ijL G>l. , bu~ 11 lm ostw ' ntitw. Nor th west Geur!!;ln. [on l v o11 e amnll b ut illlporiant fr!w rncm t )N o:vthwest (:;l:eol!;il!. N onc h w os~ eo rgin. (Laurentian and . other ~ys tems(? ). These have not bee n differentiated in Middle Gn. GEOLOGICAL SYSTEMS IN NORTHWESTERN GEORGIA. Easte1n border of tma.lte?ed 1ocks are all more or less metamorphic or igneous. The upper beds. belong to systems distinct from (2i) :28 GEOLOGY OF THE PALEOZOIC GROUP. the lower, just as the Paleozoic group is comprised of several systems. In several scattered regions in America, there are well marked series of crystalline accumulations d,evoid of determin-able fossils, which overlie the lower Archooan, and underlie some member or other of the Paleozoic group, but they cannot be eorrelated as yet or positiYely assigned to a 'lystem in the general table. In such cases, we must simply investigate the local characteristics and wait until their true relationships have been discovered. Such rocks form important members of the metamorphic country east of the belt. under survey, against which it is brought by a gigantic fault, which has been suitably narned the * "' Cartersville Fault," uy Dr. C. vY. Hayes. It is quite probable that some of thes~ upper crystalline rocks belong to the Cambrian system; but as they occur east of the physiCal break, they will not be considered here. Range of Geologico! Fwmations.-Throughout the belt repotted upon, the rocks range front the Cambr.ian to the Carboniferous system, inclusiYe. But the lower beds of the Cambrian system, and possibly portions of' the upper Ordovician formations, are wantigg....._,, In the northwestern portion of the area surveyed, there are most .'ltriking repetitions of the formations. The northwestern side of the Lower Paleozoic strata of the Coosa valley are brought in contact with the various upper members of the Paleozoic group; but particularly with the rocks of the Carboniferous system. This fi:wlt has been explored from Yirginia to Alabama, and was first uamed [by Prof. J. J. Stevenson,i- the "Saltville Fault," since locally called the "Rome Fault," by Dr. Hayes.t Iu Georgia this fault amounts to a Yertical displacement of from 7,000-10,000 feet. <:>Bull. <'eological Society, Am. Yoltfme Ij:. 1890. P>lge 147. t ,1, J. Stevenson, Pro. Am. Phil. Soc. XXII. Phila, 18R4. :j: Bull. Geological Society, Am: Volume II. Page 144. PALEOZOIC FORMATIONS OF GEORGIA. SYSTEM. CARBONIFEROUS Serie~. Coal Measures. NAmes of Formations in Safford's Equivalents in Georgift. Tenn . Coal Melli'ures. Coal Measures. Smith's Equivalents in Alt<. Coal Measures. Hayes' Equivalents. {Walden Sandstone. Lookout Sandstone. - Lower .orSubCarbon iferous. Mountain Limestone. :Floyd Shales. Fort Payne Chert. Mountain Limestone. Bangor Limestone. Bangor Limestone. Siliceous Group. { Oxmore Sandstone and "Shal(S. Fort Payne Chert. Floyd Shales. Fort Payne Chert. DEVONIAN. Chattanooga Black Shales. Black Shale. Black Shale. Cliattanooga Black Shales. SILURIAN. ORDOVI<.;IAN. Clinton. (?) Hudson. Trenton. Chazy. Calciferous. Red Mountain. Dyestone, gr. White Oak Mt. and Clinch Mt. Sandstone. Chickamauga tll)elllding Rockmart Slate). ' Knox Dolomite. Nashville. Trenton. Maclurea. Knox Dolomite. Red Mountain. Trenton or Pelham Limestone. Knox Dolomite. Rockwood. . Chickamauga Limestone. Knox Dolomite. \!:BRIAN. Potsdam. (Up. Com) Acadian. (Mid. Cam.) Georgia. (Lower Cam.) - - -- --- --- Oostanaulo. Shales. Kuox Shales. Knox Sandstone. {Montevallo ShRles in eluding Weisner quartzite { Conneso.uga Shales. Rome Sandstone. Coo'a Shales. Chilhowie Snunstone. -- Ocoee Conglomerate. - ..- - . _ -- - ~- -: --,:<-- - - --:--::-- -;:-_ .-:.::-.-. - - - - - -----~- - - -, - - . - . - - - - : _ ... ~-----,....- _--=:-- - :30 GEOLOGY OF THE PALEOZOIC GROUP. Value of Fossils.-The gt'Ouping3 of geological phenomena scarcely reached the dignity of a science until William Smith, an English mineral surveyor, discovered that certain fossils were char- acteristic of special ):>eds, and were not found out of their proper hotizons. He made use of his discovery a century ago, in order to ascertain whether the rocks were above or below the coal horizon. Lithological characters of themselves are only, at best, local indica- tions of age, or of horizon; for rocks of the same position over widely separated areas may be of 'entirely different characters, or rocks tf the ame characters may belong to differebt horizons; consequently geologists must ultimately depend upon the fossil contents of differ- ent beds. Again, many physical breaks occm in the succession of i'ltmta, and characterize certain epochs in one locality, without leav.. ing traces iu ot.hers. They are not always coincident with the great ehauges in the types of fossil remains. Thus, there is a closer. re- lationship between the .~edimentation of the Knox shales and the Knox dolomites than between the Knox dolomites and the overly- ing Chickamauga fotmation, although both of these latter are highly calcareous deposits; yet the relationship of the animal remains is such as to cause the Knox shales and Knox dolomites to he placed in different systems. In.deecl, it is only on account of the inability to pel'fectly correlate the minot gtouping ovet widely separated areas that local nomenclature lasts longer than a temporary pro- . vtston. This of formations, inability arises from various thinning onL or thickening bteaks in of strata, tahned cionntthi neurieh"- placement of one kind of deposits by another, with the consequent changes, unequal development and preservations of fossils. As an illustration : sandy shore deposits are apt to be replaced by clays found in deeper water; or limestone;,, when the waters were clear enough to favor accumulations of animaJ life and their consequent remai nt>. Thus, on the flanks of mountainous countl!ies, sandstones or shore deposits occur, whilst, us the formations recede towards the plains of the continent, these fragmental members diminish in mag- 'fHIDKNESS OF STRATA. 31 nitude, and are often replaced by limestones which are more favorable for the preservation of fossils thau the clays and sandstones. Acco.rdingly, by tracing continuity in the stmtigraphy, portions of the beds may be found which are fossiliferous, and thus the horizons can be determined; still, the general types of the whole remain with local variations. Throughout the southwestern end of the Appalachians, the fossils of the Lower Paleozoic formations are not generally preserved; and on the lithological characters one must often depend in surveying the development of many formation s, "ith only occasional references to fossiliferous strata. THICKJ\ESS OF THE LOWER PALEOZOIC FOR~IATIONS . The difficulty of making accurate determinations of the thickness of the various formations is considerable, as the extensive sections of the different rock formations are commonly in decayed conditions, or the strata are buried or obscured. As a consequence, the apperently great thickness may have to he reduced, owing to unperceived undulations or faultings. However, estimates based upon incomplete obsenations are made. Long ago, Prof. Safford* e::;timated the thickness of th e rocks, in E ast Tennessee, which pass into Georgia, as follows: ORDOVICIAN. CAMBRI AN. ~ashville ai1d } f Trenton l Knox Dol mite ( Knox Shales, ~ Knox Sandstone. l Chilhowie, ? Ocoee, 2,500 feet . 4,000 " 1,.500-2,000 " 800-1,000 " 2,000 " 10,000 Thus the extended thickness of the Cambrian in East Tennessee, without the Ocoee conglomerate, which is not included in the report, is from 4,300-5,000 feet thick; and the Ordovician or Lower Siln- *Geol. of Tennessee, 18ll9, pp. 158-60. 32 GEOLOGY OF THE PALEOZOIC GROUP. rian, is 6,500 feet. To the rocks belonging to the Cambrian r:;ystem, Mr. A. R. McCutchen assigned a thickness of 10,400 feet.* In Alabama, Prof. Eugene A. Smith gives the maximum thickness of the Cambrian deposits exclusive of the Ocoee conglomerate, as 10,000 feet; and that of the Ordovician system as 4,900 feet. -r Dr. C. Willard Hayes estimates the thickner:;s of these same formations in the southern Appalachians at from 6,600 to 8,500 feetj: for the ~\mbt:iau lHid ab v tlt 1 bil b wi and from ! 7 0 to 6 : 00 for the rrloYician syswm.: Th J lt't:'l.-illlllltl thi ku :;, f tb Cam- bl"ian n +. o'f close upon the- ttHti.nl :md, w her stre~uns l' ' l\1'1' nt ' we1 pi Iiug tltc washln gs of Lh lnntl . With the Ol:i illnti c 11. in Lit 1 ,. 1 of tlt ' J an~ aut.l ..eu th' lo aHti >s of au h leHo its uaLurall bnng 1, b ing buried by newer sand bars, or having these formed upon the latemuddy sea floors. .t Geology of Tennessee, 1869, p. 199. t Geological Survey of Alabama. "Cahaba Coal Field," 1890, p. 150. OOSTANAULA SERIES. 37 In the country at present reported on, Indian mountain (mostly in Alabama) is the only knob that is considered. Its position is beneath the Oostanaula shales, the basal sandy members of which may be of identical horizon with that of Indian mountain. Some .of the sandstones on Cohutta, Pine Log and other mountains may belong here, a~ suggested by Prof. Little; however, these are on the metamnrphic side of the "Cartersville Fault," which is the limit of the present survey and of this paper, but are :approached in examination of its boundary. OOSTANAULA SERIES, COOSA VALLEY PHASE, This is the lowest formation in which fossils have been found in f Dr. Hayes' nomenclature.* The rocks, as a unit, are best developed in the.Chickamauga valley, as also in Whitfield county, .although in Polk county the separation into Safford's Maclurea limestone and Hayes' Rockmart slates is very distinct. The Chickamauga series west of Taylor's ridge is notably an impure bluish limestone, often in thin beds and more or less flaggy. These limestones are frequently fossiliferous. In places, the rocks are intercalated with beds of shale. When the calcareous matter is dissolved away from the limestone, owing to weathering processes, prominent ledges of flaggy material of sbaly character remain in relief. These limestones are usually at low angles from 10 to 20, although steep in places, and often protrude through the soil and form the rocky pavements of the country. The Chickamauga series characterizes narrow valleys and low rocky ridges ; this formation also extends upward often to a considerable elevation in the neighboring mountain ridges, which are capped by more durable rocks. Sometimes the rocks do not appear through the soil, especially when the outcrop is narrow and in valleys at the foot of mountains. The soil which.results. from the decay of these J'ockR is usually a stiff, reddish or brownish clay,. forming some of the _most fertile '*Bull. Geol. Soc. Am. Vol. II., p. 143. 46 ROCKliiAR'.r SLATER. lands of Georgia. In this part of Georgia, the thickness is from 1,200 to 1,800 feet. In Polk county, the lower subdivision or the Maclnrea limestone forms massive beds, some of which are remarkably pure limestone, -often fine granular in texture, and from light to dark gmy in color. In that district, it is o;lightly metamorphic, forming gray and colored marbles. In weathering, they do not u5ually disintegrate but have their surface worn away by solution, thus producing rounded hummocks (see plate I, whete these hummocks have been covered by higher matetials now removed), rising up in the valleys and sometimes forming considerable hillocks, even to an elevation of one to two hunched feet. The formation is often characterized by caverns. This portion of the Chickamaup;a series has probably a thickne:;s of' 600 or 800 feet. The Deaton ore beds, occurring northeast of Rockmart, overlie the Maclurea limestone at low angles. These beds are ferruginous limestones, varying in thickness from a few inches to a few feet. They are dark gray, fine grained and compact, and sometime contain 30 per cent of iron. More commonly the beds arc earthy and weather into ferruginous clay, or angular slabs of iron ore. The thickneas is from 100 to 200 feet. Similar bed;; occur in vVhitfielcl county. These ore heels represent some portion of Safford's iron-limestone series in Tennessee. (See plate I.) The Rockmar"t Slates of Polk and adjacent counties form the upper member of the Chickamauga series. The rocks dip at angles varying from 20 to 40 near Rockmart, and approach the vertical, near the Carterroville fault, a few miles to the south. Farther west, they cover the Maclnrea limestones on a rather flat rolling country, .although about Rockmart they form ridges. The slates weather to a grayish, reddish or variegated color, and are broken into small chips covered by thin soil. They are semi-metamorphic and in places have a cleavable fissile structure. Some of the upper heels, -which are not fissile, weather into a bed of beautiful clay, capable CHICKAMAUGA SERIES. 47 Qf being carved into ornaments, or the so-called Caenstone. The estimated thickness is 1,200 feet. Another feature of the Chickmanga er i :-.;1 in thn ridges south of Rockmart, i.s a heavy bed of breccia 90mpo \ l .,(' nu g ular and sub- angular chert with some slate. This i. I)) 11 t.' 1 in t 1~ hard rock whl It lws h '<' II t'1sed f(>t ,mill t n . ~l:'hi : lll'eocin poin ts < au p > b f.(h st u1lmnc! n ~b e do e o-f th Kn d111'0mite, jtl'fit flS Lit e l>r ill nt th bu. l uf' tb ]\Ill x 11 lotllii. " (u J d 11 puoo 44) point d to a di atu .!I)Hll(' , ,thnut ti J~ lo~e rJf t he \ un btian }) l'tod, (hr t h e deP sit~, altnongL oxpo c I to >nl. ~t limit d xt nt , I eJ n to tbu has f t lw 'b i I an nngu r; rlf!s. The local features of the Chickamauga series will be noted in later chapters on the various counties. 48 GEOLOGY OF THE PALEZOIC GROUP. CHAPTER V. GENERAL CHARQATElUSTICS OF THE SILURIAN SYSTEM. RED MOUNTAIN SERIES. The Silurian system overlying the Chickamauga limestone is only imperfectly represented in the southern Appalachian region by a series of rocks which Safford, in Tennessee, described under the names of Clinch mountain sandstone, White Oak mountain sandFtone, and the Dyestone group; and Smith, of Alabama,. named the Red mountain, or Clinton series, which Mr. Hayes has renamed Rockwood. All of these rocks appear to belong to horizons, including the Medina, Clinton and probably lower Niagara series, with the upper portion of the Siluriat1 system wanting. There is no ground for local subdiYisions, although great variation in rock masses occnr. Thus, in Murray county, on Rocky Face, and other ridges, massive sandstones, capping the lower shales, give rise to bold, high but narrow ridges. Taylor's ridge, to the westward, is of a similar characterl but with a diminution or sandstones. \Vestward of this last ridge the sandstones become less abundant and are replaced by thick deposits of shale, which are seen in "Shinbone ridge" (or the foot-hills of the Lookout_plateau). Here the ridges are natTow and low, but with interrupted points rising two or three hundred feet aboye the valleys, owing to their protection by Sub-Carboniferous cherts. On account of the strata inclining at considerable angles, usually not exceeding 30, bnt sometimes nearly vertical, the characteristic feature of the formation is that of narrow ridges. (See plate V opposite.) The mountains and ridges are portions of synclinal folds, which, for jnstance, pass under the Carboniferous rocks of Lookout mountain. Thus, the formation usually bounds anticlinal valleys, the centers of which are occupied by older formations. PLATE V. SHINBONE RIDGE, (Red Mcmtain Series, etc.), a lo ng th e foot of Lookout Mountain, at Rising Fawn. RED MOUNTAIN SERIES. 49 The sandstones are often massive, and vary in color from light gray to brown and red. The shales are commonly fissile, in thin beds, amongst which there are intercalated, at various horizons, thick layers of sandy shale which passinto fiaggy sandstone; sometimes there are thin beds of fossiliferous sandstone, as well as beds of hematite or red fossil ore, which renders this formation extremely valuable. These iton ores occur somewhat above the medial horizon. The iron ore beds are commonly made up of masses of shells converted into oxide of iron, leaving the structure of the shells, amongst which there are flattened concretionary nodules. Above the drainage level, this "fossil ore" does not usually contain much calcareous matter, but below the water levels, where it has not been leached out, there iH sufficient calcareous matter for self-fluxing, and the calcareous layers are better pre~erved than near the surface. The total thickness of the Jormation in Georgia reaches from 800 to 1,100 feet, and is best shown at the end of Pigeon mountain, where it is exposed by railway cuts across the whole formation, dipping regularly at about 8 to the east of southeast. In Alabama, the formation dwindles to about 100 feet in thickness. A~; a surface feature the Red Mountain series forms only narrow belts. The rocks appear to lie comformably upon the Chickamauga limestones. which often rise high in the sides of the mountain. Overlying the Red Mountain series, a thin deposit of black shales, belonging to (probably the upper part of) the Devonian system, occurs. Whilst unconformity is not recognizable, yet it is probable on account of the great gap apparent in the geological succession. 50 GEOLOGY OF THE PALEOZOIC GROUP. CHAPTER VI. GENERAL CHARACTERISTICS OF THE DEVONIAN SYSTEM. CHATTANOOGA BLACK SHALE. The Devonian system in Georgia is represented by only from ten to twenty-five feet of black shales, which are valley making. At the surface they are rarely exposed, owing to the usual covering of debris from the adjacent ridges. Still, where the. streams cut across the formations, the black shales are usually found between the Red Mountain beds and overlying cherty limestones. In Alabama, they dwindle to a thickness of ten feet, whilst in Tennessee the same beds increase to a thickness of 100 feet. The top layer" of the shale become lighter colored and contain rounded concretions. At some points, the black shales are wanting, thus permittiug the contact of the Silmian and Carboniferous systems. This shale is commonly mistaken for coal. It is often characterized by sulphur and mineral springs. CARBONIFEROUS SYSTEM. 51 CHAPTER VII. GENERAL CHARACTERISTICS OF THE CARBONIFEROUS SYSTEM'. CONTENTS. CoAL MEASURES. MOUNTAIN LIMESTONE. FLOYD SHALE. FOR1' PAYNE CHERT. The Lower or Sub-Carbonifero u erie. i xtensively developed' in northwestern Georgia in thr e out 90 fe t it1 hlcknes-;. I I fi H' Dh~ bhe sides of th ' n ouu tai.t1 wbi h a1 ar ped with oa l Mclts- lll'e: , a nd ext u I: d wn into t h vnlJ y . I is }I I ighl (o. . ili fel'o ns rock , rich in riooicl ste ms. W ithin the lim est. n ~ cnt numntnin u bcrl of !'lanu to n , is ~ llJH I. T lt upp 'r 1 r tiou of t h li ne Lo 11e be nw ' somew hat e~:ut h y a: i u.p proa b t h sbtd . of th onl M asure,. .A: a ..urth' ro k , it is most cum;pi U!usly d ' VP IO] I at Lhe e nd of Pjg on rn Hm ta i n. T he M uu tu..in L imeto ne usutlll y Li a L 1 w a ngles beuca h th Coal Measpr c ba in f:l of the mountain plateaus. THE COAL MEASrR ES. Th e Coal Measures lie in synclinal basins capping Sand, Lookout PLAT~~ VJ. LOOKOUT MOUNTAIN, Seen from Ri si ng F a wn (1,000 feet hi gh) , show ing the escapement of conglomerate capping and protectin g the plateau. COAL MEASURES. 50 and Pigeon mountains. The same rocks of these formations also cap one or two ridges to the eastward of Taylor's ridge. These outlying fragments are neceRsary, in showing the former wide extension of the Coal Measures which have been removed by denudation (see pages 18 and 25). In contrast with the rugged character of the Red Mountain series, the topographic featnres of the Coal Measures are mountain plateaus, which have been preserved, owing to the nearly horizontal hard sandstones so largely prominent in the series. The total thickness of the Coal Measures in Georgia reaches from 1,400 to 1,600 feet upon Lookout mountain, and to halfthat thickness on Sand mountain. The Coal Measures may be divided into the Lower Coal Measures and the Upper Coal Measures. The Lower Coal Measures on Lookout mountain have a thickness of 600 feet. This is characterized by shales, succeeded by 40 feet or less of sandstone or fine grained conglomerate and another deposit of shale, followed by heavy sandstones and eonglomerate which reach a thickness of from 175 to perhaps even 250 feet. Included in this succession of rocks, there are two beds of coal, one of which may be workabie in places. This conglomerate forms the striking feature of Lookout mountain, as it sunounds that plateau as a battlement wall, broken into by occasional streams (plate VI.). The rocks commonly dip at low angles from both sides into the mountains, and form a basin. At some few points, however, the disturbance;-; have been great, and have thrown the rocks into steeply inclined positions. The Upper Coal Measures consist of a succession of shales ~vith bedded sandstones, and reach a thickness of 840 feet, including seven seams of coal of variable thickness from fom feet to a few inches. As the upper part of the series is made up of shales, these deposits have suffered extensive erosion, but remnants of the higher beds still constitute the productive Coal Measures of Lookout mountain. The Coal Measures on Sand mountain have a somewhat different .54 GEOLOGY OF THE PALEOZOIC GROUP, physical appearance, and are represented by about 500 feet of shales :and sandy shales; with both the lower and upper conglomerates, here mostly sandstone, which are less developed than on Lookout mountain. The Lower Coal Measures contain seven seams of coal, :some of which,however, are thin. Above these Lower Coal Measures :about 300 feet of the Upper Coal Measures are composed of shales with some thin sandstones and sandy shales; these deposits are followed by a capping of sandstone. In this upper series there is at least one seam of coal. It is noticeable that the conglomerate, or its equivalent in the form of sandstone on Sand mountain, occurs above the most pro-ductive part of the Coal Measures in place of below, as on Lookout mountain and most other regions. It will be seen in comparison with the coal fields of Alabama that the volume of the Coal Measures is greatly reduced in Georgia, for the thickness in Alabama is 5,525 feet, whilst in Tennessee the series has a thickness of from 200 to 2,500 feet. The conglomerate consists of a coarse sandstone, occasionlly charged with pebbles, usnally not greater than from half to threefourths of an inch in diameter. The beds are sometimes thin, but occasionally form masses from 10 to 75 feet in thickness. Tlie shales may be argillaceous and constitute a fire clay, or in places they are sandy and pass into pure sandstones. In some places, the shales are ferruginous and weather to a red color; in other places they are of a bluish tint. In order to better understand the structure of the Coal Measures in Georgia, reference to figure 14 will show a section across the formation and the relationship of the Carboniferous system to the other formations. Scale 3 Mile.s Vi'rll'cal 100 Feet FIGURE 14.-Section from Sand to Pigeon Mountoins; C, Coal Measures; Om, Mountain Limestone; Heavy line is Devonian; R, Red Mountain; Ch, Chickamauga; K, Knox series. RECENT FORMATIONS. 55 CHAPTER VIII. HECENT FORMATIONS, AND EVOLUTION OF NORTRWESTERN GEOl'tGIA. LAFAYETTE(?) AND MODERN. In the decayed rock accumulations over the whole Paleozoic belt have been in process of formation throughout most of the periods from the Carboniferous t.o the present day, but we have one remnant of a later formation than the Coal Measures. This remnant -consists of the deposits of graYel and loam found at altitudes from 50 to 150 feet above the waters of the Coosa basin. These gravels are the equivalent of the Lafayette (?) Eeries of southern Georgia, hut. there accumulations have been latgely removed by subsequent ,Jenndation, so they are mostly seen to-day upon the hills within two miles of the rivers. In the Coosa basin, the gravels do not occur at elevations higher than 800 feet above the sea; however, in the higber country, amongst the crystalline rocks to the east, along .the tributaries of the Coosa and the Tennessee rivers, apparently, the r;ame gravels occur to 100 feet above the modern streams, at .elevations from 1,500 to 2,000 feet above the sea. These deposits modify the agricultural features of the country. Along the Chickamauga and other valleys west of the Coosa basin, in Georgia, the gravels and loams have not been recognized-a rather remarkable absence. The gravels are usually composed of quartz, derived from the crystalline rocks, with occasional pebbles of local material. 'fheir position above the rivers is indicative that they could not l1ave been so deposited from the swollen volumes of the streams, 56 GEOLOGY OF THE PALEOZOIC GROUP. but their deposition was favored by the slack water of the estuaricl" occasioned by the submergence of the southeastern part of the continent, in this region, to a depth of nearly 800 feet. The occurrence of the same accumulations at high elevations in thr mountainH to the east is probably an indication of considerable warping movement of the earth's crust sinee the depositions of the Pleistocene epoch. It must be emphasized, however, that the deposits have been largely removed by denudations ~mbsequent to thPir aeeumulations during the late subsidence of the laud. The only modern formations represented is the river alluvium of the present streams, which sometime;; has a width of a mile or more, adjacent to the principal rivers; but is not greatly developed along the smaller streams. There are remnants of terraceo;, butthese belong to the Lafayette series. The continuing decay of the older rocks, constituting the common soil of northwestern Georgia cannot, of course, be regarded as a distinct formation. EVOLUTION OF NORTHWESTERN GEORGIA. From the generalized descriptions of the geological formation;; of the. Paleozoic belt of Georgia, florne interesting knowledge as to the growth of the continent may be inferred. At the close of the Archrean era, or rather at the close of those periods which produced the more recent crystalline rookH, the crystalline belt to tlw southeast constituted elevated land from which t.hc water:': were washing the decaying products into a sea eovering the now Paleozoic belt. Fragments of the old shore lines and remnant,., of riYer deposits are occasionally 13een in tho:;e masset~ of 13andstoue, ,;uch a:,; I udian mountain; however, the :mbsequent physical c:hange:; have obliterated these early c:onditions of the growth of northwestern Georgia, leaving only unmistakable remnants of the Middle Cambrian period in the thick shaleo; of the Oostanaula series. These shales were in part an off-shore deposit, but probably a not difltant accumulation, as shown by their sandy character; still, at times, EVOLU'l'ION OF NOR'l'J-1\\'ESTERN in this period that the iron, manganese and beauxite ores were deposited among the forming limestones. At the close of the Knox dolomite epoch there appeared to be local interruptions, as shown by the presence of breccias near the base of the Chickamauga series in Polk county. But the Chickamauga sea was characterized by an influx of more or less muddy waters, which interfered with the calcareous growths. This influx, however, was more or less interrupted, as some beds of pure limestone were formed in basins protected from the muddy streams. ~-\ fter the elose of the Chickamauga epoch, the Paleozoic sea was flooded with muddy waters, carrying down the sands and clays which now form the Red Mountain series. The shore lines of this epoch had moved many miles westward of those of the earlier Cambrian days, and are preserved in the heavy sandstone deposits of the eastern ridges of the Red Mountain series, whilst the Red Mountain series further westward i~> composed mostly of clays which were carried into deeper water. However, along with these deposits some beds of limestone were formed. The upper part of the Silurian system is not represented, KO that it is probable that for a considerable length of time the whole of northwestern Georgia became dry land, and this condition .58 GEOLOGY OF THE PALEOZOIC GROUIJ, continued far into the Devonian period, which is represented by -only a few feet of shales, although the Devonian system, elsewhere on the continent, reaches a thickness of 13,000 feet. With the advent of the Carboniferous period, the waters of north western Georgia, driven farther seaward by the growth of the land, became the home of a rich m~rine fauna, which has built up the great deposits of limestones. However, into a portion of that sea, enormous quantities of mud were carried and locally deposited, as in Floyd county. Perhaps, elsewhere in the State, there was a temporary elevation of the lowest Carb:miferous rocks, which, however, were not subjected to great erosion, as the unconformity -between the limestones i"' not apparent, eYen where the shales are wanting. Later on, the Sub-Carboniferous sea appears to have gradually become muddy, and the basins becam_e filled with the t>hales and sandstones of the Coal Measures, which occasionally gave rise to swamps, producing in Georgia at least nine beds of coal, .separated, however, with mechanical deposits washed down from the outward growing shore line of the State. It is probable that the Sub-Carboniferous Bet\ during its early days extended over most of northwest Georgia, as outlying fragments are met with. The Coal Measure Heries extended ten or twelve miles eastward of Pigeon mountain, as shown by outlines on Little Sanrl and Rocky mountains east of Taylor's ridge. These indicate an enormous erosion since the Carboniferous period. Throughout the Paleozoic era, the succesHion of strata appear:; to have suffered no other disturbance than occasional interruptionf:l, owing to temporary rising and sinking of the lands, without any great disturbances in the position of the strata. The faulting, overthrowing and folding of the f(Hmation8, which Ul'e represented by the mountains and valleys of to-day, did not take place until .after the clo8e of the Coal epoch; still sufficient time has elapsed to permit atmospheric and ri\'et erosion to remove thousands of feet of the various Paleozoic strata, and lea\e the present valleyf::, DENUDATION OF LAND. 59 ridges and mountains, forined in a large measure, owing to the durability and position of the strata favoring or retarding the grinding away of the country, by subsequent rains storming the rocks through several geological ages, as shown in figure 15. , ......-------- --.f:. . ,_...-... - .....-..-. FIGURE 15.-Tbis shows a section of fifteen miles, from which the Coal Measures and other formations have been removed by denudation, with the formation of valleys. The denuded beds from Coal Measures (C) to lVIiddle Cambrian (Mo), care represented by dotted lines. F, great faults. From the Coal epoch to the Lafayette (which is probably Pliocene) northwestern Georgia appears to have been continuously dry land, followed by the submergence and re-elevation of the Lafayette epoch, since the beginning of which, howev~r, the mountains to the eastward pf the Coosa basin have been probably elevated to a greater extent, compared with the country to the west, than before that time. But this study of physical geography .cf the past and the growth of this section of the State cannot be properly separated from the growth of the adjacent States. 60 GEOLOGY in the northeastern corner of the county. The southeastern -,ide of the valley is bounded by somewhat rugged hills, which ~in the northwestern corner of the county, at Hermitage or "Ridge Valley," rises into a ridge of 500 to (iOO feet in Armstrong's Mountain. . Along the Etowah river t.he country is rolling without crested ridges, as also the higher country drained by Dyke's creek. Spring creek flowing northward and Dyke's creek flowing south- ward are the only important streams in the eastern part of Floyd county. IN YARTOW COUNTY. Between the metamorphic hills and the Etowah river, the country is undulating without sharp crested ridges. On the border of Floyd county there are sonie high ridges. 70 GEOLOGY OF THE PALEOZOIC GROUP. Northward of Cattersville a broad, undulating valley extends along the base of the metamorphic mountainous border to beyond the county line-with its character somewhat broken, near Pine Log Postoffice, amongst low ridges and hills, at the divide of waters flowing southward and northward. Between this valley and the meridian, a mile or two east of Kingston, the country is variable and rolling, with broad surfaces and numerous streams, but generally with high crested ridges. But from Kingston to a point on the Gordon county line, three miles east of Adairsville, there is a chain of ridges, and the country is somewhat broken. Westward of Kingston and Adairsville the country is rugged, and in the northwestern corner of the county, near Armstrong mountain, it is quite broken. Southwest of Kingston, and southwest of Cassville the country is rugged, but with softened contours between. West of Cartersville," and back from the river, several isolated domes rise to heights of 500 feet above the Etowah valley. Between these and Cass station the valley is gently rolling. N umerons small streams flow from the metamorphic girdle northward to the Etowah. Northward of the river about two-thirds of the eountry is drained by the streams flowing into the Etowah; the northern portion draining through Gordon count3:. IN GORDON C'OUNTY. The Oostanaula river flows through a continuation of the "fiatwoods," a belt composed in part of comparatively flat land, and in part of minor ridges. The valley of that river, as well as the Coosawattee, above Resaca, is a broad, irregular plain. The Oothcalooga, Sallacoa and Pine Log creeks are the principal secondary streams, and all flow northward, through rolling valley lands. West of Lilly there are some ridges, the highest rising 150-250 feet above the drainage plains. The central portion of the county forms a gently undu- PHYSICAL FEATURES OF :HURRAY COUNTY, 71 lating meridional belt. Farther east, the streams have moulded the features into greater undulations of bills and valleys. On the whole, the topography of the country is simple as far as the metamorphic belt at its eastern edge. IN MURRAY COUNTY. Between the Connasauga river and the Cohutta and other mountains, the country has a simple structure with gentle undulations. The elevations range from 750 to 850 feet above the sea. South of Dnnn postoffice there are some short ridges rising to 1,200 feet. So also north, from near Loughridge postoffice for about six miles there is a chain of crested ridges rising to from 1,000 to over 1,200 feet above the sea. The valleys of the Connasauga river and of the principal creeks (the Holly, Mill, and Sumach) have considerable breadths. These streams have numerous tributary branches. IN WHITFIELD COUNTY. From the Connasauga river to the Cooahulla creek, the features -of the county are similar to those of Murray county, but somewhat more rugged. In the vicinity of the East Tennessee, Virginia and Georgia Raifway, the county is characterized by several parallel {Jhains of interrupted ridges, from 100 to 300 feet above the valleys, which are sometimes narrow and again broad and undulating. These cherty ridges form the northwestern water-shed of the Coosa drainage which flows towards the Gulf of Mexico.. Separated by valleys more or less underlaid with shales, the ridges extend throughout' the western part of \Vhitfield county; however, the hold Rocky Face ridge rises to an elevation of from 1,500 to 1,700 feet, crosses the western part of the county and forms the eastern water-shed of the East Chickamauga creek which flows through the valley about 900 feet above the sea. The western part of the county is occupiecl by "Taylor's ridge" and its parallel .spur, Dick's ridge, including some valleys within the mountains. 72 GEOLOGY OF THE PALEOZOIC GROUP. The East Chickamauga aqd the Cooahulla creeks are the only streams of importance flowing through the county, apart from theConnasauga river upon its eastern margin. IN CATOOSA COUNTY. The eastern part of Catoosa county is similar to 'Vhitfield, with a continuation of the same ridges and valleys, including Taylor's ridge and its extension, beyond Ringgold, the White Oak mountains. These mountains rise into a bold, narrow ridge from 1,300 to 1,500 feet above the sea. Westward of the mountains two forks of the Chickamauga, and the Peavine creek flow through broad valleys, separated by cherty ridges rising from 100 to 300 feet. IN CHATTOOOA COUNTY. East of Taylor's ridge, and between it and John's 'mountain are Dirt Town and Armuchee valleys, separated by a plateau, known as Little Sand mountain. This plateau rises 300 to 500 feet above the valley, whilst John's mountain, to the east, has an elevation of' from 1,300 to 1,468 feet above the sea, or 600 to 800 above the Armuchee creek. Dirt Town valley is broad and rolling. The Armuchee creek drains to the southeastward into the. Cooiia river. John's mountain forms the eastern boundary of the county. In crossing the county, Taylor's ridge has an elevation of 1,300 to 1,400 feet above the sea. Between it and Pigeon mountain the valley is traversed by some cherty ridges rising 200 or 300 feet above the Cbattooga ri\er and tributaries. The northwestern corner of the county is represented by the plateau of Pigeon mountain rising to an elevation of 1,700 feet above the sea. IN WALKER COUN'l'Y. This large county presents two features-the broad valley, east of Taylor's ridge, and that of Lookout creek. These have an elevation of 800 to 90lJ feet above the sea, with a number of cherty ridges extending in a northeastward direction, rising from 100 t~ PHYSICAL FEATURES OF WALKER COUNTY. 73 250 feet above the general elevation. of the valley. One of the most prominent of these subordinate elevations is Missionary ridge. Into the county, a northeastern spur of the Lookout mountain extends, which is known as Pigeon mountain, with an elevation of from 1,800 to 2,000 feet above the sea, but with one point rising to 2,331 feet. Along the top of this mountain, the boundary of the county is located, and thus the features pass into Dade county. Lookvut mountain presents an elevated plateau from 1,800 to 2,000 feet above the sea, but with a few points rising higher. High, Point has an elevation of 2,408 feet, and Round Top, to the south, 2,378 feet above the sea. Round mountain has an elevation of over 2,200 feet. From this point, Rock creek rises and flows longitudinally along the surface of the mountain, forming one of the most picturesque features of Georgia, adjacent to Lula falls and Lula lake. McLamore's cove, between Pigeon and Lookout mountains, is nothing more than an enlargement of a similar stream to that of Rock creek, running longitudinally along the mountain. This cove is drained by the west branch of the Chickamauga creek. East of Pigeon mountain, the Yalleys are drained southward by the / Chattooga river. IN DADE COUN'l'Y. Lookout mountain is deeply incised by lateral valleys known as Trenton's gulf and Johnson's crook. Fox mountain is an isolated remnant of the Lookout plateau. Lookout valley is traversed by a number of ridges parallel to its sides-a similar repetition, but on a smaller scale, to the topography east of Lookout mountain Separated by the deep valley of Lookout creek (which has an altitude in Georgia of from 800 to 900 feet, is Sand mountain forming a plateau somewhat lower than Lookout, from which the principal stream flowing in Georgia is Nickajack creek. In Lookout valley,however, there are some isolated remnants of the former extended plateau. '74 GEOLOGY OF T HE PALEOZOI C GROUP. LA.KELETS, SINKS AND CAYER. In the Knox dolomite country, especially connected with the gra)r lands, there are many lakelets or ponds, sinks and caves. These lakelets are simply lime sinks containing water. Sueh are of commonest occurrence east of Adairsville, and west of Cartersville. To a lesHer extent lime sinks are seen in the belt of Oostanaula .shales, but these are of small size owing to the inferior development of the underlying limestones. Lula lake, in Walker county, is simply a pothole in the cailon of the stream. The sinks are always situated over limestone formations, arid are closely connected with the system of caves whieh traverse them, :as they are simply surface depressions occasioned by the falling of the roofs of the caverns. Hardin's cave (lot 104, 17th district), about three miles south-east of Kingston, is one of the largest caves seen, and of g-reat extent with far reaching galleries. Some of the chambers are 20 to 25 feet high. Owing to the sloping roof the cave appears higher. The floor is covered with four to eight feet of cave dirt, overlaid by fallen blocks. It was once a source for saltpetre. These caves are of geological interest. That in Ladd's mountain gives (see plate) some records of the date of its excavation. The mountain is now an isolated peak rising 500 to 600 feet above the hroaJ Etowah valley. The rocks dip at gentle angles, and some portions of the eaves show that its excavation was subsequent to the mountain uplifts, which disturbed the strata. But the caves, in this isolated knob, are above an elevation whete any sufficient stream capable of forming such cavities could now gather. This shows that the excavation took place before the great rock decay and atmospheric erosion had lowered the \'alley of the Etowah below the level of the dome and caves, else there had been no gathering ground for them to give rise to the subterranean stream. In :short, the excavations of the cave commenced immediately after the completion of the monntain uplifts, at the close of the Paleo- CAVES. 75 zoic era, but their formation bas long ceased, owing to the lowering of the general level 9f the country by denudation. At Cave Spring, near Nannie, Woodlands, and numerous other places, extensive caverns also occur iri the limestone formations. In northwestern Georgia, beyond the Coosa basin, caverns are oc l (P. .) .he r d bml pr vai_l.; in t h va lley of F i II creel< ~l nd a lon g t he jn rlotion f t,he "Kon x. 3(> 1omi_te bed' o.nd the snooeedin g li m. on . R tw >n Fitsh ree k n.ncl R ook rnat , the o tmtry l om po eJ f rolli tlg low h el'ty l'idges. All f b elts t.ten.d northea0 i.n dit , ti u . 80 E ., whil..J. 0 f et be oml (ea. twn.rd) ue dip i. qnJ y 4:)0 ;o . 0 'o mbining t his trllctltt'e wi th th lir noted i u th E:\ ~bclnr a lim to u s, we itud t hat t.h rc is a fo ld uucllooal overthrow passing along a line just east of Cedartown, with the axis about S. 10 W. Owing to this folding, the underlyin g Knox dolomite is brought up to the surface in two or three subordinate ridges south of Cedartown. W'hilst the strata are seen to dip nearly eastward, ~yet the easte!'!: border of the basin is defined by the Knox dolomite, owing to the undulations and foldings of th e rocks; to which are evidently du e the metamorphism that has hardened the shales and somewhat cn."tallized th e limestones. The southern border of the Rockmart s1ates is defined uy ti1e GEOLOGY OF POLK COUNTY, 85 Cartersville fault, beyond which Dug Down mountain is composed of hydromica schists. In ' this basin, the slates are more or less valley making, but underlie some chert (Lower Carbon.iferous) deposits. The characters of the Fish creek basin are similar to those of the Cedar creek slaty basin. They extend around to that of Rockmart. At Hightower Mills, the hydromica schists of Dug Down mountain abut against the slates, and.dip 45 S. 80 E., the trend of the fault not being that of the strike of the rock beds. Five or six mil~s to the eastward, at Simpson's Mills, the Rockmart slates are at very high angles, whilst the overlying hydromica schists of Dug Down mountain overlie the former (owing to the Cartersville fault) at. only from 20 to 25, in direction S. 30 to 50 E. The Rockmart series, in the Rockmart district, form bold ridges, some of which are covered with cherty deposits (Lower Carboniferous). In the slate quarries, at Rockmart, the beds are more or less. jointed, but dip at 45, and more southeastward. In the railway cut, east of Devitte's lime kiln, the slates dip 25-30 in direction S. 50 E. In some places, the decay does not reach more th"an a few feet into the slates. In weathering, the surface sometimes becomes bluish, but generally yellowish gray, or fi!.Ore rarely yellowish brown, being covered at several points; the lower slates weather into a thin soil, and into the banded and indurated clay known locally as "Caen stone," susceptible of being turned and polished (see Economic Report). In the Rockmart district, the slate ridges form a rough country, but to some extent the rolling valleys are a slate formation . . Conglomerates occur at about two miles south of Rockmart, in a ridge on the road to Simpson's Mills. They consist of irregular mas:'les of slate and quartz, cemented into hard rocks, reaching GEOLOGY OF THE P ALEOZOIC GROUP. nearly 200 feet in thickness, and dipping 60 or 70 S. 40 E. The rocks are underlaid and succeeded by the slates. At this point the disturbances have been great. These constitute a lower member of the Chickamauga series. The slates are elsewhere considered in their economic bearing. RED MOUNTAIN SERIES. Overlying the Rockmart slates, at a point four miles southeast of Esom Hill, near the foot of Dug Down mountain, there occur thick beds of massive quartzitic sandstones, fOVering only a small area. These may be referred provisionally to the Red Mountain .series. Similar sandstones in some of the ridges beneath the SubCarboniferous chert belong to this horizon. LOWER OR SU BCARBONil'EROUS SERIES. Overlying the slates of the Rockmart series, there are several Tidges covered with blocks and fragments of chert south of Cedar,town, between Young's and E som Hill. Again, the cherts on the ridges in the Rockmart district belong to the same horizon, and may be referred to the Fort Payne chert. In places, the chert forms a bed pf sandstone, which is ferruginous in part (as on Mr. vVest's fa;m); and also Iiear Rockmart. The preservation of the Tidges, as also those of the Rockmart district, are due to the protection given by the flinty beds and cherty gravels. MODERN DEPOSITS. "Except the conti~ued action of the weathering of the older rocks, the creeping down the hillsides of decomposed material, and the occasional deposits in swampy ground (which are rare), no modern formations can be considered as occurring in the country, for the streams are not flowing through such lands as would permit of bottom formations; still th ere are a few places where streams overflow the basins through which they pass." GEOLOGY OF FLOYD COUNTY. 87 CHAPTER XI. LOCAL GEOLOGY OF FLOYD COUNTY. CONTENTS. OosTANAULA SHALEs. KNox DoLOMITE. RED MouNTAIN. Sun-CARBONIFEROUS: Fort Payne Chert; Floyd Shales ; Coal Measures. LAFAYETTE(?) AND MODERN. OOSTANAULA SERIES IN COOSA VALLEY WEST OF THE OOSTANAULA FAULT. The rocks of this formation are mostly reddish, greenish or varie- gated, calcareous shales, forming gray or brownish soil or reddish farther north. However, there are thin beds of earthy and siliceous limestones, and in the upper portion, the limestones are more mas- .sive, and veined with white calcit()s. On the Georgia and Alabama line, this series covers a country :about ten miles wide. It dwindles down to a narrow belt at Rome. But northeastward it broadens out into a belt one or two miles wide. On the southeastward side, the outline is somewhat regular :as is marked by the topographic features in the more sandy ridges (Knox or Rome sandstone), or lowest portion of the Cambrian sys- tem exposed. Owing to the remarkable fi:mlting on the north- western side, there are two marked troughs nearly surrounded by the Lower 'Jarboniferous series. This belt occupies a comparatively level region, from 120 to 150 feet above the river, and forms the "flatwoods" country. Some points rise higher and the hills are capped in some places by cherty gravel (remains of overlying patches of Knox cherts). North of Rome, ridges are more characteristic of this belt than south of that 88 GEOLOGY OF '.rHE PALEOZOIC GROUP. point. But, as a whole, the country presents no very prominent features. The soil has lost most of its calcareous matter and is often poor, but again, it appears of fair value. The most notable limestones form a surface of about 200 feet in width, and is situated at a short distance from hills along the Oostanaula :l!wlt. These limestones are dark colored and earthy, but mottled with numerous veins of white calcite. This limestone forms a characteristic bed. About half a mile northeast of Thomas' Mills, it dips 45 S. 40 to 50 E. At a roadside quarry, about half 1J. mile southwest of Thomas' (on Kirk's Groove road) the bed dips 25 N., 20 E., and just beyond the dip is again S. E. Again, one mile west of Cunningham station, it is a notable feature. About three mile southwest of Rome, a bluff of the mottled earthy limestone rises 30 or 40 feet above the river. The limestones also occur in the northeastern corner of the county. The shales dip at variable angles. Near the Alabama line (one mile north of Lnmpkin'~-J store) the shales dip 50 S. 20 E., whilst at a point near the line, but two miles from the border of the series, there is a narrow belt of shaly limestone dipping 75 S. 10 E. These variations, as well as many foldings, seen in overlying horizons from Rome to Cave Spring, show very great disturbances and numerous foldings. Southeast of Livingston therE' is a belt of shaly limestones which are somewhat fossiliferous. Upon approaching Livingston, the soil changes from a residual deposit to a recent series-probably the Lafayette series-which will be noted later. N~rth of the Coosa river the faulted character of the northern border of the series is striking. One long, narrow tongue, forming an anticlinal belt of shale, has been carried westward of the great overthrust fault and there preserved, whilst similar strata, once lodged upon Horseleg mountains, have been removed by denudation. GEOLOGY OF FLOYD COUNTY. 89 OOSTANAULA SERIE::3 EASTWARD OF THE FAULT. The ridges of hills which bound the southeastern side of the "flatwood" belong to the lower division of the Oostanaula series, and have been called Knox or Rome sandstone. Still the shales, often calcareous, predominate in this lower member. The sandstones form thin beds amongst the shales and are very rarely in thick layers. The sandstones are more or less earthy, and when the thin beds are broken up angular or subcubical fragments result and then lie scattered oyer the often yellowish soil. One of the best sections seen is where Big Cedar creek cuts across the formation, some three or four miles northeast of Cave Spring, near Connor's Mills. On the stream just named the earthy sandstones are shown, and dip 30 S. 60 E., resting on dark shale. In a ravine, near by is "Slide Rock" at the same dip. It is a quartzitic bedded sandstone with a drab colored surface, but bluish in the interior. This is the most massive bed of sandstone seen, being two feet thick. It is succeeded by other but more earthy and thinner sandstones. This slide rock has its surface highly polished, as if glaciated ; but the !'moothed surface passes beneath other rock and is a case of slickensides, due to internal movements of the rocks. Just beyond, near the ford of the creek, on road to Thomas' Mills, the sandstone members are exposed. In the vicinity of'Rome, the different members of the Oostanaula series are very much disturbed and broken by faults, many of which are seen in sections where road cuttings, etc., have been made. In the northern suhnrb, there is much dark shale amongst the saudstone. The shales dip 45 S. 60 E. northeastward, the crested ridges are interrupted, and are usually of no great height. The soil is often of yellowish color, or, again, reddish. These sandstone members of the series do not cover more than from half of one to two miles in width (except locally), and are known where best developed by their ridges being covered with angular blocks of sandstone, and are confined to the zone west of the shale-formed valleys, :90 GEOLOGY OF. THE PALEOZOIC GROUP. through which the East Tennessee, Virginia and Georgia Railway extends. The ridges often dwindle to insignificant features. The variegated calcareous shales of the higher members of the Oostanaula series are characterized by zones of impure bedded limestones, often in thin layers with earthy partings. Its topographic feature is valley making, covering a belt from one to two and a half miles (in the northeastern part of the county) wide, and giving rise to fine farming lands. But the shales themselves may form subordinate ridges. Owing to faulting, a spur extends into Polk .county; but the valley passing northwarfl to Cave Spring continues northward under the name "Van's" valley and extends to Rome. At Cave Spring the series is folded and dislocated, as seen in a :Section on the hills west of the town as shown in figure 9, p. 20. Some of the shales are siliceous, of dark color and indurated. Disturbances almost equal .to those of the "flatwoods" are shown in the shales on the ridge between Cave Spring and Thomas' Mills. In many places the limestones appear in the valleys. Thus, at Connor's Mills, and Little Cedar creek, about three miles northeast ()f Cave Spring, thin bedded limestones (some two feet thick) are developed in the shales to a thickness of about 50 feet. Here the dip is 30 S. 30 E. At various places in Van's valley, limestones are exposed along the branches. . Just west of Cunningham station, in the valley, borings have been made, and these limestones with a dark brown color were found to be more than 90 feet thick. They dip at low angles of less than 10 towards the southeast. About a mile and a half northeast of Cunningham, about 25 feet of these same limestones are again exposed in a railway cut, dipping at low .angles. Jnst south of Rome the shale series present more hilly characteristics and are particularly disturbed and dip at various angles up from -!0 to 60,:and in variable directions approaching S. 60 E. In everal road cuts the beds are much faulted by small throws in different directions. At this place, in some brown shales, thel'e is a GEOLOGY OF FLOYD COUNTY. 91 fault hading 20 to southward, whilst the beds dip at about 40. A qua-rter of a mile farther south (at end of a hill) there is another fault hadi!Jg 60 to northwest. These differences show complex movements and distortion. At a quarry just south of Rome, along roadside the disturbed shales dip 50 to 60 S. 60 E. Along the Etowah river, just above Rome the dist_urbances of the .strata' are well shown. At the waterworks heavy limestone beds were struck at thirty feet. This is in part a flinty limestone and in part a compact dolomite rock, resembling some beds of the Knox dolomite, but in position near the junction of the calcareous and the siliceous beds of the shale series. The rock is much fissured by subterranean drainage. Fossils are not preserved, but the lithological character suggests a fault or overthrow, bringing Knox dolomite into the horizon of the well without its appearance at the surface. The thickness of the rock is more than 60 feet. Just above the waterworks, sections of the shales and limestones are shown. Impure limestonE-s, in beds from one-half to two feet thick, occur in the mottled shales, some of which have the appearance of hydromica. These dip 30 S. 65 E. Some of these limestones are dark blue, fine grained, of crystalline texture, having a thickness of 100 feet or more. A few hundred feet higher up the river, where E. T., V. & G. Railway crosses the Rome I-tailway, there is a fold and overthrow, the axis of which trends N. 30 E. The rocks are very much crushed but where not too much distorted show vertical jointing in direction S. 65 E. and N. 45 E. There is not only folding but also faulting. Owing to the great disturbances and dislocations the true structure about Rome is somewhat difficult to recognize. A spur of the upper part of the series runs from Rome up the valley of Silver creek, and at several points the limestone beds are seen. Amongst the Knox ridges between Silver creek and Cunningham, there are ~everal spurs of the shale series. Northeastward from Rome the ~hale bearing valley widens out somewhat and forms an excellent 92 GEOLOGY OF THE PALEOZOIC GROUP. agricultural district. Wherever the streams cut across the shales the included limestones appear in their valleys. References to the economic phases and the soils are made elsewhere in this report. K~OX DOLOMITE SERIES. West of Cave Spring there is a narrow basin of this series~ brought into position by faults already referred to in Polk county. Otherwise the series covers only the comity southeast of the valley already described, or most of the country southeast of the East Tennessee, Virginia and Georgia Railway (Alabama branch). South of the Etowah river, the western part of the Knox dolomite country is characterized by ridges of the gray cherty lands, with red, loamy intervening valleys. The broadest of the Knox valleys are those of Silver creek and Spring creek, and outside of them the country is rather broken. Between these streams there is a belt of the red Knox lands, as also east of the latter creek. However, all the ridges are not of gray cherty land but most of those of the more abrupt configuration. In many of the valleys there are subordinate ridges of brown ore. In some of the less abrupt ridges and gray land country there are beauxite beds. In various regions, especially in the vicinity of Cave Spring~ manganese ores occur. In many localities, on the ridge and along some of the streams, the dolomite or magnesian rock is exposed in an undecayed condition showing the character of the formation. From the economic standpoint these characters are noted elewhere. The dolomite, as shown in the ridge east of Cave Spring, is a dadr colored, more or less Parthy, siliceous rock weathering to a lighter shade. It is massive, often with indistinct hedding. The dip is 30 S. 70 E. In this ridge there is one of the largest caves in Floyd county and through it a large stream flows, whence the name of the town, _Cave Spring. Overlying the Cambrian shales already described, the lower GEOLOGY OF FLOYD COUNTY. 93 beds of limestones are well exposed about a mile east of Cunningham station, in a ridge rising over 400 feet in height. For nearly 300 feet of this elevation, the rock is seen, but the upper part of the ridge is covered with a mantle of stony soil and cherty gravel, but fertile soil. The limestones are dolomitic, somewhat earthy, and of dark color, but mottled with white calcite. The bedding is massive, and dips 10 southeastward. A mile and a half east of the last, and at the northern end ot the next ridge, on the land of Mr. Gibbons, there is a rock similar to the last mentioned, but of darker color forming a bold outcrop. It is peculiar in containing more or less angular fragments of breccia of impure dolomite, derived from older masses. But the whole is conso1idated. These rocks have been quarried to some extent for a dark marble, noticed elsewhere (Egyptian quarry). On the spur of Armstrong mountain, near Hermitage (Ridge Valley), the mountain rests upon Cambrian shales, and above them, 200 feet or more of the limestones are seen. The beds vary from one to eight feet thick, dipping less than 10 S. 60 E. Locally, some beds dip southwest (pl'obably the results of a lime sink). Some of the lower beds are dark limestones, with crystalline facet.s; others are mottled with clayey matter. The upper rocks are of compact dolomite of light color. This chain of ridges continues through the northeastern corner of the county, and east of 'Nannie dips at 20 S. 60 E. All of these deposits are from beds belonging to near the base of the Knox series, or perhaps some of the beds may be of Cambrian age, as in Tennessee, although lithologically connected with the Ordovician system. But so far, fossils have not settled the horizon. On various ridges, the undecayed rocks occur near the surface, and also in the side of the valleys, as for instance, the thin bedded magnesian limestone!'! along the streams on the Home road, from HounsaYille, about four miles from the former place. The siliceous beds of the Knox dolomites are also often seen, and sometimes 94 GEOLOGY OF THE PALEOZOIC GROUP. these are ferruginous, as for example, just east of New Prospect church, about six mileo northward from Cave Spring. Other siliceous limestones decaying into gray soil, occur near the manganese deposits of Major ,J. M. Couper on border of Polk county, and of Mr. Stokes, also on border of county, near C. R. & C. Ry, In Bartow county, however, some characteristics are bett8r exposed than in Floyd county, and will be noticed hereafter, and in that county will be found the descript,i"on of the section shown at Dike's creek in Floyd county. The Knox dolomite is usually decayed to a great depth, except on the higher ridges, the product being various forms of calcareous clayey land, and on the ridges often a cherty arenaceous soil. As the result of decomposition, great deposits of white kaolin of various degrees of purity are often seen. These beds contain much undecomposed feldspar, are commonly more or less associated with the iron ore, and were probably deposited in lenticular masses. Sometimes they arise from the cherty dolomites, in which case the white clays are chatged with cherty fragments, as at Cave Spring. West of the E. T., V. & G. Ry. (Atlanta division), the country consists of narrow ridges and valleys, and many beds of brown ore, manganese and also beauxite occur. In the southeastern corner of the county, the valleys are broader, with frequently the red soils and iron ore beds. The same remarks are true for the Knox formation of the county north of the Etowah river. The greater dislocation and repetition of the ridges of the Knox series occnr adjacent on the northwestern border of the formation, and consequently the greatest change of features and resourcesgiven in detail elsewhere. RED MOt:NTAIN SERIES. Southwest of Rome, the Red Mountain series occurs on part of Ho,seleg mountain, forming a sharp ridge, capped with heavy Randstones. This ridge is a remnant of an anticlinal elevation, with the GEOLOGY OF FLOYD COUNTY, 95 sandstones preserved in places, so as to make the surface appear like a monoclinal ridge. Another small outlying ridge occurs farther west-Judy mountain. When disintegrated, the sandstones produce cubical or rectangular blocks, which become scattered over the surface of the ground. . Lavender mountain (with the highest point 1,683 feet above tide) is a spur composed of the Red Mountain series. The southern end of the ridge is badly dislocated and folded. In the cut of the Central Railway, the average dip of the shales is 25 S. 60 E. for the eastern portion; proceeding northwestward, the dip increases to 45 , beyond which the shales dip 60 to the northwest; but at a short distance, west of a ravine, the beds again dip southeastward at 30. ln part, t.he beds are much jointed with fmcture seams trending S. 80 E., and dip 60 to 70. In part, the rocks are heavy bedded shales, often calcareous, but weather to red, sandy shales. There are some flags of red sandstone from six to twelve inches thick, intercalated with shales. Some heavy bedded quartzitic sandstones also occur in the series. The whole formation is from 800 to 1,200 feet thick. Near the northern end of the ridge, tbe strata, upon the eastern f!ide, dips 20 S. 60 E. But in the mountain, the dip increases to 60 in the same direction. Upon the western flank of the ridge, the Fort Payne chert occurs. This indicates the anticlinal charac- ter of the mountain, but with the axis west of the summit, thus producing the superficial appearance of a monoclinal ridge. The rocks are shales, shaly sandstones, and some sandstones in beds two feet thick. John's mountain and a spur of Taylor's ridge form the boundary of the county, but they will be considered in the geology of Chat- tooga county. 96 GEOLOGY OF THE PALEOZOIC GROUP. SUB-CARBONIFEROUS. FORT PAYNE CHERT. At the surface, the Fort Payne chert is characterized by cherty soil. This is shown upon the flanks of the ridges bounding Texas valley; also upon the west side of, and at the northern end of Horseleg mountain, and upon the southern end of Horn's mountain. In a few sections only are the cherty limestones exposed, as in Horn's mountain and on flanks of Lavender mountain, in belts too narrow to be shown upon the map. FLOYD SHALE. The seri8s (named by Hayes) is best developed in this county, and in position lies above the Fort Payne cherts, and below the Mountain Limestones, which only occnr beneath Rocky mountain. The rocks are composed of yell0w, brown and black shales, often in heavy beds, calcareous shales and shaly limestones, and occasional beds of pure limestone. Some of the limestones and calcareous beds are very fossiliferous, as west of Rome, nPar the lime kiln, and at other places. Near Rome, the rock is a dark blue shaly limestone, in thick beds, and dips at 10 S. 60 E.; whilst elsewhere, the dip is 20 to 30. But in crossing the formation, the variation of the dip, sometimes S. E., and again N. WT., shows great foldings and probably faultings, so that the true thickness of the formation cannot be estimated with any degree of accuracy. This formation gives tise to a portion of the "flatwoods," with yellowish and dark grayish soils. Some sandstones occur as local features in the series, and give rise to low ridges in Texas and Dirt Town valleys. COAL MEAS URES. A remnaut of the lower portion of the Coal MeasUl'es occurs on an outlying ridge in Floyd county, called Rocky mountain_ Its greatest geological interest is its position of fifteen miles east of the GEOLOGY OF FLOYD COUNTY. 97 most eastern plateau of the Coal Measures. It is an index to the great amount of erosion, which has removed the Coal Measures from Georgia. (See question of erosion under Chattooga county.) Rocky mountain is represented by eighty feet of massive sandtones a n l on lomel'att~ i ~:; in g in ver tiunl wn.tls, espcci::tlly n_p n tll w tern side of the ridge. Below th sand b ne Lhe undetl yiug tra:tu me oucealed fo1 250 ot 3 0 fe t but t;hey are probably (l0ffi1 os.ed of shal s. :Dhe s~m dt3tones dip 20 . 0 E. LAFAYETTE (?) SERIES, AND MODERN DEPOSITS, The loams and gravels above the greater streams in this belt of Georgia are provisionally correlated with the Lafayette formation of southern Georgia. Objections to the introduction of endless local names led to the use of this nomenclature, as their valley deposits probably belong in that series. These deposits are extensive, and occur even as far as a mile or two back (rarely three miles) from the greater streams, and reaeh elevations ro higher than in keeping with a depression, when the o euni level f tlte wat ts allowed th ncc nm nlations of th . Lafay- t te rmin ~ts f~:~t n rth as olnrubus, with. -ptobahle embaym nts uorthward. li'J' ut tb ypical L!tf~tyettc se ries in that la ti.tud , thcr i:-- no fu,rt,her d.i fferen e in IP c.hal'Mt l' f tlr - e dep s.i ts i.u Eloy l cou.nty than betw n . bore accnmu.laiious and those Jorm d in exteoai.v . ba.y J: channels from t wo t:o fout miles in wioth, su h us ex isted ul ng the lower pnr f t.he valley, when son tbe rn l'gia wn 7.00 OL' 80 fee below the present alti-tude, whic!t IJtought he s tt far in land. These Lafayette accumulations are usually red clayey loams, and coarse, well water worn gravel, up to four or even six inches long. It is mostly quartz, bnt occasionally with some local Paleozoic calcareous and fossiliferous stones. The deposits seldom reach a thickness of twenty feet, but commonly eight or ten, of which the gravel may be from two to five feet thick, or again wanting. The gravel (7) 98 GEOLOGY OF THE PALEOZOIC GROUP. underlies and to some extent graduates into the loam. A few places may be taken as typical representatives. Livingston is on a plain about a mile from the river, with the sandy soil derivcd from the Lafayette deposits. Underneath, the gravel rises to 100 feet above the river terrace, which is about 20 feet above the ordinary water-line. On the north side of the Coosa river, near Coosaville, these gravels rise 140 feet above the river, or about 780 feet above tide. On the hills about Rome, the same deposits occur up to from 140 to 150 feet above the river, or about 790 feet above tide. V.lest of Nannie, and opposite the foot of Turkey mountain, the gravels rise again to 140 feet above the river (the Oostanaula), or something less than 800 feet above the sea. There are frequent remains of terraces at 100 feet above the rivers, but these are imperfectly preserved. The principal terrace, often half a mile or more wide, is commonly between twenty and thirty feet above ordinary water, and is liable to floods. 'Vhilst the measurements are only aneroid, yet from the large number of observations, it may be said that the Lafayette deposits rose to the height of 140 feet above the rivers in Floyd county, and are now principally found, not in the valleys but on the hills ; for since their accumulation enormous erosion has broken their continuity, and there remain only fragments of the former great sheet, as it has been mostly swept away, by denudation, just the same as has the Lafayette series in parts of southern Georgia. Agriculturally, these deposits give rise to variety in the distribution of the soils. The Lafayette soils are often liable to be mistaken for red Knox dolomite soil~. GEOLOGY OF BARTOW COUNTY. 99 CHAPTER XII. LOCAL GEOLOGY OF BARTOW COUNTY. CON1'ENTS. OosTANAULA SERIES. KNox DoLOMITE SERIES. CHICKAMAUGA SERIES. LAFAYETTE (?) SERIES. MoDERN SERIES. MouNDs. OOSTANAULA SERIES. Exposed along Tom creek, about Woodlands, the valley through this broken country shows a narrow belt of these shales, forming an anticlinal basin, in which the limestone members are seen Upon its western side the limestones dip 40 N. 60 vV.; upon its eastern side the shales dip at variable angles, S. 70 W. At Kingston there is a small area of the shales. Northward a narrow belt of the series a few hundred yards wide extends to Cement. This is an anticlinal where the western strata dip 10 N. 70 W. In passing from the Connesenna valley, the belt broadens in the valley of Oothcalooga creek to a width of about three miles in region of Adairsville. At the southern end of the basin, the limestones (forming hydraulic rock at Cement) form a prominent low ridge. (See plate XI. in Economic part of report.) The rocks are more or less impure limestones, with earth seamings, so that they may weather into thin banded laqJ.inations, which are commonly characteristic of some of the beds of the limestones of this series. The series at Cement is exposed ic the workings, 100 GEOLOGY OF THE PALEOZOIC GROUP. so that measurements can be made. The section in descending shows: Blue limestone ___ ________ _ , ____ - -- - - 8 feet Slaty limestone (cement rock) _______________ 4 " Blue limestone _____ _, ________________ __ _ 6 " Argillaceous earthy limestone _____ . __ __ __ 2 " Siliceous limestone (hydraulic rock) .- ____ _ 4 " Siliceous limestone (cement rock) ____ __ ___ 7 " Fine black limestone _____ ___ __ _________ l~ " Earthy limestone ____ ------ ___ -------- _ 3 " Shale___________ .. .. ___ . __ _ - - The analysis of the cement rock is given in the Eeonomic Report. It is highly siliceous limestone, with alumina and iron. Some of the beds are composed of limestone with interlacing seams of earthy matter, giving a peculiar netted appearance, which is often characteristic of the limestones of the series. At many points in_ this belt of Cambrian deposits, the limestones reappear and form a ridge or little escarpment like that at Cement and east of Adairsville. This valley in the Oostanaula series forms a very fertile belt. The rocks dip at low angles, and form an anticlinal valley belt, in which there are caverns and lime sinks. Southwest of Cartersville a tongue of the shale series has been brought to the surface by undulations of the strata. In places it contains limestone beds. Along the branch a mile westward of the town, the shale is indurated to a hard semi-metamorphic slate of dark color. Along the road to Ladd's mountain the decayed shales are sometimes blue : but the weathered shales are generally reddish, although of lighter color than the soils resulting from the Knox dolomite. Along the road just mentioned, about a mile from Cartersville, the beds dip to south of west; half a mile be- GEOLOGY OF BARTOW COUNTY. 101 yond, undulations of the strata are seen in the beds, which immediately underlie the residual Knox dolomite clays. Here they contain thin calcareous beds. FrouRE 18.-Junction of Oostanaula shale and overlying residual Knox dolomite earths. In the section (figure 18) decayed Knox dolomite succeeds an anticlinal of Oostanaula shale. To the east of this exposure the clays are mottled red and bluish, and in composition are like the non-calcareous metamorphic schists of the neighboring mountains. (See Economic Report upon the clays.) Along the Tennessee road, shales frequently occur, and about three miles north of Cartersville (at Dr. Felton's) an impure limestone (forming a light colored impure marble) is seen along a branch (on east side of road) dipping southeastward. Although the rock is metamorphosed and crystalline it belongs to the shale series. Along Petty's creek, about four miles from Cartersville, the limestones of the shale series are exposed, and dip 70 S. 80 E. The valley along this creek is undulating and fertile. At the low divide between it and Sallacoa creek, the country is somewhat more broken. Here a dome resembling a northern drumlin in outline (about 60 feet high and 400 feet in diameter) is seen. Beyond, the softened features are renewed, and at Boliver (crossing of Pine Log creek) the limestones appear at the surface, and are penetrated with caverns, out of which large springs flow, The rocks of the overlying metamorphic series are decayed,. and the hydromica schists often weather to a bluish color, and sometimes occur in the edge of the valley. 102 GEOLOGY OF' THE PALEOZOIC GROUP. Just beyond the county line, at Erwin, the limestones lie beneath metamorphic schists, which have been forced over them. At Roger's (old) furnace the limestone occurs in the valley, and near by is brown ore apparently resting upon it. . At Cassville the shales have more or less calcareous seams; in some cases they are indurated and resemble hydromica slates and Knox dolomite. Most of Cedar creek and its branches flow through the shale country; and the limestones of the series are commonly exposed by the streams, showing the dip at from 10 to 15 S. 60 W. on Cedar creek and its branches. Along little Pine Log creek and other branches the limestonet> rise through the shales. In this Cambrian series, in northeast Bartow, the shales rise into flattened ridges covered with indifferent land. But adjacent to the streams, and on the lower grounds, the agricultural features greatly improve. The calcareous shale formation, especially along its borders, is characterized by extensive fertile valleys. One or two small outlying patches of the shales rise through the overlying dolomite, as for example, three miles southwest of Cass statioi1. KNOX DOLOMITE SERIES. The characters of the middle and upper beds of the Knox dolomite are somewhat better shown in Bartow county than in Polk and Floyd counties. Along the Rome railway, the ends of several spurs have been cut into. The charactetistics ~een here extend into Floyd county, but the sections along the rail way are here noticed as a unit. From Dyke's creek, to east of Wooley's ferry (three miles west of Kingston), there are several sections from which the following observations were obtained: ,Just east of Dyke's creek, the bluffs exposed in the railway cut rise 25 or :35 ft!et ; the surface of the GEOLOGY OF BARTOW COUNTY. 103 limestone is imperfectly rounded, and much more rugged than the limestone of the Maclurea series, or of the underlying Cambrian beds. The bedding is well defined, in layers from three to five feet, although these often become broken up or else end abruptly, owing to small faults. These fault lines, or joints, in many cases, are f:'lvorable to rock decay, and hence, seams of clay are often seen filling crevices fotmed by weathering. The texture of the rocks is sometimes semi-crystalline, as in the case of the lighter colored purer dolomites; but commonly, it is earthy or siliceous. The surface often weathers to dark colors, but the decay does not usually penetrate deeply into purer rock. All degrees of impurities are seen in the various strata. At places, gteat beds are made up of impure, laminated, calcareous beds, one or two inches thick, which are so earthy that they weather into siliceous, shale-like beds. In the purer rocks, which are more durable, occasional layers of dark flint (like in chalk beds) one or two inches thick occur. In other cases, the flint predominates in beds one, two or more feet in thickness. St1ch beds have given rise to the sheets of vesicular chert often occurring on the ridges. Again, the chert is disseminated in irregular concretions through the dolomite, and as the calcareous matter is dissolved away from such exposed beds, the clay, sandy matter and flints are left. The finer matter, being washed off by rai us and rills, finally leaves the ridges covered with mantles of cherty gravel, with some larger blocks. Many of the flints are more or less translucent in the beds, but those left upon the surface, after the rock decays, are white or staine!) with iron. At the mouth of a small stream, ou the border of Bartow and Floyd counties, at a railway cut, a bluff of residual earth, left from rock decay, rises 60 feet high. On both sides of Wooley's ferry, there are fine exposures of the undecayed rock, rising in the blnfls, out of the yellowish 104 GEOLOGY OF THE PALEOZOIC GROUP. residual clay. The structure of the rock is shown in plate II., opposite page 42. Repetition of strata as shown in figure 16. As shown in plate, the bedding is often indistinct, but with lines of flinty concretions. The hard dolomite rocks rise up out of the residual clay in a remarkable manner, especially well shown as in plate III., page 43 (south of Dalton). These masses of decayed rock are too great to have originated only along joint lines, and there seems no reason why portions of the beds shouH have remained solid, whilst other portions of the same horizon should show decay for the whole height of the exposed bluff.c; (30 or 40 feet). It is probably due to minor faults bringing some of the more durable rocks into contact with some of the less permanent. The solid rocks appear more frequently upon the eastern side of the deeply decayed masses. Occasionally, the residual clay shows bedding, but this is generally quite obliterated. The dip of the rocks at Dike's creek is less than 10 S. 60 E. Locally the dip was seen to be also S. W. aud N. E. West of Wooley's ferry the dip varies from nearly level to 15 N. 60 W. A short distance beyond this exposure the strata dip to S. E., showing a low anticlinal. In short the whole breadth of the formation is one of repeated undulations. Some sandy layers are included in the formation; and Alg::e were found near the county line. Ladd's mountain, three miles southwest of Cartersville, is an isolated inass, but may be taken as a type of the dolomite ridges. (Plate IV., opposite.) It rises about 500 feet high, with a northern and southern wend. Its face has been uncovered for quarry purposes. The rock is a siliceous, hard and somewhat brittle dolomite, from light to dark in color, but all fine grained, compact and crystalline. The layers are tl,ick. The bedding is disturbed, and in places appears as if the rocks had fallen into cavities, which may have been the case. The dip is 10 S. 80 W., and owing to form of exposure and undulations, the direction cannot be accurately de- GEOLOGY OF BARTOW COUNTY. 105 termined; but probably a little south of west. There are joints of 50 feet or more in depth, which have been opened by decay and filled with clay. These commonly trend east and west, and are 20 to 00 feet or more apart. There are other joints with directions northeast and southwest, and again others at right angles. This mountain is pierced with caves, some of which are vertical channels. These have been formed by streams dissolving out the limestone after uplift of strata, but before denudation of the valley, as already pointed out. The caves contain large and beautiful stalactites. About two miles west of Ladd's mountaii1, there is another similar isolated 'ridge about 500 feet high, the top of which is covered with chert; but ravines on western side show hard, crystalline dolomite. These beds dip 20 S. 60 E. Accordingly, the intervening valley is synclinal. Other similar ridges occur farther west. At Hardin's (Saltpetre) Cave (lot 104, district 17) about three miles southward of Kingston, the dolomite is exposed in a ridge. The beds dip 20 N. 70 W. The rock is dark colored and of fine grained texture. The cave descends to a depth of about 80 feet, and the chambers are of large size, with numerous ramifications and many chambers. There are very few stalactites. (See article on caves.) At Kington (or Aikins') lime quarry, two miles east of Kingston, the solid rock is again seen. The decomposed covering '\'aries in depth to a remarkable degree, as before described (figure 1, page 10). The rock is darkgray dolomite with bands of black flint or chert. Along Two Rock Run creek, south of Kingston, dolomite is exposed in a ridge. Hence to the Etowah (at Hardin's Ferry) the country is composed of low gray hills, which also appear above the river for a short distance upon the south side, beyond which to west of Ligon Postoffice, the red and iron-bearing ridges prevail 106 GEOLOGY OF THE PALEOZOIC GROUP. (trending east and west), or rather a succession of hills and valleys, like a billowy sea. On a farm of T. F. Nichols, a well in process of excavation showed the red earth to a depth of 30 feet, below which the residual clay becomes light colored but not cherty. (Depth of well is more than 60 feet.) South of the Etowah, and along Euharlee creek, much of the country is rolling, without abrupt ridges, and with red and grayish red soil, and some ore deposits derived from the less cherty series of the Knox dolomite. Along the river, and for a mile or two back, upon the hills, the Lafayette accumulations cover the residual clays, in many places to an altitude of 90 feet (obse~ved). North of the Etowah river and west of Cartersville, the Knox series has produced a rolling country with some isolated rocky 1 ridges. Southwest of Cass station, the cherty ridges are more prominent. Northeast of Cass station there are two spurs with iron ore deposits, forming basins over. the Cambrian shales. North of the Etowah river the formation is undulating, and even the gray lands are less rugged. Between Tom's creek and the Connesenna creek, the country is occupied by both ridges and rolling red lands, in some places iron bearing. Between Adairsville and Armstrong mountain, the country is often rugged and cherty, but with some iron bearing hills. The belt of country between the Cambrain shales east of the western.& Atlantic railway, and the south fork of Two Run creek and Cedar creek is formed out of Knox dolomite. Upon the western side of this elevated region there are. prominent ridges, but elsewhere there is a somewhat more softened topography with rolling plains, which are often cherty. At Mr. Combs's, east of Adairsville, the Knox series dip 20 northwest. Adjacent to the streams, there are broader depressions, and in several localities iron bearing and red lands, derived from the lower portion of the formation, are seen. GEOLOGY OF BARTOW COUNTY. 107 CHICKAMAUGA sr;:RIES. Near Taylorsville, the Chickamauga limestone just enters the county; and two miles north of this village a small basin is seen. LAFAYETTE (?) SERIES. Along the Etowah river, the loams and rounded gravels occur upon the hills to a height of 90 feet. However, the greater portion has beP.n removed by subsequent denudation. The gravel is often coarse, and composed of well rounded :quartz. Along some of the smaller streams, as the upper waters of Pine Log creek (vicinity of Pine Log .Postoffice), :Coarse water-worn pebbles of sandstone and conglomerate occur. These are of local origin, derived from the metamorphic rock in the mountains to the east. MODERN DEP03ITS. To a limited extent only do river deposits occur. Along the Etowah river they are hardly more than twenty or twenty-five feet above ordinary water. Generally the other streams do not. give rise to extensive bottom lands. For these bottom clays, see Economic Report on Clays. Deposits containing fmgments of small bones are found in Hardin (Saltpetre) Cave, near Kiugston. These accumul~tions are from four to six feet deep, and are more or less covered with fallen blocks. The emth has been used in manufacture of.saltpetre. MOUNDS. ThrQe miles north of Cartersville, there ara three prehistoric mounds (known as the Tumlin mounds). The largest of these covers about three acres, and is built up to a height of 40 feet, with steep sides but a flat top. The two smaller mounds seem to have been protective, and are situated just above and below the great mound, and between it and the river. They do not cover more than half an acre each, and rise about twelve feet above the plain. Some at"chreological remains are said to have been obtained from these mounds. 108 GEOLOGY OF THE PALEOZOIC GROUP. CHAPTER XIII. LOCAL GEOLOGY OF GORDON COUNTY. CONTENTS. OosT~~AULA SERIES. KNOX SERIES. RED MouNT-AIN SERIES. CHATTANOOGA BLACK SHALE SERIES. SuB-CARBONIFERous SERIES: Fort Payne Chert and Floyd Shales. LAFAYETTE AND MODERN SERIES. FAULT. OOSTANAULA SERIES. Across the western portion of Gordon county, there is a belt of shale defined upon the western side by the Sackville fault, which brings the Cambrian system into contact, often without topographical breaks, with the Carboniferous rocks which, in part, are com- 1) ed of dark heavy shal s, an ] in part Jf t1e 1emai;u f Ler y lime t n . . Th t'O lc 11 r e 1111 re t' le. s variegated shales, hut r rl bing le and li ~h t red nnd yellowish soil are pt yul nt. Th re i also a modetutc d v h11ment f th 111. ttl d e~uth y lim e:tou s so characteristic of the formation in a similar position farther south. In this section of country the shale series constitutes gently undulating plains with low ridges. The western belt in this vicinity is more cultivated than it is in the "flatwoods" southwest of Rome, and has generally a more fertile appearance than farther south, with growth of timber like that on the neighboring rich lands to the east. In a field in the trough, north of Turkey mountain, the contact of red Cambrian shales and the brown Carboniferous shales GEOLOGY OF GORDON COUNTY, 109 is strongly marked-the actual contact being represented by crushed shales of a few feet thickness. The shales of the river region are flanked on the eastern side by the lower beds of the river, brought up by a fault. These have occasional thin seams of decayed yellowish sandstone which form interrupted ridges. In the region of Resaca, the anticlinal structure of the basin in the southern part of the county still continues. At that point the limestones dip 15 N. 60 W. In some cases, as west of Resaca, the shales are of darker color, but commonly the belt of those deposits closely resemble those of a higher horizon in the series. The timber on these ridges is the same as elsewhere on the Oostanaula series-short-leaf pine, red and spani'5h oak, a few sycamore and hickory, some chestnut, and black jack on some of the poorer ridges; but the lands do not generally indicate sterility. Most of the country, as shown upon the map, is underlaid by the shale formation. The valley of the Oothcalooga is the most fertile, with deep red soil and the limestone beds exposed in t_he valley. In the formation, there are occasional limestone sinks. Eastward of the Knox lands, the Cambrian formations are more or less broken with the red shingly beds predominating. These, where not weathered, are often of dark color. Along the streams the limestones are exposed. The surface soils are thin upon the upper ridges; but in the valleys, especially of the Sallacoa, and along the foot of the metamorphic mountains, to the east, they are of good quality. An anticlinal basin, projecting westward upon the Bartow-Gordon line, is composed of dark red shale lands, bounded by the ridges of the Knox dolomite series, dipping at low angles. K:!I'OX SERIES. Northwest of Adairsville there are small areas of the Knox series, in which the more rugged features of Bartow county become softened to a gently undulating country. 110 GE OLOGY OF THE PALEOZOIC GROUP . To the east of the Oothcalooga basin the ridges continue from Bartow northward along the western part of the Knox basin, but diminish in height. Elsewhere in this basin there is a gently undulating country, composed of gray land. A small basin east of Calhoun has the same softened character. RED MOUNTAIN SERIES. In the northwestern corner of the county, Horn's mountain rises into a prominent ridge 800 or 900 feet high. West of Sugar Valley the ridge is capped by shales and sandstones of the Red Mountain series, the strata dipping southeastward. Upon the eastern flank, there is a characteristic red soil, but the "fossil ore" beds are wanting, as the formation scarcely reaches that horizon. CHATTANOOGA BLACK SHALES. Upon the eastern side of Horn's mountain, the deposits of the last series are succeeded by the black shales of the Devonian system, which are well shown at the old iron ore pits northwest of Sugar Valley. The accumulations do not exceed 20 feet in thickness. SUB-CARBONIFEROt'S SERIES. The Fort Payne chert occurs ou the southern end of Horn's mount~in, and also above the Devonian shales upon the ea<;tern side of the mountain, fart.her northward, and contains brown iron ore. In !the valley east of the mountain the Floyd shales, with their flaggy brown or red weathered shales, are seen. These form a strong contrast with the weathered red shales of the Oostanaula series to the east, which are thrust over the eastern edge of the Floyd shales. THE LAFAYETTE AND MODERN SERIES. On the hills and for a distance of two miles, the red surface deposits of loam and of quartz gra.vels are seen up to an elevation of 80 feet. Distant from the rivers they are not seen and this elevation GEOLOGY OF GORDON COUNTY. 111 is as great as the country near the greater streams attains. The characters are the same as in Floyd county. The valleys oi the Coosawattee and Connassauga rivers, and of some of the larger creeks are wide, but defined by irregular hills. These .plains are from fifteen to twenty-five feet above the ordinary stages of water and are liable to be flooded. IFAUL'l'. As the Oostanaula shales belong to the Middle Cambrian horizon, an enormous fault becomes apparent. This fault is equivalent to a vertical throw amounting to from 7,000 to 10,000 feet. However, upon examination, this dislocation is found to be an overthrust fault, whereby the older formations to the east have been pushed over the Carboniferous formations for a distance of four miles and a half, this measurement being obtained from the occurrence of an area of Sub-Carboniferous strata, which rises through the capping of the overthrust Oostanaula shales. The outcrops just referred to are situated west of Resaca, and have been exposed, owing to denudation, removing the overthrust strata from this area. 112 GEOLOGY OF THE PALEOZOIC GROUP, CHAPTER XIV. LOCAL GEOLOGY OF MURRAY COUNTY. CONTENTS. 00STANAULA SERIES. KNOX SERIES. CHICKAMAUGA SERIES. RED MouNTAIN SERIES. LAFAYETTE AND MODERN. OOSTANAULA SERrES. Between the Connasauga river and the foot of the Cohutta mountains, the Oostanaula shales cover the whole southern part of the county, as also along. the river and along Holly creek valley. The greater part of this region is made up of the red and variegated shales, which are often dark where not decayed. These deposits weather into shingle, covered by thin soil, where they form ridges. The limestone of the series frequently appears along the streams. A long the Connasauga river, Holly creek and other valleys, at the foot of the metamorphic mountains, shale containing more calcareous rocks form fertile valleys. The characteristics are simply an extension of those of Gordon county. The beds frequently show a great amount of internal folding and mmor faulting. KNOX SERIES. Overlying the last series, there is an elongated basin of the Knox dolomite. It is usually'an undulating country composed of fprtile red lands-both hills and valleys-in its southern and central portions (as about Spring Place). Further north there are some rolling gray lands. At several places magnesian limestones of the Knox dolomite series are exten- GEOLOGY OF MURRAY COUNTY. 113 sively exposed in ridges, as on the property of Captain Tilton, and others west of Spring Place. (Se1! Economic Report.) As the Oostanaula shales and limestones often underlie the metamorphic rocks at the foot of the Cohutta mountain range, so along Sumack creek, the Knox dolomite passes under the metamorphic zone to the east. CHICKAMAUGA SERIES. Succeeding the Knox dolomtt ael'ies thete i a narrow belt occupied by higher slates, etc. But betwo~u them and the Knox series there are various beds of t he g r:ay li rue&tune, exposed in the valleys as near Loughridge on the E'a tern side, and as east ot Cohutta Springs P. 0. Overlying the limestones, there is a bed of variegated and brown shales, with occasional calcareous seams. The rocks are not metamorphic. These shales dip at moderate angles to the east-southeast. North of Loughridge they rise iu ridges of considerable height, which, however, owe their preservation to a capping of Red Mountain sandstone. Between the ridges and the mountains, there is a broad, fertile valley modified by the disintegration of the sandstones overlying the shales. The metamorphic strata of Cohutta mountains are seen overthrust upon a portion of the Chickamauga series. RED MOUNTAIN SERIES. Capping the crested ridges of the Chickamauga series, there is a. consolidated fine grained sandstone, occurring in thick beds which aggregate about 200 feet. It is these rocks which give rise to the crested ridges. The rock is fine grained and consolidated into a light colored quartzitic structure. These rocks are probably identical with Safford's Clinch mountain series or one of the variations of the Red Mountain ser!es, as on Rocky Face. LAFAYETTE (?) AND MODERN SERIES. At various points above the Connasauga, the red loam and (8) 114 GEOJ.OGY OF THE PALEOZOIC GROUP. quartz gravel of the Lafayette (?) rises to about 80 feet above the .rivers. 'The flood ,plf!.,in~:~ of the Counasapga a.re not so ,hJgh above this Jl"iver as further'south, and only rise 15 to 20 feet above the ordinary .stages of the waters. GEOJ,OGY OF WHITFIELD COUNTY. 115 CHAPTER XV. LOCAL GEOLOGY OF WHITFIELD COUNTY. CONTENTS. OosTANAULA SERIES. KNOX SERIES. CHICKA~1AUGA SERIES. RED MouNTAIN SERIES. SuB-CARBONIFERous SERIEs. LAFAYETTE AND RII:CENT SERIES. OOST A.'S AULA SERIES. The Oostanaula shales present the same features as in other counties, being divisible into shingly beds (upon its eastern ridges), fertile anticlinical valleys and the low ridges with thin sandstone layers at the western area. (In this location, the grounds for lithological distinction into the Knox sandstone and Knox shales, obtain more forcibly than at any points to the scwth.) In the valley of the Connasauga river and Cooahulla creek, the characters are identical with those of Murray county. In the western part of the county the Oostaoaula shales are repeated by faulting, making four belts (see figure 19 and map). Such is the narrow fertile valley in which th~ E. T., V. & G. Ry. is built from Dalton oo the Tennessee line. From Cove City, northward, there is another such valley between great faults. This shale valley is pinched out west of Varnell, but again continues to the northward Another fertile shale valley, is that in which Tunnel Hill (P. 0.) is situated, but its western side is. succeeded by a ridge of the lower beds with sandstone (or Knox sandstone). This belt widens out eastward of Gordon Spring. 116 GEOLOGY OF 'l'HE PALEOZOIC GROUP. KNOX SERIES. An elongated basin of the Knox dolomite occurs between th~ Connasauga and Coahnlla creeks. It is an undulating country o:n> e:l m H~l y of gray lands. At Cedar Ridge another small basin occur:;. Here the dolomite limestones are preserved and to some extent quarried. Some of the beds are earthy, and other;.; contain dark flint nodules. East of the valley of Varnell (station) there is another trough with a character similar to the last-rolling gray lands with so me nherty ridges. It is, in part, succeeded by higher rocks. W e8t of Varnell there are two belts, in part, brought together by a fault. These belts are somewhat characterized by interrupted ridges, bnt they are largely gray lands forming a rolling valley. West of Tunnel Hill another chain of interrupted ridges extends northward. Some of these ridges appear to be ore-bearing. CHICKAMAUGA SERIES. A belt of these Silurian rocks succeeds the Knox serief! in the northeastern part of the county. The limestones are seen in so me of the valleys. The upper beds are brown and variegated calca- reous shales which, in part, give rise to deep red soils. Some or these beds are highly ferruginous (see Economic report); others are siliceous. The limestones sometimes occur in thick beds. It is probable that the iron ore beds represented in this county belong to the Deaton sub-series. The Dalton basin is made up of Chickamauga shales. Owiug to the limitation of limestones, and some sandstones, a chain of crested hills extePds northward from Dalton. These latter sandstones may be remnants of the Red Mountain series. Between Dalton and Tunnel Hill there is a trough of the Chickamauga formation, with brown shales predominating, but intercalated with limestones and sandy shales. These deposits extend through the gap of Rocky Face mountain, west of which there is a GEOLOGY OF WHITFIELD COUNTY. 117 long narrow trough of valley lauds. The Chickamauga rocks extend upward into the mountain side. RED MOl'N'l'AIN SERIES. Rocky Face or Chattoogata mountain forms a chain extending from near Tunnel Hill southward. This chain is dislocated into parallel but discontinuous zigzag ridges to Horn's mountain and is composed of the Red Mountain series with the different riclgelets connecterl by rocks of the same formation. The ridge rises up into a bold mountain from 1,500 to 1,791 feet above tide. It is capped with a quartzitic sandstone lying in heavy beds, dipping 25 N . .80 E. at the gap in the ridge north of the road. At Dug Gap, a few miles to the south, the strata dip 45 S. 80 E. Whilst there are some shales upon the eastern flank, from the summit of the mountain downward upon the western side, the section shows heavy bedded gray quartzitic sandstone, 20 feet; laminated sandstone in thick beds, 40 feet; red sandstones in thick layers with shaly partings, 40 feet; brown and red compact shale, with seams of sandstone, 200 feet; laminated shales weathering red, 200 feet. Below this elevation such shales as are exposed appear to belong to the Chickamauga series. The deposits represented in the mountain appear to rise to but do not include the "fossil ore" beds. Higher shaly beds occur on the east side of the ridge. Part of Dick's and Taylor's ridges are on the western border of this county; but they will be described in the other <:ounties. CHA l''l'ANOOG A BLACK SHALE. The black shales overlying the last formation and described in Gordon county, extend northward upon the eastern flank of Horn',; mountain into \.Yhitfield county. SUBCARBO.NIFEROUS SERIES. LTpon the eastern side of the mountain just described, the Sub- 118 GEOLOGY OF THE PALEOZOIC GROUP. Carboniferous cherts and shales from Gordon comity extend into Whitfield county. FAULTS. No county in northwestern Georgia has the strata so much repeated into striking features, owing to dislocations and subsequent erosions, as Whitfield county. FIGURE 19.-Hepetition of formations owing to faults and folds between Rocky Face and Cohutta mountains. F, Faults; K, Knox dolomite; m, Oostanaula shales. RECENT FORMATIONS. The most notable deposits are the gravels and loams upon the western side of the Connasauga river, similar in position to thm;e upon the eastern side of the river in Murray county. GEOLOGY OF CATOOSA COUNTY. 119 CHAPTER XVI. LOCAL GEOLOGY OF CATOOSA COUNTY. CONI'ENL'S. OosTANAULA SERIES. KNOX SERIES. CHICKAMAUGA SERIES. RED MOUNTAIN S:WRIES. CHATTANOOGA BLACK SHALES. SuB-CARBONIFERous SERIES. OOSTANAULA SERIES. The Oostanaula shales cross this county m two belts, one ot which, however, is divided by a spur of Knox dolomite brought to the surface by a fault. These belts form rolling valley landR, the more eastern of which, however, is traversed by ridges, owing to the presence of some sandstones which appear in the lower part of the series, and known as the Knox sandstones in Tennessee. This belt is brought into contact with various formations all the way from the Chickamauga to the Sub-Carboniferous series, owing to an exte.nsive fault. The western belt of this series occurs along Peavine creek, which is an anticlinal valley, with the strata often dipping at high angles, bringing to the surface flaggy limestones and shales, which are probably the remains of impure calcareous rocks. Some beds of limestones are also seen. KNOX DOLOMITE SERIES. From Tunnel Hill northward there is a chain of ridges of this formation, forming light-colored cherty ridges and gray rolling lands. Some of these ridges show the occurrence of brown ore, 120 GEOLOGY OF THE PALEOZOIC GROUP. manganese, etc. Across the center of the county there are two ()ther belts of Knox dolomite, sometimes rising as much as 300 feet above the undulating valley lands. These are situated on either side of Peavine valley. In the northwestern corner of the county, the rolling gray lands in front of Missionary ridge are also composed of Knox dolomite. Generally speaking the soils along these three belts are gray lands, or sometimes thinly coated with cherty gravel, which material often thickly covers the ridges. Occasionally red lands are seen. The three western belts extend southward into Walker county. The South Chickamauga creek cuts through the central ridge and exposes the undecayed Knox dolomite. At Grayville the extensive linie quarries have brought to view the character of the rock for a depth of nearly one hundred feet. The strata dip 40 S. 60 E. The beds are very massive and weakly marked by occasional lines of bedding. The stratification, however, is indicated by bands of coloring produced by impurities. The common thiclmeHs of the strata is from bix to eight feet. Some layers have flinty seams through them. This steep inclination, however, does not recur everywhere throughout the belt. The limestones are rather dark gray in color. The residual earth upon the surface does not usually extend to a depth of more than from two to fifteen feeL, and is composed of the material after the removal of the calcareous matter from the dolomite. CHICKAMAUGA SERIES. Two belts of this formation cross the county. The eastern zone is the valley of South Chickamauga creek; it occurs along the western side of Taylor's ridge and White Oak mountain. Whilst this valley is composed of fertile red land, yet the limestone beds, or those interbedded with sandy shale-a residuum of decayed calcareous rocks-come to the surface at low angles, dipping into the mountains at 10 or less to the S. 70 E. GEOLOGY OF CATOOSA COUNTY, 121 Along the West Chickamauga creek this formation constitutes a broad belt of fertile lands, through which the rocks rise to the surface in the anticlinal valley. These rocks, dipping at low _angles, produce extensive outcrops, and the roads over them are characterized by great roughness; but the material is at hand for making the best roads in the State. RED MOUNTAIN SERIES. Taylor's ridge terminates at Ringgold, to the north of which White Oak mountain commences and extends into Tennessee, thus forming one continuous chain, interrupted, however, by the passage -of South Chickamauga creek. This ridge is narrow, and rises to an elevation of somewhat over 1,300 feet above the sea, or from 400 to 600 feet above the valley. The lower portion of the ridge is composed of the Chickamauga series, but the upper portion consists of shales with heavy sandstones, which cap the ridge; these :are often quartzitic in texture. The formation of the mountain top reache composed of shales and thick layers of gray sandstone, above which there are other sandstones which are of red or brown color. Farther north, the strata dip to the southeast, but come up again after forming an anticlinal basin at the southeastern end of the West Armuchee GEOLOGY OF OHATTOOGA COUNTY. 125 valley. Again, these strata dip at low angles to the southeast, and then rising reappear in Dick's ridge. Thus Dirt Town valley, and its continuation, 'Vest Armuchee valley, forms a synclinal basin, but with the central portion of it broken by the anticlinal ridge west of Subligna. East of Summerville, a good section of the rocks is seen along 10 S. 60 E. Near the top of the pass, the dip increases to 20. the newly excavated road. Upon the eastern side the dip is Upon the western side of the mountain there is an abnormal dip of 20 S. 60 W.; but farther west, the rocks dip normally towards the southeast. The thickness is 1,100 feet. In this locality, the higher rocks are composed of shales, underlaid by earthy sandstone, rarely thicker than one foot, separated by shaly partings. Some of the ledges are composed of :1 fine brown sandstone; others are mottled; but nowhere are the strata more than two feet thick. The lower beds of the series are mostly shales. The fossil ore bed lies above the heavier sandstone layers, and is seen at several localities, with a thickneEs of about twenty inches, forming a bed, dipping rather more steeply than the eastern face to the mountain, along which it is occasionally expol'ed in ravines. John's mountain is a bold ridge about twenty miles long, and is, geologically, part of a chain of dislocated ridges of the Heel Mountain series, connecting Rocky Face, Horn's, and Taylor's ridges, and has an elevation of 800 or 900 feet above the valley. It is capped with heavy ledges of sandstone, having a thickness of about 200 feet, interbedded with some shales. The lower part of the formation is shaly. In the central part of the mountain the rocks dip from 20 to 25 S. 60 E., and pass under the Sub-Carboniferous basin t0 the east. Dirt Seller mountain forms a synclinal basin of the Red Mountain series, embracing the beds of the series as high up as the fossil ore, which occupies the trough a few feet below the snrfaee shales. The ore has a thickness of between one and two feet .. 126 GEOLOGY OF THE PALEOZOIC GROUP. This mountain is the only plateau-like elevation composed of the Red Mountain series. Upon. the,eastera side of.Pi~on m(lpntain, Shinbone ridge consists of a serrated chain of hills, rising from 200 to 250 feet above the valley. This ridge is the outcrop of the Red Mountain series, which passes under Pigeon mountain in a synclinal trough. The higher points of this chain of hills have been preserved by the capping of cherty gravel or fragments of rock derived from the Fort Payne series. The strata dip at 20 N. 50 W., which may be taken as an average dip, but in placE's the beds are much disturbed, and even dip at75. Whilst the rocks are mostly shales, with occasional flags of limestone, yet the shales form compact, thick lamination.,, and pass into sandy flagstones of red color. This red colrmations hav e been removed by denuilation, with the formation of valleys. The denuded beds from Coal Measures (C) to Middle Cambrian (Mo) are represented by clotteJ lines. F, great faults. their hardy materials, resisting the diminishing power of degradation as the streams reached the base level of erosion. As the Coal Measures then capped Taylor's ridge, and all of the country thence to Pigeon mountain, the amount of material removed from the surface may be roughly estimated at not less than from 2,000 to 6,000 feet, as is represented in figure 20. The mountain movements have taken place since the commencement of this great erosion. A similar outlier occurs in Floyd county. Lookout mountain forms a plateau cros~:>ing the extreme northwestern corner of the county, and rises up to 1,700 or 1,800 feet above the sea. The lower strata of the Coal Measures consist of shales which are mostly concealed, whilst the upper part of the mountain is bounded by a wall of sandstone or conglomerate (see plate VI., page 53) often in thick or heavy beds. Back from the brow of the mountain, higher beds of the formation occur. The GEOLOGY OF CHATTOOGA COUNTY. 129 dip of the rocks, as seen in Neal's gap, averages from 5 to 10 N. 60 W. Beneath the conglomerate at least one bed of coal occurs, having a thickness:of from 1 to 1} feet at the locality where seen-a mile north of Neal's gap. This is a portion of the wide-spread coal seam. At Gilreath's mill, the south fork of Little river cascades over the sandstones, belowlwhich the coal is again seen. The top of the mountain consists of sandy soil derived from the di sintegration of the sandstones and sandy shales. (9) 130 GEOLOGY O.F THE PALEOZOIC GROUP. CHAPTER XVIII. LOCAL GEOLOGY OF WALKER COUNTY. GONTENTS. OosTANAULA SERIES. KNOX SERIES. CHICKA.MAUGA SERIES. RED MoUN'l'AIN SERJES. CHATTANOOGA BLACK SHALES. S un-OARll ONIFERous SERIEs. COAL MEASURES. OOSTANAULA SERIES. East of Taylor's ridge a belt of Cambrian shales enters the county from Catoosa, and terminates southwest of Villa now. It is brought into position owing to a fault upon its western side, and the subsequent removal of the Knox formation from the valley at the head of E ast ArmucbPe creek. In part, these are low ridges produced by the sandy members ,vhich are present in the series; otherwise, tile belt forms a valley. Through the central part of the valley, the most western basin of the shales connects the siMilar basihs in Catoosa and Chattooga counties. This is an anticlinal valley, occupied by the usual fertile soils. The rocks are shales or sandy shales, the remnants of decayed calcareous rocks. Included amongst these shales, beds of limestones occur, which are exposed along the streams as is the case everywhere over this formation. KNOX DOLOMITE SERIES. East of Dick's ridge, as also east of John's mottntain, ridges with of rolling valleys, carved out 'this 'fcirniation, form prominent feat- GEOLOGY OF WALKER COUNTY. 131 ures. These ridges are repeated, owing to an anticlinal and fault structure. The soil on the ridge is usually covered with chert, and on the rolling lowlands, it is gray, with only occasional basins of red material. Between Villanow and Furnace at end of John's. mountain, the beds of dolomite rock are well shown and dip gently southeastward. Between Taylor's ridge and Lafayette, there is a broad belt of the Knox series, which forms undulating valley land with occasional ridges. Here the soils are gray or cherty upon the ridges. This belt constitutes the eastern slope of the Lafayette anticlinal valley. The western side of the anticlinal forms a narrow chain o ridges of the same formation. These ridges are much interruptedi by valley depressions. Missionary ridge, with the rolling lands in front, is also composed of Knox dolomite, and occupies the position of an anticlinal from which the rocks have not been sufficiently eroded to exposethe underlying Oostanaula series, as in the Lafayette (town) anticlinal valley. The ridges are often deeply covered with chert,.and the rolling valley lands are composed of cherty or gray soil, with occasional developments of red land. At several points, the streams. have exposed the rocks to a limited extent. CHICKAMAUGA SERIES. A narrow belt of these deposits skirts the western side of Horn's mountain, and unites with the synclinal basin surrounding the northern end of John's mountain. Two small exposures are seen passing under Dick's ridge. These limestones and shales are valley-making. Occasionally the limestone is exposed at the surface, as also sandy flags which are probably the remains of impure limestones. These rocks give rise to rough roads where highways. cross them. West of Taylor's ridge another belt of the same formation under- GEOLOGY OJ<' THE PALEOZOIC GROUP. lies a valley along the foot of the mountain, from which the rocks extend upward into the base of the ridge. East of Missionary ridge, and occupying the valley of the 'Vest "Chickamauga creek, there is a synclinal valley occupied by the lime:stones and shales of this formation; indeed, it is from this region .that the local geological name has heen adopted by Mr. Hayes. 1V hilst there are usually fertile red soils in this valley, yet the lime.,tones, dipping at low angles, form outcrops of considerable extent, which give rise to thin soils and rough roads. Besides the more or less impure limestones there are beds of calcareous shales, some of which produce rough sandy flags upon weathering. The sbaly members cannot be separated fmm the limestones in the series. The same rocks ri::;e up on the western side of the Missionary ridge anticlinal. Another small basin surrounded with the Red Mountain ridges rises up through the northern end of the Missionary ridge anticlinal, forming the typical basin of the reel or brown lands. RED :010UN'l'AIN SERIES. In the eastern part of the county, the northern end of ,John':-~ mountain rises to form a bold feature. This, as well as Mill creek ridge (forming a part of the connection between Horn'.-; mountain and Rocky Face), is composed uf the rocks of the Red Mountain series. On these mountains the sandstone members predominate to :-;uch an extent as to give rise to the bold features. Taylor's mountain and Dick's ridge togethet fu t Joe.: not incl n] he bigh !:it. 1ed _f h 1oal Measures, whiol1 occnr in the interior of the mountain, and on Round mountain. The following section is obtained from the careful reduction of the measurements along the Chickamauga railroad. It extends from the top of Round mountain to the base of Eagle cliff. FRet Laminated shales with a few layers of sandstone on Round mountain (partly concealed) . . ____ _ . __ 200 GEOLOGY OF WALKER COUNTY. 139 Feet Shales ? (concealed)---- ..... ~ _ _ _____ ----- - _ 65 Shale _____ __________________________ .. __ .. ____ .. _ 9 Coal and shale intimately interlaminated .. . __ _ 14 .Shale aml ~;audy shale, partly concealed __ _ _____ ___ 25 Coal_ ___ ____ __ __ __ ___ ___ _ ___ __________ _ 0.7 .Shale ________ __ ----------------- ../ ___ -------- 18 Sandstone, gray laminated ______________________ .. _ 35 Coal (3.5 to 4.5 feet) dips 1 E. S. E. ; altitude at mouth of Durham seam mine, 1,849 feet above tide. There is a slaty parting in the middle of the seam. This bed is probably represented on the southwest side of the mountain at an altitude 30 feet lower___________ ___ 4 :Sandstone, irregularly and often thinly bedded and un- dubting_ ------- ----- - ---------- ____ _ 80 Red shale _______ .. _ __ . ____ . _ _ __ _. _ __ _ 11 Black shale,_______ _ 4 Shale and sandy shale with a seam of limestone ____ . __ 10 Blue shale above and variegated shale below _ _ _ 7 Coal (alt.itude 1,668 feet)---- - - __ _ ______ _ _ 1.8 Thin laminated blue shales __ ____ __ 70 Red shales _____ . _ __ . 35 Coal _ . __ __ __ __ ____ . _ .. _ .2 Light blue clay ____________________ _____ .-~ -- -- - 2 .Shales and sandy shales, passing into sandstones and un- dulating so as to frequently appear and disappear for a distance of 3 miles, but characterized by some recog- nizable layers, estimated at__ _ _______ _________ ___ 150 CoaL ___ _., 1.7 Sandy shales in steep undulation .. __ _ _ __ 1 to 3 Heavy bedded sandstones _____ . _ _ __ ___ . ____ . - -- 25 Coal ____ .. ______ __ __ ________________ _ __ _ ___ _ 0.2-0.8 Upper conglomerate and sandstone (at Eagle cliff) __ __.150 140 GEOLOGY OF THE PALEOZOIC GROUP. :Feet Shales laminated and also thick bedded ___ ___ __. _- _120 Lower conglomerate and sandstone __ __ . - ________ 40 Shales, more or less concealed __ __ _ _ ______ .. _(~) 250 On the southwestern side of Round mountain, there are proba- bly two coal seams, different from and situated above the coal seams given in the above table. Beneath the upper conglomerate a bed of coal occurs with a thickness of from one to three feet, and said to be still thicker at some points. These coal seams are, probably, identical with thm;e at the bead of McLamore's cove and in Pigeon mountain. The coal seamsbeneath the upper conglomerate are in the same position with others seen at various points near Rising Fawn. One of these coal bedR occurs at Stephens' gap on the east side of John- son's creek, beneath the sandstone, which dips 18 S. 60 E., rest- ing upon fire clay. Above the furnace, on the northern side of the creek, there is a vein of coal formel'ly opened. This Yein oc- curs in shales at a considerable depth below the conglomerate. The vein is said to vary from nothing to eight feet in thickness. Near the point of the mountain, to the west, another vein of coal occurs immediately below the conglomerate. As the mountain has been unequally eroded, especially "here the conglomerate is brought into high angles on the eastern side, the upper sandstones have been removed in places, as also some of the underlying shales and coals. The erosion must have been great, as the Coal Measures above the conglomerate have been generally denuded, except where protected by the form of the basin of Look- out plateau. GEOI,OGY OF DADE COUNTY. 141 CHAPTER XIX. LOCAL GEOLOGY OF DADE COUNTY. CONTENT.;. KNOX SERIES. CHICKAMAUGA SERIES. RED MouN1'AIN SERIES. CHATTANOOGA BLACK SHALE. Sun-CARIIONIFF:Rous SERIH:8. UoAL M E11SURES. KNOX SE-&~5. Cherty ridges of the Knox dolomite formation enter t.he county from Alabama and extend only a few miles into Georgia, south of Rising Fawn. These are the lowest rock series of the anticlinal valley of Lookout creek. CHICKAMAUGA SlRIES. On both sides of the anticlinal exposure of the Knox series there are developments of the Chickamauga formation. The limestones are conspicuous, 'and form strata dipping from the valleys often at low angles in both directions. Whilst they are in part valley making, yet some of the rocks rise ~1p 'in ridges or make a stony floor to the valley. Some of the' beds include light colored, fine grained limestones, breaking with a conchoidal fracture. From a point north of Rising Fawn, down the Lookout valley, the Chickamauga series forms a fertile valley, whete the soils are of red or brown color derived from impure limestones. In places these rocks are more or less massive beds of impure, often flaggy limestone, coming to the surface and forming low ridges. Else- 142 GEOLOGY OF 'l'HE PALEOZOIC GROUP. where the ' decayed soil deeply covers the undecayed rocks. Whilst. the beds mostly dip at angles from 10 to 20, yet portions of the folJs dip as much as 60. The formation is about 1,200 feet thick. RED MO"UNTAIN SERIES. Both basins of the Chickamanga limestones are surrounded by chains of undulating ridges rising from 100 to 300 feet above the valleys. The higher points are, however, commonly protected by cherty covering of the Fort Payne chert, or sometimes by remnants of the cherty limestone itself. The character of the ridges may be seen in plate V., page 5:3. The rocks are mostly laminated shales with some flaggy layers, and of a red color above the drainage level. There a1e occasional thin layers of limestones. Below the drainage level the rocks are more calcareous. The fossil ore is usually present in from one- to three beds, and has a thickness varying from two to even seven feet, but usually it is not over two and a half feet thick, especially above the drainage level. Below that horizon the ore is always highly calcareous. On the eastern side of the valley the formation passes under Lookout mountain, and on the western side, it passes under Sand mountain. CHATTANOOGA BLACK SHALE. Overlying the Red Mountain series, the Devonian black shale everywhere succeeds it. As this shale is very easily disintegrated and removed, it is only preserved beneath cappings of the next formation. As a consequence, it is seldom seen except in occasional washouts or along streams, or along roadsides where tionary beds ____ - ___________________ - _ . _______ 6. Shale __ ___ _ _________ - ---- _ ----- _ 15 .. Sandstones, thick bedded _______________ . ___ __________ 15. Shale ______ _____ ___________ __ ----- - .. 10 Shale with some thin layers of sandstones __ __ 95 . Shales(?) concealed .. --- _ ___ -- -- - ______ 90 Limestones ____________ ------------- ____________ . __ - Other lE)ss perfect sections and borings have been obtained~ some of 'Yhich are given in the Economic report. The Coal Measures give rise to light sandy lands. The shales ex posed at the surface are usually weathered red, but those seen m. the mines, below atmospheric actiob, are generally dark blue. (10) 146 GEOLOGY OF THE PALEOZOIC GROUP. CHAPTER XX. RECEN'r FORMATIONS WEST OF TAYLOR'S RIDGE. West of Rocky Face and Taylor's ridge, none of the gravels which have been referred to the Lafayette formation were seen, nor were the red loams; but these last might have escaped observation where there was no gravel, as they are superficially difficult of distinction from red residual clays. The valleys are very little higher than the lands of the Coosa basin. The explanation may lie in the fact that the district referred to stood a little higher than the Coosa basin during the submergence which allowed the yalleys of the Coosa basin to have been submerged. At any rate the quartz gravel eoming from the metamorphic highlands to the east would have been obstructed by Taylor's ridge. Still west of this regioQ, there were hard sandstones which could have supplied material for the production of gravel. At any rate, if loam were laid down, during the Lafayette epoch, it has been removed by subsequent denudation to such a degree as not to attract attention at the present time. As the rivers have not made extensive flood plains the bottom lauds are not conspicuous, although the streams overflow irregular lowlands to a limited extent. But it is not a country of true bottom lands. The soil is everywhere the result of the rock decay, and varies according to the source. These residual earths eommonly cover up the undecayed rock formations, where the natural strata ate exposed in only exeeptionally favorable places; but the residual earths aRsist in locating the underlying formations. The rocks are often sufficiently fossiliferous for their identification; and in the coal mines some beautiful plant remains occur. PART II. ECONOMIC RESOURCES OF THE PALEOZOIC GROUP OF GEORGIA, IN POLK, FLOYD, BARTOW, GORDON, :MURRAY, WHITFIELD, CATOOSA., CHATTOOGA, WALKER AND DADE COUNTIES. llY J. W. SPENCER. ECOKOMJC RESOURCES. 149 ECONOMIC FEATURES REPRESENTED ON THE GEOLOGICAL MAP. COAL MEASURES .. . . .... . Coal, gray sandstone. MOUNTAIN LIMESTONE . Limestone and building material. FLOYD SHALE . .... ..... .. Limestone and building material. FORT PAY~E CHERT . . . Road metal, brown ore. CHAT. BLACK SHALES ... RED MOUNTAIN . .... . .. Fossil ore, brownstones and flagstones. CHICKAMAUGA . . . .... Slate, limestone, iron ore, ochres. KNOX DOLOMI'FE .. . . , .. Brown iron ore, manganese, beauxite, limestone, kaolin, road metal. OOSTANAULA SHALE .... Cement, black metal. marble, sandstone, road THE Iron and manganese ores, ochre, soapstone, METAMORPHIC ROCKS heavy spar, graphite. N O'l'E.-The occurrence of the ores, building materials, soils, physical feature~, conditions of the roads, etc., are all dependent upon the geologieal stt..wture, and before any information, of scientific value, relating to their distribution and modes of occurrence could be given, it was necessary to prepare. a detailed nccount of the geological structure of the belt mrveyed. For information coucernmg the local geological conditions reference must be made to the first part of this report and to the geological map. 150 ECONOMIC RESOURCES. CHAPTER XXI. BROWN IRON ORE3 AND THEIR MODE'3 OF OCCURRENCE. CONTENTS. KINDS OF BROWN ORE. SouRcEs OF BROWN ORE. MoDES OF OccuRRENUE oF BROWN ORE: "Note, Iron Ore of the Knox Series; of the Deaton Series ; of the Sub-Carboniferous Series. KINDS OF ORE. Except the "fossil ore," the most important iron deposits of the Paleozoic group belong to brown ores and limonite varieties. Limonite, in its purer crystalline form, is more or less globular or botryoidal with the internal structure fibrous and more or1 less silky in luster, having a degree of hardness varying from 5 to 5.5. The color is dark, rich brown, and the luster is sometimes metallic. Other varieties have an earthy appearance, of dull yellow or yellowish brown color, and soft-varying from one to three or four degrees of hardness. According to the admixtures, the color of the powder varies from ochre to yellow brown. In composition, limonite is a hydrous sesquioxide of iron, containing, when pure, iron, 59.92; oxygen, 15.68; water, 14.40 per cent. Commercially, the percentage of iron falls helow these figures on account of impurities. When limonite has lost its water, the mineral becomes hematite, and then the metal rises to 70 per cent. As a matter of fact, very little of the iron ores, passing under the name of brown ores in northwestern Georgia, are pure limonite, but are usually admixtures of this mineral with hematite derived from the former by the loss of the water. Thus the percentage of BROWN IRON ORES. 151 iron is increased, as most of the available ores contain only two to four per cent. of moisture. This mixture of iron bearing min- erals is commercially known as "Brown Ore." This always con- tains more or less admixture of clay and sand. Amongst the ele- ments associated with the ores, in small quantities, which have a bearing on the value of the iron, phosphorus only need be men- tioned, as it renders the iron brittle when present in excess of mere traces. . . The brown ores vary much in physical appearance, with the modes of occnrrence and geological sources. It is frequently red, earthy, in small concretionary particles and masses; occasionally in large boulders; and again in irregular sheets. In all of the re - sidual ores of the Paleozoic series, the appearance is much more l"!arthy and of a darker color than the beds of brown ores, sue h as are seen in the metamorphic rocks east of Cartersville, which have often an ocherous appearance. SOURCE OF THE BROWN ORE. The brown ores of the older Paleozoic belt have been entirely derived from ferruginous limestones. Whether the iron was in the condition of carbonate or of sulphide is of little consequence, for where available it is now always associated with the remains of decayed limestones, some of which were highly calcareous with but little flinty matter; whilst again to a lesser extent, the iron deposits are derived from the siliceous beds, with a marked difference in character. Some of the iron bearing limestones may have been ferruginated after their formation, and that irregularly, by iron bearing streams, often flowing transversely, across the formations, from the older metamorphic rocks to the east; for frequently the trend of the ore bearing ridges is across the general direction of the formations, which normally extend from eastward of north to the opposite direction. Possibly, the directions of some of these former iron bearing stteams can be recognized; but probably 152 ECONOMIC RESOURCES. a greater proportion of the ore has been deposited synchronous with the rock formations adjacent to mouths of streams, or in lagoons, or as pointed out, in connection with manganese and aluminum ores. As all the valuable deposits are of secondary origin, often derived from the concentration of the ore upon the decay of the limestone, commercially the questions are: '' What fonnations contain o1'e, and what are the rnodes of occui'rence /" The origin of the deposits is similar to that of manganese, a discussion of which appears under that head. THE MODES OF OCCURRENCE OF BROWN ORE. NO'l'E . In the Geological Survey, the consideration of this subject is that of primary importance rather than a list of the known beds, a., the object of the survey is to aid in the development of the resources, and in making known the belts of the same. without the investigations recorded in the first part of this report, no key to the situation could have been obtained. Under such conditions the .survey would have been only a catalogue of discovered iron bearing properti es, without a scientific knowledge of the same. The applied deduction s are here given as if the reader were familiar with the first part of the report. The principal brown ores occur in distinct Lower Paleozoie formations-the Knox dolomite and the Deaton ore series, but it -also occurs to a small extent in the Sub-Carboniferous series. IRON ORE OF KNOX DOLOMITE SERIES. From investigation, the first general deduction arrived at is the occurrence of the largest amount of workable ore upon subordinate -elevations in red land derived from the lower Knox strata. The () bservation that such ore deposits are abundantly situated near the margin of the Knox formation can now be extended and explained PLATE Vll. BROWN ORE RIDGE AND PITS, In residual Knox clays, at Grady, near Fish Creek, Pclk County. BROWN IRON ORES. from fuller surveys. This condition is dependent upon the accumulations of ore being largai\t in the lower and less siliceous numbers of the Knox series. These lower beds approach the surface, not merely along their northwestern margin, but where undulations of strata have brought the more calcareous beds to the surface. The presence of these beds has favored valley making, owing to their :solubility and the absence of a protective covering of chert. Thus, by the deformation of the stiata, the lower iron bearing beds are lifted up to view, adjacent to the underlying shale formations. But again, the ore deposits occur at no great geographical .distance from overlying Ordovician limestones and shales, and, near the junctions of the formations, as in the Cedartown and Fish creek districts. This, however, is due, pot to the presence of different formations, but to the undulations of strata and the elevation of lower beds, which have been reduced to valleys, owing to the removal of the C!\lcareous matter, in localities where the cherty beds have not been sufficiently protective. 'J'his same condition obtains where undulations of the Knox series is not overlaid by higher rocks, as northwestward of Fish creek, \vest of Seney and Dnward. Consequently, wherever there are broad valleys, carved out of low~r dolomite beds, with red lands, ore beds are more or less common, and accordingly, there are several parallel belts. Naturally, the removal' of the calcareous matter, would produce valleys, wherever it comes to the surface, but the ore deposits re.'iist erosion and becomes more or less protective. Consequently, the brown ore is most commonly found on subordinate ridges in the valleys. (See plate VII. on oppoRite page.) As already stated, the form of the ore is usually in small concretions, sometimes becoming large boulders, or occasionally beds of limited extent, very much disturbed. This refers to the ore in the red bilk The ore bank is an accumulation of ore deposit remaining from thte decay of a great thickness of rock, and in many places, it is known to be more than from 40 to 50 feet deep, ' 154 ECONOMIC RESOURCES. above the natural drainage level; and often passing far below it in other localities. In these regions, but. little dependence, or indeed value need be placed upon the bedded portions. The accumulations pf the "wash" ore are of greatest value on account of their better quality and more ecDnomic working. A characteristic of these ore beds is the rising up of ma~ses of clay-technically "horses" amongst the ore. .Often the clay is white or pink with but little iron, and standing up in strong contrast with the ore. These clays often show a commingling of much undecomposed feldspar, and appear to have been deposited as irregularly as they are now found. (See analyses under clays.) The proportion of concretionary ore in the banks varies, but has been worked where it ;rields upon washing even less than onefifth of the mass; seldom is it more than one-half. The large oremasses, whilst being mostly made of limonite, are more expensive to work than the wash ore. The small ore has lost most of its water, and is usually of a brown or reddish color. In portions of the cherty beds of Knox dolomite, brown ores occur similar to those just described, but their development is of less extent; perhaps due to the lower degree of concentration, owing to the protective mantles of siliceous matter. Again, vesicular beds of chert-the calcareous matter being removed and leaving the cavities-are often rich in iron, and occur in massive strata. The ore in such beds is usually too iililiceous for present use, and the wash ore is generally less extensively developed in these gray than in the red hills. Between these two characters of beds-red hills rising in the Yalleys, and gray ridges-there are intermediate conditions; so that the sharp lines between the relations of the ores cannot always be defined. Stratification is not usually seen in the residual accumulations, as is already noticed; and consequently, the tracing of the beds is rendered difficult. This absence arises, in part, from the disturbed }'lO U R~: 22.""7White "clay horse" in brown .ore bunks ut Grady. 156 ECONOMIC RESOURCES. condition of the strata, and, in part, from the irregular falling of the decayed beds into underground cavities, thus obliterating bed.ding. This is seen in some cases, as on the State line, in Etna pits, where some of the ferruginous rocks have been in heavy beds. (See plate VIII. beyond.) The ferruginous beds can occasionally be. traced short distances and are then found to g1aduate into ocherous beds of clay, and .eventually become obliterated. The ores of the Knox dolomite are often thickly strewn upon the surface of the low ridges, as pebbles, in size, from that of shot to large cobble stones, or boulders. In such cases, the ore may continue downward to the depth of nndecayed rock: The hills are of deep red color, not only from the presence of ore, but from the coloring in the clay. Othet portions of the hills are simply covered with deep red soil, and beneath them the ore is sometimes found. Such is especially the case when this covering is of the Lafayette series. It may be stated here that when the Lafayette loam does not contain gravel, it is not aJ ways easily recognized from the residual !:iuperficial formations w.hich have the same general appearance. The covering of the valuable ore beds is often shallow. It is seldom more than eight feet thick. In it, the quantity of the ore often reaches twelve or fifteen per cent., and justifies the washing of this coveritig sheet, but the amount is seldom enough to warrant its use when the ore is only screened. Sometimes, the ore occurs b~neath day horses. In' these cases, it may soon become valueless, because of the masses of clay that must be first removed. ORE OF '!'HE DEATO~ SERIES. These ores differ in appearance from those of the Knox dolomite. They ne\er form_ concretionary or rounded gravel, but they make more or less angular shingle, scattered over the subordi- BROWS IRON ORES. 157 nate ridges. When these deposits are worked tar enough, the ore is found more or les'l in beds of variable thickness. However, these beds often pass into ferruginous clays and soft ochres. (See plate I., frontispiece.) The mineral is mor,;tly limonite and is often yellowish, but that exposed on surface is brown or red. It may be slightly magnetic, on account of being a8sociatecl with semi-metamorphic rocks. Thus, it appears, that the rocks were ferruginated before the metamorphism of the strata situated immediately to the south. The ore is deri vecl from ferruginous limestone, which may be seen in Deaton mine, near Taylorville. Here is found a dark, undecomposed compact crystalline limestone, containing 25 per cent. of iron. But usually the rock is disintegrated, leaving beds of shingly ore. At this named locality, the underlying Maclurea limestone was rendered cavernous, and the roof being composed oi iron-limestones, has fallen in, making a confused mass of ore. This will be noted later and may also be seen in plate I. (Frontispiece.) Ores of this horizon occur in low ridges in -Whitfield countyr lying in thick beds, associated with the limestone. The mineral, however, has a more specular appearance than seen at Deaton. These ores belong to a horizon which may be correlated with Safford's Iron-Limestone series. ORE3 0&' THE SUB-CARBONIFEROUS SERIES. The lower member of the Sub-Carboniferous series consists of the Fort Payne chert, a siliceous or cherty limestone, in which somelayers consist almost entirely of siliceous matter. In many localities some of these beds are highly ferruginous to such an extent as to give rise to beds of brown iron ore. Such may be seen on the ridges of southern Polk, where the ore is compact and approaches hematite in appearance. In limited quantities the ore of the same horizon is sometimes 15 8 ECONOMIC RESOURCES. seen in the extreme north western portion of the State. On Horn's mountain the .ferr!}ginous bed~ are near the base of the series immediately overlying the- hlaclf"shaJes' of the Devom1tn system, on the eastern flank of the mountain. The original rock is de_cayed, and the calcareous matter is almost entirely removed from the limestones, leaving a concentration of residual clays (sometimes in "horses") in which boulders and irregular laminations ofore occur iu workable quantities. If mining were carried below the drainage level, it is very doubtful if the ore would be sufficiently concentrated for an available supply of iron. This ore contains much more of the yellow limonite than the Knox ores. BROWK IRON ORES. 159 CHAPTER XXII. LOCAL DISTRIBUTION OF BROWN ORES. CONTENTS. K:wx ORES IN Por.K CouNTY: In the Basin We>i of Little Cedar Creek; Valley adjacent to E. T .. V. & G. Railwuy; Along East & West Railway of Alabama; Fish Creek District; Long District; Recapitulation. KNox ORES lN FLOYD CouN'l'Y: Cave Spring District; Spring and Silver Creek Districts; Recapitulntion. Kxox ORES IN BARTOW CouNTY: Flpring and Silver Creek Districts; Tom Creek and Connesenna Districts; Recnpitulation; Ores of the J'tieturnorphic Rocks. Sun-CARBONIFERous OREs. DEATON ORES. BRowN ORES IN GoRDON, MuRRAY, WrnTFIELD, CATOOSA, CHAT'l'OOGA, W ALKEI\ AND DADE CouNTIE~: Knox Ores; Deaton Ores; Sub-Carboniferous Ores. KNox OnEs IN PoLK CouN rY. A portion of this county has already been reported on, but for the sake of fuller treatment of the subject, the general features gi veh before will be included in this present and more extensiye.report. Only a few properties in the:ore belt could be named, as every section bearing ore C)1Jld not be visited, but those mi.tn.ed will aid in the location of the richer belts in the ore bearing zone. BROWN ORES IN. THE BASIN \\'EST OF THE LlT.rLE CEDA.II.. CREEK. This is a basin about two miles wide and eight long, extending from Indian mountain, in Polk county, into Floyd. Owing to faults, this basin is isolated from the other portions of the Knox series. Here the country is made up of somewhat narrow valleys and rugged, gray, cherty ridges. In this basin, there are several 160 ECONOMIC RESOURCES. deposits of brown ore of the usual type, but these often go below the drainage level. Thus, on the property of Mr. Linton Sparks, lots 139 and 140, 17th district, there are pockets of good and of indifferent ore, side by side, and these appear to have been derived from different beds. On the ridges near by there are several surface exposures of thick siliceous beds, some of which contain ore rich in iron. These sheets occur on. the Stott-Folger and other properties. Again, there are other ferruginous beds of ore of inferior value to the ore banks, which can be more economically worked. Some of the ore is manganiferou10. In a pit of Mr. Sparks' the ore is seen to pas.s clown beneath a clay horse. The outlet of this basin is "Hematite" siding on the E. T., V. & G. Railway. BROWN ORE IN THE VALLEY ADJACENT TO THE E. T., V. & G. RAILWAY. On the east side of the valley a chain of ore-bearing ridges from Alabama enters Georgia at Etna, on the extensive property of CoL Hamilton. On the western side of the valley, except near Oredell, the hills are slaty and barren. The bottom of the valley ~s generally underlaid by Cambrian shales or slates, but the ridges to the east are composed of overlying decayed Knox dolomite,. partly brought iuto position by a fault. Along the western flank of the ridges there are subordinate ore banks. On the State line there are extensive workings which have exposed the ore to a depth of 60 or 70 feet without reaching its bottom. As usual, it is a heterogeneous mass, but contains thick bedsof solid ore, as if disturbed by the falling of the roofs over limesinks. In fact, the true stratification of the Knox ore beds is gen-erally lost. The ore has a less concretionary and more massiveform than is generally seen farther east in other Knox deposits, and contains more or less included flint. Northwestward of the Stateline, there are many extensive ore banks belonging to the Etna Company. The analyses of some of theEe I'LATE VII I. BRO'WN IRON ORES. 161 Dres will be given in the sequel. However, it may be noted here that considerable manganese is seen in various places, and that .sometimes the f r h working h w :lfj re cence of vitriol. Beyond Etna, similar .~,. , bauks o 'tu at. 1: ty r ' (Wood's, etc.) and Oredell, ,being ~mbordtna ridges of' red Ul'e-bcacing lands rising in the valley, or on its margin. In an artesian well snnk at Oredell the ore was found to continue to a depth of one hundred and eighty feet. In a cut along th e railway the decayed formation shows much co nfnalo n bnt nppetLl' to d ip a val'ia bl aogl e~ u T. 15 W. and th red po ita seem to belong to ouc horizo n. In n p'it nea t' l y, t he Ol'C pass s under a whi t ln:y ll or 1 r 15 .11 t t.lJiut~, below whi<:b it wo 11 lcl hltru ha tb ' whole cha.in of ridges boun ~ing tJh val- l y 'II t f th East Tennessee, irg11na and or :ri}l ail wa fi:mlls a beJt of un.try d lt in ot 1i Ige. BROWN ORES ALONG THE EAST AND WEST RAILROAD OF ALABAli{A, Upon the western border of the Ordovipian or Lower Silurian ,slates, the Machuea limestones 'are valley making. Beyond these, many beds of iron-bearing Knox ridges occur. These form. th e great deposits of the Cedartown district. This belt enters Georgia at Esom Hill, near which place are the Brewster and other banks. At various points the ore banks reoccur, such as at Mr. Rice's, near .Berry station. (11) 162 ECONOMIC RESOURCES. The largest assemblage of ore banks is two or three miles south and west of Cedartown, amongst the chief of which are the Reed,. Ledbetter, Peek, Wood and other deposits, many of which are now included in the properties of the Augusta and the Central Mining Companies. Continuing onward, the ore appears at 1\fr. \Vaddell's and Mr. Frank Sheflets, two and a half miles north of Cedartown,. and on some other land~;. These ore banks rise from a few feet to fifty or one hundred feet above the valley. The ores are mostly small, concretionary lumps or masses, but with some greater blocks . or boulders. . In Peek's mine, ore has been seen approaching a bedding, and on au abandoned hill, ferruginous chert bluffs are seen. In all of these banks clay horses rise up and interrupt the pockets of ore (as represented in figure 22, page 155), but the ore has frequently a known depth of more than 40 feet. To one unfamiliar with the ore the first impressions are often disappointing,. as the value of the fine ore is greatly obscured in the clay. Southeast of Cedartown these ore banks are not continuous throughout the belt. Two of the ore-bearing ridges rise up through overlying Chickamauga shales two miles south of Cedartown. Another iron-bearing locality occurs east of the shale basin south of Cedartown, near Young's mills, and at the Cleveland, Pittman, Cox and Ray hanks, between Young's and the metamorphic region to the south. FISH CREEK DISTRICT. A few miles to the eastward, ore beds of the Knox series are again hrou g ht t Lb sm1nce, ncar Fish cr ek. A Gra ly . l:at i n t\1 -re i an a elllbla of .hng o re bankf.! b lo ng ing to the ~ b e to k e Iro n 'oropany anrl to the C ntml .l\l[ioiug Jnn1paoy . 'l l.1 er ar large -tn lejw it of t h u uo. l e with g reat. olay ( oft 11 w L..i.te) h .r. e. , ri sing intl>t he re a cUimuations. See ph1t i . thor ridges ext end southward a. at H.i 1-ma.n's a.ud 'imr>: on miu (lo 1 l o, 21st d.istri t) W. 0. M urris' (1 ts lO c an.d 113 ) ;, anrl dl's. ~Io rgnn'. ~lU Ll MI.'. Win.n's ( l 1 6C, ':-. Lt ilistri t). BROWN IRON ORES. 163 This belt continues, with interruptions, northward, to between one and two miles west of Seney and thence into Floyd county. Northward of Grady, on this belt, ore occurs on lands of T. H. Peek and adjacent properties; on several lots belonging to Mr. T. Colbert (as on lot 306, 21st district), B. F. vVest and others, thus showing the continuity of this belt across the country. LONG DISTRICT. Another belt is adjacent to the East Tennessee, Virginia and Georgia Railroad, between Rockmart and Seney, especially in the region of Long station. These deposits are on subordinate ridges on the western side of the valley of the Chickamauga series. From these beds large quantities of ore have been shipped, the principal mines being those of the Central Mining Company, the Randall and the Cochrane. RECAPIT ULATION. There are now well established six different belts of brown ore deposits, dependent upon the geological structure as described elsewhere. These are: ( 1) in the fault basin north of Indian mountaiu ;(2) t htl from Etuato a.v 'prin ; (') th Cedartown (4) thaL,' uilien.s of 'edttrLo Wll; C'') the li'isb cr ek z n , (H) t he L on r 11tation cli sbrict. T hor n1 ' ntly-ing d ~> . i s of 1 town t , e J iltl ly ~Ull \l n g th h rt ti .. .. .. .. .. . . .. .. .. from 0.147 to 0 858 One analysis showed 16.39 per cent. of silica. Another anslysis gave 1.396 per cent. of phosphorus. The-above analyses were 174 ECONOMIC RESOURCES. made in the laboratory of Messrs. Cooper & Hewitt, Reegelsville, Pennsylvania. The analysis of the iron produced in May, 1890, showed the presence of: Silica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0. 253 Manganese. . ... . . . ....... . . .. .......... , . . . . .. ......... . . . 0.144 Phosphorus . . ............. . .. . ......... ... ..... . ....... . .. 0.412 Sulphur. ..... ..... .. ...... ... ............ . , . . .............. 0.000 0. 337 0.124 0.393 0.000 The character of the ore, as ready for shipment, differs from that in the beds only in concentration. THE ANALYSIS OF THE ORES. FROM THE DB:ATON (COUPER) MINES. I. Metallic iron.. . . . . . . . . . . . . . . . . . ... , ... . 48.56 Silica . . . . . . . ... , . , . . . . .. ..... . . ... . 14 .25 Phosphorus . . . . . . . . . . . , . , .. , .. . .. .. . . 0 .363 S~1lp~ur . ... . .. . , , .. ... , . ........ , . . .. . Trace. T1tamum .. .. ........................ . 0.011 vVater .... . .... . .... .. .. . . .... . ...... 1.30 Lime ... ... . . . .. . ..... . ..... . . ... .. . ..... . Alumina . . ... ... ... ... ...... . . . . . . .. II. 49.32 11.04 0 .335 . 2 . 53 0.73 III. 49.80 12 .03 0.287 Trace. 9.0-! One individual analysis gave iron only 33.12 per cent., and others showed the phosphorus below 0.3 per cent. MODE OF WORKING THE ORE BANK~. Until comparative~y recently, the ore was simply dug out of th e banks and screened, thereby losing a large portion of the best ore. The product was thus concentrated to nearly 50 per cent. of metallic iron. In some cases, the ore was roasted before use, whereby further impurities, as adhering clay, were removed. Washing of the ore is not adopted in the small er workings, but this method is much more costly than where the pay dirt is washed, not only on account of greater cost of labor, but also because of th e smaller product. Under such conditions the richer deposits can only be worked. Now a great change has been brought about by the use of screw washers, whereby ferruginous earth with only a small BROWN IRON ORES. 17 f). per cent. of iron concretions cau be concentrated and sent cheaply into the market, with composition as given above. In a few cases,. the cost is further reduced by the use of steam shovels. Under the former system it frequently costs a dollar a ton for raising the ore_ At the Deaton mine, the ore can be put on the cars at less than fifty cents a ton. The plant for washing costs $2,500 and upwards. But in the larger pits this has now become necessaty. Still, even during the summer of 1891, many small pits were being worked, and the ore transported by wagons, three miles or more, to the railways. THE ORE PRODUCT. In 1890, the brown ores derived from the Knox series amounted to about 200,000 tons, shipped outside of the State. Besides this quantity, about 60,000 tons were consumed in furnaces in the districts. vVhilst railway facilities are close at hand for the shipment from. many districts, yet there are many others too distant to be, as yet, in the market. OCHRE WORKS. Recently ochre works have been established at Rockmart for the manufacture of paint from the ferruginous clays in that district. At Cartersville, an establishment has been in operation for someyears. The ocherous clay is not then obtained from the Knox series,. but from decayed, metamorphic rocks south of the town. Hencefurther notice will be postponed for a future report. 176 ECONOMIC RESOURCES. CHAPTER XXIV. RED IRON OR "FOSSIL" ORE . CONTENT.~. HEMA'l'l'l' E "FossiL" ORE. liioDES OF OccuRRENCE. HEMATITE. Hematite has a hardness of 5.5 to G..J; specific gravity 4.5 to 5.3. "\Vhen crystalline, the luster is metallic, but it also occurs in an "earthy form. The color of the earthy form is red, with a cherry red or reddish brown streak. When crystalline, the color is steel grey or iron black. The fos,il ore belongs to the red variety, although it often contains small concretionary particles, having a steel grey or iron black luster. Hematite is the sesquioxide of iron, and, when pure, contains 70 per cent. of metallic iron and .30 per cent. of oxygen. Hematite, especially the earthy -varieties, arises from the dehydration of limonite, which itself may be formed from the decomposition of the carbonate or sulphide of Iron. THE FOSSIL ORE. Fossil ore is essentially hematite-of the earthy variety, and is a mineral of secondary origin; in short, it is a limestone converted into iron ore, and contains the impurities of the original limestone. Above the drainage level, the calcareous matter has been completely removed, leaving the ore in a concentrated state, but containing more or less sand and clay as impurities. Below the drainage level the calcareous matter still remains, to a greater or less extent; FOSSIL ORES. 177 or, in other words, the ore bed is a ferrnginou'J limestone, containing from 10 to 25 or 30 per cent. of iron. The structure of the ore is essentially that of a mass of broken shells intermingled with small flattened nodules. This form is best seen in the ore above the drainage levels, from which the calcareous matter has been removed. The ore at greater depths approaches a massive, granular structure. This more compact mineral is known as "hard ore," whilst that above the drainage level, which is richer in iton, is designated the" soft ore." Owing to the concentration of the iron by the removal of the calcareous matter, the soft ore may contain iron to the extent of .50 per cent. or more. The change from the soft ore to the hard ore is sometimes gradual, but at other times sudden, with thP. lower portion of the same outcrop much harder and more compact than the upper bed. The source of the ore appears to be the ferruginous shales, in which the ferruginous limestones are interbedded, and which have been, in part, converted into ore beds, owing to the percolation of rain waters, and the deposition of the iron into the ;)ssil beds, and the simultar1eous removal of an equivalent amount of calcareous matter. The exact process, however, i-; not known; but from the structure and preservation of the forms of the shells it is manifest that the greater part of the ferrugination took place subsequent to the formation of the limestones. :VIODES OF OCCURRENCE . The fossil ore beds in Georgia are entirely confined to the Red Mountain series, which is part of the Silurian system. This ore bearing horizon is commonly correlated with the Clinton beds of New York, although the typical subdivisions are not sharply defined in the southern Appalachian region. The thickness of this formation in Georgia, as noted elsewhere, reaches 1,100 feet. Whilst a portion of the formation, especially the eastern outcrops, contains massive saiHlstones, yet in the richer portion of the series (10) 178 ECONO.MIC RESOURCES. almost the entire succession of beds is made up of shales with occasional :-;andy flags; indeed, the fossil ore bed has often the form of ferruginous flagstones. The ore beds vary in thickness from 10 inches (or sometimes less) to as much as 7 feet, although thicker, in places in Alabama. The common thickness, however, is from 20 to 36 inches. It is sometimes in one solid bed, or divided into two or more layers, and, occafoiionally the layers are separated by laminations of shales; thus considerable variation is produced, although the continuity of the beds is remarkably constant. The ore appears to occur somewhat abo\'e the medial horizon of the Red Mountain serif.s, and in a hotizon higher and newer than the heavy sandstones, such as are found in Taylor's ridge and eastward. vVhilst the Red mountain beds commonly lie at angles of 20 or 30 or less, yet the formation is folded and distorted to a very great degree, so that the beds sometimes clip at as mucl,1 as 80. Thit-~ folding, or undulation, sometimes gives rise to a superficial appearance of a duplicate set of beds, as shown in figure 24. At this point FIGGRE 24.-At Wessboro mines. Folding and faulting (F) ofbecls. Ore bed (0). not merely are the undulations seen, but also r:;harp faults. vVhilst the Reel Mountain ridges rise up to form bold mountainr; in Taylor's ridge and eastward,-owing to the protective cappings of sandstone rock, yet the Red Mountain ridges which skirt Pigeon and Lookout mountains contain no hea\')' beds of sandstone, and thus the features are not so strongly marked across the country; but in many places, these foothills, composed of the ore formation, have been protected by interrupted cappings of F~rtJPayne chert, which FOSSIL ORES. 179 ba ve preserved the ridges and left a serrated chain of hills, rising two to three hundred feet above the valleys, as shown in plate IX. Upon these ridges, where not obscured by the chert, loose rectangular blocks of the fossil ore often mark the occurrence of neigh boring bedl:l of iron ores. However, the iron ore is commonly obscmed by the covering of disintegrated red shales. 'Vhere the capping of chert is iuterrupted, the ridges are iutersected by tramoverse depressions, which sometimes cut the ore beds in two, and expose their outcrops in the gullies, thus causing the continuity of the ore to be interrupted at the surface. At greater depths, however, these interruptions probably are of rare occurrence; and the or.e extends downward forming sheets beneath the drainage level. Above the drainage level the shales are e\erywhere decayed, thus leaving the roof.<; of the mines in weak condition, although they become stronger the farther they recede from the surface, but below the drainage level, adjacent to the harder ores, the rocks become com pact. In many localities the ore has a preservative effect upon the hills, and is found near the surface, and more or less parallel with the hillslope. In such cases, the overlying shales are quarried oft~ without any attempt at mining, and the limit of such removal does not usually exceed 15 feet; but the ore is often taken out from beneath the shales by mining processes, as shown in plate IX. 'Vhilst the ore beds, in some places, arc situated in the upper part of the Red Mountain series, yet the horizon is not fixed but somewhat variable. In many cases, there is only one bed; yet, in others this is lwoken up into two or more layers with shaly partings. vVhen these shaly layers are thin, they do not prevent the mining of the ore; but in places, they become thick and then the amount of ore in the indiddnal beds is insufficient to pay for the .removal of the intervening rock. In some cases, the ore becomes shaly or sandy, and is too poor for working. In the Red Mount~in series, the shales above the drainage level are mostly red, although greenish or bluish where not weathered. 180 ECONO.MIC RESOURCES. Also there are occasional layers of limestone, which have escaped ferrugination. Some of the shales become very sandy flagstones, and contain a large percentage of iron, but not sufficient for economic purposes. Indeed, the amount of iron in the worka- ble beds is only a small percentage of the metal in the Red Moun- tain series. Below the drainage level, besides the ore beds, there are other layers of limestone, which have not been ferruginated. Sometimes the soft ore, near the surfaces, graduates into hard ore, below which again it becomes soft, owing to the admission of percolating waters, due to fracture and local faulting. The hard ore, below the drainage level has also a greater thi:ckness than the soft ore at the surface. FOSSIL ORES. 181 CHAPTER XXV. LOCAL DISTRIBUTION OF FOSSIL ORE. CO;:i!TENTS. DIR'l' SELLER 1\-IOUNTAIN, SHINBONE RIDGE. LooKOUT MouNTAIN. TAYLOR'S AND DICK'S RIDGE, DIRT SELLER MOUNTAIN. This is a synclinal plateau entering the county from Afabama. Its surface is somewhat undulating, owing to unequal atmospheric erosion. This table-land rises 600 feet above the valley or 1,400 to 1,500 feet above the sea. This is the only table-land built out of the Red Mountain series, which usually gives rise to narrow steel) ridges. The strata lie at low angles and the fossil ore layer commonly occurs near the top of the series, still remaining covered with only a few feet of shales. where seen, it is composed of the rich "soft ore" variety. The ore bed is covered with disintegrated shale, which has been removed in workings, for the extractioJJ of the ore. Mining operations have not .been carried far underground. To the northern end of the mountain a branch railway has been constructed from Lyerly. SHINBONE RIDGE. Skirting Pigeon aud Lookout table-lands, as well as the eastern side of Sand mountain, the serrated ridges of the Red Mountain series noted elsewhere form prominent features, as shown in plate V., page 48. These narrow ridges rise from 100 to 300 feet above the valley. 182 ECON0111IC REtlOU.RCES. In some localities, the preservation of the ridges is due to the ore beds, but the higher points usually owe their preservation to the remains of the Fort Payne chert series. Entering the State from Alabama, the first mines occur at Menlo, where the ore bed is divided into layers of nearly eqnal thickness, the whole varying from two to three feet. The upper layers are composed of soft ore. The strata dip at 20 N. 50 vV. and the m~e lies near the surface of the ridge upon its western side. Between this ridge and Pigeon mountain, there is a narrow valley. A short distance from the exposures noted, where the strata clip, at comparatively low angles, the ore beds are found dipping at 75; and at one point the local synclinal was noted. The red ore continues northward throughout Shinbone ridge, and dips under the mountain to the west. These ore bearing ridges are, however, interrupted by occasional ravines. At Btonco, the hard ore is being worked by a shaft over 200 feet deep. Adjacent to the foot of the shaft, the strata dip 80 N. 80 W. .At this locality, the disturbance'> are great. On the eastern edge of the ridge, the dip is eastward; thence the strata pass into an overthrow at the mines, ~nd afterwards Hatten out beneath the plateau of Lookout mountain to the west. As this mine goes below the drainage level, the soft ore gmduates into the hard variety. The former averages about 55 per cent. of metallic iron, whilst the hard ore contains from -o per cent. downwards (see Composition of the Ores). The ore bed varies from three to three and a half feet, and lies in variable positions, owing to the physical disturbances. At a depth in the mine, several beds of nnferruginated limestone occur. Although these are compact, yet they are more or less impure, and their weathered remains at the surface produce some of the red flaggy layers, which are of common occurrence at some horiz,Jns in the shale. The best exposed section of the Red Monntain shales is seen along the railway cut at Dug Gap, which crosses the end of Pigeon FOSSIL OREB. 183 mountain. It is shown along horizontal exposures, where the average dip is 8 eastward. Feet Red laminated shales. -- --- --------------------- 510 Brown shales ___ _ -------------- 180 Shales with numerous layers of flaggy sands!one, including some bands rich in iron, at a point 1,170 feet from the western end of section ______ - - ------- ... _ .. _______ 600 Reddish laminated shales . ------ _ -- - -- __1,140 Shales with hard flag-stones.- --------------------- 180 Laminated shales.. ____ ___ ____ __- . _ . ___- _. - -- __... ----. 270 Shales with thin flag-stones _____ _ _____ .. __ .. ___ 720 Hard red sandstones (14 inches thick) and shale beds with iron ote separated into thin seams __ ___ _ _____ __ _ _ 90 Hard sandstone.'>, shales and flag-stones ___ ______ .___ __ __ 450 Shales and flags with 2 feet of ore s_eparated into layers by thin shales ____ ,_ ____ - ------ - ------- _ 90 Red and brown laminated shales __ ____ .. ------- -- ----- - 480 Ditto, with occasional flag-stones ___ __ . __. _ _____ . _1,280 Hard blue shales passing into red laminated shales, with some flag-;,tones ___ ____________ ---- - -- ---- _ __ _ 960 Devonian shales at western end of tunnel. __ _____ ___ _ The longitudinal section reduced to vertical thickness gives 1,100 feet as the total depth of the Red Mountain series. The ore formation gives rise to ridges about the northern end of Pigeon mountain. Again, it skirts both sides of the anticlinal valley of McLamore's Cove, and is seen on the property of Mr. Dougherty and Mr. Clarkson at the head of the cove, where the exposed ore beds have a thickness of from 6 to 18 inches. The ore beds are commonly more or less covered with shaly soil, and the full extent of the deposits is not known, owing to the few natural exposures. These ore belts continue n'orthward, along the eastern side of Lookout mountain, almost to the Tennes'>ee line. 184 ECONOllliC RESOURCEf-l. Along the Chickamauga and Round mountain railway, there is a longitudinal.section across the series, having a length of about half a mile. In this section, there are fewer flaggy beds than at Dug Gap, just described. At this locality the shales are more massive and less laminated than to the eastward; The strata dip at 20 N. 70 \V. with some local disturbances. A short distance south of the railway just mentioned, the W essboro mines are in operation. The position of the ore beds is similar to that just mentioned, but with local disturbances produced ft'om faults and changes of dip, vatying from 20 to 70, as shown in figure 24. Here the soft ore, in the hillsides, has a thickness of 2 feet. The covering of the ore is removed until the limits of profitable working is reached, beyond which the shales are undercut for short distances, as shown in plate IX. But deep mining ia not continued far into the hillsides. East of High Cliff Postoffice, there is a separate basin of the fossil ore series, bounding an anticlinal valley. The ore where seen occurs in red shale, and has a thickness of only from 6 to 10 inches, but there may be other localities where it is thicker. IN LOOKOUT VAI,LEY. The Reel Mountain series forms a chain of serrated hills (see plate V., page 48) skirting both sides of Lookout anticlinal Yalley, that is, both dip from the valley and pass under the two mountains on either side. Near the Alabama-Georgia line, as also near the Tennessee State line, the beds unite and cover the lower anticlinal formation. Throughout the series in Lookout ,alley, the ore is generally met with, although interrupted by ravines crossing the ridges. In many places the soft surface ore has been extracted to as great a depth as would be permitted by the system of removing superincumbent earth. (See plate IX.) PLATE IX. FOSSIL ORES. 185 Underground muung has not been resorted to except at Rising Fawn. On the ridges about the furnace, most of the superficial soft ore has been exhausted, but the hard ore passes down at low angles beneath Lookout mountain. The total thickness of the hard ore beds reaches 7 feet. Only in one locality, on Pudding ridge, north of Rising Fawn, is the surface ore as thick as 7 feet ; even here the principal layer is only 3 feet, with the remaining 4 feet interbedded amongst shaly seams. Throughout the ridge the soft ore is generally from 20 inches to 3 feet in thickness. In a boring at Rising Fawn, Mr. Eleven found the hard ore 7 feet thick at a depth of 80 feet. Throughout the whole valley there are many workings in the foot ridges beneath the table-lands. The soft ore east of New England City has a thickness of about 2 feet, and is largely used for the manufacture of rE>d ochre. TAYLOR'S AND DICK'S RIDGES. Near the Alabama line a limited amount of ore is seeu in the easteru side of Kincade or Simms' mountain (a part of Taylor's ridge). Some ferruginous sandstones ocrur at Kitchen's gap, east of Holland. At High Point, the ridge has been pt'eserved, owing to the presence of heavy bedded sandstones. On the land of Mr. Sculett, where the rocks dip 60 N. 30 vV., on the eastern ridge of a synclinal fold, fragments of fossil ore are found over the sandstones. At various points to the northward, the ore is also seen. In one place it is said to be 34 inches thick. Nearly east of Summerville Mr. Cleghorn owns an ore bed 'from 16 to 20 inches thick; this is of a good quality. It dips 26 S. 40 E., and is somewhat steeper than the easteru face of the mountain, ftom the summit of which the ore descends in the form of a mantle, thinly covered with shales, which have been removed by washouts in several localities, thus exposing the ore in the ravines. At various points throughout the ridge the ore is exposed. On the Greenbush-Lafayette road, the ore is seen upon the eastern 186 ECONOMIC RESOURCES. siCle of the mountain and in ravines, where it has a thickness of 12 inches. Taylor's ridge and Dick's ridge together form a synclinal basin, with rocks of the latter ridge dipping 80 N. 60 W. at Wood's gap. In Dick's ridge, to the northward on Mr. Hamilton's land, the ore is from 10 to 12 inches thick. At no point north of this place is the ore known to be thicker. Ore blocks also occur on Dick's ridge at G:ordon Spring, and also near Ringgold.' On White Oak mountain, a continuation of Taylor't> ridge, no important ore is seen. On the ridge above vVest Armuchee creek, near Subligna, the ore outcrops on Mr. Simms' land. The ore horizon of Taylor's ridge is above the massive sandstones of the Red Mountain serie:->, and consequently, has suffered from atmospheric degradation, which has been carried so far as to remove t~e valuable ore from Horn's, Rocky Face and John's mountains, the strata of which reach to the horizon of the fossil .ore scnes. FOSSIL ORBS. 187 CHAPTER XXVI. COMPOSITION OJ!' FOSSIL ORE. A:kets in the beds. Scattered through the clay there are extensive accumulatio,ns of black powder, which may be mixtures of various oxides above described. All of them contain some water and often to the extent of several per cent. With all of the manganese ores more or less silica is included, even in the concretionary and stalactitic masses, and in the prepared ore more or less clay adheres to the grains or lumps. Besides these ores there are in Georgia many admixtures of manganese and iron ores which are of value. COMPOSITION OF THI!: ORE~. At the disposal of the survey, analyses from a few localities have been obtained, but they are types of the ores in the Knox series. At the mine of Major J. M. Couper, south of dave Spring, the purer ore yielded the following analysis to Mr. J. Blodget Britton: Metallic manganese _____ __ .. _.. ____ ____ _.: ___. ____ . ___ 53.44 Ferric oxide ___________ -- _______ __ ____ _ ____ _____ 2.83 Baryta __ --- - ----- -- ---- - - - - - - - ---- --- - 8.62 Water ________ __ - - - ---------- -- --- - - - - ------- -- 1.56 Silica ____ __ ____ . . _ -- __ __ _ - - - - - ------- - -- -- - 7.79 Alumina .. -- - - . _ ___ __ ___ _____ ___ - - - 1.52 Lime ____ __ ____ ___ _ - - ---------- --- --- - - -- ____ __ 0.08 Phosphoric acid (Phosphorus, .064.) --- ---- -- - -- - -- - 0.147 Oxygen with manganese, undetermined, etc _______ . ___ __ 24.013 100.00 (13} 194 ECONOMIC RESOURCES. In_this case the potash was not determined. In other samples the amount of watir is larger. For commercial purposes the analyses of car load lots is of more .value than that of picked samples. On December 1st, 1889, a car load of 30,200 pounds, from Major Couper's mine, yielded the following results: Manganese __ _____ ___ __ -- --- ___ - --- -- - - __ _ __ ____ 46.749 Iron __________ .--- --- - - -- ___ __ _ _ 1.746 Si1ica ______ ____ _______ __ --------- - -- __ ___ __ _13.050 Phosphorus _____ ____ _ - --- ____ _____ ---- _ _ 0.059 In October, 1890, shipments from residuary surface ores yielded: I. Manganese ___ _.42.685 Iron __ ___ -- --- 1.729 Silica.. ___ - - _10.000 Phosphorus ______ II. 42.938 5.240 8.009 III. 42.578 1.50 11.95 0.089 IV. 42.307 2.40 10.39 0.072 On Mr. Asbury's property, northeast of Cave Spring, surface ore sent to Carnegie & Co. gave the following result: Manganese Iron .. _ Silica ___ __ Phosphorus _____ . - - - ----- - ___45.189 7.840 --- 7. 62 0.053 The ore from the Barnsley estate at Woodlands gave the follow~ ing analysis to the Pittsburg Testing Company: Manganese_ _____ ____ .... . __ . ___ _.. . ____ __. __ -__ . -43.730 Iron _. __ __-____ . ___ __. ___ __ _. - - _ _ _ . _ _1. 10 Silica ______ ... _ ----- --- ____._:3.5:0 Phosphorus ______ _ __ __ _ __ __ __ - ---- - -- --- - -0.129 Many other analyses of car load shipments to Carnegie & Co. have been seen but the above are representative products of the washed ore. MANGANESE. 195 In all of the ores moisture is included to the extent of from 1 to 8 per cent. The silica varies from 7 per CQut. up to J 6 per cent., which makes the ore less desirable, as it should not contain over 12 per cent. The iron ranges from 2 to 14 per cent. or more. The shipper is paid for the iron, but its low price compared with the manganese reduces the value of the ore. In many deposits the amount of iron is so large that the mineral may be considered as a manganiferous uon ore. The presence of phosphorus has an important bearing on the value of the ore, as its greatest use is in steel manufacture. Good ore should not contain ovet 0.2 per cent. of phosphorus. However, the ores of Georgia manganese are usually as low in this objectionable element as those of Virginia, which yield the largest supply. A large number of shipments of ore from Georgia show only from 0.05 to 0.167 per cent. of phosphorus, and the ores are consequently low in this element. In the working of this ore it is very important to reduce the quantity of silica or chert by sorting and washings. MODES OF OCCURRENCE OF MANGANESE ORES. Manganese ores occur in the Arcbrean rocks of Georgia, as near Mount Airy, in certain semi-metamorphic rocks, whose age has not been settled, eastward of Cartersville, and in the Knox dolomite series of the Lower Paleozoic group. The Cartersville ores have been extensively worked for many years, their product in 1887 being 9,024 tons and in 1888 15,568 tons. Thos~ mines border the zone of the 1present survey, but in this chapter they will not be discussed further than the statement that they are associated with certain metamorphic sandstones and shales, and are often of a more highly crystalline character than those belonging to the Knox zone. Manganese occurs in mountain folds all the way from Nova Scotia and New Brunswick, along the Appalachian ''ally from Vermont to Alabama, and in a like district of Arkansas. This 196 ECONOMIC RESOURCES. metal is not confined to one Paleozoic horizon but occurs in Cambrian rocks of Virgini~, the Knox or Calciferous series of Georgia, beneath the Upper Silurian of Arkansas*, whilst on the Bay of Fundy the ore is found in Lower Carboniferous rocks. Throughout the Appalachian regions the manganese deposits occur in formations skirting the northwestern side of the crystalline rocks, which, in Georgia, are seldom more than 25 miles distant. The manganese deposits of Polk, Floyd and Whitfield, and border of Catoosa, counties have not been correlated with those extending from Tennessee to Virginia, aJild occupy, in part, a different horizon. WhilAt in those States, the ores occur near the contact of quartzites, of various ages, and succeeding shales and limestones, sometimes being in one or another of these beds*, the manganese of the belt from Polk to Whitfield counties occurs in beds of residual clays and cherts, belonging to the Knox dolomite series, and more particularly on the ridges of the western portion of the zone. The occurrence of manganiferous clays is common in the mountain states. But in this western manganese belt of Georgia, the clays and cherts have been entirely derived from the earthy and impure Knox dolomites, deecribed in the local geology of Bartow county, in the first part of this report. There, the limestones are shown to be in part earthy and in part highly chP.rty. These are eas-ily disintegrated by leac~ing of the calcareous matter, leaving more or less confused sheets of clay in some places, whilst in others there are cherty accumulations, or these only partially depleted of the calcareous matter. The clay deposits have been the most easily eroded, and hence form valleys qont!lining often low ore bearing hills. The more cherty beds afford protection against erosion, and hence are most commonly seen on the ridges, although *See the excellent Report of Dr. R. A. F. Penrose, on the Manganese ores of Arkansas. Geological Survey of Arkansas, 1887. MANGANESE. 197 sometimes the top of such ridges are covered with a mantle of red clay, with little or no chert. The ore was originally bedded in the clayey or cherty dolomitic sand, perhaps as the carbonate, but more likely as a hydrous oxide, in position simqar to its modern occurrence, in the clay. It probably now differs from the original form of deposits by such ~haoges as are ineident to the beds which have been disturbed upon the removal of the calcareous matter. Whilst the depth of decay of the rock is known to exceed 210 feet, in places. The exploration for manganese has not been carried to the solid rock, except where occasional protrusions of semi-undecayecl rock approach the surface, -in which the ore is sometimes seen; yet occasionally masses of rock have escaped decay and are embedded in the decomposed rock or clay, thus sometimes causing the structure to be deceptive. The manganese is found in the form of grains, nodules, pockets or lenticular sheets, conforming more or less to the bedding. These lenticular beds and pockets are of various sizes and forms, and may be very much disconnected, or occasionally united with stringers. FIGURE 25.-Decay of Knox dolomites; L, the lower calcareous beds, weathering to siliceous loams; C, cherty dolomite, weathering to sandy soil with cherty gravel and loose blocks on the soil; M, pockets of mnnganese or iron in the decayed remains of limestone; S, surface red soil with fine concretious ore. The relation of the lenticular beds to the undecayed rock is indicated on the late Bank's property of Major Couper. On the side of a ridge, on the Couper property, the cherty beds (c) are seen at several horizons, dipping at about 20 southeastward. 198 E CONOMI C RESOURCES. Between the somewhat disturbed beds, there are the residual clays derived from the limestones (L), and in these, manganese pockets (M) are seen (as shown in figure 25). On this same hill the upper beds have been most disturbed, and above the manganiferous residual clays the cherty layer is very much broken. Overlying this again is the surface mantle of manganiferous red clay. In this section iron ores oceur in po!>ition above and below the manganiferous beds. The ore in the individual pockets may amount to hundreds of tons. These pockets sometimes contain massive ores, or else are composed of an aggregation of nodules, the whole following the bedding of the original rock, which generally dips southeastward. There are also thin seams of ore or layers of nodules penetrating the clay or rock in various directions, and brown ore is often commingled in the beds. The chert and cherty clays are usually gray, or sometimes brown, or pockets of black clay are colored from presence of finely eli vided ore. The color of the beds varies. It is often deep red or chocolate tinted from the presence of manganese. Again, it may be yellow, brown or black, and beneath the surface often like that of the typical gray cherty land. The depth to which the ore descends is not known, but as the lenticular beds sometimes dip 20, or more, the pockets of the ore may be eventually reached in solid rock, which, however, will be generally found only below the drainage level, as the rock decay is very deep. Closely related to the manganese beds, brown ore is often found, even almost in contact with the manganese, as at Tunnel Hill. These iron ore beds, however, are of great extent and more constant than the manganese deposits, but the higher price of the manganese permits of the working of the less concentrated mineral. The chocolate-colored surface clays result from disintegration of the rocks which may be free from any large cherty particles. Such MANGANESE. conditions occur on the summit of many ridges, whilst the low~r porti01;s often show, in places,. more or less partly undecomposed and often cherty rock. Through the surface residual clays the ore is scattered in small particles, nodules, or even large masses of a ton in weight. It is possible that a portion of these grains and concretionary masses are not simply residual from the decomposed rock, but are of secondary chemical or molecular origin; owing to segregation in the porous residuary earths, and thus concentrated since the decay of the rock, especially in the red surface clays. 200 ' E GONmU C RESOURCES. CHAPTER XXIX. LOUAL DISTRIBUTION OF MANGANESE OREI:! IN THE KNOX SERIES. CONTENTS. UAVE SPRlNG DIS'l'.RIC'l'. WOODLANDS 0~ BARN8LEY DISTRICT. TUNNEL HILL DISTRICT. WORKINGS O.F MANGANESE DEPOSITS. There are three principal distl'icts of manganese occurrence in the Kno'x dolomites of northwestern Georgia: These are on ridges extending from south of Cave Spring northward to near the Etowah river; a belt near the border of Bartow and Floyd counties, north of the Etowah river, in the region of Woodlands (Ba~nsley estate) and the Tunnel Hill district, on the border of Whitfield and Catoosa ronnties. These districts are of broad extent, and include the distribution of the belts occupied by parallel ridges. CAVE SPRING Dl:OTRICT. Manganese ores occur along with the iron at many localities, but the most important deposits are on a belt commencing in Polk county and extending eight or ten miles northeastward, with occasional scatte:J:ed deposits to near the Etowah river. The largest deposits which have been exploited are those of the Georgia Manganese and Mining Company, commencing in Polk county about two miles south of Cave Spring, and extendi~g two and a half miles northeastward. The best deposits are on lots 1140, 1162, 1163 and 1141 (Bartow), 3d district (Polk county); 1009 (Ware) 1233, 1216, 1217, 1160, 1161 (Dougherty) and also on lots 947, 998 (Hancock), 1146 and 1142 (Floyd county). MANGANESE. 201 The principal works are on a bill 195 feet above the valley of Cedar creek. The summit is covered with a red or chocolate or brown clay, varying from 2 to 15 feet in thickness, and containing manganese gravel. The ore of the surface clay is mostly in small grains and nodules, although masses of a ton in weight have been met with. Through the clay there is also much coarse manganese powder, which is not of value at the present time. It is probable that this clayey surface of the ridge was formerly more extensive, but bas been washed from the sides of the hill. Beneath the clay covering the deposit is brecciated cherty clay and the disturbed remains of the decayed manganiferous cherty limestone. (See figure 25, page 197.) Through this clay some layers appear to be entirely free from man"ganese. But other seams contain lenticular masses or pockets of manganese ores; and the general position is probably that of the original beds of dolomite, dipping at about 20 southeastward. A shaft has been sunk to a depth 50 feet and has penetrated large masses of ore. Stringers of manganese extend irregularly through the ore-bearing lands. While much of chert is broken up and cemented into brecciated conglomerate, masses of partially undecomposed cherty rock occur in the clays. As far as the shaft has been sunk there is no appearance of the original solid rock. Near by, on the sides of the hills, the partially solid strata appear with the beds, dipping, in some cases, as low as 10, nearly eastward. Layers of manganese ore are seen, especially in the clays of the decomposed limestone, above and below some of these beds. Much of the ore is concentrated by the remo~al of calcareous matter, although part of the manganese has also been lost. Some of the manganese concretions in the clay may have been segregated from the mineral dissolved out of the original rock, and thus a portion of the "shot-ore" pellets and concretionary nodules may be arcounted for, especially in the Emface clays. (See figure 25, page 197.) 202 ECONOMIC RESOURCES. At other openings, the ore is seen in more cherty decayed rocks than that just described. Between the conditions of the surface, red clays and the ore in the cherty residual clays, there is every variety of conditions of occurrences. The ore beds, just described, have associated with them two extensive deposits of bro,vn ore. This commonly close association of iron and manganese ore has already been refened to. Northeast of the Georgia Manganese and Mining Company (Major J. M. Couper, President) property, the surface ore is shown on the lands of Mr. Asbury (lot 922), Mr. Simmons, and others. On Mr. Asbury's, the lower part of the hill is cherty, and the manganese accumulations are scattered over the red or chocolate colored clay. Again, to the northeastward, the manganese occurs on ridges of red laud belonging to Mr. W. I. Taylor (lot 840, 3d district), and on other adjacent hanks. On a ridge to the eastward of the last deposit are the Rice or Hatchet manganese beds (lot 822, 3d district), near New Prospect church (lot 822). Mt. Harper, of Rome, and others own portions of this ridge. The summit of the ridge is of red clay, but the lower portion is of gray cherty formation, with masses of the rock of the same structme as the other deposits seen in the Cave Spring district. Brown iron ore also occurs on this ridge. The localities given arc only a few of the known deposito; in the district, hut they locate the belt, and are typical. There are many places, whete explorations have been made, pits sunk, and more or less ore takeJJ. out. The ores in this belt are not confined to one series of ridges but occur on several parallel hills, and extend on the Polk-Floyd county line, from Major Couper's mine to near the C. R. &C. Railway, as seen on the lands of Mr. Stokes__:__the belt of country having a breadth of several miles. Longitudinally, the deposits are interrupted, not only on account MANGANESE. 203 of the topographic features, but on account of the nature of the deposits being large in some portions of the beds, and almost inexplicably nisappearing in others. The geological conditions for the occurrence of the manganese ores continue from northern Polk county to the Etowah river, although narrowing somewhat in breadth in passing northward; laterally, the belt extends ftom Van's valley, to near Spring creek. Manganese and manganiferous iron ores also occur in the narrow Knox basin west of Cave Spring, already referred to in connection with iron ores. The manganese is on Mr. Simmons' and other properties. These deposits are about two miles west of "Hematite Siding" on the East Tennessee, Virginia and Georgia Railway. The basin is narrow and only a few miles in length, and totally disconnected from the Cave Spring district by Cambrian shales. THE WOODLANDS OR BARNSLEY DISTRICT. On the low ridges adjacent to the valley of Tom's creek, manganese is found in deep red or chocolate colored loam, like that on the top of Couper's hills, near Cave Spring. In places there is scatteted chet't upon the surface of the ground. The occurrence is similar to that near Cave Spring. One pit, 20 feet deep, was opened, and fifty tons taken out of it. In part, the deposit resembles a breccia, with manganese oxides for the cement. In this locality, there are a large number of deposits exposed on the surface, but not opened (see land lots 95, 63 and 84 and lot 36 of Mr. Morrow, and lot 97 of Mr. Conway). Brown iron ore occurs in proximity to all of these deposits, and so does beauxite. The ores of the belt continue in ridgE's to near Nannie, where large surface accumulations of manganiferous nodules were seen on the land of Mr. Price. TUNNEL HILL DISTRICT. A narrow belt, mostly a chain of ridges, extends from a point west of Tunnel Hill, east of northward, into Tennessee. This chain of ridges is of variable elevations, sometimes rising over 100 204 ECONOMIC REf:>OURCES. feet. n is prim:uil a chujn of gray h ty lant) , al bough man y p int show but littl ' ch .L"t upon h urfac , where t hat is of r ed so il. 'Ibe or in the anr facle pits is mostly iu t h red re inual clay, which baJ:J a variable depth. pon this belt, at about t nree mil from T tmnel J-lill, h at a Minincr ompuoy have made some exteru ive op nin t\ud diffi.r nt shafts-on said to b 21 fi et iu t h r idnal decayed cLel"ty c1ay1l. Mangane. e, often lo: ] re ern:blin.,. that l; 'of ar- t ... ville (m()re or l :s crystallin e) is l'i en ou th stufa .e about the e mines, which wer I. , ua t th ti.me of my vi it. At seve1a.l pit up n th sndace brown iron m e 1 al so xpo. ed . 'l'b two miuernl in one place, come i nt lo e Flation hip. Part of t be iron is a fhr -mtmgau ' or" Th d p ore in t h e g1ay ar th wn ttot een, wing to the shaft being lol'ied. Manganese ore was seen to limited extent upon the ridges of Knox dolomite southwest of Tunnel Hill and at other points, but the quantities were not large. THE WORKINGS OF MANGANESE DEPOSITS. Hitherto the manganese bearing surface clays have heen screened, as in case of brown ores, and several pockets have yielded a few hundred tons. Pits ha ve not often b - n nnk mot thun b nty r tbil'ty fc t. The 1 L eri u attempt at prop rly worlcing tho l 'O ' in thi belt wa 'r'l Jnruen ] b ' M aj . J. (. ouper, ~\t tl1 mines uear ave Spting. H ere an improved p.laut wu cou t.Ju ted w:itb two ' rn i. b r .II. , d tlbl log wa her screen , fiv e- g i.ggers, tc. The water for wnsbiu" is brought fr m edat ree k, a nl.iJ e a..;vay. It .is only by meau f Lbe improved m Lh d10 f wn. hiuu t ha the sepal'utiug f t he sil iceo m1 matt l' fl'Om the ore can b Hati factorily aoa rnplished. At Tunnel Hill a still more extensive plant has been constructed, but it has not been in operation up to the present date. MANGANESE AND IRON. 205 CHAPTER XXX. ORIGIN OF MANGANESE AND IRON DEPOSITS. The position and general relationship of the various belts of manganese ore have been described. But if their origin were better understood, this greater knowledge of the necessary condition~ of depoeition would be of service in determining the variations in the modes of occurrenoe and distribution of the ores. The rocks of the Paleozoic belt of northwest Georgia were formed from the degradations of those of the crystalline or metamorphic zone to the eastward. From the enormous decay of those rocks, the manganese, as well as the iron, was obtained. Many of the crystalline rocks contain much iron; and where iron occurs, smaller proportions of manganese usually are found. Along streams and springs one often sees deposits of yellow or red oxide of iron, and sometimes stains of black (from manganese). Th'lse encrusting deposits have been derived by chemical solution from old(j.r minerals and have subsequently been redeposited. Such transportation, ac0umulation and deposition can be seen going on to-day. Among the commonest crystalline rocks in Georgia are hornblendic, or syenite gneiss, and granite, garnet rocks, etc. Manganese is associated with the iron of the hornblende, garnet, pyroxene or other rocks. Thus in the decay of these silicates, iron, manganese and aluminous compounds are liberated. Some other materials, suclt as rhodonite or silicate of manganese, hold the metal in a more concentrated state in pockets in crystalline rock. But the great supply comes from the concentration of the metals from the common rocks, containing only small a proportion of iron and manganese. 206 ECONOMIC RESO~RCES. The decay of the crystalline rocks has been in progrees for au enormous length of time, but a great portion of the disintegrated material is washed off into the streams and carried into the sea to build up new lands.. The crystalline rocks at Atlanta are decayed so far that they may be considered completely rotten to a depth of 95 feet. However, incipient decay may reach as much as 300 feet In the disintegration much of the iron, manganeee, and some alumina have been leached out of these rocks and deposited elsewhere. The agents of rock decay are carbonic and various vegetable acids acting mainly on and near the surface of the rock; also sulphuric acid, arising from the decay of pyrites in the rock. These acids, in the presence of reducing agents, haYe the power of dissolving out the iron oxide and manganese, along with the magnesia, potash, soda, etc. bf the rock. The removal of these compounds leaves the rocks porous and favors the erosion by rains and rills The carbonates of iron and of manganese are carried off by the streams and are sooner or later deposited as the oxide or sometimes as the carbonate; the carbonate of manganese, appearing somewhat more stable than that of iron, is apt to be carried farther than the iron, or at least more or less separated from it; for the carbonic acid upon exposure escapes and the mineral becomes oxidized, as seen in the coatings of the red or the black films of these metals upon pebbles, rocks, etc. The iron may be taken up and afterwards deposited as the sulphide, but this does not appear to be the case with the manganese. Such being the primitive somce of the brown iron anu the manganese ores, their deposition would be expected along the streams nnd in basins lying not distant from the zone of rock, which gave origin to the metallic accumulations. Thus the manganese belt is situated upon the northwestern flank of the crystalline or metamorphic formations. MANGANESE AND IRON. 207 The Paleozoic rocks which contain the manganese and iron were derived from the same sources as the metah; (the calcareous matter being indirectly secreted from sea water through the agency of marine organisms); and amongst these accumulations the ores as well as clays and beauxite were deposited. The~;e ores are most abundantly founi in the limestones, and to a less extent in the shales, but east of the belt of exploration they occur in the sandstones and slates. As has already been seen the ores follow tht trend of the ridges, being in zones whose general course is a little east of north. Also it has been shown that the deposits are not continuous throughout th& zones. It has been further pointed out that the richer deposits are on chains of hummocks trending westward. Any one familiar with the various coast lim~;,; is aware of the common occurrence of low islands, numerous channels and lago~ms, such as are found along our own shores. The manganese, being converted into the solu b'le carbonate by superficial waters, at its original highland source, was borne by the ~:>treams which were eventually retarded upon entering the dismembered water basins along the coast. Adjacent to the streams, and in the quiet waters of the lagoons or the estuaries, the conditions are favorable for the conversion of the soluable carbonates of manganese into oxides. Under these conditions, the metals borne down by many streams, in both solution and to a small extent in a finely divided mechanical condition, would haYe been deposited in. separated basins, all of whic.h we.re, however, in a general trend, parallel with the direction of the coast line. Thus the interrupted character of the ore beds can be accounted for. The metals are generally disseminated to a small extent amongst all the rocks, but they are concentrated only in limited areas. The same streams brought down more or leso clays and sands as mechanical se.dirnent. These were deposited along with the metals and greatly in excess of them. (See Origin of Beanxite.) 208 ECONOMIC RESOURCES. As the ores under consideration occur in limestone deposits, it is probable that the lagoons may have been similar to those amongst aoral reefs; even the intercalated siliceous beds are poorer in the metals than the more calcareous layers. The ores of the clay and sandstone regions may have originated in local basins similar to those on our own coast, interrupted by sand bars ~nd islands. Other sources may have given rise to a small quantity of the ores, but those of Georgia have originated entirely from the decay of crystalline rocks brought from the older Archrean lands into the basins in which the Knox dolomite was being accumulated. In some cases the ores were originally segregated into large pockets. But the secondary decay of the Knox rocks in removing calcareous matter, bas further concentrated the metals into a smaller volume of rock. Especially upon the surface, this is noticeable, for.here the clays and sands have been to some extent washed away, which has scarcely been the case within the mass of the rock. Furthermore, the ores Hpon the surface in the residual clays may not b.e entirely in place, hut have been partly concentrated by washes from other portioll'l3 of the higher hills, now reduced far below the level of the protecting gravel ore, on account of the erosion of the land surfaces. In this connection it is again suggested that the concretionary and stalactitic nodules may have been originated in part by a secondary solution of the finer particles of ore ~nd been redeposited in more concentrated forms in the surface clays; So, also, in the crevices of the lower clays, and in the spaces amongst the brecciated rock, the ore sooms and cementing ore were concentrated by the filtering waters, from the man~nese poorly scattered through the rock mass. In all cases the ore is largely associated with siliceous materials, part of which came from the lands, but part from those secretions along with limestones which produced the chert, and this MANGANESE. 209 excess of silica is that which must be rejected in the use of man- ganPse compounds. If the workingsJ:of the manganese beds b~ carried down below the drainage levels and decay&of th(rock, the larger pockets of ore will probably be similar to those seen in the clay, and the partially decayed cherty rock, but in a more compact form. However, the ore in smaller pockets and nodules will likely be found less c~ncen trated and more sparsely disseminated as the great volume of calcareous matter of the rock has not been removed by solution. (14) 210 ECONOMIC RF;SOURCES. CHAPTER XXXI. ALUMINIUM ORES. CONTENTS. NoTE oN ALrM AND ALuMINIUM. SouRCES oF ALUMINIU~r-Betmxit e : Cryolite, Kaolin, Clay HALLOYSITE AND GIBBSITE. NOTE ON ALUM AND ALl'MINIUM. Aluminium compounds ate much sought for in the manufacture of alum, etc., which is used in great q nantities as a mordant for setting the colors of dyes, ann still more largely for sizing in the manufacture of paper, these two requirements consuming an enormous tonnage of the different ores. To these demands others have been added in the production of aluminium. The uses of this metal are now growing very rapidly, .owing to the reduction of its price. Its earlier uses were restricted on account of its high price. Until 1884 all of the metal used was imported. That yeat the importation amounted to 590 pounds, valued at $8,416. In 1~83 Colonel Frislnnuth, of Philadelphia, ptoduced 63 pounds, and in 1884, 115 pounds. Since then the production has very rapidly increased, so that in 1889 it amounted to 47,468 pounds, valued at $97,335,* and in 1892 the ptoduct was increased to about 350,000 pounds with a further diminution in price to 50 cents a pound, although it has been again advanced in price as the supply is not equal to the demand. It is variously estimated that the cost of production can be reduced to from 18 " Bulletin of Eleventh Census, No. 79. ALUliHNIUM ORES. 211 to 20 cents per pound (Hunt.) The demand for the metal is rapidly increasing on account of its lightness (one-third that of copper) durability, etc. SOURCES Oll' ALUMINil:l\L The primitive sources of aluminium are the crystalline rocks which contain this element. Indeed, next to quartz, it is the largest component of crystalline rocks and shales. Amongst the older formations it is locked up in the fornt of the feldspars and micas, in granite, gneisses and schists. In o~her rocks it occurs in various shales, clays, kaolin, etc. Also several minerals are largely composed of it. Thus corundum (with its finer varieties, sapphire and ruby) is pure alumina; cyanite is a silicate; so are garnet and topaz, but these contain various other elements. The sulphate of aluminium occurs to a limited extent in a natural state. The most important aluminous minerals are cryolite, kaolin (with allies including clay) and beauxite. 01'yolite is the double fluoride of aluminium and sodium. It i8 imported entirely from Greenland to the extent of nine or ten thousand tons a year, at a cost of from $9 to $10 a ton. It contains thirteen per cent. of aluminium or about twenty-four per cent. of alumina, but its value is enhanced by its contained soda. Kaolin and Cla,ys.--Kaolin occurs in clay-like masses, in texture fi'om compact to mealy. Hardness 1-2.5, specific gravity 2.4-2.63. The luster is earthy to sometimes pearly. It is usually unctuous and plaRtic. Pure kaolin is white, soft and clay-like, and made up o microscopic pearly scales. The composition is typically: silica 46.3, alumina 39.8, water 13.9 per cent. It may contain iron, lime, magnesia or potash in small proportions as impurities, which affect its fusibility as the purer mineral is infusible. Kaolin is a decomposition product of the feldspars,.and is liable to contain free quartz, or indeed, some undecomposed feldspar. 212 ECONOMIC RESOURCES. Clays are primarily of the same origin as kaolin, but differ in that they contain more or less fine quartz, and undecomposed feldspar, etc. The composition is extremely variable, from almost pure typical kaolin to even a predominance of free quartz. The kaolin and clays are not considered here in connection with their importance in brick making, pottery, etc., but as association::; of beauxite and iron ores. In the brown iron ore beds, clay ".horses" of great size, and many other beds of white clay are of common occurrence. 'These are sometimes tinted reddish or purple. They also occur of yarious colors, often tinting streaks through the clay. As a type of their composition, the analysis from a clay "horse" in the brown ore deposit at Grady is given in the chapter on clays. The economic valne of these deposits will be considered as a separate subject. In their associations with beauxite care must be taken in the separation of clays as they reduce the value of the mineral shipped. HAJ.LOYSITE AND GIBBSITE. Halloysite is clay-like, massive or earthy. Hardness 1-2, gravity 2.4. The massive varieties may be somewhat pearly with con- choidal fracture, color white or tinted. It absorbs as much as 20 per cent. of its weight of water. It is infusible, but it is decom- posed by acids. The typical mineral contains alumina 37.7, sili1:a 43.3, and water 19.0 per cent. The mineral obtained from the Fort Payne chert, in Dade county, and analyzed by Mr. H. W. Shephard, of Philadelphia, showed a colloid form (favorable for porcelain manufacture) and gave: Alumina __ _. _ _ _ _ _ _ ___ . _. ___ . __ . . . _ 30.76 Ferric oxide.... ------- -- __ _ ________ _ .. . - - - -- 0.36 Silica __ _ ---- -- -- - \Vater __ - - ______ _. _ --------. ___ __ ___ _ 45.15 23.5.5 99.82 ALUMINIUII[ ORES. 213 This mineral occurs in the Fort Payne chert (Sub-Carboniferous). The cherty li1i1estone when weathered leaves kaolin-like clays intermingled with the residual chert. In places these white clays occur in large pockets or irregular beds. Sqme of the deposits form earthy or again porcelain-like, halloysite. Such deposits occur on the property of Mr. Blevin, south of Rising Fawn. Large pockets also occur on property of Mr. Alexander, about .four milea from Subligna, on the eastern side of Taylor's ridge. " 7heu more exposure8 are made, there is no reason why many beds may not be found in the deposits of this formation, which is quite widely distributed. In the manufacture of aluminium or its compounds, this mineral is inferior to beauxite only in containing a larget quantity of silica, and a smaller proportion of alumina than the former mineral. Gibbsite, another mineral composed of hydrous alumina in stalactitic, mammillary and incrusting forms, has been found on the Barnsley estate in connection with beauxite. It has a smooth surface, with internally a faint fibrous structure. H=2.5--3.5, gr. 2.3. In color white, grayish, greenish, a reddish white. It has a clayey odor when breathed upon. In composition it is alumina 65.6, water 34.4 per cent. 214 ECONOMIC REHOURCE8. CHAPTER XXXII. BEAUXITE. CONTENTS. PROPERTIES. ANALYSES. DISTRIBUTION AND COMPOSITION OF GEORGIA ORES. USES OF BEAUXITE. MoDES oF OccuRRENCE. ORIGIN OF BEAUXITE. BEAUXITE IN GEORGIA. PROPERTIES. It is a concretionary pisolitic granular mineral, also earthy and clay-like. The luster of the more compact varieties is often waxy. Hardness from one to about three; specific gravity 2.55. In color it varies from white to gray and deep red, according to amount of iron present. If the iron be regarded as an admixture, the mineral is a hydrate of alumina, with a composition of: alumina, 74.1; water, 25.9 per cent. In this case the composition is near another mineral-diaspore-which is not found in large quantities. But a portion of the alumina is replaced by variable quantities of ferric oxide, and silica is present, probably from admixture with kaolin. Titanic acid is always present in the Georgia mineral, and traces of lime, magnesia and rarer elements also occur. Accordingly, the mineral is of variable composition. Its appearances are deceptive, as often the most perfectly concretionary forms are of lower grade than those less promising. The clay-like varieties have been called Wocheinite. ALU)UNJUM ORES. 215 Sometimes the pisolitic conctetions are deeply co lored with iron, whilst the matlix is of lighter color. Near the urface the mineral Fwun~> :26.-Section of a con cretionary pebble of beaux ite, showi ng pisolitic structure. The pellets vary in size from small g raim to an inch in diam eter -but th e smaller sizes are commonest. is often vesicular, owing to the removal of t he alumina ftom the interior of the cavities, in which siliceo us O\' ferl'llginou s dust alone is often left. Thi removal of aluminous matter redu ce the value of the mineral. The quantity of iron often increase with th e depth of the deposits below the . ul'face; still the iron is no objection, as a vahmble by-product is obtained in the manufacture of alumina. A numbet of analyses of beauxite were made by Prof. H. C. White, Pre ident of the State College. These were chosen as type of different varieties from variou localities in Floyd and Bartow conntie. , and were not taken frorn the deposits, becaus~ t hey were known to be of good quality. ANALYSE3 OF GEORGIA BEA XITE. Sarnple 1. At Flowery Branch (lot 21, 23d district) nea r H ermitage, Floyd >COUnty . 216 ECONOMIC RESOURCES. Variety: 'Vhite porcelanous mass, with subordinate pisolitic grains; associated with white clay beds upon the side of a ridge: . Alumina ___ _____ __________ __ ___ -- ----- -- --- -~ ----46.72 Ferricoxide ____ ___ - --- ------- - ----- -- . 2.1-! Silica _ -- - ----- -- . ----- Water_______ __ Titanic acid ___ ___ _____ _ - - - -- - 29.01 . 20.15 -- - -- - - 0.87 Sam:ple 'lJ. From Mr. Doyle's (lot 906, 3d district) farm about seven miles northeast of Cave Spring, Floyd county. Variety: Large concretionary pellets of whitish color stained with iron oxide. Interior of pellets partially dissolved away, leaYing a semi-vesicular mass somewhat pooret' in alumina than wonld be expected. It occurs in the valley: Alumina ______ _____ . ____ _ ---- _______ - ----- .52.13 Ferric oxide . ___ .. . ______ __. ___ . ___ _. _ _ ____. _ _ 1.12 Silica ___ __ - - - ---- - -------------------- __ --- ___ 19.56 ''Tater. . -------- - --- _______ .. ------ ___ ___ 24..,.:L Titanic acid . . -- ----- -- - --- ----- 2.0R Sample 3. From land of Mr. Culberson, one mile from Cave Spring. Variety: Small pisolitic concretions in mass, grayish white, with some iron stains. It occurs on top of a ridge: Alumina _____ - - -- ____ ___ ___ ----_------_ 39.75 Ferricoxide ___ ______ ___ __ __ __ _ ___ ---- - 1.62 Silica ___ ______ _____ _ ____ ___ _ -- - - ------------ _41.47 'Vater ___ __ . - . ___ _____ __ ____ -- --- -- _ ___ _16.14 Sarnple 4. On a farm of Mr John Henry (lot 910, 3d district) near New Prospect church, six miles northeast of Cave Spring. ALUMINIUM ORES. 217 Variety: Light reddish porous mass, as the interior of the grait1s is largely dissohed away; somewhat earthy. At a depth the min- eral is not likely to be so porous as on top, and consequently richer in alumina. It occnrs on side of a ridge: Alumina_____ __ ------- __________ __ ___ _o6.1 Ferric oxide ______ __ --- ___ __________ __ ___ _10.64 Silica _ __ ___ ----- - ------------------------ -- __ 2.56 Water _____________ -- ---- --- _ ~ ------- _30.10 Sample 5. Near the last named locality. Variety: '"'hitish mass, with occasional pisolites. Taken from side of a narrow gully: Alumina _______________________ _ - 58.61 Ferric oxide_ _ _________ . 2.63 Silica ______ _ -- ---------- ------=- ---- ----- - 8.29 Water_________ _ ----------- -- -- - -- 27.42 Titanic acid - ----------- 3.15 Smnple 6. On land of Montague & Company (late Mr. Connaway, lot 97, district 16), Bartow county, north of Kingston. Variety: Earthy and white with reddish concretions. It is located on side of a ridge: Alumina ____ ---------~--- ---- --- ---------- 43.18 Ferric oxide __________________ _ __ ____ __ _ _______ 8.74 Silica _ ___ -------- ___ . --- - - _ _ ___ 28.11 Water ____ _________ _______ ______ _______ 19.22 Sc;.mple 7. On lot 61, 23d district. Variety: Earthy looking mass of large concretions. Adjacent deposit is of higher grade. The sample was chosen to see whether 218 ECONOMIC RESOURCES. much beauxite were lost in the rejection of the poorer and more clay-like earths. It is a clay mixed with much beauxite: Alumina _____________ ---------- - - - _----- . --.36.86 Ferric oxide - 1.28 Silica . ----- -- - - ---- ------ _______ 40.02 Water __ --- -- - -- - ------ --- .20.64 Sample 8. On land of Mr. A. W. Bobo (lot 534, 3d district), about three miles north of New Prospect church, Floyd county. Variety: Small concretionary boulder, with small pisolitic grains. Stained with iron oxide along fracture lines. It occurs on side of a ridge: Alumina ___ _ - ' ( . 2 Ferricoxide __ ------- ------- ---- -- --------- 2.16 Silica __ ___ _ --- ----- - - _____ _ ____ -------- - _ 6.62 Water . ... . __ . ___ ----- __ ___ __ 31.1 Sample 9. On land of' Mr. Shaw, two miles southwest of Adairsville, Bartow county. Variety: Mixed white and reddish vesicular concretions: Alumina_ -------- ... Ferric oxide_ . ___ __ _. Silica . _ . _ _. __ - _ "rater ___ __-- __ 51.22 - . --. - -. -- - - 4.83 --- -.13.33 ___ 29.82 Sample 10. On lot 2:3, 16th district, Bartow county. Variety: Hard red porcelanous mass of concretions. Occurs on surface of a ridge: Alumina_ --------- - -- ---- - .53.31 Ferric oxide ____ __ ---- ___ --- __ _ - -- - - ----- -- __12.92 ALUMINIUM ORES. 219 Silica ___ __ ---- - - _ ------ ---- - ---- - -- _ 1.16 Water ____ . ____ _ ------ - ---- ----- - ---- - -- - . _29.60 Titanic acid __ ___ __ __ - - - 3.22 Sample 11. On Mr. Seay's land, lot 108, 16th district, east of Linwood. Variety: White, small grained pisolitic in mass : Alumina ___ . _________ __ __ __________ ______ ______ ___ 45.21 Ferric oxide_. __ .. _____ ______ .. _. _____ ________ ________ 0.52 Silica ___ ___ _ ___ -- - - . __ ---- -- ___ ----- 35.88 Water __ _ .. _____ . ___ ______ ___ _ _____ ______ ._ ______ 17.13 Sample 1f8. On lot 115, 16th dh;trict, belonging to the Barnsley estate of Woodland. Variety: White, small grained pisolitic in mass. Situated on a flat-topped ridge: Alumina ______________ _______ .. __ - _____ ____ _______ .61.25 Ferric oxide ___ - - ----- - --- - - - - - - -- - --- - ---- -- 1.82 Silica ___ __ -- - - --- - - -- ------- . - -- - - - --- --_ 1.98 Water . . - ----- - - - _ :31.43 Titanic acid ___ _ - - - - - - -- 2.38 Samples 13, 14, 15. Other analyses of beauxite from the Julia mines (Barnsley estate) yielded the following results to the Pittsburg Testing Laboratory, and kindly furnished by Mr. B. F. Armington: Alumina _____________ ____ . ... . 67.53 Ferric oxide _ __... - - -- - - - .... trace Titanic acid . -- - - -- - ... ___ 2.92 Silica ___ -- --- - -- - --- - ____ _ 1.34 Water ____ _ _----- - __ _______ _ . 28.00 60.61 0.21 4.18 2.47 32.00 60.63 trace 4.76 3.20 31.00 99.79 99.47 99.59 220 ECONOMIC RE':iOU RCES. Sample 16. From the Knowles property: Alumina ____ __ _ ______ _ - - ----- -- - ----- ---- - - - -61.88 Ferricoxide ___ __ _ __, ____________ ----------- - __ 0.21 Silica ---- --- ---- - - - - ---- --- ----------- ___ __ ___ _ 2.13 Titanic acid _ - - - - _ -- ____ . _ ---- __ 4.04 " Tater_ __. __ ____ _____ - _. _.. _ _ ______ -. __ - ~ ___ _ .3 1.50 99.7fi Titanic is always present, and where not determined separately, it is included with the alumina. From these analyses, the yariations in composition are seen to be vety great. Some of the samples were from pits, others from the surface. The vesicular varieties are mostly superficial, and in some cases contain a smaller amount of alumina. The iron seem~; to increase upon descending beneath exposed surfaces, and consequently the redder varieties are more abundant at a depth. Still the amount of ferric oxide is often small, considering the depth of color of the mineral. In some cases, the silica, as if free, renders the mineral gritty, but much of it is combined, so that the siliceous mineral h1ay be regarded as containing a kaolin-like constituent. Indeed. the beauxite is commonly associated with a clay, often of white color. (See clays.) The ore varies greatly in its affinity for the contained water. In some cases this is easily. driven off by roasting, but other samples require to be heated to redness before losing all of its water. In the above analyses, where 28 to 32 per cent. of water occurs, a portion of the moisture is evidently hygroscopic. DISTRIBUriON AND CO~fPOSITION OF FOREIGN ORES. Beauxite iR so named from its oecurrence near the town of Beaux in France, where it occur.~ to a depth of 30 or 35 feet and said to ALUMINIU.llf ORES. 221 extend for 90 miles. It also occurs in Austria, Germany, Ireland and Scotland. In America, it was first worked by ::VIr. J. vV. Hawkins, near Hetmitage, in Floyd county, Georgia. The same belt extends into Alabama. It was also found by Dt. Brauner, State Geologist in Arkansas. The analyses of foreign ores upon the next page is taken from a treatise entitled, "Aluminium," by Mr. Joseph M. Richards:* THE USES OF BEAUXITE. Owing to the large percentage of alumina, and its solubility in acids, the demand for the mineral is rapidly increasing. Of minetals available in commercial quantities, none is so desirable for the manufacture of the compounds of aluminium, especially alumina (the direct source of the metal), the sulphate and compound alums. The mineral, when powdered, is decomposed by "chamber acid," (dilute sulphuric acid), and the silica is left behind and separated. By this process the iron is also dissolved, and, being objectionable, it must be separated, or reduced to an ineffective condition; consequently, the mineral is not accepted for use by this process when it contains more than from 2 to 3.50 per cent. of iron. However, a large proportion of silica is admissible, up to 14 or 20 per cent., or even more, but if too much is present the quantity of the product is greatly reduced. Owing to competition with the foreign mineral, grades below 55 per cent. of alumina are not genemlly acceptable. As has been seen, titanic acid is generally present in onr beanxites. This is not an objectionable component, for it can be retained along with the alumina, as so much of its sulphate as is formed acts like that of the other metal in setting the size oe the color in paper mannfaetnre or in dyeing. ;'Publbhed by Henry C. Baird & Company, Philadelphia. ANALYSES OF EUROPEAN ORES. i ll 1 1 1 21 1 3 1 4 1 5 1 6 1 7 8 9 1 10 1 12 1 13 1 14 115l l6 1 17 Alnmina ...... C\0 ofril .n-ts 12 43 44 61.8\J 45.76 55.6176 .3 50.f;ij -l!l 02 7:1 .0 t)3 .Hi 72 . 8744.454 1 ll4. o 2!-l .SO Ferric Oxide .. :Ui .U 12 (l 2 36 ::' . 11 1.96 18.9(3 7.17 6 .2 14. 36 12. !!(} 4.:Ui 23.55 13.4930.310 .4 2 .0 3.67 Silica ......... 3 - 0~ 1. 0 7. 95 15 . 05 6.01 6.41 1-!.41 1. 0 5 . 14 10. 2i 2.1 5 4.15 4.2515.012 . 0 7 .fl 44.76 Potash ad'fl. soda .... . .. . . .. .. . . . .. .. . 0.38 .. .... .. .. 0 . 211 0.31 .... . 0 . 79 0.78...... . ... . .. .. Water ........ 12 . 0 12 .0 40 . 33 35 70 27.82 27 .\ll 32.3316 ..1 28.38 25 .91 18 .00 8.34 8 .50 9 . 72:! .924 7 13 86 11, 1 and 2, Beauxite from Beaux; 3, from Irish Hill; 4, from County Antrim; 5, Glenravel; 6 and 7, Hadamar (Hesse); 8, Klein-Steinheim; 9 and 10, Landorff; Commercial quantities from Dublin, imported and .made into alum. Wocheinite varieties: 12, dark; 13, light; 14, Red Brown Beauxite; 15, yellow; 16, white; 17, white, Wocheinite from Austria. ALUMINIUM ORE~. 22 3 By another process the mineral is fused with soda. In this case, the quantity of silica is restricted to from two to four per cent., a~ more would make its use too costly. It is by this process that the alumina for reduction to the metal is made. Iron in the beauxite is not an objection, for a valuable by-product is obtained. Ah\minium is now rapidly growing in use in the arts. The abundance of its compounds is coextensive with the clays. In commercial quantities, its oxide, or pure alumina, prepared from beauxite, or hydrated oxide, is the chief source from which the metal is extracted in the largest quantities. The aluminium has such strong affinity for oxygen, that the separation is difficult. Iu the more recent and cheaper processes, the metal is reduced by powerful electrical currents, from alumina dissolved in molten cryolite (which is not decomposed) in an electrical furnace. The affinity of oxygen for the metal is better appreciated by stating that the Pittsburg Reduction Company finds that a horse-power of electrical current, working from 18 to 22 homs, liberates only one pound of metal. The Yalue of beauxite is regulated by the price of the imported mineral, which can be delivered in Philadelphia or New York at about $6.50 per ton. But the Georgia beauxite commands a higher price, on account of its easier solubility compared with French ores. It has been sought for shipment 'to Germany. As much as $8.50 to $13.00 per ton have been paid for Georgia beauxite in Pittsburg and Syracuse. At interior markets, the transportation from the seaboard must be added, so that the Georgia beauxite can be shipped with better advantage to Cleveland, Lockport, SyracuHe and Pittsburg, than to tboHe coastal cities. Another application, when deHiccated, is its value as a refractory material in open hearths, especially in the basic processes of steel manufacture. The quantities of Georgia beauxite are extensive, and with the increasing demand, a large supply can be obtained. 224 ECONO.MIC REHOURCES. ~lODES OF OCCURRENCE 0~' BEAUXI1'E. Beauxite occurs amongst the residual deposits of the decomposition of the Knox dolomite series, and extends from Polk county to Gordon. It is also found in continuation of this belt in Alabama. So far, it is not known outside of this formatio;J, although Halloysite, a mineral of similar composition, occurs higher, in Sub-Carboniferous series. At .Beaux, the mineral occurs in grains in compact limestone. In Arkansas, the beunxite lies between soft Tertiary beds (Branner), adjacent to igneous rocks. In Georgia, beauxite deposits are associated with the higher members of the Knox dolomite series, and the belt is closely coincident with the manganese zone, but not with the more cherty members of the series. In elevation, the beauxite bearing ridges are usually 800 to 1,100 feet above the sea. The beauxite occurs upon the sides of the gently sloping ridges, especially in coyes amongst them, and not usually upon the detached and subordinate valley ridges, as in the case of the best iron ore deposits. Brown iron ore deposits occur in the vicinity of all accumulations of the aluminous mineral seen, and manganese is found upon higher portions of the same or adjacent ridges. Beauxite appears in nodule.~, and in more or less earthy forms, in pockets, and in ill defined IJeds in the residual clays of the Knox dolomites. Its mode of occurrence is more or l(>SS similar to that of brown ore, (>Xcept that the softer mineral has not withstood surface degradation as well as the iron or manganese ores. Sometimes the nodules are small, but again large boulders are seen. Thel'e deposits are known to reach a clepth of 50 feet or more, but the full extent has nowhere been proved. The surface of the ground is frequently yellowish, and with bnt little flinty covering. Upon it, boulders, nodules, or sometimes pebbles of the concretionary mineral, are strewn. The mineral is oftee only sparsely scattered through the snrface clays, in which ALU~HNIU~f ORES. 225 occasional boulders alone may occur, as if dumped into the mud of a sea bottom ; such, of course, is not the case, but this condition probably arises from the creep of earth down the hillside during long ages; thus, the' beauxite beds are sometimes covered by from two to eight feet of clayey deposits. Consequently, the source of the beauxite is sometimes higher than the localities, where it appears upon the surface, although generally it is to be found near by. THE ORIGIN OJ<' BEAUXlTE. This is an open question. Its situation along with the iron and manganese ores in dolomites suggests a common genesis. The formation skirts the crystalline rocks of central Georgia, whence the materials were originally obtained. Prof. Brauner says that the Arkansas beauxite, although in Tertiary rocks, is located near eruptive syenites, or hornblende granites. Such rocks in Georgia have given rise, in part, to the iron and manganese minerals. The feldspar, in othets, contains the aluminium, and there remains only the necessary Rolvent to transport and deposit it as the mineral beauxite. In the weathering of the rock~ carbonic and vegetable acids remove the iron, manganese, lime, etc., from the hornblende, and potash and soda from the feldspar. So also carbonic acid in water can dissolve small quantities of alumina; thus the same waters can remove the iron, manganese and alumina.* The alkalies derived from the decay of feldspars can also dissolve the alumina. Thus. transported, the alumina may be precipitated i in the lagoons in *When alumina is precipitated by fixed alkaline carbom\tes, a small portion of alumina remains in solution at first, but this is deposited by degrees after the solution has stood a few days in the open air, at a temperature sufficient to expel the carbonic acid.-( BeTgman.) t The above explanation of the origin of the beauxite deposits is supported by Coquand in writing upon the French mineral, but differs in not being due togeyser action. (lo) 226 ECOKOMIC RESOURCES. which the ferruginous and manganiferous clayey limestones were being formed. The white clays associated with the beauxite and iron ore deposits are usually of fine texture, indicative of deposition in quiet waters. The frequent replacement of part of the alumina by ferric oxide further shows the presence of both metals in the original solution, but in variable quantities at different times and places. Upon the subsequent decomposition of the Knox limestone, the calcareous matter being removed, the ores were concentrated, leaving accumulations of beauxite more prominent than in the original beds. The position of the beauxite appears to be more or less in pockets and lenticular masses in certain strata, and if workings are ever carried beneath the decayed rocks, the mineral will likely be found in pockets in compact limestone. Indeed: some of the apparent clays may be found to be the soluble aluminous mineral, which is so far as known in Georgia, generally more or less oolitic and concretionary, as are the iron and manganese deposits. The beauxite beds or pockets are less interrupted, and are much more extensive than the latter named mineral. BEAF XITE IN GEORGIA. ' The general distribution of the belt of ore is now known, and a large number of deposits have been visited. Often they have been found on different parts of the same ridges with apparently no reason for their intervening absence. The beauxite also occurs on many properties adjacent to those given but not mentioned, as land boundaries were not known. About a mile northeast of Cave Spring, a light colored yariety occurs on the summit of a ridge belonging to Mr. Culbertson. The bed appears to be quite extensive; and some of the ore is reported as giving a higher analysis than that of the specimen reportell on a previous page. ALUMINIUM ORES. 227 At other points, a mile and a half south of Cave Spring, the mineral is also reported. Northeastwar<.l, about six miles. from Cave Spring, both the reel and the whitish mineral occurs on the laud of Mr. John Henry, lot 910, :3d district. This is on the west side of the ridge and exposed by washouts descending the hill (see analysis). Much ore is shown upon the surface. At a short distance to the north, is New Prospect church, and back of it, on lot 820 (Mr. Myles Mosley), is a light gray, earthy looking mass, with concretions of beanxite, beneath from two to four feet of gray soil. This is near the western foot of a ridge on which are iron and manganese ore'3. Indeed, near the beauxite, a siliceous iron ore is seen. On lot 534, 3d district, is the deposit of Mr. A. W. Bobo; it lies in a cove on the eastern side of a ridge. It is a mixture of gray with some white and red beauxite, and much clay is associated with it. The grade is high (see analysis). It has been profitably worked. On properties near by, other deposits (Mrs. W. S. Johnson's, lots 692 and 677) are reported, and extensive deposits of iron ore have been worked on adjacent lots. Upon the eastern side of a ridge1 cast of the last named, Mr. J. A. Howell's land (lot 610 or 615) contains beauxite in a cove, and also large deposits of brown ore. On lot 906, 3d district, Mr. Doyle'r; farm contains beauxite (see analysis). This is in the valley, and may be only float. It lies on northwestern side of another ridge. To the east, Mr. Scott's farm, lots 897 and 960, :3d district, now owned by Mr. J. vV. Hawkins, contains the white and red mineral, occULTing on the lower part of the ridge and covered with more or less creep soil. On the side of u: .valley eastward, beauxite occurs on property of Mr. R. S. Brammon (lot 22d district). Upon the western side of a ridge, east of the C. R. & C. Railway, Dr. J. C. Reece has much light colored 228 ECONOMIC RESOURCEH. beauxite on lot 60, 22d district. This occurs on the western side of a ridge. This land here is gray, with very little chert. In this district we thus see that the beauxite occurs on numerous parallel ridges, extending from Polk county northward to near Hilver creek. Indeed, there seems no reason why the mineral may not be found nearly all the way to the Etowah river, along the more rugged western portions of the Knox dolomite series, west of Spring cteek valley. Some beauxite ha;, been reported east of this stream, but the existing conditions are different from those farther west. Northeast of Rome the beauxite belt reappears, as on the lands of Mr. Wisnant and Mr. Walters and other properties. The belt continues northeastward, and is extensively developed near Herlllitage. This is the localtiy where :Mr.J. W. Hawkins first found it in.1887. More than 4,000 tons have been taken out of a pit on lot 61, 23d district (to October, 18Hl). This pit is more than 100 feet in diameter and 50 feet deep without reaching the bottom of the deposit. The beauxite is of red and white colors, the different varieties prevailing in different parts of the pit. It occurs in nodules and bouldere made up of concretionary pisolites, bedded in an earthy mass. Or, again, it may be in the form of loose gravel-like masses, in which case it is apt to be silioeous. One of these boulders yielded <>ixty-four wagon loads. At this digging more or less earthy mineral and clay bands oceur along with the beauxite or between the pockets. Also horses of clay prevail in the pit, so that more than half of the material has to be rejected. Much beanxite is lost with this refuse. The redder mineral seems to prevail in the lower parts of the accumulations. The deposit is covered with from four to eight feet or mote of light tinted red clay. Some of this surface covering is probably of creep origin, as it occurs on the side of a ridge. The surface is strewn with some cherty fragments. The beauxite here appears to be in great lenticular pockets:1peculiar to certain beds of the origi- ALUMINIUlli ORES. 229 nal rock. The bedding is mostly obliterated, but some bands of red clay, dipping southeastward, indicate the relation to the original bedding. The locations of the beauxite are near the head of the cove in the ridge. In another opening on the same property the white clay also prevails. Boulders of beauxite are occasionally scattered through the clay beds. On Flowery branch, lot 21, 23d district, light colored beauxite and white clay occm on the gently rising ridge. (See analysis of clays.) In this region beauxite occurs on many other propertie,.:;; and is said to be found on lots 22, 19, 30, 39, 103, 104, 147, 134, 136, 23d district, by Mr. J. W. Hawkins. The ore of this region is shipped from Cunningham station. There are many iron ore deposits in this (Armstrong Mountain) district, which are more or less associated with the superficial cherty accumulations. Northeast of these deposits the beauxite is found on Mr. Shaw's fatm, lot 31 (?), 16th district, about two miles south west of Adairsville. Here the mineral occurs as boulders in yellow clay. In descending into the mass the pisolitic grains become fewer. At the surface it is a light L'eddish mass, with the interior of the grains dissolved away, and the partial cavities containing a light reddish powder (see analysis). The situation of the deposit is on the west side of a flattened ridge. This chain of deposits continues to the border of Gordon county. In a coye on lot 32, 15th district, on property of Mr. J. M. Pinson, there is a large deposit of the white mineral, but it has not been analyzed. West of Linwood (late Hall's Station) beauxite occurs on the Barnsley estate (lot 115 and others in the 16th district, Bartow county) at ~Woodland. It is found in large boulders beneath a yellowish, sandy clay soil; on a flattened and also on more rugged ridges. H is a light colored, in part compact pisolitic mass of high grade (sea 230 ECONOMIC REF:IOURCEH. analyses), and again in loose oolitic gravel. Iron and manganese ores occur near by. On the east side of the valley there are oth~r deposits of high grade, which contain gibbsite. Large exposures may now be seen since the removal of three to fiye feet of soil. Other ridges to the eastward contain large deposits of beauxite. On the ridge to the westward of the Connesenna creek, near Cement, beauxite occurs in yellowish reel clay beneath yellowish soil, covered with only a small amount of chert, although the ridge is generally cherty. An example may be seen in the deposits of Montague & Co., lot 97, 16th district. Woodland is in a narrow valley excavated out of Upper Cambrian slates. Beyond, various ridges contain beauxite, as lots 107, 108, 109, 102, etc. Eastward of Linwood some of the propetties show large deposits, as that of Mr. Seay (lot 108, 16th district). This beanxite is whitish, oolitic and porcelaneous in places. Other deposits are reel. On lot 108, the mineral is covered with from six to nine feet of yellowish soil. There are extensive iron ore deposits in thi~; l>ame region. In the Knox series in the eastern part of Bartow county, beauxite also occurs, and at many other localities in the formation it may likely be found. The Bobo, Hermitage and Barnsley deposits are those where the principal workings are located. At other localitie~; in northwestern Georgia, beauxite occurs upon the narrow belt of Knox dolomite associated with white clay and sparingly with brown iron ores. Thus heauxite ii'O found on a lot of Mr. Taylor, west of Summerville. Elsewhere, in the narrow belts of the formation, bea uxite may be looked for, as well as in the broader belts of the Coosa basin. ALU)IINVM. 231 CHAPTER XXXIII. ALUi\fiXUi\f, ITS SOURCES AND "C"SES. BY R. L. PACHARD. FROM AUTHOR'S SHEETS 01' "MfNERAL RE30URCE3 OF THE UNfTED STA'.rES FOR 18nl." NoTE.-Owing to the rising importance of aluminum iLnd its sources of supply, the editor hfls deemej it advis~tble to !tppcnd the paper to th11t ol this report of the survey of the State as it was only received after the Georgia report was iu type. BAUXI'rE fN El:ROPE. "The mineral received its name from Baux, a village in the south of France, where it was first found, and the more highly ferriferons variety was regarded and worked as an iron ore, but proved too refractory. It sometimes ran as high as -!2 per cent. metallic iron. The analysis by Berthier revealed its true character. The geological occurrence of the bauxite of Baux was studied by H. Coquand (Bttll. de la Societe fieologique de F'I'Ctnce, vol. 28, p. 98, 1811), wl10 describes the mineral as of three varieties, pisolitic, compact and earthy. The pisolitir. variety does not differ in structure from the iron ores of Franche Comt6 and Berry, although the color and composition are different. It occurs in highly tilted beds alternating with limestones, sandstones, and clays, belonging to the upper cretaceous periods, and in pockets or cavities in the limestone. The limestone containing the bauxite and that adjacent thereto is also pisolitic, some nodules being as large as the fist, and pisolitic bauxite has sometimes a calcareous cement, and at others is included in a paste of the compact mineral. i\f. Coquand supposed that the alumina and iron oxide composing the bauxite were brought to the ancient lake bed in which the lacustrine limestone was formed by mineral springs, which, discharging in the bottom of the lake, allowed the alumina and iron oxide to be distributed with the other sediment. In some cases the discharge occurred on land, and the deposit then formed isolated pat'Ches. He refers to other similar deposits of bauxite of the same period in France. Sometimes the highly ferriferous mineral predominates over the aluminous (white), at others diaspore is found enveloping the red mineral, while in others it is mixed with it, predominating largely, and sometimes manganese peroxide replaces ferric 232 ECOKO"MIC RESOURCES. oxide. In some places the ground was strewed with fragm ents of tnbero.us menilite, very light and white. l\1. Ang~ (Bull. Soc. Geolog. de France, 1G, p. 345, 1888 ) describes the bauxite of Var and H~rault and gives an alysis of it. Over 20,000 tons were being mined in this region annually at the time of writirlg his report (1888). In the red mineral of Var druses occur with white bauxite running as high as 85 per cent. Ah03, and 15 p er cent. H zO, corresponding to the formula AlzO g+ HzO. He refers to the prevailing theory of the formation of bauxite, according to which solutions of the chlorides of aluminum and iron in contact with carbonate of lime undergo double decomposition, formin g alumina, iron oxide , and calcium chloride. Other deposits in the south of France , in Ireland, Austria and Italy, he says, confirm this view, because they also rest upon or are associated with limestone. The bauxite deposit in Puy de Dome which he studied could not, however , be explained by tt.is theory because it was not; nssoniated with 11rn estone, b uL rested dhectly upon gneiss antlwt\s J~tUtly ove1ed by bas(llt. Til geological s keLcb mnp of t be deposit Jlear 1.adl'i11.t, I' uy de Dome, wh i h he gives. shows gne~ss, llasa1t witla uncovered bau.,..dte lm:gely predomi nating, and pntcheF.> of miocen e clays, while a geoJoical section o( the lepnsit. 'rl s(tr Yill vey n tc, H mnlt, shows the 1 ed o[ bauxite conformably following the flexures of the limestone formation when covered by more re en t l1ed , Rnd wl1en exposed and denuded occupying cavities and pockets in th e li mestone. This oc urren a is substantially the same as that of the neigh borin" Buux. 1\f. Ang6 agrees with l\1. Coquand in at- tributing the bauxite to geyse11ia n origin . 1-[e uses as nn illustration of the contemporaneous formation of ],)auxite the deposits from the geysers of Yellowstone park, which is evidently due to a misunderstanding. He made no petrographical examination of the bauxite of Puy de Dom e, nor did he attempt to trace any genetic relation between the latter and the accompanying basalt . The occurrence is, however, noteworthy, and an examination might show that it is another instance of the direct derivation of bauxite from. basalt, which is m aintained in the two following instances, somewhat imperfectly in the first 1!o be sure, but with greater detail in the second. The first is a paper by Lang in the Berichte der Deutschen Ohemischen Gllsellschaft, Vol. 11, p. 2892, 1884. He describes the bauxite in Ober-Hes- sen which is fotm d in ~he :flolda i u ouncl mfl B e$ up to the size of o. man's heat! , embedrl d in a clay wbich is colbred with iron oxide. The composition var ies ve1y wido ly. The 1etrog1aphical examinnti.on sh we l s ilica, iron oxide, m agnetite, a nd augi te. The hemicaJ composit ion and J etrograph ical exarrrinntiou shoWB tl e bau.'< ite to be a decomposition prod uct o( basttlt. .By the weatl ering of t he plugiodase ieldspars, aug ite, and ol i vin , ne ndy rtll the ~:~i llca h~d l)een ,removed, to ether with t he greater 1an of the li me ani.l magnesilt; the iron huu been ox ldi;~etl nm1 hydrn.te of alu LDinn forme d as shown ALUllliNUM. 233 by it~ easy solubility in hydrochloric acid. 'l'he residue of the silica had crystallized as quartz in the pores of the mineral. 'fhe more detailed account of the derivation of bauxite from basalt is given in an inaugural dissertation by A. LiebreicH, abstracted in the Chemisches Cent?albl(ttt, 1892, No. 3, p. D4. This writer says that the well known localities of ba~xite in Germany are the southern slope of the '\Vesterwald near Miihlbach, Hadamar, in the neighborhood of Lesser Steinheim, near Hanan, and especially the Western slope of the Yogelsherg. Chemical anal?ses show certain differences in the composition of bauxite from different places, the sm'aller amount of water in the French bauxite referring it to diaspore, while the Vogelsberg mineral is probably Gibbsite (hydrargillite). The bauxites of Ireland, of '\Yesterwald, and the Vogelsberg, show by certaiN external indications their derivation from basalt. The bauxite of the Vogelsberg occurs in scattered lumps or small masses, partly on the surface and partly imbedded in a grayish white b reddish brown clay, which contains also similar masses of basaltic iron ore and fragments of more or less weathered basalt itself. Although the latter was associated intimately with the bauxite, a direct and close connection of the two could not be found, but an examination of thin sections of the Vogelsberg bauxite sh.:>wed that most specimens still possessed a basaltic (aname>ite) structure, which enabled the author to determiue the former constituents with more or less certainty. The clay from different points in the district carrying basalt, basaltic iron ore, and bauxite were examined, some of which showed clearly a sedimentary character. Some of the bauxite nodules were a foot and a half in diameter and possessed no characteristic form. They were of an uneven surface, light to dark brown, white, yellowish, and gray in color, speckled and pitted, sometimes finely porous and full of small colorless or yellowish crystals of hydrargillite. The thin sections showed distinct medium-granular nnamesitic structure. Lath-shaped portions filled with a yellowish substance preponderated (the former plagioclases) and filling the spaces betiVeen these were cloudy, yellow, brown, and black transparent masses which had evidently taken the place of the former augite. Laths and plates of titanic iron, often fractured, were commonly present and the contours of altered olivine coulrl. be clearly made out. The anamesitic basalt of the neighborhood showed a structure fully corresponding with the bauxite. Olivine and titanic iron oxide were found in the clay by washing. The basaltic iron ore also showed the anamesite structure. BAL'XITE IN AMERICA. The American occurrences of bauxite so far observed are in Alabama, Georgia and Arkansas. Prof. Eugene A. Smith, State Geologist of Alabama, has kindly furnished the following information in regard to the bauxite of that State. He writes: 23 4 .ECONgging the boat over the sands and in hoisting and loweri.ng it. Th e Jist of pr oposed uses continue to increase. Disregarding them, tho actual liB ia su fll.ciently varied. Small articles, viz., drinking cups , rul ers and 11aper-cutters, perfumery stands, smokers' sets, ash-receivers, to thp.i k Hud ma tch holders, watch caMs. 1 monade shakers , card receive 1s, butter tlishes, rings , spo ne, p icture fra111es, bracelets, napkin rin gs, sleeve 1\nd collt\1' buttons, scad and s ha wl pi ns, pe.m acks, dog coll ars , key chains, haiiI ills, penil cases , a u lrnll \ni ld n s 1Ue ndv r tis ed. In Germany aluminum tubing is used for penholders, umbrella handles, walking sticks, billiar d cues, chair legs, photograph frames, r cent. to 0.30 per cent. iron, and 0.10 per cent. to 0.25 per cent. silicon. The foil was polished, freed from fat with caustic soda, washed with alcohol, dried in the bath, cut up, weighed, and introduced into the acids. In this fine condition the action of the acids was as shown in the following table, the weight being the amount of metal dis9olved expressed in grams per square meter. The action lasted twelve hours. 2-10 E CONOMIC RESOURCES. ACTION OF VARIOUS ACIDS 0:-1 ALlDIINU)I FOIL. ACIDS. ~ ~. Temper- Sample~. a .= a.ture ~ f (centi- '.11 EO grade.) A. B. C. D. - - -- ---:------- - -- - -- Grnms. G1ams. Glams. Gl'a?ll~. 15-20 ts.io 1s . oo 16.40 H.:.o } [) C-2QO 21.00 21.80 17.50 16. 40 15o-:zoo ~4.50 2!\ . 00 2~.00 20.00 15-20 ~5.80 2:\ , 70 24.60 22.40 ] 50-200 19.00 lH. OO 17.\JO 16.30 ... 1U8 i.o:oo 15-20 15-20 1~:gg ,~:gg J50-2QO 29. 50 1\). 60 18.00 16. 60 15-20 l6.:JO 16. 30 H.OO 13. 40 150 240 . 22~. 1!i0. 200 . no 150 267 . 250. ~10. 220 . J.OO" ..... ......... .... . } Vi o l nl Vll'l l 100'' .. .... .. ... ......... !Lc.l.!nn. u.cWuu . According to these results almoHtpure aluminum, \HJ.,5 per cent., is attacked even in the cold by nitric and sulphuric acids , so that the metal Hhould not be used in apparatus for preparing these acids. As to the action of drinking fluids, coffee, tea, beer, wines, brandy, etc., the following appears to be the state of the case: Messrs. Lii.bbert and Roscher, Chern. Cwtmlbl., 1891, Ed. II., No.18, p. 780) tested the resistance of aluminum to the action of alcohol, ethe r, ald'lhyde, coffee, tea, wines and antisepticH, by allowing aluminum leaf to remain in concentrated solutions of the different liquids four days at the temperat ure of the room, and the fluid s were examined either directly for alumina or were evaporated and the ignited residue so examined. Thb conclusion reached was that aluminum possesHes only a slight degree of resistance to the agents named, except alcohol, ether and aldehyde, and that it is therefore ummitable for wares which are to be used for acid drinks, coffee, tea, etc., or artides which are to be cleaned with soda or Aoap. Its application in daily life would therefore be very limited. On the other hand, G. Rupp, (Dingler, 283, I, January 21, 1892,) criticizes the methods employed by Liibbert and Roscher for determining the action of the fluids by eHtimating the alumina contained in them, as well as the use of aluminum leaf for their experimentA, which is attacked much more easily than the compact metal, the former being acted on even by boiling water, while the latter is unaffected. His own experiments were made upon aluminum vessels (canteens, drinking cups, etc.) and foil, the object being to determine the availability of the metal for uHe in the army. The carefully dried and weighed vessels were filled with the different fluids or the foil was immerAed in them, and the action was allowed to continue four, eight and twenty-eight da_vs, at the temperature of the room with frequent stirrin g. The fluirls included wines of different kinds, beer, kirHchwasser, P.ognac, coffee, ALUl\IINUl\J, 241 tea, milk, drinking water, 1 per cent. solution of tartaric acid, acetic acid (1 per cent., 4 per cent., 10 per cent. solutions), vinegar (10 per cent.), soda solution (1 per cent.), besides butter, honey and preserved fruits. The articles were then cleaned, dried and weighed, to determine the loss of weight. The results, which fill a large table, flhowed that in most cases there was absolutely no action and in the few cases where there was a perceptible loss of weight it was flO trifling as to be disregarded. To the objection that continued drinking of fluhls containing a small quantity of alumina would eventually be dangerous, the author points out that thte ash of all the fluids usually drank contains alumina, as well as most foods and drinking water itself. His conclusion is that thbre is no objection to the use of aluminum for canteens and similar vessels. These conclusions of Rupp were confirmed by Dr. A. Arche (D'io.gleT, Vol_ 284, No. 11, p. :255), whose experiments show that the purity of aluminum (usii1g the percentage of silicon as a means of classification) has much to do with its power of resisting the solvent action of fluids, and they also show that the mechanical preparation of the metal is an important factor. He found that hammered aluminum was least attacked, rolled metal came next, a'ld then the dra.wn metal, while cast metal was much more easily attacked (by acetic acid). ME'rALLURGICAL USE. The quantity of aluminum used in this country in the manufacture of iron and steel castings is probably from2i) to 30 per cent. of the total production. In Europe it is estimated by Professor 'Vedding to be 5.Jc per cent. This use, as was explained in the last number of this series, consists in adding from 0.10 to 0.15 per cent. of aluminum to iron or steel just before casting, by which blow-holes are prevented and sounder casting are produced. This u;;e is becorning general. The beneficial effect, as was shown by experiments referred to last year, is due in part at least to the deoxidizing action of aluminum upon carbon monoxide at a high temperature, a reaction which was demon,;traterl directly between the metal and the gas. This subject has not yet received an exhaustive examination. For this purpose it would be necessary to know the composition of the iron or steel operated on in each case and make comparative tests on the different specimens. It is also probable that the method of melting employed has an effect on the result. A detail of manipulation in the method of applying aluminum, especially in castings for steam and pump cylinders and other castings intended toresist high pressures, is reported in Dingler's Joumal (Vol. 284, No. 11, p. 255). The addition is made by first forming a mixture of aluminum and iron, which is effected by placing the proper quantity of heated aluminum in the bottom of a small ladle, running some iron into the ladle from the furnace, and waiting until the mixture begins to stiffen. Then the iron to be operated on is (lG) 2-!2 ECONOMIC RESOV RCEH. run into a large ladle and the iron-aluminum mixture is poured into it, whereby an intimate mixture of the whole is effected. For 100 kilograms of iron to be operated on :200 grams of aluminum are used ( =0.20 per cent.) The iron is not poured at once from the large ladle, but is allowed to stand until it is orangey ellow and a thin film begins to form on the surface. As soon as this occurs the film is removed and the iron is poured. The mold should be kept full. No reason is assigned for this procedure, but it appears that iron containing aluminum is inclined to shrink excessively and that this tendency must be obviated by pouring as cold as possible. According to a paper read by Mr. .T. w.I,angley, at the Gleu Summit meeting oi the American Institute of Mining Engineers, the practice in the United States in pouring ingots is as follows: The aluminum, in small pieces of _!i or H pound weight, is thrown into the ladle during the tapping, shortly after a small quantity of steel has already entered it. The aluminum melts almost instantaneously and diffuses with great rapidity throughout the contents of the ladle. The diffusion seems to be complete, for the writer has never seen the slightest action indicating want of homogeneity of mixture, all of the ingots poured from one ladle being precisely alike so far as the specific action of the aluminum is concerned. The quantity of aluminum to be employed will vary slightly according to the kind of steel and the results to be obtained. For opened-hearth steel, containing less than 0.50 per cent. carbon, the amount will range from 5 to 10 ounces per ton of steel. For Bessemer steel the quantities should be slightly increased, viz., 7 to 16 ounces. For steel containing over 0.50 per cent. carbon, aluminum should be used cautiously; in general between 4 and 8 ounces to the ton. If these statements are put in the form of percentages, it will at once be seen how extremely minute is the quantity of aluminum which causes such marvelous results, for the num- bers are : 4 ounce5 = 0.0125 per cent.. .. ...... . .............. = 1-8000 5 ounces = 0.015(i per cent. . = 1-().500 8 ounces = 0.0250 per cent. ..... , H\ ounces ~ 0.0500 per cent. . .. . . . . . . . = 14000 = 1-2000 SOLDERING. From the articles which occasionally appear in the trade journals, both in this country and Europe, and the patent list, it appears that the difficulties of soldering aluminum have not been overcome. Some of the new solders are introduced here without comment. Chloride of silver has been recommended as a solder. It is to be finely powdered and spread along the junction to be soldered and melted with the blow pipe. Mr. Joseph W. Richards makes an alloy of aluminuml part, zinc 8 parts, tin 32 parts, and phosphor-tin, containing i) per cent. phosphorus, ALUJ\IINU!Il. 243 1 part. The aluminum is first melted, then the zinc is added, and finallv the tin, which bas been u!elted separately and mixed with the phosphor-tin." The nlloy is poured into small bars for use. The object is to provide in the phosphorus a powerful reducing agent to prevent the formation of the film of oxide which mmally prevents the intimate contaq_t of the opposed surfaces. (United States patent 407780, October 5, 1891.) Another formula is, cadmium 50 parts, zinc 20, tin 30. The r.inc is first melted, then the cadmium is added, and finally the tin. (Dingler's Jou.mal, Vol. 284, No. 6, page 144.) Electroplnting the surfaces with copper and then applying the solder was mentioned last year. Other solders which have been uAed are composed of- COMPOSITION OF CERTADI SOLDERS FOR ALUMINtTM . I. n. III. IV. \', Per ern/.. Per cent. PeceHt. Pel' cent. Pecent. ~A:nlruJ:m: .irn.~u: :m:: : .. ::.: :: :::::: ~ :: :::::: ::;::::::::::: 12 M 80 9 G 85 7 5 88 G 4 90 4 ~ 94 In making these solders the copper should be melted first, the aluminum then added, and the zinc last. Stearin is used as a fiux to prevent the rapid oxidation of the zinc. When the last metal is fused, which takes place very qnicldy, the operation should be finished as rapidly as possible by stirring the mass, and the alloy should then be poured into an ingot mold of iron, previously rubbed with fat. The pieces to be soldered should first be cleaned thoroughly and roughened with a file and the solder placed on the parts in small fragments, the pieces being supported on a piece of charcoal. The place of juncture should be heated with the blast lamp. The union is facilitated by the use of a soldering tool of aluminum. This last is said to be essential to the success of ~he operation. Alloy I. is recommended for small objects of jewelry; alloy IV. is said to be the best adapted for larger objects and for general work, and is that most generally used. The successful performance of the act of soldering appears to require skill and experience, but 'the results obtained are said to leave nothing to be desired. Soldering tools of copper or brass should be avoided, as they would form colored alloys with the aluminum and solder. The skillful use of the aluminum tool, however, requires some practice. At the instant of fusion the operator must apply some friction, and, as the solder melts very suddenly, the right moment for this manipnlation may be lost unless the workman is experienced. ALLOYS. It is regretted that no statistics of the production of aluminum bronze and 244 ECONO;'IIIC RESOURCES. ferro-aluminum in this country can be given for 1891. Both of these valua- ble alloys have been produced by the Cowles Electric Smelting and Alumi- num Company for a number of years, and have found their way into the market on a considerable scale. The ferro-aluminum made by this com- pany was used as a vehicle for adding aluminum to iron and steel in mak- ing sound castings when that method was first introduced. Aluminum bronze is coming into use in Germany for torpedoes on account of its strength and non-corrodibility, and for telephone wires. It was estimated that280,000 kilograms would be used during 1892. The 5 per cent bronze has been used for some time for nozzles of gas motors on account of its non-oxidizable char- acter, and the 12 per cent. bronze is used for the pins of needle guns, for which purpose it is said to be better than steel. The number of patents which have been granted for aluminum alloys, either where that metal forms a minor ingredient or has small quantities of other metals added to it for special purposes, shows that experimenting in this direction is increasing. .As yet much of this experimenting is done with- out definite knowledge or aim on the part of inventors. Doubtless, in time, valuable conclusions may be derived from this kind of work, after rigid ex- periments with a definite purpose or idea have been undertaken. Of alloys formed with aspedfic purpose in view, that containing a small quantity uf titanium, and another containing silver, were described last year. Others are mentioned in a lecture by Mr. Hunt, president of the Pittsburg Reduc tion Company, whose statements are valuable because they are based on knowledge and experience. He says: "The alloys of from 2P,~ to 12 per cent. aluminum with copper have so far achieved the greatest reputation. With the use of 8 per cent. to 12 per cent, aluminum in copper we obtain one of the most dense, finest grained, auJ strongest meta,ls known, having remarkable ductility as compared with its tensile st.rength. A 10 per cent. aluminum bronze can be made in forged bars with 100,000 pounds tensile strength, oO,OOO pounds elastic limit, and with at least 10 per cent. elongation in 8 inches. An aluminum bronze can be made to fill a specification of 130,000 pounds tensile strength and 5 per cent. elongation in 8 inches. Such bronzes have a specific gravity of about i .50, and are of a light yellow color. For cylinders to withstand high pres sures such bronze is probably the best metal yet known. "The 5 to 7 per cent. aluminum bronzes haTe [1, specific gravity of 8.30 to 8, and are of a handsome yellow color, with a tensile strength of from 70,000 to 80,000 pounds per square inch, an elastic limit of -W,OOO pounds per square incll. It will probably be bronzes of this latter character that "ill be most used, and the fact that such bronzes can be rolled and hammered at a red heat with proper precautions will add greatly to their use. Metal of this character can be worked in almost every way that steel can, and has for its advantages its great strength and ductility, and greater power to withstand ALUMINUM. 245 corrosion, besides its fine color. With the price of aluminum reduced only a very little from the present rates, there is a strong probability of aluminum bronze replacing brass very largely. "A small percentage of aluminum added to Babbitt metal gives very superior results over the ordinary Babbitt metal. It has been found that the influence of the aluminum upon the ordinary tin-antimony-copper Babbitt is to very considerably increase the durability and wearing properties of the alloy. Under compressive strain aluminum Babbitt proves a little softer than the ordinary Babbitt. A sample 1Yz inches in diameter by 1Yz high began to lose shape at a pressure of 12,000 pounds. A similar sample of the sam& B abbitt metal without the addition of the aluminum (having a composition of 7.3 per cent. antimony, 3.7 per cent. copper, and 89 per cent tin) did not begin to lose its shape until a compressive strain of 16,000 pounds had been spplied. Both samples have stood an equal strain of, 35,000 pounds. In comparative tests of the ordinary Babbitt metal and the aluminum Babbitt metal, the latter has given very satisfactory results. "The following alloys have recently been found useful: Nickel-aluminum, composed of 20 parts nickel, and 8 parts aluminum, used for decorative purposes; rosine, composed of 40 parts nickel 10 parts silver, 30 parts aluminum, and 20 parts tin, for jewelers' work; sun bronze, composed of 60 parts cobalt (or 40 parts cobalt), 10 pal'ts aluminum, 40 (or 30) parts copper; metalline, composed of 35 parts cobalt, 25 parts aluminum , 10 parts iron, ;nd 30 parts copper. "Prof. Robert Austin has discovered a beautiful alloy containing 22 per cent. alq.minum and 78 per cent. gold, having a rich purple color, with ruby tints. ''The addition of from 5 per cent. to 15 per cent. aluminum to type metal composed of 25 per cent. antimony and 75 per cent. lead makes a metal giving sharper castings and much more durable type. " Mr. A. H. Cowles makes an alloy for electrical purposes consisting of manganese 18 parts, aluminum 1.2 parts, silicon 5 parts, zinc 13 parts, and copper 67.5 parts. This alloy has a tensile strength of 26,000 kilograms and 20. per cent. elongation. Its electric resistance is greater than that of "neusilber," and it is therefore especially applicable for rheostats. ( C!temiker-Zeitung, March 12, 1892.) Mr. C. C. Carroll makes an aluminum alloy for dentists' fillings, consisting of silver 42.3 per cent., tin 52 per cent., copper 4. 7, and aluminum 1 per cent. It is reduced to powder and then forms an amalgam with mercury. ( U. S. p atent 475382, May 24, 1892). Mr. Chas. B. Miller has patented an antifriction alloy of lead 320 parts, antimony 64, tin 24, aluminum 2. (U. S. patent 456898, July 28, 1891.) Mr. Thomas MacKellar has patented an alloy for type metal of lead 65 parts, antimony 20, and 10 parts of an alloy consisting of equal parts of tin, 246 ECONOMIC RESOURCES. copper and aluminum. The tin-copper-alu:ninum alloy is first melted, the antimony added to it, and the mixture is then added to the melted lead. (U. B. patent463427, November 11, 1891.) An aluminum bronze alloy contains aluminum 12 to 25 parts, manganese 2 to 5, copper 75 to 85. It is the product of John A. ,Jeancon. ( U. S. patent 446351, February 10, 1891.) The antifriction metal (Babbitt metal plus aluminum) contains antimony 7.3 parts, tin 89, copper 3.7, with from~ to 2.5 parts of aluminum. It is patented by Alexander W . Cadman. ( U. S. patent 464147, December 1, 1891.) ALUM!Ntni DIPORTED AND ENTERED l'OR CONSUliPTI.ON IN THE UNITED STATES FROM 1870 TO 1891. Year ending- I II Qu&ntity.l Value. Year ending- I I Quantity. V&lue. Pounds. June 30, 1870.... .. ...... ... ................ .. 1!\tl ........ ....... .................. 1!ml........... .... 2.00 1H74...... ......... 683.00 1875...... ......... 434.00 J87G ... ........ .... 139.00 1877.......... ..... 131. 00 1878........ ..... .. 251 .00 1879.... ... ........ 284.44 1880..... ... .... 340.75 18Xl...... ......... 517.10 $ 98 341 2 2,125 1,355 1,412 1,551 2,978 3,423 4,042 6,071 111110 30, 1882.............. . 1833............ .. . 1884 .. ............ . lSil about 35 miles, with an area of 160 square miles; and the area of Sand mountain in the State is 50 square miles. The outlying ridges of Rocky mountain and Little Sand mountain do not contain any . workable coal seams. ON SAND OR RACCOON MOUNTAIN. This table-land crosses the extreme corner of the State, contain- ing several workable seams of coal. The total thickness of the Coal Measures on this plateau, in Georgia, is 800 feet. A complete section of the lower 500 feet is given on page 144 in order to illus- trate the structure of the Coal Measures, and as it is here considered from an economic point, it may be repeated. Feet Irregularly bedded sandstone or conglomerate __ __ ___ . ___ _70, CastleRockcoal __ _ _____ - - - --- - -- __ wanting Shale _. . --- _ _-. ---- _________40 Dade coal seam___ ____ __ __ _____ _ __ ____________ average 3 Sandstone and sandy shale, variable _ ,_ , __ ______ _12 Coal (Reese's red ash seam)--- ___ __ ______ _,._ _ 4 Shale ____ . _ _ 6 Sandstone, or conglomerate-upper half thin bedded, lower half thicker, with shaly seams__ __ . ____ _ .. _... ______ 20 Coal, variable ____ -- ---------------- 0.5-3 '- 248 ECONOMIC RESOURCES. Feet Sandstones and shale ____ _________ ___ ____ ... ___ __ _. __ 10 Blue shales _ . ______ _______ __ __, ____________ ____ 10 Sandstones, thin bedded, and shales or sandy shale __ _~ __ _15 Coal, 8 to 15 inches ___ _ ______ __ _____ ____ _____ _ _ 1.25 Shales, middle layer:; heavy bedded _.. _ __. __ ___ _ . ___ 54 Coal, smut ________ __ ____ ___________ _ Shale _ _ -------- - ---------------- _______ __ 15 Coal, smut ____ __ -- __ ---. _ - --- -- --- - --------Shale ______ .. ______ ___ ___ ______ ___ ___ . ______ 4 Concretionary beds_ _ . _.. _ --- - - --- - ---- - ---- - -- 6 Shale. __ ______ _ 15 Sandstones, thick bedded __. ___ . _ _ ___ ___ 15 Shale ____.. ___ _ ________ ..___ ___ ___ __ _ 10 Shale with some thin layers of sandstones_ _______ __. . 95 Shales, concealed . ______ __ ____ _ _ _____ ____ _ 90 Limestones_ _____ __ . . . _______ ----- The principal workings are at Cole City upon the Dade coal seam, and also upon Reese's red ash seam. The coal lies in a basin, with a trend about N. 30 E. In the mines, the beds usually dip less than two feet per hundred, although at one locality, the seam rose 70 feet at an angle of 45 (Capt. Evans). The average thickness of the Dade seam is 3.5 feet, and it is moderately uniform over coniliderable areas. However, in places the coal seam pinches out, whilst in others the thickness is 9 feet, and at one place it is 17.5 feet. The Sand mountain coal has been extensively worked since 1873, but it was worked a quarter of a century earlier by Mr. Cooper and by Messrs. Gordon & Russell. The earlier workings were upon Castle Rock seam about 5 miles westward of Cole City. There the seam varied from 3 to 4 feet, but it is wanting near Cole City. _Section at Castle Rock downward from the brow of the mountain:: COAL. 249 Feet Conglomerate, capping table-land __ . . . ___ ------ 35 Coal ____ __ - - - - - -- --- - -- ---- -- -- -- ____0.5-3.4 Shale _ _ ------- -- - --- -.------ -- -- - - ------ _ 75 Coal (red ash yein) _ --- -- -- -- -- -------- - ------ ____ 1.5 Shale, exposed __ ---- - --- - -- - -------- - -- - -- _ ___ "- -- 100 At one locality the Castle Rock and Dade seams unite, owing to the absence of intervening shales. The Castle Rock seam in the original locality, is now exhausted as a source of coal. Another seam, called Reese's red ash seam, occurs a few feet below the Dade seam, and reaches a thickness of 4 feet. The conglomerate of Sand mountain is mostly represented by massive sandstones of variable thickness. The upper conglomerate overlies the Castle Rock seam, which in position, is perhaps the most widespread bed of Coal Measures in Georgia. A comparison with the Lookout coal will be given under the latter locality. The three seams of the Dade Coal Company, which have been worked on Sand mountain, occur between the lower and Iipper conglomerate. Beneath the lower conglomerate, which is thinner than on Lookout mountain, one workable seam occurs and possibly two; besides which there are still two other seams that may be seen. The highest of these seams, below the lower conglomerate appears to be the Etna bed of Sand mountain, situated on an insular plateau between the Georgia line and the Tennessee river. The sections at Etna* and Cole City below the lower conglomerate, have about equal thickness, and each contains four known seams. The lowest of these at Etna are from 0.5 to 3 feet, whilst at Cole City, these two are represented by a few inches, which produce a zone of smutty shale along the exposed section. North of Cole City the table-land rises about 300 feet above the upper conglomerate. Near the Tennessee liue, a mile from Mr. Liedermann's house, the ridge is capped by about 20 feet of sapd- -:;'Geology of T en nessee, by Jas. M. S'afford, p. 383. 250 ECONO:mc RESOURCES. stone, beneath which only shale was seen in the few exposures. But at 75 feet below the surface a bed of coal, from 2 to 3 feet thick, occurs. Othet beds may be found, but they were not exposed. Near the Etna line, just mentioned, Prof. Safford records the occurtence of three beds of coal from 2 to 6 feet thick-the middle having the greatest thickness, but containing interbedded layers of slate. This is notable when compared with the deposits on Lookout mountain. The upper plateau ridge of Sand mountain is limited to a small area, owing to extensive denudations, leaving the upper conglomerate of Castle Rock region most commonly forming the margin of the table-land of Sand mountain; but even this conglomerate is wanting in places tipon the eastern side of the mountain. The surface of the plateau is often deeply indented by thP valleys, formed during the long continued action of evanescent streams. Thus, the sudace of the table-land is left more or less rugged. Upon the eastern side of Sand mountain, several borings haYe been made by the New England Company; the records of which were furnished me by Mr. E. C. Stevens. SECTION 1. Feet Surface earth____ __ ------ ------- - - . ----- ___ . 18 Sandstone - - ------ ____ ___ . _ _ ___ __46.5 Castle Rock coaL _____ _ __ . ____ _ ------- ___ ____ .wanting Shale - - --__ Dade coal . _ _ _ . _ _____ _ - ------ - . . 28 ] 25 Conglomerate or sandstone . ____ .. _ Coal______ ___ _____ _ Sandstone Shale _ __ _ ___ Sandstone _ ____ _ __ . C6al __ . __ _ ____ .:. _. Shale ____ _... . _ _4 3 . 2i) - -- -- J. 2 J. [j G .5 21.5 0.75 16.75 COAIJ. 2'51 Feet Coal _ 0.33 Sandstone ______ ____________ ------------. ---------- 5.66 Shale ___ ____ _ __ -- --- --- . _ ------- ---106 The above section is on lot 91, tenth district. SECTION 2. Feet Surface --- ---- _ __ __ ___ -- - -- ____ _ ___ 3 Sandstone_ _ __ __ ________ __ _ --- ----- _ 7 Conglomerate _____ ________ , _________ ---------- . Al Castle Rock coaL ___ ____ . ___ . _ . - . --. - -. _--- .. - . . _ . _____ 0.75 Sandstone -----~- _____________ ._________ ___ . __ --- _____ 4.25 Slate __ ____ . ____ . _ __ _ _ __ ______ __ . . . __ ... . _. __ . __ .. __ 20 Dade coal _________ __ _________ __ :___ __ ___ _. __ ______ ___ __ 3 SECTION 3. Feet Surface 3 Conglomerate _____ - - ---- -- - -- - __ _ ___ .. ___50.75 Castle Rock coaL. __ .. _____ . _. __________ _ __ _ ____ ___ ___ 0.25 Shale _____ __ __ _ ------ ---- - ------- - ---- 8 Dade coal. _____ ___ __ ___ __ _ ____ __ __ __ __ 4 SECTION 4. Feet Surface ____ _. . . .. . __ .. ____ __ . 3 Sandstone . _____ ... __ -- - ---- __51 Conglomerate. ---- - -- __ -------- -- _ - -- - . 12 Castle Rock coal ___ . --- --- _ ___ .... - --- --------- 0.25 Conglomerate. ____ .. ____________ .. _ ____ .. _______ . __ 6.25 Shale __ ~ ____________________ . __________ . ____ .. _______ 2.5 Dade coaL ___ ___ ___ ---- - -- --- _ ------- -- - 0.5 Slate __ - -------- .- __ ---~----- ------ __ _____ ___ 30, 252 ECONOMIC RESOURCES. SECTION 5. Feet Surface 1.5 Sandstone _____ . _ . - .. ___________________ . ____ ____ ______ 8.5 Conglomerate _____ ---------- ___ _____ __ --_. __ _______ . 25.5 Castle RockcoaL -- ---- - -- -- ------ - ----- _ 0.25 Conglomerate ___________ . _____________ :._ ____________ 8.75 Shale : _... ___________________ . __________________________ 28 Dade coaL ______ . ____________ . _. ____________ . ______ . _ i SECTION 6. Feet Surface . ______ . ____ . ___ . _________________ .. ___ _ _ _ _ ____ 3 Conglomerate_ ___ ___ ____________________ _- . _.. .________ 22 Castle Rock coaL______________ _ _ _ ________ ____ __ ____ 0.25 Sandstone _____________________ ----------------------- 4.75 Shale -- -- - - -------- _ ____ _ -------------- ----- .15 Sandstone._____ _ _ ... ______ _______________________ 70.15 Conglomerate _____ . __ __ ____ ____ - _____ ____ __. __ .. 50.5 Shale __ - ---- -- -- _ ----- - - - -------- - --- - - -- -- 3 Conglomerate --- -- - ______ __ , _________________________ 12 Shale ____ --------------------------- --------- -- ---- - -- 2 Coal _____ ____ _______ -- _______________________ _ __ --. 3.5 Shale ---- .. ___ _____________________ __________ ________ 10.3 Surface _ . __ ___ ___ SECTION 7. __. __ _ __ __ . _ . . Feet 5 Shale_------------------------------------------ 7 Coal ____ ____ _ ____________________. __ ______ ______ ___ 1 Shale ______________ ____ _______________________ _ __ __ 9 Sandstone ----- --- __ __ ----- - --- ------- --- ___ ___ 103 Shale - - -- ------- - - ------ ---- ----- _________ _ 6 Sandstone __ _ ___ - - --- - ----------------- ---- - - --- 4 Shale ___ ' ._.____ ___________________________________ .. 129 Limestone..__ _ ___ . _________ ---- - --- . -------- - --- --- -.. COAL. 253 From these sections a con;;iclerable variation of the different strata are seen. At one place, the conglomerate is wanting owing to surface erosion, whilst at another it has been preserved to a thickness of 90 feet. Although the coal seams vary in thickness, they have a wide distribution, and vary in thickness from 0 to 7 feet. So also the strata intervening between the coal seams are constantly changing thickness, yet the general chatacteristics of the formation are constant. Whilst the Coal Measures occupy a long, synclinal trough, yet the individual beds are separated into basins of various extent, and represent the ineli vidual marshes of the Carboniferous period, when the region was occupied by extensive swamps more or less separated by such humnwcks as rise in the extensive swamps of Florida to-day. These changes in surface features gave rise to the thinning and thickening of the coal beds. Yet many of the deposits, although separated,. had donbtless a synchronous origin. whether represented by a thinner or thicker seam of coal; the Castle Hock bed has a remarkably wide distribution ; so also has the Dade seam. The Reese's red ash seam may, in places, be mistaken for the Dade seam. The whole surface of Sand mountain is underlaid by coal beds,, but the surface erosion has deeply incised the mouutain and produced many valleys, whereby the beds of coal have been extensively wasted. In fact, the extravagant waste of nature has been something enormous, destroying coal beds in Georgia far more extensive than those remaining. The coal seams are rarely exposed at the surface, as the outcropping beds are decayed and covered or obliterated by the residual earths forming the superficial soils. Even when the streams have cut through the formations, the coal beds are often indicated only by blackened or smutty shales; the thickness of which is often reduced to less than that of the coal. Consequently, after the locations of the beds have been made, the coal must be exploited 264 ECONOMIC RESOl'RCEH. in order to tell its value. In some cases the coal seams are so intermingled with coal shal1" as to impair their value. LOOKOUT MOUNTAIN. Lookout mountain consists of a plateau encircled by a wall of the uppei' conglomerate, corresponding to that of Sand mountain . . Above this trench, upon the central part of the mountain, portions of a higher plateau re inain, having a thickness above the conglomerate, reaching 750 feet. In the upper conglomerate, near Lulu lake, at Lookout point, beneath High point and elsewhere, a thin seam of coal is observed. Above this horizon there are at least fhe beds of coal. The best section of the upper Coal Measures may be seen along the Chickamanga and Round Mountain Railway, noticed in the scientific description of the mountain, and repeated here. It may be noted that all of these coal seams, in the following section, are in. a horizon above the upper conglomerate, and therefore, above the Castle Rock seam. The coal in the vicinity of Cole City, is geologically lower, but at the same time at a higher horizon than the Etna coal fields of Sand mountain in Tennessee. SECTION ALONG ROUND MOUNTAIN AND CHICKAMAUGA RAILWAY. Feet Laminated shale"! with a few layers of sandstone on Round moul).tain (partly concealed) __ __ _ __ 200 Shales? (concealed) -- . _____________ _ 65 Shale__ ______ - ------------ 9 (b) Coal and shale intimately interlaminated 14 Shale and sandy shale, 1;artly concealed 25 (c) Coal __ --- 0.7 Shale __ 18 Sandstone, gray laminated ______ __ ____ -- . :35 (d) Coal (3.5 to 4.5) dips 1 E. S. E.; altitnde at mouth of Durham Seam Mine, 1,849 feet above tide. There is a slaty parting in the middle of the seam. This bed is probably represented on the southwestern side of the mountain at an altitude 30 feet lower..- 4 COAL. 255 Feet Sandstone, irregularly and often thinly bedded and undulating ___ ____ ______ __. _____ ___ __ ___ . _ 80 Red shale ____ __ _ _ ___ __ __ 11 Black shale ___ ____ __ _ 4 Shale and sandy shale with a seam of limestone ___ _ 10 Blue shale above and variegated shale below. _ _ 7 (e) Coal(altitude 1,668feet)----- _______ __________ _ 1.8:3 Thin, laminated, blue shales _ _ ___ . _ _ _ _ _ . 70 Red shales. __ . - ---- __ _ 35 (f) Coal ___ _ ___ __ __ __ ___ . _. ___________ ~ _ 0.2 Light blue clay ___ __ _ 2 Shales and sandy shales, passing into sandstones and undulating so as to appear and disappear for a dis- tance of three miles, but characterized by some recognizable layers, estimated at ____ __ ________ _ 150 (g) Coal _____ _ _ __ .. - _________ . . ___ _ _______ _ 1.66 Sandy shales, in steep nndnlatious __ . ______ --- 1 to 3 Heavy bedded sandstones __ ____ __ (h) CoaL _ _ ____ ____ ___ 25 ________ 0.20to0.83 Upper conglomemte and sandstone (this is at Eagle cliff) --- - -- ... -- 150 Shales laminated and also tbicl{ bedded ------- - 120 Lower conglomerate and sandstone __ __________ __ 40 Shales, more or less concealed _ . ___ _ 250 (?) Round mountain rises above Lookout table-land as a prominent eminence, and upon its western side there is a be~ of coal 27 inches thick, and another double bed with each layer about 2 feet thick, but separated by about 4 feet of shale. These beds are above seam b (or that now being worked). The double seam may be the equivalent of c. upon the eastern side of Round mountain. There is probably another seam upon the western side of the emmence. 256 ECONO~IIC RESOURCES . The dip at the min es is less than one degree; so also the dip of the beds ou the western side of the upper ridge is low, although at one locality it amounted to 12. On the eastern side of Lookout plateau the strata dip northwestward, increasing to 12 or more, bringing the upper conglomerates to the great elevation of High point, but cutting off the eastward contin nation of the basin of the upper coal series, which lies in the central part of the mountain. The basin has, however, been very much eroded. In the vicinity of Eagle point, the rocks dip 20 N. 70 to 80 'V. Still farther northward the strata dip at much greater angles, but again flatten out towards Lookout point. So also they flatten out to the southward; consequently the beds, at least in the central part of the mountain, lie at low angles or gently undulate. It is only iu the central pOI'tion of the mountain that the Coal Measures remain. Several of the beds have a workable thickness. Below the upper conglomerate there are at least two coal beds known at several points. The upper of these is closely relat~d to the conglomerate, being situated immediately below or within the sandstones. It is, probably, the representative of the Castle Rock coal on Sand mountain, and appears to be one of the mo~t widely distributed of the coal seams. It is of variable thickness and quality. Under High point the coal bed varies from one to three feet, and is shaly. ~outh of :Moore's gap the bed is still thicker. On the western side of Lookout plateau, overlooking Rising Fawn, a bed was opened of variable thickness, from 0 to 8 (?) feet. At Stephen's gap, on the south side of Johnson's crook, a coal seam has a thickness of fl'Om 1 to 3 feet. The position of the c0al at this point may be seen in the following section of the Coal Measure!": Feet Conglomerate, on brow of mountain_ .. _____ . __ . __ _. _ 50 Shale __ ________ _ ------ - -- -- ---- __ ____ 30 Sandstone __ ___ ______ ___ __ ____ ______ _ __ 15 Coal -- -- ----- ---- -- - -- ---- - --- __ _..4-lOinches COAL. 257 Feet Fire clay_ . _ _________ - - -- - - - - - - - - - - - - - - - - - - - 7 Sandstone_________ ____ ______ Shale __. __ __ _ _ _ --- -- ------ - 10 ___ _ __ _ _110 This seam appears to belong to the lower of the two beds noted as occurring below the upper conglomerate. The rocks dip 18 S. 60 E. The same rocks and the upper coal seam occur in the ravine at the head of Trenton gulf, bnt it varies from 4 to 10 inche,;; in thickness. Another seam of coal occurs about 30 feet below the conglom- erate, and is situated in the shale beds. As there are few diggings in the shale, the development of the coal is concealed by the disintegrated shales. In position this coal seems to be near that of the Dade coal beds. Above Rising Fawn furnace some extensive openings were formerly made, where the seam was from 3 to 5 feet thick, and said to vary from 0 to 8 feet in thickness, but there were no general workings. Owing to the covering of shale on the mountain side, the exploration of this bed can only be accomplished by borings or diggings, and may be founrl to have an extensive development in some localities. At various points south of High point, upon the eastern side of Lookout mountain, the coal beds reoccur, and also on Pigeon mountain. Along the stream north of Neal's gap coal occurs immediately below the upper conglomerate. About a mile and a half north of Dougherty's gap, in a small ravine trending northward on the east side of Pigeon mountain, a foot of coal occurs beneath the heavy sandstone. This is along a synclinal axis. 'V4ilst there is somewhat of a general correlation between the coal beds of Sand and Lookout mountains, yet the variation in the thicknesses of different portions of the same basins, give rise to changing conditions. (li) 258 ECOKmUC RESOURCES. ANALYSES OF THE COAL. Analysis of the Dade coal seam by Dr. Gustave Bidtel: I. Fixed carbon _______________ 61.69 Volatile matter ____ __ ___ _____ 27.15 Ash __________ .__ __________ .10.59 Sulphur ____ ---- - - - - - -- -- __ 0;58 Phosphorus _ _____ .___ .. ____ _ II. (Old veius.) 74.8415.86 9.31 1.45 0.059 Analysis of the Reese Red Ash seam (next below Dade seam): I. Fixed carbon ___ ---- __ __ _66.55 Volatile matter ._, __ ---- ____ 28.64 Ash ____ __ ______________ _ 4.41 II. (New veins.) 83.22 12.92 3.26 Sulphur ____ --- ~ ----- - -~ 1.04 1.05 Analysis of Dade coke : Ash 26.12 22.91 24.74 16.73 21.73 20.15 Fixed Carbou. 64.98 71.79 68.15 76.58 69.66 70.48 Volntile Matter. 7.92 5.30 7.11 6.69 8.42 8.88 Phosphorus. .061 .073 Sulphur. .63 .28 Analysis of Round Mountain coal (seam d), by Dr. G. Bidtel, of Chattanooga : Fixed carbon _______ __ ________ __ __ __ ________ __ ___ .. 79.10 Volatile matter ___ ____ _________ ____ __ ____ _______ ____ .. 16.03 Ash ___ _________ ___ ____ ____ _____ ___________ _____ 4.81 Sulphur_ ___ -- - -- - - ----- --- - - --- ---- --- - - -- - - ___ 0.36 Phosphorus______ ___________ _.. . _____ _ . _________ ___ 0.007 100.307 COAL. 259 Another sample of this coal was analyzed by Mr. A. S. Hewitt, of New York: Fixed carbon ______ . ___ . _-- --- ________________ - -- . 75.956 Volatile matter ___ - - - --- ----- ------- - - ---- --- 21.011 :Moisture ____ -- - - ---.-- ------------ --- --- -- 0.615 Ash (salmon colored)-- - . - ---- - --- -- --- ______ __ 1.940 Sulphur ___________________ . ____ . _____________ ____ 0.478 Analysis of coke: Fixed carbon ______ ____ __ _ - -------------~-- ______ 90.31 Volatile matter.-~- _________ . _____ ___________ __ _ --- __ 1.20 Ash - ----------- ----- ------ ------ -- -- ----- - - --- - 8.53 Sulphur ________________________________ .. ______ ___ __ 0.53 The coke stands a high pressure. ANALYSES OF RISING FAWN COAL. Ash. I. 2.93 II. . 3.92 III. 7.68 Fixed Carbon. 76.59 75.60 75.08 Volatile Matter. 20.01 19.89 17.24 Phosphorus Sulphur. 1.09 .006 1.27 For comparison the two following analyses of favored types of northern coals is given : Pocahontas. Fixed carbon ..... . -- - -- --- - -- _ . 74.25 Volatile matter . _____ _ __ ___ --- ----- . 18.81 Water . _______ _ . . _ .. __ . __ . __ ______ 1.01 Ash __ ----- - - - - ---- - -- - ------ - - 5.19 Sulphur_ __ , . -- - -- . . __ _ - - - - ___ __ 0.73 Connellsville. 59.62 30.18 1.26 8.23 0.73 COAL MINES. Dade Coal Mines have been largely worked for many years._ The great proportion of the coal is made into coke at the ovens situated below the mines ; it ie then shipped to Chattanooga and Rising Fawn for the production of pig iron. The mines are extensive, 260 ECONOUIC RESOURCES. and some of the galleries, now honey-combing the mountain, are 3,000 feet long. Two seams are being worked upon at presentthe Dade and Red Ash. The output, from April 1, 1891, to Ap:r;il 2, 1892, was coal 9,888 tons, and coke 104,437 tons, or a total output of coal amounting to about 145,000 tons. The Chickamauga Coal Company, operating Round mountain coal mines, commenced shipment August, 1892, and their operations indicate an output of 50,000 tons for the fit-st year. The Dillon Land Company, Mrs. Howard, President, owns a considerable portion of Round monntain, but no mines have been operated i1pon thie property, which is the second largest upon Lookout mountain. Besides the Dade Coal Company, the New England Company own extensive coal lands on Sand mountain, but have not worked any of their beds. Smaller interests are scattered over both Sand and Lookout mountain. 261 CHAPTER XXXV. LIUESTONES, LIME ROCKS, CEMENT ROCKS. CONTENTS. LIMESTONES. DoLOMITE. DISTRIBUTION OF LIMESTONES IN GEOLOGICAL FORMATIONS. 00STANAULA LIMESTONE AND ANALYSESj CEMEN'l' ROCK. KNOX DOLO~UTE AND ANALYSES. CHICKAMAUGA LIMESTONE AND AXALYSES. CHARACTER AND COMPOSITION OF LIMESTONES. Limestone is used for constmction and road-making purposes, and for lime and cement manufacture. It is largely nsed as a flux in blast furnaces, etc. The calcareous matter is also a necessity in productive soils, and if not present in them it must be added. Hence, the applications are extensive and variable. Pttre limestone is the carbouate of lime and contains lime 56, aud carbonic acid 44 per cent. It is easily scratched with a knife, as the haruness is 3 ; specific gravity 2.50-2.80. It dissolves with effervescence in dilute acids. Carbon dioxide or carbonic acid gas in water, clissol ves the mineral or rock, to be only again deposited npon escape of the gas from tpe water. Upon ignition the rock gives off carbon dioxide and leaves lime. The rock is rarely pure, but often approaches it with a semi- crystalline texture, and usually light gray color, but it may be of any color, owing to impurities. t The limestone often contains a small proportion of carbonate of magnesia, in which case its general properties are not materially 262 ECONOl\IIC RESOURCES. affected. It is sometimes rendered harder by included silica. The most common impurity is siliceous clay. Indeed, the clayey materials are sometimes present, to. even such proportions as to cause the rock to be considered a calcareous clay or shale. Sometimes the limestone and clay are naturally commingled, or again the clay, as an impurity, may occur in layers. For most purposes, the presence of clay in limestone impairs its value. Iron oxides are ofteu present in the rock, not only enough to give it coloring matter, but in proportion sufficient to affect its character. Organic matter may amount to even several per cent. In small quantities, phosphoric acid is commonly present in the limestone, and this adds to its value for agricultural purpose. Dolomite or J.lfagnesian Limestone is a compound of the carbonate of lime and magnesia, and typically contains carbonate of lime 54.35, and carbonate of magnesia 45.65 per cent. But with this double compound, one or the other carbonate may be in excess. It is a little harder than limestone, bring 3.5-4 degrees, and also a little heavier, with gravity 2.8-3.0. Unless powdered, it does not readily dissolve with effervescence in cold dilute acid. The general characteristics are similar to those of common limestone, and indeed, it is not always popularly distinguished from the latter, as it undergoes the same variations. Hydrnttl-ic o1 cement rocl~ is a limestone or dolomite containing free silica, clay and oxide of iron in such proportions that when burnt the compounds will combine and resist the action of water. DISTRIBUTION OF THE LniESTONE IN GEOLOGICAL FORl>IA'l'ION8. OOSTANAULA LIMESTONE AND ANALYSES. In the belt of country surveyed there are limestones occurring in the Oostanaula shales in the country west of the Oostanaula fault. These are more or less siliceous and clayey limestones, but of variable texture. Upon the western side of and not distant LUIESTONES. 263 from the Oostananla fault (see map), the limestone occurs in layers up to three feet in thickness, and are more or less veined with white calcite (pure limestone). As a type of this rock, partial analysis has been made from a sample, about three miles southwest of Rome. The pure veinous calcite war; rejected in the sample analyzed by Mr. J. M. McCandless, which gives a type of the massive rock: Calcium carbonate __ __ __--- - -- - - --- - -- --- - - --- 74.38 Magnesium carbonate - - --- -- _ -- -- ----- - - - - --- . 8.79 Alumina _____ - ---- - --------------- -- - -- ------ 3.50 Ferric oxide __________________________ --- - -------- _ 2.05 Silica _____________ ___ _ - - - -- -- -- ------ - ------ 10.95 The coloring matter is organic, and consequently in burning, a light lime is produced. Southwest of Rome bluffs of this rock rise 30 or 40 feet above the river. Else,vhere it forms extensive surface exposures. Throughout the enormous development of the Cambrian shales, east of the Oostanaula fault, there are various beds of more or less impure bedded limestones belonging to the shale series. In color they range from dark brown or almost black to light gray; but they are usually dark colored. These deposits vary from 20 to 100 feet in thickness. Near Cunningham station a boring has been made 90 feet into the rock without penetrating it. It is sought for as a black marble, which is quite beautiful, taking a bright polish, but contains earthy matter, and is not highly crystalline. If reference be made to this formation on the map, the occurrence of the limestone may be expected at points not distinct from the margins of the various belts of the shales, and in the valleys. It is also exposed in nearly every stream flowing over the formation. Some of these beds form fairly good building stones, others are 264 ECONOMIC RESOURCES. rich in clay or iron, but they have all withstood the action of the weather. Sometimes these rocks form low bluffs. The limestone is found at numerous places in the narrow belt near the East Tennessee, Virginia and Georgia Railway, from CaYe Spring entirely across Floyd county. In the northeast portion of Bartow county, the limestone is shown along most of the streams, and also ou the sides of some of the ridges. From near Kingston to east of Adairsville there is a belt of about 45 feet of t.his limestone forming a ridge (a section is friven in the geological descri()tion of the formation, page 100). The rock varies in character; some of the beds produce a light-colored cement, which is extensively manufactured by Major George "raring, at Cement. TJ1e composition of this rock is seen in the analysis by the late Mr. vVilliam J. Land. The best bed for hydraulic purposes is a fine grained compact earthy rock, about seven feet thick: I. Calcium carbonate . ---------- _ ----- _43.50 Magnesium carbonate _ . _ __. _ _ . ______ . _ 26.00 Silica ____ ___________ ------ - ______ 22.10 Alumina ____ _______ _______ --- ____ _ . __ _____ 5.45 Ferrous oxide .. ---- -- --- - -- -------- -- --- 1.80 Organic matter ________ __ _ . __ -- __ _ ____ _ 0.15 Watet .. ____ _ ____ ________ 1.00 II. 55.00 26.10 10.00 6.10 2.00 0.50 0.30 Only a very few beds produce hydraulic cement. The cement bed contains much more magnesia than this limestone formation generally does. Its hydrauli c properties are derived from the silica uniting with the lime, magnesia, alumina and iron to form a cement. Some of the beds of the limestone could be used for construction pmposes. Non-hydraulic lime was formerly made from some of the layers. The lime works on this belt were started in 1845 by Mr. Charles A. Howard. In 1851' the manufacture of cement was commenced, and is now largely operated under Major G. H. Waring. The ridge is shown on plate X. (opposite), where also two of the kilns are shown. PLATE XT. LD!ESTONE BLUFF OF TilE OOSTEi'\AULA SHALES AND KILI\S AT CEMENT. LIMESTONES. ~65 The value of cement-making rock depends upon the above named constituents, which may be regarded as impurities in ordinary limestones, being in such proportions, that when the rock is burnt they will combine and set into impervious cement. There is no reason why at many other points on the liml:'stone beds of the Cambrian shales, cement-making rock may not be found, as well as that where it is already operated. Indeed, some of the earthy beds of the succeeding Knox dolomite series may be found valuable for hydrauli~ purposes. In the valleys of the various narrow belts of the Oostauaula series, west of Hocky Face and Taylor's Hidge, similar limestones also occur. LIMESTONES OF THE KNOX DOLOMITE SERIES AND ANALYSES. Most of the calcareous beds of this series are magnesian limestones or dolomites. The structure of the formation is de- scribed in the first part of the report'; only from the economic standpoint are these rocks considered in this chapter. whilst some limestones are in thick layers, others do not show well defined and uniform bedding (see plate IT.), consequently the compact rocks have often a thickness of many feet. Some of the belts are earthy in texture, others are semi-crystalline. They are commonly more or less siliceous. In color the rock varies from dark to light gray, so that in any quarry a variety of shades is obtainable. The dark coloring matter is partly organic, so that the lime made from the rocks is of a light shade. Tlie more crystalline beds are capable of Y.ielding good building stone and good magnesian lime. The character of the more crystalline but dark dolomite may be inferred from Mr. McCandless' analysis of the rock at Cave Spring: Calcium carbonate __ _ . _.. ________________ ____ ____________ 53.44 Magnesium carbonate _______ ____ .. ______________ . ______ ..41.15 Alumina and ferric oxide _____ ____ _____ , ------- 1.50 Silica . _ ____ ___ _______ __ _ _ ____ ______ . _______ 3. 75 The coloring matter is partly organic. 266 ECONOUIC RESOURCES. Along the western border of the Knox series, there are heavy beds of dolomitic limestone exposed on ridges for a thickness of 200 to 300 feet. It is mostly a magnesian limestone and often of clark color. Its composition is variable, sometimes sufficiently pure for furnace uses, or again containing much clayey matter. This is the same rock formation which occurs east of Cunningham station, and near Hermitage, in Floyd county. East of Cunningham quarries have been opened, as also on another ridge a short distance to the northeast belonging to Mr. Gibbons. At these places the rock is dark brown and mottled with calcite veins. The coloring is from organic matter, and consequently the lime is of light color. It makes a very handsome ornamental stone when polished. As it is somewhat earthy, it is most suitable for inside work, where the polished surface is not exposed to the weather. The following sample is from the "Egyptian Quarry," on the farm of Mr. Gib- bons: The 0omposition of this rock is seen from the analysis by Mr. J. M. McCandless. Calcium carbonate _______________ _- ---- -- - ------ __ 52.05 Magnesian carbonate __ __ ______ ___ ---- ------ -. Alumina __ _______ ____ - - -------- __ ___ - ___ 36.32 2.68 Ferricoxide _______ ___ --- --- - -- -------- ____ :...1 Silica ___ -.___ _ __ _ ___ ___ _____ _____ __ 6.47 The rocks of this horizon have been used for flux at the Ridge Valley furnace, near Herniitage. All the other rocks of the Knox series to the eastward have different physical appearances and characteristics. Of the fine grained, light gray dolomite of Dyke's creek, Mr. McCandless obtained the following composition : Calciumcarbonate _____ -------------- -- ---- ___ __ ____ 52.64 Magnesian carbonate ____ __ _ __ ____ ___ -- _____ ______ 39.44 Alumina and ferric oxide ---- ---- - ---- -------- --- 1.76 Silica__________ ___ _____ -------- ---- -------- __ _ 6.25 LIMESTONES. 267 Three or four miles east of Adairsville, various dolomitic limestones occur on the ridges. Some of these are suitable for building purposes. At only a few points in Gordon county do these rocks occur exposed upon the ridges. Just west of Spring Place, in Murray county, and at other points northward these rocks occur in high bluffs. Some of the dark varieties constitute a kind of black marble susceptible of high polish. It is, however, a more or less impure limestone. Again the same rocks form a bluff at Cedar Ridge in Whitfield county. On many of the ridges of the Knox series, the limestone may be discovered at or near by the summit or npon one of their sides, and also adjacent to the valleys. Still mure earthy ridges are found than on the ridges just described. Exposures are made at several places along the Rome Railway; at the Kingston lime quarry (in operation); at old kiln southwest of Kingston ; at Hardin's Cave, and on many ridges north of the Etowah river. In some cases, these are covered with cherty mantles, but streams often expose the beds of magnesian lime rock at a depth of a few feet. On Ladd's mountain (see plate IV., page 44) three miles southwest of Cartersville, is one of the most extensive quarries opened, \vhich supplies three large lime kilns. Here, an exposure of more or less imperfectly bedded, compact limestones, of various textures, is seen to a height of 150 feet. The analysis of the lime was made by Mr. Pratt for the company: Lime ___________ _- -.-- - -- - _____ _- _-- - -------- 34.070 J\'Iagnesia __ _ - -- -- - -- -- - -- _________ -- -- ____ 55.736 Alumina and ferric oxide ___ ___ . _ . _____ __ _. ______ _ 1.236 Silica_ ______________ .___ __ __________________ ~ __ . 7.252 Moisture __ ___.____ ___ _ __ __ __ __ . . ____ ______ _ 1.622 Occasional layers contain flinty matter which has to be rejected. Some of the layers are suitable for building materials. At various locations, situated on the ridges ofthe Knox series 268 ECONOMIC RESOURCES. in Catoosa, vValker and other northwestern counties, the dolomite rises in cliffs as near the end of John's, and near the Tennessee line at Grayville, where high bluffs have been cut into by quarrying for lime (see local geology), as there are extensive kilns situated there. LIMESTONES OF THE CHICKAMAUGA SERIES AND ANALYSESo These rocks are mostly pure limestone, non-magnesian. They occur adjacent to the branches of the Cedar creek, from Cedartown southoward, along Fish, Camp and Euharlee creeks. On a number of ridges, in the Rockmart district, the limestones rise up to form bold bluffs, but except in this region, they do not form high ridges. The rock is often in compact, thick beds. Many portions are of light gray color. The texture is compact and semi-crystalline, as the limestone is semi-metamorphic. Some of the beds are suitable for building stones. For lime or for fur- naces, their quality may be inferred ftom tbe analysis. Sample from Cedartown, iwalyzed by the late Mr. W. J. Land: Calciumcarbonate ________________ . -- - - _ - -- - 94.37 Magnesian carbonate ___ ' __ __ __ ______ . . ___ __ ... _ _____ 2.10 Alumina __... __ __ ___ - -------- _ _______ ____ 2.23 Undetermined . ---- --- ____ . ____ ______ __ 0 1.30 100.00 Sample from Devitte lime quarry, on side of a bold ridge, ana- lyzed for the Cherokee Iron Company. This limestone is exten- sively used in fluxing and fot lime: Calcium carbonate . _________ ------- __ __ -- - - 95.203 Magnesian carbonate _ _____ -- --------- Alumina and ferric oxide _____ . __ 0 _ _ _ _ _ _ _ _ _ _ ___ Insoluble .. _____ . _____ _____ . ____ _________ _ 2.171 0.400 2.300 100.074 Various other ridges are favorably situated for the extraction of limestone, but they do not occur outside of the district given. LUfES'fONES. 26 9 This rock afforrls our best non-magnesian lime. The limestones exposed in the valleys at the edges of the Rockmart series, in the narrow basin of.Murray and Whitfield counties, are of similar character to those in Polk county, although less extensively developed, but they are available for local uses. In the belts of the Chickamauga series in Walker, Dade and other counties the limestones are sometimes in thick, compact beds, but more frequently the laminations are more developed than in the Polk district, as also their earthy character. Still there is considerable variation, from quite pure limestone to others very impure as may be seen south of Trenton. In the valley of Lookout creek there is a fine grained, .compact, light-colored limestone, which yielded Mr. McCandless the following analysis: Calcium carbonate________ -- ___ . __ __--- -- __ __ _-- -- _ 55.47 Magnesiancarbonate ______ - ----- - ---- --- ---- --- 25.33 Alumina and ferric oxide (mostly alumina) - -- - .. _ __ _ 9.50 Siliceous residue ___ ___________________ ------ ----- - 8.16 98.46 This rock has the appearance of lithographic stone, but breaks with a conchoidal fracture. Near by (south of Trenton) another light-colored, but crystalliue rock, is of much greater purity. Calcium carbonate _____ __ ___ __________. _ _------ ______ 91.40 Magnesian carbonate _______ ___ _ _______ -- - .. ----- - 3.75 Alumina and ferric oxide __ ____ ____ __ ____ _.:_ ____ ____ ].80 Siliceous residue ___________ ____ _ ___ _ - --- - - -- - -- -- - 2.82 99.77 The limestones of the Chickamauga series furnish abundance of road material, and by selection good lime and building material, which last is often in layers of convenient thickness. ~70 ECONOJ\IIC RESOURCES. DEATON LH'I:ESTONES. As a building material, this series does not furnish a source for limestone. But some of the ferruginous beds, as at the Deaton mines, contains 30 per cent. of iron and are self-fluxing and may yet be used in that connection. RED MO'C'NTAIN LUiESTONE. Amongst the shales of this series only occasional thin layers of limestones are seen above the drainage leyel. But in mines below the drainage beds level, a foot or more in thickness occur. They are commonly earthy and siliceous and usually somewhat ferruginous. Except in connection with .mining iron ore, they are of no economic value. FORT PAYNE LIMESTONES. These limestones are too much commingled with chert to form good building material, but they produce excellent road material. They usually occur at the edge of the Mountain Limestone, and on ridges succeeding the "fossil" ore beds. FLOYD LUIESTONES. west of Rome, and elsewhere, there are limited exposures of heavy bedded limestones, occurring in this formation, forming good building material and also lime. But the exposures are not numerous. MOUNTAIN LU!ESTONES. This rock is of enormous development upon the sides of Sand, Lookout and Pigeon mountains, being most uncovered at the northern end of Pigeon mountain. It occurs in thick beds, and is available for building purposes of all kinds. The color is often attractive. The rock has usually a compact texture. It varies in degrees of purity. High up upon the eaotern side of Sand mountain, a variety with crystalline texture yielded Mr. McCandless the following analysis : LIMESTONES. 271 CalCium carbonate . ___________ ------ -- .. ------- . ___ . 80.60 Magnesian carbonate __ ..: .. ---- --- .. ---- --- --- -- __ ___ _ 2.45 Aluminaandferric oxide .------------------------ 3.20 Siliceous residue __ ------- -- - --- -- ----- - ----- _____ 12.70 98.95 The upper beds are often the more earthy. Near the base of the series, at Rising Fawn, the rock yielded (J. M. McCandless): Calciumcarbonate ____________.________________ ______ 96.13 Magnesian carbonate _________ _____ ------- - --- ____ 2.05 Alumina and ferric oxide__ .. ________________________ 1.00 Siliceous residue _____ . _____ .. _- __ _ ____ . ___ . _ . _ . ____ _ 0.95 100.13 From these analyses it may he seen that there is a great range in the varieties of limestones, but such as yield excellent lime, good for furnace use and of qualities suitable for building purposes, with often a fine gray or bluish color. 272 ECONO.i\JIC RESOURCES. CHAPTER XXXVI. SANDSTO~ES. CONTENTS. OF 'HIC CHILHOWIE SERIES. OF THE OoSTANAULA SERIES. OF THE RED MOUNTAIN SERIES. OF THE Sun-CARBONIFEROus SERIES. OF THE COAL MEASURES. OOSTANADI,A AND CHILHOWIE SERIES. Quartzite or crystalline sandstone, of beautiful fine grained texture, is found on uncovered cliffs, in abundance, on Indian mountain, near Etna. Owing to its hardness, the cost of building material is high, but when needed, the quantity and availability of this durable material is unlimited. At a few points in the ridges south of Rome, along the eastern side of the Oostanaula fault, Randstones occur, but the beds are rarely two feet thick, and are not generally exposed at the J of iron, are unsuitable, as these give too great fusibility, so that the bricks will not stand the high temperature of the kilns, or become too brittle. Shales are often more desirable than clays, as they contain less grit, which causes the brick to wear more rapidly away. Again, good pavers are made from an admixture of fire clays or semi-fire clays, which will fuse the whole together; but the less mixed materials are those preferred. These notes on brick paving, are added as an accompaniment to good roads, which belong to the province of the engineer, but the question of clays belongs to geology. CJ,AYS OF NORTHWESTERN GEORGIA AND ANALYSES. COJ\IPOSITIONS OF CLAY. Pure clay or kaolin contains : Silica _____ _ ___ ______ _ . ____ ______ ___ . . ____ - ------ Alumina ____ ______ ______ - - - _ . _.. __ __ _ _____ ___ Water _______________ __ _____ ____ ___ ____ _ -- - --- - -- 46.3 39.8 13.9 100.00 It is primarily derived from the decay of feldspar or similar minerals. Comparatively little clay has the above simple composi- 280 ECONOll:liC RESOURCES. tion. Generally a portion of the feldspar is only partially decomposed, and contains potash or soda. So, also, lime and magnesia may be present in traces. Iron, with smaller portions of manganese, is commonly present even in light colored clays, and in colored clays the quantity of iron is often large. In onr Georgia clays there is often a remarkably large per cent. of titanic acid. In addition to all of these constituents, which are present in onl.v small percentages, there is an admixture of ,free silica. Indeed, the clayey character of these superficial earths is maintained when the quantity of alumina is diminished to only~a few per cent., owing to the exeess of free silica. In nature, the silica often increases fio that the earths pass into clayey sands rather than sandy clays. In north western Georgia, there are several types of clay-(1) the kaolin-like clays, (2) the clays derived from the decay of limestones and calcareous shales, (0) tho3e formed from the disintegration of shales, and (4) alluvial deposits. K \OLIN TYPE. These clays occur ae "horses" (see figure 22, page 155) or in sheets or pockets in the residual earths, derived from the decay of the Knox dolomite and Fort Payne chert series. Sometimes they are pure white, with occasional stains of iron, or the stains may pervade the mass in the form of streaks. Again, the clay::; are of purple tint. They often occur in large bodieti. In the cherty remains of other portionf:i of the Knox dolomite, the silireoul' nodules are imbedded in white, siliceous, chalky clay, as near Cave Spring; or in Lookout valley, in Fort Payne chert. From this siliceous matter, the white clay could be mechanically separate hold the waters where the drainage is bad. East of the Oostanaula Fault the border is characterized by crested l'idges, eastward of which the shales generally form valleys. This is true in most places, where the shales are in belts from one to four miles wide. In the northeastern portion of Bartow, and thence northward, the shales form many valleys, but there are numerous .\i ba l. - uv r 'I] i llitlt' v ui ng d dp. . Spenkin g gencral.l y tb t ~td s l'nnnin~ inn nor t heast ruuucl Ppposit dire in lntve!!O d ~fa ir g mrli ents, aml on. the ridge t h .gtA.(Ii nts ae no difficult. Except ~l ll l'O' .i11 th ' J'i yd, Bartow, and to a small extent in Gordon a.nd Whitfield counties, and in the counties to the westward,. the vallE>ys are often narrow.. The roads trending longitudinally bave good gradients in most of the large valleys, but in the narrow valleys, their heads are marked by heavy gradients. Hoadscrossing these ridges from east or southeast to the westward can sometimes be built so as to pass around the hills; but more ftequently tbey cross some portions of them, and then the grading may be vety bad, as ridges from 200 to 300 feet have to be ascended, and not always by gentle inclinations. These roads, apart from the main thoroughfares, are often very difficult of travel. And the "bad road" in a given region is only a relative expression; for on a so-called good mountain road, I have had a carriage wheel broken by weight of the load thrown obliquely upon it. These sharp ridges have commonly loose cherty rock upon their surface, which could be used for road metal. Amongst the red lands of the Knox formation, the conditions obtain for good roads, but the mud may often be deep, the gray lands are more siliceous, and much less muddy. THE LOCATION OF ROADS. 293 ROADS ON THE CHICKAMAUGA SERIES. The limestones usually form valleys, often broad, with. good gradien"ts; however, there are some bold knobs or ridges in the Rockmart district. The residual clay of these limestones forms deep, sticky mud when wet, and afterward leaves hard rutted gror~ond. In many places the limestones, in variable beds, floor the valleys and form rough stony roads, where these are not properly built, as seen in vValker and other counties. The shaly lands, in places, are in gentle undulations, but other slates form bold ridges, as near Rockmart. ThesB soils are commonly shallow, and seldom produce deep mud. There is u,;ually limestone for road-making in proximity to the Chicimmauga soils, which, more than any, need macadamized roads. The shale roads' .are often faidy good, without al'tificial improvement. ROADS OVER THE RED MOUNTAIN SERIES. Roads upon this formation are almost invariably across narrow ridges, along which there are no longitudinal highways. Amongst the shales, there is much siliceous material, and the muds are natumlly deep. There are always enough sandstones, or flaggy sand rocks at band for making good road material. This formation give<; rise to the bold ridges-Taylor's, Lavender and others noted.across which there are only occasional roads, which are steep, .owing to the ascent, of several hundred feet. Across the lower ridges, such as Shinbone, these roads are needed at only few localities, and the gaps are generally low. ROADS OVER FORT PAYNE CHERT AND FLOYD SHALE. This chert gives rise to crested hills which are often steep. Along these ridges roads are seldom constr.ucted, but highways often cross them. The surface is usually covered with cherty fmgments or gravel. Roads along the foot of such ridges are gravelly. The Floyd shale gives rise to sandy clays which do not produce deep 294 ECONOMIC RESOURCES. muds, but often these are flat lands, and the ,'loil holds water. Some of the calcareous shales form a good road material. ROADS ON THE MOUNTAIX LIMESTONE SERIES. The residual clayey lands derived from these limestones occur only on the. sides of the mountains and in the narrow valleys between them, and ridges covered with Fort Payne chert. These clays produce heavy roads in wet seasons. Owing to the proximity of the gravel on the cherty hills good road-making material is at hand. On the mountain sides, where the limestones come to the surface, the roads are commonly rough, as the ledges of rock are not properly graded. ROADS 01\ THE COAL MEASURES. On the plateaus of these deposits, the roads are usually very sandy, but occasionally cross flat exposures of rough sandstones. On ascendi~g the mountains, the sandstones have to be crossed by the roads winding along the mountain sides to the top of the plateaus. As these passes are nDt generally well built, or when built, are subject to the greatest damage from rains, we find some of the roughest roads in the state-this condition arising from waut of properly constructed roadways, for the materials are at hand for building good highways. SUMMARY. Roads runmng northeastward and southwestward have been or could be located with good gradients. At right angleR, the ridges can often be avoided, but very commonly such is not the case, where the crossings are often poorly located and badly conBtructed. The roads on the soils derived from the Oostanaula shales have often good gradients, and the mud may not be deep. The gray Knox dolomite ridges form a broken country, but the mud is siliceous and not deep. The roads on the red lands of the '!'HE LOCATION OF ROADS. 295 series have better gradients, and are muddy in wet seasnns, followed by ruts through hardened mud. The muds of the Chickamauga limestones are apt to be deep Th~ roads in the Rockmart slates are not deeply muddy. Materials for road-making are often conveniently near the highways. The roads on Red Mountain series only cross the ridges, and the quality depends upon their gradients, as the material generally produces fine road beds, except when there are sandstone ledges, which produce rough roads that ought to be properly broken and macadamized. The Fort Payne chert gives rise to gravelly roads, which only cross the ridges. The Floyd shales produce sandy clay roads over flat lands. The Mountain Limestones form muddy clay roads upon the mountain sides and in narrow valleys. The Coal Measures originate sandy roads npm~ the plateaus; and tipon the mountain sides the sandstones produce rough, stony roads, where not properly b~ilt. NOTES ON CONSTRUCTION OF ROADS. The two greatest impedi'ments in gradients of the roads are: (1) the crossing of spurs in valley roads, when there is no obstruction that would have prevented the road being built around it; this condition is a too common blunder; (2) in crossing ridges or spurs t.be crest of the ridge is cut thus : FIGURE 27.-Showing bad gradients of roads (abc), especinlly at the summit (D), which is rarely graded in keeping with the rest of the work. This outline has in part arisen from some attempts at grading, which is often very good to ncar the crest, where the gradient is so 296 ECON,OMIC RESOURCES. steep as to demand the greatest possible strain upon the horses in order to gain the summit, and then only to plunge down a declination of the same shape. This outline is not alone due to bad construction, but is the fault of nature and negligence of man. It .arises, in part, from the road washings during heavy rains. In every case the crest should be removed, for in its upper portion the strain is greater upon the animals than the tension upon the remainder of the ascent. On the roads, crossing the ridges, oftentimes more gradual .ascents could be made. Throughout the belt surveyed, it may be .generally said that the roads running parallel with the ridges are fairly well located, with the exceptions mentioned. The roads do . not generally, except as stated, become so "bad" .as in many clay districts of the north, or elsewhere, even in the state, owing to the more or less sandy constituents of the residual soil; still they need great improvements. With a snpply of road metal much of the district is provided already. SOURCES OF ROAD MATERIAL. In the region of the large rivers s01ne gmvel is available. The limestones of the Oostanaula shales afford numerous local supplies. The chert ridges of the Knox dolomite series, and Fort Payne t, they must be laid out by competent engineers, and constructed under re- sponsible supervision, and not under neighborly direction at a semi-picnic frolic. It has been estimated that the loss occasioned by bad road::> costs the United States no less than $350,000,000 a year. What people do not directly pay for, they do not feel, but he who provides against losses is the thrifty and well to do man, and so with States; for extravagant wastes and the gloomy side of bad roads ought not to be perpetuated. The bright side of good roads is not merely in dil'ect profits, but the increased value of lands and the increased comfort in travelling. A country without railroads is cheap to-day. A district from which it costs more to convey the product to the nearest market than from it to the markets of the world must also be cheap. This cheapness is overcome by good roads. In another State, cmnks, we are told, wanted good roads. They were ridiculed_; one man built a mile of good road at his own ex- pense. This object lesson, rising above laughter, soon resulted in seven good roads through his county. Not far from a great city a farm was worth fifty to seventy-five dollars an acre, but could not be sold. The owner farmed at a loss. At last, a good road was built, and the land was then sold for $200 an acre, with facilities for turning it into a truck farm. As t~is question of roads is one now attracting great attention, both in Georgia and elsewhere, the digression of the subject may be excused, as duty has carried me into the question of the relations of the roads to the geological formations of northwest Georgia, and the materials for their improvement. PART III. SOILS OF THE PALEOZOIC GROUP OF GEORGIA, IN POLK, FLOYD, BARTOW, GORDON, :M:URRAY, WHITFIELD, CATOOSA, CHATTOOGA,WALKER AND DADE COUN'l'IES. BY J. W. SPENCER, PH. D., STA'rE GEOLOGIST, AND I H. C. WHITE, PH. D., PRESIDENT OF STATE COLLEGE . (309) SOILS, 311 AGRICULTURAL FEATURES REPRESENTED ON THE GEOLOGICAL MAP. COAL MEASURES . . .. ... . . Table lands, poor sandy soil. MOUNTAIN LIMESTONE . Mountain sides and valleys, fair soil. FLOYD SHALES... ... ' .. Flats or valleys, thin soil. - FORT PAYNE CHERT..\ .. Gravel ridges, little soil. CHAT. BLACK SHALES . . . Narrow valleys, no surface soil. RED MOUNTAIN SERIES . Crested ridges, little soil except on sides, there fair. CHICKAMAUGA SERIES . Valleys and some ridges; good soil. KNOX DOLOMITE . . ... .. Gray cherty ridges, gray and red plain and valley lands; latter very good soils. . OOSTANAULA . .. ' ......... Wide valleys, good soil; ridges, thin and poor soil. METAMORPHIC FORMATIONS .................. Mountain ridges and valleys, on the border of the Paleozoic group of rocks; this soil often thin and poor. 312 ECONOMIC RESOURCES. CHAPTER XLII. FORMATION AND CHARACTERISTICS OF SOIL OF THElPALEOZOIO BELT OF GEORGIA. CONTENTS. COLOR DISTINCTIONS. ORIGIN OF THE MATERIALS OF THE SOILS. How THE SoiLS WERE FoRMED: The Formation of Limestone Soils as illustrated from the Knox Dolomite Series; Sources of Plant Food in Limestones; Formation of Shale Soils; F most needed. Prof. Hilgard's long careful studies have shown that a valuati(ln of the soils may be derived ftom the analyses, when based upon solubility of the r.omponents, and in this case rejects those portions of the elements of plant food which are not soluble in diluted hydrochloric acid. In the analysis of the soils given in this report we have the quantity of both the soluble and in:-;oluble lime, potash and pho;,:pboric acid, upon which deductions can be based. ,Lime.-Ptof. E. vV. Hilgatd ha;; found that the percentage of available lime present in productive l:loil must not fall below 0.100 per cent. in t.he lightest sandy soil; in clay loams not below 0.25; and iu heavy .clay soils not below 0.5 pet' cent., and better still, 1vith even 2 per cent., above which it i~> of no special value, except mecl\anically. Pho8pho1ic Acid.-If the pho~:>phorie acid be less than 0.05 per cent. there is a serious deficiency. In sandy loams, with lime 0.10 per cent. of phosphoric acid renders soil fairly producti\e for eight or fifteen years; if lime be deficient, double the amount is required. He has fuuud the soluble pho~>phoric acid present in splendid table- 326 E CO NO~IIC R ESOUR CE S. lands of the Mississippi river to the extent. of .30; whilst on the black prairie of Texas, it bas amounted to 0.46 per cent.. Potash, if present to less than .06 per cent. in soils, shows them to be deficient in alkali. Deep sandy soil with less than 1.00 per cent. may be productive. With the amount of clay in the soil, the potash increases. In 8andy loams it fall below .30; in clay loam:'; it ranges fl'Om .30 to .50 per cent. Soda to the extent of from one-eighth to one-third as much as the potash is sufficient. Sulphuric Acid to the extent of 0.02 or 0.04 is adequate. It rarely amounts to more than 0.1 per cent. Chlorine is of only slight importance. It is always present in sufficient quantities. Fer-ric Oxide is a necessary plant food perhaps, but Hilgard finds its greatest benefit derived from the absorptive power of ferric hydrate. Red lands resist drought better than light colored lands. (The moisture also depends upon humus, clay and lime.) The per:;entage of iron varies. From 1.5 to 4.00 per cent. in some conditions may only slightly tint t.he soils. But the red lauds may contain 12 or even 20 per cent. of ferric oxide as previously noted. Red lands also appear to be a carrier of oxygen and facilitate nitrification, even though the soil contains a high percentage of humus. But damp red lands (from bad drainage or overflows) reduce the ferric oxide to ferrous salts which blight the crops. Moistwe.-At 60 Fah. cultivatabl8 soils contain from 1.5 to 23 per cent. of moisture. Pure clay seldom exceeds 12 per cent., ferruginous clays and also calcareous clays 1.'5 to 21 per cent.; and in peaty soil it may rise to 23 per cent. Physical Condition.-Beside the chemical composition ofthe soil, its physical characteristics have a strong bearing upon its agricultural value, such as texture, abs0rption of moisture, heat, etc.; and the physical features of the land, bottoms, plains, hillsides (steeper than 20 are almost 1 navailable), etc. SOILS. 327 THE CONSUMPTION OF MINERAL CONSTI'l'Ul~NTS OF PLAN r FOOD BY COT- TON, CORN AND WHEAT. The consumption of mineral _constituents by cotton, corn and wheat has been calculated by Prof. E. W. Hilgard; the area pro- ducing the crop is assumed as an acre in each case. The determina- tion here given explains agricultural phenomena in connection with the soils of northwestern Georgia. O~yel!t Bartow, central Gordon, and elongated basins in Murray, W:hitfield, Catoosa, Chattooga, Walker and Dade counties. The lower beds of the geological formation give rise to fertile red lands, whilst the higher and more siliceous members originate gray> cherty ridges and undulating gray plains. (22) . '338 ECONOMIC RESOURCE!'~. These two groups of Knox soils are very strongly marked. The ,first consists primarily of red loamy lands, from yellowish to deep rorange red loaq1s and heavier underlying clays. The surface is :sometimes more sandy and of light color, where a portion of the 1red clayey matter has been washed out. When of deep color, 'granules of brown ore or limonite are scattered through the soil. 'These soils are usually stoneless, or in occasional localities contain chert, as on some red ridges and hillsides. 'These lands, together with the shale valley lands just described, form the best soils of northwestern Georgia, which are amongst the best in the State. They are commonly adjacent to the shales of the valleys, but, again, the erosion has not removed them to depths :sufficient to expose the shales, as in the valley of Cedar creek, in Polk county, or along the broad red belt from Fit:>h creek extending 'into southeast Floyd and onward to the Etowah river in Bartow county. In the large valleys, and adjacent to the neighboring formations, shown on the map, such lands prevail. Again the red lauds appear upon the margin of the series south :and near Dalton. The red lands prevail on the ridges and in the valleys of the so nth and central portions of Knox belt in M turay County. East, near Varnell, the red Chickamauga lands resemble the red Knox soils. On portions of Missionary ridge and other ridges west of Taylor's ridge limited areas of the Knox soils are red, hut the gt'ay generally prevail. Red alluvial deposits ocour on some of the hills in the river regions to an elevation of from 80 to 150 feet, which is liable to be mi~:~take n for residual red soils derived from the dolomite series. These have a character of their own, and when they contain rounded gravel they al'e readily identified; but without gravel they a1e liable to misidentification. Such deposits are on hills within from one to three miles of the rivers. The red so.ils are widespl'ead on subordinate ridges, adjacent to SOILS. 339 !the valleys where they occur. On the summits of some of the .higher crested gray ridges they also occasionally occur, in which ~ase they are more stony than in the valleys. The red ferruginous ridges are often poor in phosphoric acid and humus. In the valleys the available acid may be sufficient. Only this one mineral element of fertility is necessary to be added where the soils have been ex- ;amined. But on the iron ore bearing knobs the red soil is deficient .in organic matter as well as in phosphoric acid. The following analyses were taken as types. No. 8 is soil from ~the farm of Dr. W. I. Benham, situated in a broad valley about four miles west of Cartersville. It is deep red loam and composed -Df very small earthy granules and free quartz. It is highly fertile. _No. 9 is a deep red soil on an ore bank four miles southwest of KingRton. It is composed of rounded grains of quartz (-lo to Th --of an inch in diameter), coated by a large amount of clay. It is -very deficient in available phosphoric acid and organic matter, but -contains a fair share of unavailable acid. No. 10 is from the surface of an ore bank southwest of Cedar- town. It is composed of rounded grains (1 h of an inch) of quartz :in much clayey matter. It is very deficient in phosphoric acid and Drganic matter. In both No. 9 and No. 10 the ferric oxide is in ,great excess, the clayey matter is in abundance, and the soil is sti.ffer than usually seen on Knox soi-ls. Analysis Nos. 8-10. No.8. Lime (total) . . . . . . . . . . . . . . .. .. .. . .. . .. . .. .. .. . . 6. 708 Magnesia........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.214 Potash (total) .. .. .. .. .. . .. .. . .. . .. .. . .. .. .. .. .. il.821 Soda.............. . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . 1.732 .Sulphuric acid ........ ....... .. . .......... .. .. . 0.114 Phosphoric acid (total) . . .. . . . .. .. .. .. .. .. .. .. .. . 0.321 'Ferric oxide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. 750 1-ilica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 .135 Alumina .............. . .... ... ,,.... . . . . . . . . . . . 6.110 Water. . . . . . . . . . . . . . . . . . . . . . .... . .. . .. . , . . . . . . . 3. 720 Jrganic matt;e.. . .... .. . .. .. .. . .. .. .. . . .. .. .. . .. 4.654 l nO.aterm ilJed, losa_; etc. , . ... . . . . . . . . . . . . . . . . . . . . . 0. 731 No.9. 3.111 1.021 tl 671 1.101 0.420 0.063 10.356 64.500 12.680 4.310 1.204 0.563 No. 10. 3.040 0.876 0.462 0.112 0.238 0.042 10.2Ul 66.61!'! 12.340 3.600 2.104 0.354 100.000 100.000 100.000 340 ECONOMIC RESOURCES. Lime (soluble in acid) ................ . . .. . ... .. . 5 . 619 Potash (soluble in acid). . . . . . . . . . . . . . . . . . . . . . . . . 0. 509 Phosphoric acid (soluble in acid) . ............. .. . 0.242 2.570 0.408 0 . 044 2 .493' 0.27Z 0.030 In the value of the red valley lands, derived from the shales or the dolomites, the variation is not so great as between them and the red ridges, some of which, however, are rich, but generally poorer in phosphoric acid and humus than at lower levels, The ore,bearing ridges are, agriculturally, the poorest of the red lauds. The growth of timber is red, black, post and spanish oaks, hickory and dogwood; and some short-leafed pines, black-jacks, etc., on the poorer ridges; also some walnut, chestnut, gums, etc., on the lower lands. GRAY SOILS. These are derived from the siliceous members of the upper Knox dolomite series. The surface usually is covered with chert, left upon the solution of the calcareous matter, on or in the gray soil. Beneath the subsoil may be yellowish or reddish. where the chert is abundant the soil is often almost sterile. Upon the western side of the Knox belt the gray lands occur mostly upon ridges of a broken character, some of which are surmounted with a red soil upon their summits, that are sometimes stony. The intervening valleys are often narrow, bnt many contain fertile soils. These ridges have been protected from erosion by the cherty gravel covering, which, however, is more or less superficial. The eastern side of the Knox belt, in Polk and Bartow counties is characterized by more gentle, undulating country, with less cherty gravel, and indeed, it is often entirely free from it. In pr?ceeding northward, this characteristic increa,'!Cs in importance, so that in northern Bartow and acroBs Gordon county, the gray lands are mostly stoneless (except ridges upon their western border). This undulating character prevails on various belts in Catoosa, whitfield, Chattooga, Walker and Dade counties, but with interrupted ridges and valleys. In these counties the gray SOILS. 341 laud is seen in valleys as well as ou sides and tops of the ridges. There are many lime sinks scattered over the formation. The rolling lands are sandy loams, with ofoon little or no cherty gravel, :and with a yellowish subsoil, with sometimes the character intermediate between the red and the cherty gray lands. The soil is often of very fair quality (as sbown in analysis No. 11). The composition of some types of the soils may be seen from the analyses. No. 11 is from near Seney. It is gravelly land with little depth of soil. It is composed of particles of semi-glossy -earth, and some rounded quartz grains (2 -h- to 2 h- of an inch in (liameter ). It is very siliceous soil with a small amount of iron. It is badly deficient in phosphoric acid and low in humus. No. 12 is a sample of gray soil two miles south of Cedar creek, in north Bartow. It is composed of a glossy matrix, the particles of which are less than olu of an inch in diameter, in which there are rounded quartz grains 2 1J-0 of an inch. Here the available potash is low and the phosphoric acid very deficient. On the farm of Mr. Osbnrne Shaw, three miles north of vVooley's ferry, No. 13, is a drab, gray, mellow siliceous soil composed of rounded grains of quartz (-lo of an inch in diameter) loosely embedded in a small amount of earthy matter. This gray land is on the :mmmit of a rolling country and produces good crops. The analysis shows a soil with more than sufficient available min-eral food, but the humus is not abundant; still the crops are good. No. 14 is a dark gray soil near ~Wooley's ferry. It is composed of crystalline particles in an opaque matrix composed of very small grains. It also contains so1ne rounded particles of quartz ( rh of an inch in diameter), This soil is not stony. It is low in available lime ; deficient in available potash, and very poor iu phosphoric acid. Tbe quantity of iron is large, and the objentionable condition of ferrous oxide favoring the light color prevails. No. 15 is a gray soil (analyzed by Mr. McCandless) just west .of Taylor's ridge, on the road from Lafayette to Greenbush. There 342 BCONOMIC RESOURCES. is considerable variation in all of the soils of the same formatiow:: between those situated east and west of Taylor's ridge. Analyses Nos. 11-15. No . 11. Lime (total) .... .. ... . . . . ... _ 1.240 Magnesia ....... . ....... ....... . 0. 092 Potash (total) .......... ...... . . 0 .262 Soda .... . . . .... .. ...... ....... . 0 .314 Sulphuric acid . . ........ .. . .... . 0 .092 Phosphoric acid (total) ........ . 0 .01.') Ferric oxide .... . .... . . . .... ... 2 .962 Silica . ... .... . ........ . ..... .. 82 .018 Alumina . ............ . . ...... . . 5 .352 Water . . . .. . ... . ...... . .. . ..... . 3. 115 Organic matter.. . .. . .... .... .. . 3.675 Undetermined, loss, etc .. . . . . 0 .863 No. 12. 1. 62.'5 0.732 0.156 0.210 0.096 0.034 3-212 79.326 6.821 2.312 5.111 0.365 No. 13. 2. 964 1.213 0.436 0.287 0.183 0.240 3 .231 79.039 4.794 2.648 4.113 0.872 No. 14-. 1.04-2 0 .021 0 .092 0 .064 0.0140 .028 10 .350 84 .781 4.222 2.606 3 561 0.354 No. 150 .16(} 0.133 0.54& 0 . 359 0.056 0.071 2.306 86.435 5.224 0 . 7663.5340 .41(} 100.00Q 100.000 100 .000 100.000 100 .000 Lime (soluble in acid) . . . 0. 943 Potash (soluble in acid) ......... 6 .H1 Phosphoric acid (soluble in acid) 0 .008 0. 304 0.072 0.019 2 . 611 0.251 0 .171 0. 769 0 .043 0.018 0. 089 O.HJ7 0 .041 From the analyses a great variation in the value of the gray laud may be seen; yet it is thought by many to be better than red land for cotton (with use of commercial fertilizers), as the bollsdevelop well upon a smaller growth of the weed. These lands are warm, and, in wet seasons favor the growth of cotton lint which consumes very little mineral food; still much of this gray land, especially the more rugged, is not cultiyated, whilst the less stony in Gordon county is largely under cultivation. THE SOILS OF THE CHJCICAMADGA SERIES. These soils vary from red to bluish clays. When derived from the limestone they are confined to narrow belts from Cedartown southward,:in the Fish creek district and also in the Rockmart district. They also occupy many long basins in Murray~ Whitfield, Catoosa, Chattooga, Walker and Dade counties. They often border and join the soils of the Knox series and have similar character- SOILS, 343~ istics to the red soils, but form heavier clay soils. They form some of the best soils in Georgia. During wet seasons the roads across them are the muddiest in the State. The shales or slates from which some of the soils are derived, are. closely connected with the limestone members of the series. The more shaly beds occur principally in Polk county; and although they occupy those elongated belts in the northwest counties, as shown upon the map, the separation from the limestone soils are less marked. These soils are grayish or sometimes reddish and shallow, when the splintery slates come near the surface. When they have disintegrated into mellow land, the soils are loamy. The better soil contains an abundance of lime and potash, with sufficient phosphoric acid to produce fair crops, but rather low in availability. Analysis No. 16 is a sample from a mile east of Berry in Polk county. It is thin and of dark gray color, and mostly made up of subangular grains of quartz (2i0 of :m inch in diameter) in a small amount of earthy matrix. No. 17 is of the sam!:J kind of soil as No. 16. It lies on a low ridge, one and a half miles east of Cohutta station in Whitfield county, and occurs immediately above disintegrated shale. Soils in Murray and 'Whitfield counties are derived from beds more calcareou&J than in Polk county. It is composed of vitreous parti- cles and rounded grains (rlo to ofro of an inch and less in diam- eter) in opaque earthy matrix. The soils in both cases are fairly productive, but need more or less phosphoric acid. In the former in sample, the organic matter is rather low; the latter, it is large and the land more productive. :344 ECONOMIC RESOURCES. Analyses Nos. 16 and 17. No. 16. Lime (total)---- -- _________ _ _ . ___ __ 2.643 , Magnesia ____ __ __ --- ------- ------- -- Potash (total) - - ---- .. -- - ---- - - - -- . Soda ___ ___ __ _____ _ ___--- - --- -----Sulphuric acid ___ _ ____ ___ ____________ _ Phosphoric acid (total) -- -- -- ___ ____ _ Ferric oxide _____ ___ ______________ ____ . 1.106 0.520 0.231 0.164 0.067 4.204 :Silica _____ ___ -- -- --- - ----- - ---Alumina .. - - - - -- -- --- -- - - --- ---Water ______ __ ______________ _ 77. 826 4.252 3.516 Organic matter --- --- - ----- - .. - - -- - 4.710 Undetermined, loss, etc. ___ ______ ___ ___ 0.761 No. 17 '1.536 0.648 0.243 0.108 0.193 0.104 4.126 74.723 4.762 2.455 10.623 0.743 100.000 Lime (soluble in acid) _____ ___ --- ___ _ Potash (soluble in acid) -- - -- - - -- ___ _ Phosphoric acid (soluble in acid) -- - - - --- 2.209 0.311 0.049 100.000 1.307 0.132 0.058 SOILS OF RED MOUNTAIN SERIES. Soils of this formation occur only on the ridges as shown on the geological map. The soils are somewhat similar in productiveness to those of the red variety of the Knox series, but with the lime very much leached out, as would be expected from their occurrence on the hillsides. The laud is sometimes shingly. A type of these .soils of deep red color is seen in an analysis (by Mr. McCandless) '0f a sample from the eastern side of Taylor's ridge on the LafayetteGreenbush road. SOILS. 345 Analysis No. 18. Lime (total) _ -- - -- ------ -- __ _ -------- 0.078 Magnesia, ______ .... ______ .. _. __ - . _. _________________ _ 0.128 Potash (total) ---- - -- --- - -- ------- -- ---- --- 0.46.1 Soda --------------- - --------- - ---------- 0.321 Sulphuricacid __ ------ - -- ---- - -- -- - ---------- 0.073 Phosphoric auid (total) . ... __ ---- ---- -----.------ -- _ 0.135 Ferric oxide ------ ------------------------- ---- 6.655 :Silica __ - ----- -- - .. ---- -- --- - -------- __ . _ 73.304 .A lumin a. ____ ------ __. -- _ ____ . ___ __ ____ _ 12.305 Water (hygroscopic) __ ______ - - - --------------- ___ _ i.858 Organic matter and combined water_ . _------- -- _ ___ _ 4.542 Loss ---- ---- -- ------ --. ------------- -- 0.138 100.000 Lime(soluble in acid) - -- --- --------- - ---- ---- 0.032 Potash (soluble in acid)- . _______ __ .. ------ ______ ______ 0.298 Phosphoric acid (soluble in acid) __ ___ . __ - . - _.... __ 0.096 SUB-CARBONIFEROUS SERIES. The Fo1't Payne chert forms a poor stony soil which is mostly confined to the ridges that are shown upon the map or bordering the other Sub-Carboniferous series in belts too narrow to be shown upon the map. These stony belts are unimportant. The Floyd shales constitute a considerable portion of the "flatwoods" of the lo,ver basins and are poor lauds and ill drained. This deficiency does not rise entirely from the absence of plant -food, although the phosphoric acid is often low. The region is often uncultivated. Amongst these .shales there are various calcareous .beds. This formation extends up into the west Armuchee valley where a sample of soil was analyzed by Mr. McCandless: 346 ECONOl\UC RESOURCES. Analysis No. 19. Lime (total) -------------- --- - ___ _ ------Magnesia ._ ____ ____ __ _ - - -------------- ---~otH.sh (total) . --------- - - __ _____ ____ ---- oda _____ . ___ __ ___ . __ ____ .. __ . _ _ __ . __ . . . Sulphurir, acid. ____ __ _. __ _ ___________________ ___ 0.158' 0.2230.508 0.315 0.089 .Phosphoricnoil (total) -- - -- -- --------- --- - - - -- 0.085 F l'ri ox:ide_____ ---------- ----------- ______ .. 2.541 Silica _ __ __ ___ _. __ .. __ .__ ____ . ___ . __ ___ _ 87.092 Alumina ____ ________ ____ --- - - - --- - - -- -- - - -- ---- ~ -- 4.099 Water (hygroscopic) _ __ _ __ _ ___________ . __ 0.689 Organic matter and combined water --- -------- - 3.561 Loss___ ___ __ __________ _ _ 0.640 100 .000 Lim o( Juble .inncicl) _ ___ __ _ __ ___ ___ _ ____ _ 0.082 P )tlt"i (flulu l .le i.n n id) ---- _ __ ___ ... ___ _____ _____ _ 0.236 Ph pb uri a id (so luble in acid) --------- - --- ----- - 0.0.'51 Mountain limestones upon the sides of the Coal Measure plateaus and in parallel valleys give rise to drab clay lands, which contain sufficient plant food, but often most deficient in lime which has been leached out. A sample, analyzed by Mr. McCandless, was taken from the land at the head of MclJamore's cove : Analysis No. :!20. Lime (total. _____ .. ______ _______ ____ _ ___ --- - 0.143 :Mug ne ia _ -------- - -------------- ----- - .-- _ Potash(total) _ .. --------- -------- --- - -- --Soda____ __ __ ---- - - - - - ---- -. _ ------- _ _ Sulphuricacid _________ ___ ___ _ ___ ____ ________ . -- 0.778 0. 99 6 0.270 0.022 Phosphoric acid (total) . .' _______ --- - - - --- - ----- - 0.121 Ferric oxide - ------ -- ---- - -------- - - --------_ 2.991 Silica.. ___ . _________ __ _. __ . _ . ____ __ ____ ______ __ ____ 77.1 95 Alumina .. _____ ___ _____ __ ___________________ _________ 10.249 Water (hygroscopic) --- -_ - -. __ ------- ---- - 1.812 Organic matter and combined water. ... __ . _. _. __ _ 4.998 Loss. -- _ _ ___ -------- 0.425 100.000' SOILS. 347 Lime (soiuble in acid) .. . ___ _ _. ___ ____ ________ . ___ _ 0.071 Potash (soluble in acid) ______ _____ ____ __ ______ , ___ _ 0.413- Phosphoric acid (soluble in acid) _ ____ __ - - ------ --- _ 0.058- SOILS OF THE COAL MEAST:RES. These give rise to light sands of variable compositions, which are very ~oor in phosphoric acid and lime, as shown from the analysis (Mr. McCandless) of a sample from the top of Saud mountain. This soil also occurs on Lookout mountain : Analysis No. f21. Lime (total) ____ ___-- --- - ----- ___ ___ __ -----Magnesia ______ _. . ___. ___ ___ ___ .. __ . _ ._ . _____ ___ Potash (total) -- - --- - - ----------- -- - , __ ___ _ _ Soda _____ ------------------ ----- -------- ____ __ 0.1150.244 0.541 0.355 Sulphuric acid - -- - - -- - ---- - -- -- -- --- --- ----- 0.053Pbosphoric acid (total)---- _____________ _ __ _. ____ _. 0.053 Ferric oxide . _. __ . ______ . . .. _____ . ____ . __. __ ______ 2.058 Silica __ __ ---- _____________ , ___ __ _ ___ 88.627 Alumina _ . ------ - - -- __ ____ __ . ----- - - _______ Water (hygroscopic) _ _ __ ___ -- __ Organic matter and water combined _____ ___ .. - -- _ Loss___ __ _____ _ _.. __ _ _ ___ __ ____ _ _ _ _ _ . 4.412 0.405 2.9250.232 100.000 Lime (soluble in acid) --_ ____ - ___ - -- _ 0.067 Potash (soluble in acid).- ___ - - ----- _____ ,_ - - -- - -- 0.201 r:hosphoric acid (soluble in acid) ____ ______ _ _ 0.017 LAFAYETTE AJ:'D ALLUVIAL SOILS. These soils are confined to hills and flats adjacent to the rivers, and seldom reach more than one or two miles from them. The Lafayette deposits are red or dark brownloams, which occur to at elevations up to from 80 150 feet above the principal rivers and on eroded hills. These are genetically former alluvial deposits. :348 ECONOMIC RESOURCES. In many cases, they are recognized by containing rounded gravel at the base of the deposit; when the gravel is absent, it is liable to be mistaken for Knox red lands. Situated on the much-washed hills, the phosphoric acid is apt to be more or less removed. There is also a deficiency of humus. The clayey matter is abundant, making a somewhat heavy soil. A sample was taken near Siilesboro, in Bartow county, and its character is seen in Analysis No.22. The color is deep red with an abundance of iron. It is composed of free transparent rounded grains of quartz ( 2 -hr to oto of an inch in diameter) as adhering to the earthy matrix. . Analysis No. fJfJ. Lime (total) ________ _______ ____ . ____ ________ __ ____ 1.674 Magnesia ______ _ _____ ___ ____ _ __________ __ _______ __ 0.120 Patash (total) ________----. _____ __ ___ ----- ____ _ 0.748 Soda _____________ ------- ----- -- --- ___ _ .-1.3 Snlphmic acid ____ ___ __ ___ ___ ____ ----- _ 0.094 Phosphoric acid (total) --------------- ___ --- --- --- 0.082 Ferric oxide ----------------------- ----------- 12.214 Silica _ _____ ---- ______ _______ ___ . ----- _ 62.229 Alumina__ _______ ___ ____ __ ___. __ ___ __ __ ______ _ 15.962 \:Vater _____ ____ ___ ____ - _____ - ___ . ________ __ __ 4.213 Organic matter_______ __ ... __ . _ __ __ __ ____ ___ _ 1.582 Undetermined, loss, etc ____ ____ ____________ -- 0.646 100.000 Lime (soluble in acid) ___ -- ____ . ___ -- -------- . 1.381 Potash(solubleinacid)---------- - -- - ---- -- _ ___ _ 0.3~2 Phosphoric acid (soluble in acid) ___ __._ __ --_ __ _ _.. . _ 0.043 The alluvial soils characterize broad flood plains of irregular outlines. These along the Coosa, Etowah, Oostanaula, Coosawatta and Connasauga rivers rise about 20 or 25 feet above mean low water. In width, they vary from one to one and a half miles, and are usually SOILS. 349 fertile lands. Above the level, only occasionally indistinct remains of terraces are seen. The lowlands along the smaller streams are less defined, but the bottoms of the valleys are generally fertile. Superficial sandy soil is occasionally met with on the slopes, arising from the washings of a portion of the clayey matter out of the soil, leaving a lighter soil, also of a lighter color than that from which it is derived. Approaching the greater rivers the surface of the red Lafayette deposit~ are thus connected with gray sandy lands. GENERAL NOTES ON C0)1POSITION AND PHYSICAL PROPERTIES OF SOILS. The availability of the plant food ~s based upon the easy solution of lime, potash and phosphoric acid. That which is insoluble cannot be regarded as plant food in the near future. In order to estimate this solubility, the samples were digested in cold dilute hydrochloric acid (ratio, one of acid to twenty of water) for thirty days. The lime is derived from earthy limestones and calcareous shales, and the soils now contain from 50 to 85 per cent. of it in the easily soluble condition. The samples being taken from practically virgin soil show a large percentage of lime in all cases. A great portion of this lime is ptobably in the form of easily decomposed silicates. The potash is also soluble to the extent of about 50 per cent., showing the highly decomposed state of the feldspar in the clay of the soil. lVIore than 50 per cent of the phosphoric acid is soluble. In most cases, the magnesia is present in much smaller proportions tham the lime. The quantity of sulphuric acid is variable, bt7t' sufficient, being much depleted in the washed alluvial soil of the Lafayette series. The ferric oxide, in all but the red soils, falls below 5 per cent., except in No. 10, where it is over 10 per cent., and here it probably occurs to a large extent in the objectionable ferrous form. In the hilly red soils, the proportion of alumina rises sufficient to ECONOMIC RESOURCES. form more or less ~:;tiff clay. At the same time, the quantity of iron is usually high; hence, the silica is still further reduced in its ratio. The organic matter varies, being less upon the hilly lands than in the valleys. The flatwood soils often hold water, and are cut up into heavy, :rutted roads. The ridges and higher lands of the Oostanaula series, owing to the splintery character of the siliceous shales, form dry. roads with no depth of mud. The valley red lands of the series, as also the red soils of the Knox series, form moderately muddy roads, but when dry, the ruts soon disappear, or the clay is siliceous and not very heavy and stiff. The red lands of the Knox, the Chickamauga clays, and ~Lafayette series on the hillsides form the stiffest clay of northwestern Georgia. The grey Knox and Fort Payne chert lands are siliceous and cherty, and therefore, not deeply muddy, except locally, where chert is in smaller quantities. The muds of the Maclurea series are particularly stiff and deep. The shales of the Rockmart series in Polk are similar to those of the splintery Oostanaula section; but, in Murray and 'Whitfield counties and west of Taylor's ridge they .approach more nearly to the richer shale and red Knox lands. SOILS. CHAPTER XLIV. -GEOLOGICAL RELAT!I)NSHIP OF THE SOILS OF THE AGRICULTURAL EXPERIMEN'l' STATION OF GEORGIA AND OF THE COLLEGE FARM. CONTENTS. GEOLOGICAL CHARACTERISTICS OF THE V I CINITY OF THE STATION. ORIGIN OF THE SoiLS. STRUCTURE OF THE SOILS. TYPE OF THE SoiLS. CHARACTERISTICS AND Co~IPOSITION OF THE SOILS AT FARM . DEDU CTIONS FRml 0BSERYATIONS A ND A NALYSES. CoNCLUSIONs. THE RELATIONS OF PHYSICAL FEATURE!I. CONFORMATION OF THE RELATION OF PLANT GROWTH TO THE SoiL VALUE. SoiLS oF THE CoLLEGE FARM AT ATHENS. GEOLOGICAL CHARAC'IlERISTICS OF THE VICINITY ,OF THE STATION. The Georgia Experiment Station at Griffin is sitnated 011 a belt -of Arcluean or metamorphic rocks, which here forms a gentle undulating plain. The surface rocks are decayed, and only occasionally -do they appear at the surface. The characLer of the gneiss in this region is best seen in the railway cut between the farm and the neighboring railway station, where it is foliated and passes into a -qn6rtzose mica schist, that is, a rock with very little feldspar. It liei in beds dipping from 20 tv 25 S., 20 to 30 E. ThiR inclination gives some variety to the lands formed out of it, as d1fferent strata varying somewhat in character are successively brought to the surface in passing ftom southwest toward the opposite direc~tion. The dip is favorable to the decay of the rocks. About half a mile from the farm toward the southeast, ronndsd 352 ECONOMIC RESOURCES. . hummocks of gray granite rise through the gneiss. Whilst these granites are characterized by partial internal decay they are hard rocks which do not disintegrate like the gneisses, and consequently do not give rise to the soils to the same extent as the latter. The granites and gneiRses are. composed of the same minerals, but the latter is laminated or in beds, whilst the former is compact and homogeneous; yet the proportions vary. In lands formed from_ the decay of stratified limestones the earths may have a heterogeneous structure without traces of any bedding to depths of one hundred feet or more. This has arisen from the removal of perhaps ten times as much calcareous matter as there is now clay and sand; consequently the original structure is obliterated in the gradual settling of the earths. In the case of gneisses and mica schists, as at the Experiment Station, the original rock contained such large proportion of siliceous and only a small proportion of soluble matter, that upon remoYal of the latter it did not permit of enough settling of the remaining mas,'i to obliterate the original bedding; and thus below a depth of from fivr to fifteen feet the materialfl still show the stratification, although the partial decay may reach one hundred feet or more. ORIGIN OF THE SOILS. The mineral constituents of gneiss are quartz (giving nse to sand), feldspar (yielding clays with potash, etc.), micas (producing also clays, with iron, potash, etc.), and sometimes hornb1ende (yielding lime, iron, etc.). In the neighborhood of the farm the quartz predominates in all the rocks, and in some cases to such an extent that when the ot.her constituents, which are those that decay, weather out, beds of' quartzose rock remain, as shown in a depression upon the back part of the farm. This quartz rock is rich in iron, which colors it reel. But usually the feldspars and micas are so intimately mixed with the quart1:; that this mineral separates into grains anet makes more or less loamy soil. SO ILK. :353 Throughout the origin~! gneiss, veins of compact quartz ramify. Upon disintegration these give rise to angular gravel covering the surface of the ground or producing gravelly soil. Thuo; it is. that the sand of this region is o;imply the residual materials left upon the decay of the gneisses and the granite, from which most of the alkalies have been leached ont, as also some of the finer clayey matter is washed away, leaving loam of varying characteristics. This process of washing out the clay is carried on to such an extent upon the slopes of some of thE' low ridges that even a very light sandy soil is left, for the clay is more easily carried away by wac;hes than the fland. At the same time, owing to the action of vegetable acids upon the soil, the red lands are superficially con-Yertcd into gray, on aceonnt of the partial removal of the iron compounds. The rE'd color of the soils ari~es from the oxidation of the iron contained in them. ThiR reddening proce:-;>< eommonly ex-tend~ only a few feet (eighr.to twehe feet) in depth, but it is some- times seen to a depth of thirty feet, fading out, however, upon receding from the surfaee; consequently, the lightet' earths from a depth are not a! ways the equivalent of the gray land at the surfaee.. The ~oil of the station is deriyed from gneiss containing hornblende, which has furnished part of the iron and most of the lime of the soil, which is decidedly calcareous. The variationf'l are alt local, and dependent to ,;omc extent upon tbe change nf rocks underlying the surface, but mort~ particularly upon tbe effects of the wa:;hings of the surfac;e by rains and rills, in prc:;enee of vegetable matter, giving rise to variable amounts of sand, clay and iron, and also of the plant foods which are held in the earth. STRL'CTURE 01' THE SOIL. 'Yhen the rain.-; han~ wa,-;hed the surface, then the more ,Qandy soil is composed of ermrse grains of qnartz. However, beneath the heaviest washes the grains are mostly small. A.~ a general feature, the soil is made up of subangnlar (but not watPr-wol'll) transparent grain" of quartz in a matrix of decomposed roek earth, f'Oill- (~:>) 354 ECONO.MH: REHOURCE8. posed of clay, feldspar, a small proportion of silvery, shining ::;cales of mica, ferric oxide (coloring niatter), etc. This earthy powder frequently coat11 the grains of quartz ancl adheres to its sur- o-h- face. The grains of quartz are small, ranging mostly hom 2 -g.-0 to of an inch in diameter and ;;mallet, with a Yery small proportion of large grains, which appear in superficial washes. In descending below the ::;urface the amount of clay increases, as is slwwu by texture and analysi;;. TY['E OF SOILS. All of the statiori soib belong to the "reroportion of earthy matter, with a large quantity of organic matter. 358 ECONOMIC RESOIJRCES. Analysis .i'lo. 3 1. Lime (soluble in acid) --- --- _---- - - - ---. --- _. ___ _ 1.024:. Potash (soluble inacid)- - - - -------------- . ____ _ 0.120 > Phosphoric acid (soluble in acid)-- . - - - - --- . __ ____ _ 0.042; Lime (insoluble in acid)_ _ --- - ---- ------ ____ ------ 0.463 Potash (insoluble in acid) __ -- - ---- -- - -- -- - -- - ----- 0.356. Phosphoric acid (insoluble in acid) ____________ .. __ ___ _ O.Oll Magnesia __________ ___ ________ _ . ____ _________ ____ 0.098 Soda- - ----- ------------------ - - -- -- - - _____ 0.5:33 Sulphuric acid. . ---- -- -------- - ---- .. --- -- __ 0.415 Ferric oxide ___ _____ ___ ___ _ _____ __ _ . -- - ------- - ... 4.21.5 Silica .. ___ _____ _ _________ _ __ _________ __________ _ 69.702 Alumina ___ _____ ____ ------------- - - - --------- 6.320, Water ____ __ --- - -------- - --- ---------- -- - - -- -- -5.111 Organicmatter __________ ...... ____ ------ -- --- _. 10.654 Undetermined, loss, etc __ ..... _. . -- ----- __ ____ --- ---. 0.936 100.000 DEDUCTIONS JI'ROM THE OBSERVATIONS AND ANALYSES. Note.-As this chapter is a sequel to Chapter XLII. (on the Formation and Characteristics of Soils), much repetition becomes . unnecessary. Organic Matter.-In the surface soils, except No. 30 in the de-pression, there is a good supply oforganic matter. As most of the land is highly cultivated, part of this is due to artificial application. That at the well is not under cultivation at present. Clay.-All the snrface samples show a smaller proportion of clay than at a depth, except No. 30. This arises from its partial removal by washings; still the proportion is such as to form only clayey and not heavy clay soil. Iron.-The ferric oxide is in greater quantities at the surface than below, where the color given to the soil is modified by original matter; still the soils; are all ferrnginous. tiOILH. 359' Lime.-It is notable that the total amount of lime increases in one case and rliminishes in another upon descending to a depth. But in both cases it is in abundant quantities, yet its availability rapidly diminishes upon descent from the surface, at the pear ornhard, from 83 per cent. above 7 inches, to 47 pet cent. between 20 and 26 inches; and to only 37 per cent. at :36 to 42 inche:-:. At the well the analyses show 74 per cent. of the lime afi available at the surface; 58 per cent. at 2 feet; 3Fi per cent. at 4 feet, and 22. per cent. at 8 to 10 feet. In the depression near the pond only 45 per cent. is available at the surface; and about 66 per cent. on the sandy surface of Division A. Accordingly, the lime appears more and more locked up as insoluble silicates upon de,.,;cending below the surface. Still the quantity i~; abundant, and further addition. would prove of little value. Potash.-The absolute quantity of potash rapidly increase" upon descent from the snrfacc, as does the clay, showing that it bas not been extracted irom the original feldspar to the F were published as follows: REPORT OF PHOGHESS OF THE G~;OLtlGICAI . SURVEY OF 18/ii, l'l'. ]-36, HY Ch;oRCiE LrrTLil, :-'TATE GEOI"OuiS'l'. SEcOND REPI!>R'r 01' PnO CJRESS OF rrm GEOLOUICAI, ~!,RYE\' OF 18/G, PI'. 1-16, BY (iEORetl'l shtill be obosen by- the Advi ory I mwd, wh m~1y b.~ 011 liEA'L' ANJ> J\iOJSTU LUi '1'0 :Pm:lilT '..U. 8'1'f\ I.''I'UIIJ;; ,\.lU) Ll;llt Of' .- Lf..S: IUlily Soil j aloa:reous so.iJs; Olayey Soi l . . . 322 E ~SA lH ONl'l'rH'IJEN'l'll H' l'l. AN'J' Foo;n: JJ:Jom !lt.ll :Modi 11m Y .MJlilirtAI. o srr'l' UI~'tl'l'fi :.; Pt,A 11' FOOl) t1Y '0'1'- TON, CoRN AND WHEAT . . . . . . . . . . . . . . . B27 CHAPTER XLIII. G-JllOLOGI AL D HE~O AL l.tli:LATlON rrn~ Ol!~ THl!: OILS UJl' THE PALID07. IO !fORM TI NS . . . . . . . . 32V ' t' LL~ 01 'lUr( Oosr.~..N;HfLA Sl'lliiES: An ly. s . . . 329 SCilL 01~ 'l'llil KNO Siml~t~: Lted Soils 1 Gr:ay 'oils ; A.nalysr 337 ou.s OF 'I'!IB 'nr lwHI A( ClA Sr-:11u~ : nnl ,ystl, 342 ,'O(J1!> PTIIIt I J"-J) l\lOu:N'l1:A.tN Intm8: Anulyses . . 344 8oTLS OF 'I'll It S'lill- AU:Ho:Nu.rmou.: S~n;s: Jl'ort Pn.yno hort; ]1Joyd Shtl101l; .MoUJltuin Lim stteJD ______ ------------ --. ----------- 42 Carboniferous System ________ ------ ----- ___ ----------. ----- -51 Carnes' Mountain ____________ _____ .. ___ ____ . ____ _ __ -- -- ----- _61 Cartersville Fault_ __________ ______ ___ ___ ____ _------- - 2 ' 0, 84 Manganese and Iron ________ ________ - ------- - -----195 Caves _________ __ ___ ---- _________________ _44, 74, 75, 83, 105, 1,57 Changes of River Levels --. __ ----- ------------- ______ __ __ _65 Character of Streams ___ _ ______ . __ __ ------_--- --- - ---- - - . 64 Chattanooga Black Shale- General Characters_------ ______ ., ____ 50 In Gordou County____________________ 110 In Whitfield County _________________ 117 In Catoosa County ______ _____________ 121 In Chattooga County______ . _________ .126 In Walker CountY----- - -- - - -------- 135 In Dade County_____________________ 142 Cl:rattooga County Local G eology _______ __ __ _______ - - ------~ - -123 Physical Features.. --- - -- - ----- --- - ---- - - -- --72 Ores (see Resources). 392. GEOLOGICAL SURVEY OF GEORGIA. Chazy (see Chickamauga). Chickamauga Series- . General Character ..________ ---~ __ --_ - ___ .45 In Polk County--- ___ -------- __ ---------- -82 In Bartow CountY-------- ---- -- ---- - --- 107 In Murray County_ _____ ____ _-------- - -- 11~ In Whitfield County ____________________ :.l16 In Catoosa County ______________________ _120 In Chattooga County_______ --------------124 In Walker County_____________________ --131 In Dade County-- _______________________ 141 Chilhowie Series_---- ____________________________________ 35, 77 Clark, W. B. __ ----- .. _________________________._. ____________ 366 Clays __ -------------- ____ .. _________ -- _______________ - 276, 279 Analyses ______________________________ . __________ 281-288 Alluvial ____ ------ ____________________________________ 286 Disintegrated Shales __________________ ---=-- ______________ 283 Kaolin _____________________ -- ____ __________________ ..280 Residual ___________________ ______________ _ ____ -------282 Clinch Mountain Sandstone ______________ ____________ ------48, llo Clinton Series (see Red Mountain). Coal (see also Coal Measures) _________________________________ 24 7 On Sand Mountain _________________ _------ ____________ .247 On Lookout Mountain ___ ____ ________ _______ - ---- ___ ---254 Analyses ---:----- - - - --- ------ - ----- -- - - ___ _258, 259 Coke -- - - ---- - _., __- - --- ----- __ --- _____ ___ _____ _258, 259 Mines ___ .. --- ------ - ---- ____ -- -- ------ ----- __ ___ _259 Coal Measures- General Character__ __ _____ -- ------- ____ __ __ 52 In Chattooga County_------ -- ______________ _-127 Outliers of __ --------------------- ________ 128In Dade County _________ - - - _____________ _____ 143 In Floyd County--- - __ .. ___ ________ . ____ . ______ 9(} In Walker County _______ _______ _______ - .. ___ 136 Cohutta Mountain -------------- - ---- - - - ---------- 37, 62, 71, 75, ,College Farm, Soils oL ________ .. ___________________________ -11~ INDEX. 393 Conglomerate Ocoee - --- - - - -- --------- ---------- --- ------ - - 35 Conglomerates-------------------------- ----------35, 53, 54, 85 Contrasts, Lithological ------- _-- _-- _-- ____ -- _________________ 30 Connasauga Series (see Oostanaula). Continental Margins --- . ~- _- _-- _-- ___ - - .. ______ . ____________ .15 Coosa Shales. ------ ------- __ -- _-- ________________ ____ . ____ 29 Coosa Shales (see Oostanaula). Cotting's Report on Geology ____ --------_- ___ . ______________ .... 364 Cryolite ----- - ____ ---------- _-- - -- __________ .. _____________ 211 Dade County Local Geology- ---- ---- -- --------- __ _ ,. __ __ ......141 Physical Features.. ---------- --- ---- . --- --- - - 73 Ores (see Resources). Dade Coal Mines.. ____ - __ ---- _________________________________ 259 Dall, W. H ... --------------------------------- ___ .... 366,371 Date of Cave Making ___ --_-- ________________________________ 75 Deaton Series.. ---- ____ -------- ____________ ------. _____ .. -46, 83 Ores (see Brown Ore) . Decay of Limestone ---- --------- --------- --- - ------23, 44, 103: Depth of Rock _________ ---------- - ----------------10,22, 44, 82 Denudation, Enormous _________ ------ --------------69, 97, 128Depositon of Iron Ore (see Origin of). Degradation of Strata---------------------------------23, 25,26Destruction of RockR ______ -- _________________ .. ____________ ... 10 Devonian System ______ ------ __________ . ____________________ 50 Dip of Strata_ . ____________________________________________ .. 14- Dislocation of Strata ____ -- ______________________ ----- __ .16, 181 Distribution of Ores (see Each Ore). Dolomite (see Limestone). Drumlin-like Mounds _________________________ -------------101 Dyestone Group (see Red Mountain). Economic Resources __ ---- __________________________________ 147 Table of_ _________________________________ 149 Effects of Folding of Strata-------------------------- ________ 21 Effects of Rain on Strata ____ _ ______________________________ .9, 21 Elevation of Land _______________________ .. ____ . __ . ______ .. 11, 16- :394 GEOLOGICAL SURVEY OF GEORGIA. Elevation (see Altitudes). Elevation of Georgia __ - _--- __ --- __ ______ ___ __ __ ____ __ ____ __ . 67 Erosion, Depth of-_- __ --_--_- __- __ - _____ - __ __________ ____ ___ 25 Erosion of Lookout Valley ___ -- _ . - _-- _- __-- _- _____ __ _________ 25 Erosion, Enormous ------------------------------- - --59, 97, 128 Evolution of Northwest Georgia ___ __ --------------- . 55, 56 Etna Mines (see Brown Ore). Experiment Station Soils ______ ______________ --- - -- -- -- - -- - - .351 Extension of Gravels - _ -- - -------------- _- __ - ________ ___ _____ 97 Fault DefinedCartersville__________ ________ . ___ __. __________ 28 Cave Spring-- _________ __ . __ ________ . _____ ----20 Oostanaula ___ _ __ ___ _----- ___ .. ____ 37, 38, 88, 111 0 verthru sL __ ___ . . _.. . _____ . __ . __________ 19, 113 Reversed __ _ -- - --- --. --- - ------. ___ --. ___ .. 20 Rome ---------------~-- -- -- - 19, 28, 33, 87, 108 Saltville ------- --- -- --- --- -- -- 19, 28, 33, 87,108 Whitfield County ------------- __ ___ _ __ __38 Westboro ____ - . _-- ... __ - __ - ______ .. _ _. _ . ____ -134 Flagstone ----- - -- ---- - -- -- - -- --- __ __ _____________ _____ 273 Flatwoods ___________________ __________ :n, 52, 65, 68, 87, 96, 108 Floyd Shale Defined __ ___ . _________ . ___ _____________ __ ______ 52 In Floyd CountY-- - ---- - ----- - ----- - -------------96 In Chattooga County ___________________ _________ .127 In Gordon County------------ - ------- ---- _____ uo In Catoosa County ______________________________ 131 In 'Valker County ---------------- --------- 135 Floyd County, Local Geology__ _ -------- - - -- ----- --- ______ 87 Physical Feature~ _ - -- ---- -- --- ------- ---- ---- 68 Ores (see Resources) . Folding of Strata ________________ __ ___ __________ ______ __17, 18 Fort Mountain ____ __ __ -------- - -- - ______ ----- - ---- - -------62 Fort Payne Chert Defined ____________ -- -- -- ------- - ----------51 In Polk County _ - - -------- __ _ ---- - - __ __ 86 In Floyd County_____ ___ __ ___ __ __ ___ ___ . __96 INDEX. :395 uo :Fort Payne Chert in Gordon County ---- -- -------- - - - ~ ___ _ In Catoosa County ---- - - ------ - - -- - - - 110 In Chattooga-------------------------- - ---127 In Walker_____ ___ ___:_______ _______ __ ___ -,-135 lnDade------- -------- --------------------142 !Fossil _________ ___ . ____________ . ___________________ .13, 3_0, 52 Bones __ ___________ ___ - _________ __-~- ____________ _.. 107 Cambrian __ _----- --- --- ---- ------- ,___ --- - __ _40 Plants ______ -- - ---- - -- -- ---- - - ______ ------ ----- - ----146 Ore (see Red Ore) . "Fucoids---------------- - ----- - -- ____ ---------- - -------36,38 Furnaces, Iron. _____ __ ____ ___ ____ _ __ ________ _____ _. ________ 189 Gaps in Geological Series ___ ________ . ____ _____ _____ _________ -.59 ,-Geological Belts ____ ___ . _ -- __ -------- _______ --- ---- __14 Group - --- - -- - - - -- -- - -- - - - - -- - -- - - - ----- - - -- --- - 27 Structure._____ ____ _----- - --- _---- ---.---- ___ __ 8 Table _________ ___ ----------- _____________ ------29 'Gibbsite _______ -~------- ___________________ _ ___ __________ 212 Glaciated-like Rock.. ______________________ .. _________________ 89 Gordon County, Local Geology--- -- --- - --------------- -- ----- 108 Physical Features ----- - - __ - -------- ------- 70 Ores (see Resources). -Gravels, Angular (see Knox Dolomite; see Ft. Payne Chert). ::: Water Worn (see Lafayette) . Growth of Strata - - ---- - -------- . . . . _______ __ _--------- 11 ~Halloysite and Analysis ___ ______ ______________ _ __ _____ _____ 212 Harris, G. D. __ ___ . ______ ____ ..__ . __ ____ ____ ____ ____ - ----- 366 "Hayes, C. W --------------------28, 32, 36, 38, 39, 44, 45,132,366 Hardi_n's Saltpetre Cave _________ _____ _________ _____ . . 74, 105, 107 Hematite ____________ .. __________ ______________________ -- .17 6 "Hillgard, E. W. ________ ________________________ __ ___ _327-328 1Iudson Serie~> (see Chickamauga) . Igneous o]o,__.________ -------------- - ------------ -8 Incompleteness of Formations.. ------ - --- - - ------- - --------- -15 Indian Mountain __________ ____ ______ ___ _ __________ 27, 67, 77,79 396 GEOLOGICAL SURVEY OF GEORGIA. Indian ]dounds ________ ----------------------------- - ------107 Insular Georgia_____ --- ___ - __________ ___________________ ____ 15 Iron-Limestone __ - --- _____ ----- __ -- ____ _____________ _46, 83, 157 Iron OreR- (See Brown Ores)- _______________________________ 150 (See Red or Fossil Ore)-------------- - -- ______ ____ 176 Johnson, L. C. ____________________________________________ 316Joints-- __________ ______________ ___________________________ 43. Keith, Arthur _______________ ____ . ________________ _______ __36 Kaolin (see Clay). Knox Dolomite Series- General Character-- ____________ ________ 42' In Polk County __ ______________________ 78 In Floyd County . - - -- --------- ___ __ ___ 92 In Bartow County _____________ ________ 102: In Gordon County ____ --- ______________ 109 In ]durray County- --------------------112In Whitfield County ____ ______________ -116 In Catoosa CountY------------- - -------119 In Chattooga.County ___________ - ___ _- __ 123 In Walker County _________________ ___ -130 In Dade UountY----------- - -----------141 Sandstone _________ ____________________ 3~ Shale------------- - ------- - --------- - -39 Ladd's ]dountain ___ . ____________________________ ___ ____ -43, 104 Lafayette SeriesGeneral Characters ___________________________ 55 Grave~---------- - -------------------------55 - Altitude of_ ___ . _______________________ --- - - 97 In Floyd County - ------------- - - - ------ - 97 In Bartow County -------------- - ------ - - - 107 In Gordon County -- -- --- - - - ---- --- - ----- __ _110 In Murray CountY -------- --- ----- - - - ----- 113In Whitfield County _______ .. ______ ________ -- _118 Absent_________ __ -------- -------- -----146 INDEX. 397 JLakeleffi---------------------------------------------------74 Langdon, D. W , __ ______ __ - - - ----- -- - - - - - - -- -------- - -366 Lula Lake ________ ---------'----- ___ --- ------ ___ . __ --- __ 73, 74 Lula Falls------------------ ---------------- --- --------67, 73 JLimestone ______ -------- ----------------------------8, 11,261 Analyses of _____ -- ______ ------ ________________ .263-271 Carboniferous._--- --- --. --- __ -- __ -~- --- __ . ________ 270 CementRock _____________________________ -------264 Character of_------------------------------- ______ .261 Chickamauga __________ ---------------------------- 268 Composition of_ __ __ __ __ _____ ___ --- -- --- __ _ ____ . _ _261 Decay - - --------- --- - ----- - - - - -------- ---- -~ - - 23 Distribution of.. ___ -------- ------------------------- 262 Dolomite __ ------- -------------------- --- _-- ____ .262 Hydraulic .... _____ -- ------------- ----. -- ------262, 264 Knox Dolomite----------------------- __________ ---365 Oostanaula.----- --------- - ------------ ___ . _______ . 262 Red Motmtaiu_ ----- ------ ---- ___ .. -------- _- _- ___ .270 Limonite _______________ -- ___ - --- ______________ .: ___________ 150. Lingulella _____________ .______ _________ _____ .. _____________ .40 Little, George ----------------------------- ____ 36, 37, 364, 365 Lithology____ __________________________________________ ___ 8 Lithological Contrasts ________ ----- - ________________________ 30 Loams ______ .. ______________ .. _______ ________________________ 26 Lookout Mountain Folds __________________________ ______ . . --- 18 Lookout tlandstone ---------------- -- --- --------- --------29 Lookout Valley, Origin oL ____ - -----------. _--------- _______ .25 Lower Silurian System ____ - ___ ---_--- ____ - __ --- _____________ .-42 Law of Survey--- ----------------------------------------368 Le Conte, ,Joseph ___ -- ___ -- _-------- __ --- __ ---- ________ - __ - 371 Loughridge, R. H .---- -- -. - -- ---------~-------- - ------ 365 Lyall, Sir Charles--- - ______ .- -- - -- ----- - - ---- -_---- ---- __ 371 Maclurea Limestone ____ ------ ______ --------------- -------46, 82 Manganese ________________ __ ----- -- - ---~--- - -- - - ____190 Analyses of Ores of_ _ --------- -~------ -----. ____192 398 GEOLOGICAL SURVEY OF GEORGIA. Manganese, Cartersville Ore ________________ ______________ __ __ 191~ Distribution oL _____ ____ _________ - -__ ,_-- _______ - 200 Kinds of Ore------------~- ______ ---.--- ______ ----191 Occurrence oL __________________________________ 195 In Knox Dolomite __________ .. ________ ---------- __ 192 Origin of Deposits ___ _____________________________ 205 Uses oL-~------ - - ------------------------- ____ _190 'Vorkingsof____________________________________ _204 Manganite ___________ _________ ____________________________ _192 Margin of CobtiuenL ___ -- _----- ________ _______ ______________ .15 McCandless,J. M, ________ _ -- - ------- _________________ ___ :)67 McCutchen, A. R, _______ __ ------ _____________ ------32.,44, 365 McGee, W. J , __ ___ ______ __ -- -- ------- - ---- - -----3(:)5 371 Medina Series (se~ ~ed Mountain). Metamorphic Ores ______ ___________________ _ -- - - ____ - _____ --168 Rocks _____________________ ___________ ____ _______ __9 Schists ___ ------ ---------------- - ------ - - -- - 35 Metamorphism, Cause of_ ____ _____ __ _ - --- ------ - - --- -- --- - 84 Modern Formations ________________ ,')5, 57, 86, 97, 98, 107;.110, 146 Montevallo Shales- ___ - ____________ .. ________________ .. ________ 29 Mountain LimestonesGeneral Character_ ________ - __ - __ -- --- ____ 52 In Chattooga Count)'------ --- - ----------127 In Walker County ___ -- ------ - ------ 136 In Dade County_ .. _______ __-------------143 Mounds, Indian ___ - _____________________________ ___________ 107 Murray County, Local GeologY------ - ------ - ----------- ------.- --112 Physical Features------- - ---------- ________.__ _71 (See Resources). Niagara Series (see Red Mountain). Obelella ____ . _____ _... _________________ _____ - ___ - -- ________ 40 Ocoee Series ___________ . ____ _____ . ____________________ .. __ 34 Ochre Works.----- _________________________ ---------- __ .. 175 Olenellus- ____ -- ------ _:_ _- _____ - _- ___ -- .. ____ - -- __ - _- ______ 36 Olenoides----- ___________________________ - __ ---- _______ .38, 40 INDEX. 399 Oostanaula FaulL .... ----------------- - --.------ ----37, 38, -88, 89 Oostanaula Series- General Characters--------------------- ____ 37 In Polk CountY------------------------- - 77 In Floyd County - -- --- - -- - - - ------ 87 ,In Bartow County --- -- ---- ---- ------- - --- - 99 In Gordon County------ -------------- . 108 In Murray Connty ______ ---------- .... 112 ___ __ _ In Whitfield County ____ ----- ______ .... ____ ---115 In Catoosa County _____ . --- _________ . __ .... 119 In Chattooga County ...... _______ ------------123 In Walker County_------_----- - ________ .... 139 Origin of Coosa Valley ____ - __ ---------.--- _________________ 24 Limestones .. -- .. --_ .. ---- .- -- ... -- .... - ...... - ____________ 11 Lookout Valley_------------------ ________ ....... 24, 25 Ridges---- - - -- ---- ------ -.. - - ----- -- ........ ________ 22 Valleys.. -- - - ------- - -------------- - - --- --- __ __ 24. Ordovician System--- -- ----- - ------- ---- ------- ______ 42 Ores, Aluminium (see Aluminum). Iron (see Brown Ore). Iron ( see Red Ore ) . Manganese ( see Manganese Ores). Oscillations of Land __ -- .... -.... - . - .. -- _- .. - .. .. .. _.. - ___ .. ___________ 11 Oxmore Sandstones _____ .. _--_ . - __ - .. _- . ______________ .. _.. _____ 52 Paleozoic Group, Thickness of.. _____________________________ 31, 52 Soils _________ _____ -------------------- ___________ 309 Submergence.. ___ . __________________ .. ______________ 1.5 Period of Folding.... ____ .. __ _______________________ .... ________ 58 Physical Features, GeneraL-----_ .. -- ____ .. -- _____,_ .. __________ 60 Of Streams------------------------------. 64 (See Counties)_ .______ .. _______________ .. _67, 73 Polk County, Local GeologY---------------------------------- 77 Physical Features-- __ Y ______________________ . __ 67 Ores (see Resources). Potsdam Series.------------------------------------------- 2(} 400 GEOLOGICAL SURVEY OF GEORGIA. Protection of Knox Ridges ___ --- __ -- ______ - _________________ 81 Progress of the Survey_--------_ .. ---- __ ---- __________ R64, .371 Psilomelane ____ -- __ -- __ - ___ . ___________ __ . _____________ --192 Ptychoparea. _____ -------------- - -~----- - ------ -----------40 P y.coht He----- _------ - __ - - ---- __ __ -- - - -- ----- - - - --- -- - - - l. 91 Quartzite, Chilhowie ____ . _________ _------------ ------- -36, 77 Ocoee ___ - - ----- - - - ---- ---- ---- -- - ---~- - - -- -- - - 3~ Indian .MountaitL _--- __ -- _- --- _- ----- __ -- _- ______ 272 Red or ''Fossil" Iron OreAnalyseS---------------- ____ --- __ 187 Characters_ - --_- -- __ ..- . ----- - _____ 176 Distribution _____ -- _______ -- ------ _181 Hematite ______ . ________ -. ---- _-- _17 6 Mining oL- ______________________ 184 Occurrence oL --------------- 177 Source IlL - ----- --------- ----- -) 77 Thickness oL __ --- - ---- -- ------ . 183 Red Mountain SeriesGeneral Character----- ------- - ------ -48 In Polk County ______________ ----------86 In Floyd County------------- ___ _______ 94 In Gordon County ______ ---- ____ - - -----110 In .Murray County _____________________ 113 In Whitfield County ______ --------------117 In Catoosa County----- ____ -- - ---------121 In Chattooga County ---- -- __ _ ---- -- ---124 In Walker County ---- ---- -- ----------132 In Dade County ______ --- - ------ - --- - ___42 Recent Formations ______ ..__ .. ___ __ ___ ___ ____________ .. ___ 55, 146 Regional Growth of Formations ______________ -----------------15 Resaca Fault . ____ . _____________ ______ . ___________________ -111 Residual Earths, Numerous References___- ____ .. ________ _____ ____ Ridges, Origin of'_- . ___________:_ -- ---- _--- __- -- _______ -- ___ 22 Ripple Marks--- - ------ - --- - --- - ______ __ --------------- - --38 iNb:EX:. 401 River Channels, Size of------ __ -_-_--- ______________ .. ____ ____ 65 Rivers, Character of- __ ----- ...----_- _______ . _______________ __64 Roads Relation of Ro&ds to (;feologicalund Physicnl l!' nt ure -----290 _J11wacter of-- --- -- ---------------- ---------- ----290 Uos't of Bad .. ----- - -- - -- --- --- ---- -- --- -- -- - -------2H8 11 Ditf te.n.t Geologicul Formalious-- -------- - -----291, 2M c;.l>oci v ~- ue :Bad------------------------------- - ----'208 Good in'Emope---- --- --- ------------ -- -- ----- - -- 300 Locatio.ns of------ ---------- ---------- - -----------2fl0 Source of R fl.<~ 1atelinL- -- _____ ___ --- - ___ __ __ ___ ___ 2f.I O ockma~t lates- --------- ------------- -- -- -- -- --44, 81, 84, 275 HockwO(lCl , al'iea . _----- ------ - - -- ---- 7 - - -- -- -- -------------29 E k Oec.tlY---- - - ------- --- -- -- --- -- --- - -- -- --- - - -- - - --10, 82 (See Saltville Fault.) Rome FaulL-----_---- . ------ .. _- ---.---. _.- ___ - ___________ .. 28 'Rome n.ndstoJl e- - -- -------- --- -- -- - ------- -- -- -- ---- -- ____39 'nlford James- -- -- - -- ------- ------ -- -- ---40, 42 43, 45, 48, 3()6 nhJ)etre Cnve.. -. - --- - - ------ ----- --- -- --- --------- --- __ 74 r3nlnvill ifl.UIL - - --- -- - - -- - --- -- -~ -- -- .. - - ------- - ---- -- - 28 Stutdsj;OOGS------ -- -------- --------------- --- --- -- -- -35, 49 hilhowi ------- -- -- -- ---- - --- ---------- - 6 272 Oo~:~,l nsures------ - --- - -- ----- --- ------ -- ---- - --2'i!l Oosto.ut~llhL -- -- --- --- --- --- -- -- - - --------------:l72 Hed M ountn-in ___ - ---- -- - - --- ------- - -- ----- -- -~- 272 Sub- 'arbouiferons____ ------------------------ ___ 27' ~ plitlw ~- - ----- - --- -- - ------ ------ ---- -- -- --- --- - - --- ___ 25 SEll , tuUb tinn - --- - -- ---- ---- -- ---------- - -- ----- -- ---- 5(i Carbouifeous__ __-- - - - ----- -- - -- --- -- - ---- -- --- /) Dev:ouinn - --- ---- - -- - -------- - - ----- ------ --- -- - - - -- 58 Ordovi iuu ------ -------------------- - ------------ i Pliocene_------ ----- -- -- - _-- - --- - - ---- - --- __ ------ - -59 l;;ilmiun_____ --- -- ---- -- - ------ --. __--- ------ f\7 Sedimentruy Roclcs--- ------ ___-------- --- --- ------ --- (26) 402 GEOLOGICAL SURVEY OF GEORGiA. Silurian System.-----______ ___ -- ---------- -------- _------- 48 Sinks__________________ ---------------------------------- 74 Slates __________________________________ ---- ___ -- ____ 35, 275 Slickensides ________________ . _ _- _______ .- __ .- - __-- ___ - __ 21, 89 Slide Rock ______ -------- __________ --- _- ------------- _____ .89 Smith, E. A,_ ---------------------------32, 36, 38, 39, 44, 366 Soils ____________________________ ------------ ------------309 Accumulation of food oL __________ . ___ -- _____ -. --'- ______ 31S Ammonia Salts in ______ - ----------- -------------- -325 AlluviaL Formations of_--- _______ . _____ --_ - - __ -- ___ . _____ 318 Analyses from Crystalline Rocks ____ ---- ------ ______ 355, 357 Analyses of College Farm .. ---- _----- __ .-- _- _-' _________ .362 Analyses of Experimental Station------ _______________ 355, 357 Analyses of Paleozoic___ __________________________ 331, 348 Analyses of, Value oL __________________________ c _______ -325 Calcareous _______ - _______ - ____________________ :.. ____ -'-- 322 Character of.:.--------_-----_.----- ___ ------. _____ .358, 360 Character of Archrean __ - ---- --- - ---- --- ------ ---Character of Paleozoic _______ --- _________ -~ _~- _________ .. 312 Chemical Relation of Paleozoic ______ --------- ____________ 329 Chlorine in __________________________________________ .326 Clay-.--- ____________________________ ~---- _________ ... 312 College Farm ____ - _____________ --~--- ____ ------------ __ 362 Color of-- ___ - __________ . ______ .. ______________________ . 312 Constituents of Plant Food ____________ ~ __________________ 323 Consumption of Plant Food by Corn-~----------- -------327 Cousumption of Plant Food by Cotton ___________________ .327 Consumption of Plant Food by Wheat-. ______ -~ __________ .327 Corn, Salts in __-----------------_. ___ ~_~.- _~.- ________ 327 Cotton, Salts in _____________ --------------------------327 Creep------- ---------------- ____________ ----- __ 317 Depth of Residual Earth _________________________________ 315 Diminishing Solubility of Plaut Food _____ ----~-----------319 Effects of Organic Matter on __________________ -----~-----318 Effects of Plant Food on ___________________________ . _____ 325 Estimating Value ot__ __ ----------------------- ------__325 ~ 7 INDEX. 403 Soils, Experiment Stations._~ _____ ---_-------------'-----.:.--- . 351 Ferric Oxide in ______________ . __ -- ___ - - _- ---- __ -- ___ -- .826 Ferruginous ____ --- - -------.---:--------------------. ___ 322 Fixing of Plant Food --- ------- - ----- - ----"------ - 324 Formation of____ - .___ --- _--- - ----- --- --- ---- _- - -- __ _312 Formation of AlluviaL_-- __ -- __ - --- . --- --- - -- ________ 318 Formation of Archrean. _____ --- __ -- ___ -- __ - --- _____ -- _. 317 Formation of ClaY--------------------, - --------- ______ 317 Formation of 'r Jl --- ---- - - -- -- -- - -- -- -- - - __ 817 Formation of L'ittl. t,,')ue____ ------ ---- ------- ______ ;314, 317 Formation of ResiduaL ... - ___ -_- -- -- - -. ______ _ -~ _____ . 314 Formation of Sandy _____ - - - -- - -- - ---- - ----------- - --- - 317 Formation of Shale________ ------------ ------ -------- 817 Geological Relation of Archrean - -- ----- - ----- ___ __351 Of Chickamauga.---_ - ___ ---__________ 342 Of Coal Measures ---- - - - -- -- ------ 347 Of Floyd _--- - - - ------- - ----- - - - _345 Of Fort Payne- ----- - -- - -------- 34.5 Of Knox. _____ -------------------- -.337 'Of Lafayette -- - - - - --------- __ __ 347 Of Modern ___ ------~-- __ -' __________ .347 Of Mountain Limestone------ _________ 346 Of Oostanaula______ -- _________ ______ .329 Of Paleozoic ------- - - - - - - ---- 329 Of Red Mountain ________ _____________ 344 Of Sub-Carboniferous.. _- ________ _____ .345 Geology of Experimental Station ________________________ .351 Geology of Coll~geFa1m ____ ---------------- -------------_,362 Heat related to Physical Structure ____ .. ___________ _ _____ .322 Kinds of_ _____________ -' ________ _____ ________________ 321 Lime Necessary in. ____________________________________ . . 325 arly---- ___ --- ________________________ __ ______________ 322 Moisture in ______________ ____________________________ 326 Moisture R'elated to Physical Structure __ --- ---- - ------ 322 Origin of Materials of - - ------ - ---- ____ -- --- _ 314 Organic Matter in---~---~-_-----~- ____ -~-7 ----- ____ . __ .318 404 GEOLOGICAL SURVEY OF GEORGIA. Soils, Organic Origin of Limestones ____________ -_---- ___ -- ____ 316 Archooan ------- -------------------- ------ - - ___ _351 Plant Food, Sources of_ ___ ------------------------ _____ 315 Plant Food, Fixing of__._---- -------- ---- ________ --- 324 Plant Food Nece~arY------------------------------~---323 Plaut Growth ____ .. __ - __ --------_- __ ---------- ________ 361 Phosphate Necessary--_- __ -- :_--- ______ ------ ___________ 325 Potash Necessary ___ ------- ---- - - ___ ------- - - ---- __ -- _325 Physical Conditions ___ ___ ----- -- --- --------~ -- ---- -326 Physical Properties ____ ------------ __ -------- __________ 321 Relations of Physical Features of ------- ------------ -361 SandY------ - -----------------------------------317, 321 Shaly _________ --- _----- ------ __ -~-- -- - - ____________ 317 Sod~ in ________________________ _____________________ 326 Sulphuric Acid, iu_- .. _--- _-- ------ __ -- ---- _- -- ________ 326 Sources of Plant Food, in ____________________ - ________ .315 Soluble Minerals, in.---------- ______ ---- _________ 358, 360 Structures of Archooan - ------ ---- ------ ------ - - - ---- 353 Table of Geological Formations, in Relation to _____________ 311 Value of Analysis ... ---------_---_--~----- ___ ~ ___ . ____ 325 Value of Experiment Station __ ______ ------- - - - --- - 360 Spencer's Report on South Georgia___ - ______ -- __ -- ____________ 3(:)5 Spencer's Report along M. & B. Railway ----------------------36.") Springs-- ___ - __ --------------_-- ___ ------------ __________ 83 Squires, Joseph---------. _________ --- _. __ - --- _______________ 33 Stalactites _______ - ___ - ___ - ______________ - --- ______________ 105 Stevenson, J. J ---------------- --------------- ------ _ 28 Streams, Character of_ ____________________ - _- _______________ 64 Subsidence of Land ___ . ___________________ - ________________ 11 Sub-Carboniferous Series- General Characters- ---- ---- -- - - - 51 In Polk County _______ __ _____________ 86 In Floyd CountY-------------------- 96 In Gordon County __ ------ ___________ 110 In Whitfield CountY-----------------117 In Catoosa County ------ - --- ------122 INDEX. 405 Sub-Carboniferous Serit>sChattooga County------------------ .126 In Walker County------- -~- - --- --- I3fi In Dade CountY------- - ------------142 Submergence, Paleozoic____ _----------------------- ____ I5 Submergence of Georgia -- --------- - --- ----------- - - - - 26, 59 Succession of Unlike Materials- ----- -------- - - - ------- - - --- I2 Synclinals Defined ____ ------------- - ----------- ___----- ___ I6 Table of Altitudes_________ ---- - - -- - - --------- - --- - - - - --- 76 Of Economic resources- -- ~---- - - - - - ---- ---------- Geological Formations -------------------------- -27, 29 Of Soils __ ---- _- -- -- -- - - - __ _------------ ----------- Terraces. ---_ - - - ---- ------- ___ ---------_ - - -___ _____ ____ ___ 98 Terrestrial Movements- _____ .. __ - - - ----_----------------- __ 11 Thickness of Paleozoic Group ____________________________ 3I, 32 Of Formations (see Each Series.) (Also see Under Soils.) Timbers.---- .. --------_---_- --- _-- .. _-- __ -- ---- ____ - -- - ----289 Trenton Series (see Chickamauga). Unr,onformities _______ -- _.... ___ .. ___________ ...... _______ _------ II Valley11, Origin of_ _________________ __ _________ __ ______ ____ 24 Value of Fossils___ - ___ .... --_ .. _____ - ___ .. ____________________ 30 Walcott, C. D, ____ :_ _______~--'-- - 36, 38, 40, 4I, 366, 367 Walker County, Local eology- ----- - - ------ ------- - ----- ----130 Physical Fentur ------ ---- --- ______ :_, _____ 73 Ores (see Re ource ). Waterpowers -------- ..... ------ .. - ----------------------289 Watershed of Coosa Valley--------- - -- - --- - --------------- 71 Weisner Quartzite--- --------------------------------- 31) Wells in Knox Series- ------- - --- - - ------ - - - ---- - - - --- --- 82 Willet, J. E, ______ ___ _ __ .. ______________________________367 White, H. C.. ..: ____ ________ __ __ _ -- -- ---- --- -- ------~-- --367 406 GEOLOGICAL SURVEY OF GEORGIA. Whitfield County, Local Geology---- ----- --- ----- ------ ------115 Physical Features __ -- ---- - --- -- ----------. 71 Ores (see Resources). Zinc in Brown Ore.- ------------- - ----- ---- -- - ---- --------172 Atlanta, July 15th, 1893. GEOLOGICAL SURVEY OF GEORGIA. J. W. SPENCER, Ph. D., F. G. S., STAT E GEOLOG I ST. LEGEND (/) c \coal Measures :J a0 w : Mountain Cm Limestone zl.L CJ Floyd Shale 0am:: Cp FT.Payne Chert [ 3 ch Ui f--- - Limestone & Slate 0oa: ~ o ~ Knox 1 - -'' - - - - ' Dolomite o~ _ J Oostanaula ?Mt Metamorphic ------Faults Scale ? rW 3 4 W T Miles 250, ft , Contol!rs above tide. LOOKOUT Mt. 0 SG