DESCRIPTION OF THE KINGSTON SHEET.

GEOGRAPHY. arbitrary line coinciding with the Mississippi river tering a gorge through the plateau, runs westward through the sandstone find underground channels, as far up as Cairo, and then crossing the States of to the Ohio. From Chattanooga southward the or form them by dissolving the limestone. By General relations. The Kingston atlas sheet is Illinois and Indiana. Its eastern boundary is streams flow directly to the Gulf. There is these they flow to some lower outlet. Wherever, bounded by the parallels of latitude 35° 30' and sharply defined along the Appalachian valley by abundant evidence that the divide between the in the process of erosion, the sandstone was and 36°, and the meridians of longitude 84° 30' the Alleghany front and the Cumberland escarp­ Tennessee and Coosa basins is comparatively removed as it was over the coves the surface and 85°. It embraces, therefore, a quarter 'of a ment. recent and that formerly the Tennessee river of the limestone was rapidly lowered and a cove square degree of the earth's surface. Its dimen­ The rocks of this division are almost entirely of flowed directly south across the present divide was formed, sometimes, though not always, sur­ sions are 34.5 miles from north to south and 28.1 sedimentary origin and remain very nearly hori­ and by the present course of the Coosa and rounded by a sandstone-capped barrier, beneath miles from east to west, and it contains 968.7 zontal. The character of the surface, which is Alabama rivers to the Gulf. which the streams escape. Grassy cove is further square miles. The adjacent atlas sheets are Wart- dependent on the character and attitude of the All of the western or plateau division of the advanced in its development than the others. Its burg on the north, Loudon on the east, Cleveland rocks, is that of a plateau more or less completely province except a small portion in Pennsylvania drainage is wholly underground, though several on the south, and Pikeville on the west. The dissected, or elsewhere of a lowland. In the south­ and another in Alabama is drained by streams low gaps in its rim indicate the location of sur­ Kingston sheet lies wholly within the State of ern half of the province the surface of the plateau flowing westward to the Ohio. The northern face streams which formerly drained the cove, as Tennessee and embraces portions of Cumberland, is sometimes extensive and perfectly flat, but it is portion of the eastern or Appalachian mountain Berks creek now drains a portion of Crab Morgan, Roane, Rhea, Loudon, Meigs, and Mc- oftener much divided by stream channels into division is drained eastward to the Atlantic, while Orchard cove. When the basin of the cove is Minn counties. large or small flat-topped hills. In West Virginia southward from the New river all except the east­ fully developed the present positions of the out­ In its geographical and geological relations this and portions of Pennsylvania the plateau is ern slope is drained westward by tributaries of ward-flowing streams, Berks creek and the area forms a part of the Appalachian province, sharply cut by its streams, leaving in relief the Tennessee or southward by tributaries of branches of Daddy creek, will be indicated only which extends from the Atlantic coastal plain on irregularly rounded knobs and ridges which bear the Coosa. by low gaps in the rim of the cove. the east to the Mississippi lowlands on the west, but little resemblance to the original surface. Topography of the Kingston sheet. The country East of Crab Orchard mountains the surface and from central Alabama to southern New York. The western portion of the plateau has been com­ embraced within the atlas sheet is about equally has a gentle slope to the southeast from an eleva­ The region thus defined has a common history pletely removed by erosion and the surface is now divided between the two western divisions of the tion of 2,000 feet to 1,500 or 1,600 feet at the recorded in its rocks, its geologic structure, and its comparatively low and level, or rolling. Appalachian province and is marked by the two edge of the escarpment which limits the Cumber­ topographic features. Only a part of this history Altitude of the Appalachian province. The Ap­ widely different types of surface which character­ land plateau in this direction. This belt of plateau can be read from an area so small as that covered palachian province as a whole is broadly dome- ize those divisions. As indicated above, these country lying east of the Sequatchie valley ex­ by a single atlas sheet; hence it is necessary to shaped, its surface rising from an altitude of about differences are due jointly to the character of the tends toward the southwest as Walden ridge and consider the individual sheet in its relations to 500 feet along the eastern margin to the crest of underlying rocks and the geologic structure, or to sometimes bears the same name within the Kings­ the entire province. the Appalachian mountains, and beyond the cen­ the relation of the strata to the surface. The ton sheet. Its drainage is toward the east or Subdivisions of the Appalachian province. tral valley descending westward to about the connection between these two factors and the re­ southeast, and the streams have cut many deep The Appalachian province may be subdivided same altitude on the Ohio and Mississippi rivers. sulting topographic features will be more fully channels in the generally level surface. Near the into three well marked physiographic divisions, edge of the plateau the smaller streams turn and Each division of the province shows one or explained later. throughout each of which certain forces have pro­ flow parallel to the escarpment till by their union more culminating points. Thus the Appalachian The northwestern half of the sheet lies in the duced similar results in sedimentation, in geologic they form a large stream, which emerges into the mountains rise gradually from less than 1,000 feet Cumberland plateau. The general surface west structure, and in topography. These divisions are valley from a deep, rocky gorge. in Alabama to more than 6,500 feet in western of the Crab Orchard mountains is quite level and long narrow strips of country extending the entire The southeastern half of the sheet lies within North Carolina. From this culminating point has an elevation between 1,800 and 1,900 feet length of the province from northeast to south­ the folded zone forming the great Appalachian they decrease to from 3,000 to 4,000 feet in south­ above the sea. This plain is drained northeast west. valley, here occupied by the Tennessee river and ern Virginia and 1,500 to 2,000 feet on the Mary­ into Emory river by Daddy creek and its branches, The central division is the Appalachian valley. its tributaries and called the valley of East Ten­ land-Pennsylvania line. which flow in narrow, rocky channels from 100 to It is the best defined and most uniform. It co­ nessee. The altitude of the Tennessee river is 300 feet below the plateau surface. incides with the belt of folded rocks which in the The Appalachian valley shows a uniform in­ about 700 feet, and all its larger tributaries have southern part forms the Coosa valley of Georgia crease in altitude from 500 feet or less in Alabama The Crab Orchard mountains consist of flat- cut their channels down nearly to the same level, and Alabama and the great valley of East Ten­ to 900 feet in the vicinity of Chattanooga, 2,000 topped ridges, or mesas, with very abrupt slopes but the surface of the valley is broken by numer­ nessee. Throughout the central and southern feet at the Tennessee-Virginia line and 2,600 or on at least one side. They rise 800 to 1,200 feet ous ridges rising from 300 to 500 feet higher. portions the eastern side alone is marked by great 2,700 feet at its culminating point, on the divide above the general level of the plateau and lie These ridges have a uniform northeast and south­ valleys, such as the Shenandoah valley of Virginia, between the New and Tennessee rivers. From parallel to its eastern edge, directly in line with west trend, parallel to the Cumberland escarp­ the Cumberland valley of Maryland and Pennsyl­ this it descends to 2,200 feet in the valley of New the Sequatchie valley, which extends southwest- ment, their location and height depending directly vania, and the Lebanon valley of northeastern river, 1,000 to 1,500 feet in the James, from 500 ward from the edge of the sheet. The relation on the character and attitude of the underlying Pennsylvania; while the western side is ribbed to 1,000 feet on the Potomac, and to about the between these mountains and the Sequatchie rocks. The general course of the Tennessee river by a succession of narrow ridges without continu­ same throughout Pennsylvania. These figures valley will be explained in describing the struct­ from Kingston to the southern edge of the sheet ous, intermediate valleys. This division varies represent the average elevation of the valley sur­ ure. Elevations about the head of the valley is parallel to these ridges, whereas its tributaries in width from 40 to 125 miles; it is sharply out­ face, below which the stream channels are sunk reach 3,000 feet, decreasing to about 2,500 at the cut directly across them, receiving smaller branches lined on the southeast by the Appalachian moun­ from 50 to 250 feet, and above which the valley northern edge of the sheet. The most peculiar from intervening valleys. tains and on the northwest by the Cumberland ridges rise from 500 to 2,000 feet. topographic features of. this region are the coves An examination of the topographic map shows plateau and the Alleghany mountains. Its rocks The plateau division increases in altitude from within the Crab Orchard range. The largest of that a considerable portion of the valley surface has are almost wholly sedimentary and in large meas­ 500 feet at the southern edge of the province to these is Grassy- cove, which is structurally the an altitude of between 900 and 1,000 feet; above ure calcareous. The strata, which must originally 1,500 in northern Alabama, 2,000 in central Ten­ continuation of Sequatchie valley, but is separated this level the ridges of hard rocks rise from 100 have been nearly horizontal, now intersect the nessee, and 3,500 in southeastern Kentucky. It is from it by a ridge 900 feet or more above the to 200 feet, while the stream channels are sunk surface at various angles and in narrow belts. between 3,000 and 4,000 feet in West Virginia cove. Its floor is almost perfectly level to the about the same depth into it. In other words the With the outcrop of different kinds of rock the and decreases to about 2,000 in Pennsylvania. base of the surrounding abrupt mesa slopes, its valley may be regarded as a plain, on which the elevation of the surface differs, so that sharp ridges From its greatest altitude along the eastern edge area is about eight square miles, and its eleva­ ridges remain in relief and in which the stream and narrow valleys of great length follow the the plateau slopes gradually westward, although tion is between 1,000 and 1,600 feet above sea channels have been incised. From a study of the upturned edges of hard and soft beds. Owing to along its western edge it is generally separated level. Its stream flows northeast, and near the entire province it has been determined that this the large amount of calcareous rock brought up from the interior lowlands by an abrupt escarp­ upper end of the cove disappears in a cave. This plain was formed near sea level, by the work of on the steep folds of this district its surface is ment. is the entrance to an underground channel, from the atmosphere and rivers during the Eocene and more readily worn down by streams and is lower Drainage of the Appalachian province. The which the stream, having doubled back on its Neocene periods. As the surface thus carved was and less broken than the divisions on either side. drainage of the province is in part eastward into overground course, emerges eight miles to the almost, but not wholly level it is called a pene­ The eastern division of the province embraces the Atlantic, in part southward into the Gulf, and southwest, in the head of the Sequatchie valley. plain. Subsequent elevation of the land has the Appalachian mountains, a system made up of in part westward into the Mississippi. There are several other coves similar to the one brought the peneplain to its present altitude, and many minor ranges which, under various local The position of the streams in the Appalachian described, but much smaller, so that their streams the streams, being thereby stimulated to renewed names, extends from southern New York to cen­ valley is dependent upon the geologic structure. do not attain any considerable volume before they activity, have cut the present channels within its tral Alabama. Some of its prominent parts are In general they flow in courses which for long sink. Little cove is a part of Grassy cove, being surface. The remnants of a very much older the South mountain of Pennsylvania, the Blue distances are parallel to the sides of the great separated from it only by a low divide, through peneplain, probably of the Cretaceous period, may ridge and Catoctin mountains of Maryland and valley, ^following the outcrops of the softer rocks. which the waters pass underground. The drain­ be seen in the Cumberland plateau. Like the Virginia, the Great Smoky mountains of Tennes­ These longitudinal streams empty into a number age of Crab Orchard cove is in three directions, other, it was formed near sea level and was even see and North Carolina, and the Cohutta moun­ of larger transverse rivers, which cross one or the partly by underground and partly by surface more perfectly developed, although the Crab tains of Georgia, together with many other less other of the barriers limiting the valley. In the streams. The waters from the south find their Orchard mountains then, as now, rose abruptly important ranges. northern portion of the province they form the way into Grassy cove beneath the intervening from its surface. After the Cretaceous land had Many of the rocks of this division are more or Delaware, Susquehanna, Potomac, James, and ridge; those of the central and northern parts flow been reduced nearly to baselevel, it was elevated less crystalline, being either sediments which have Roanoke rivers, each of which breaks through the westward into Daddy creek; while a small por­ during the Eocene period 800 to 1,200 feet, and been changed to slates and schists by varying Appalachian mountains by a narrow gap and tion on the east is drained by the head of Berks the streams then cut the second peneplain upon degrees of metamorphism, or igneous rocks -which flows eastward to the sea. In the central portion creek. the soft limestones of the Appalachian valley. have solidified from a molten condition, such as of the province, in Kentucky and Virginia, these The process by which these coves are formed is The older plain, though deeply cut by stream granite and diabase. longitudinal streams form the New or Kanawha somewhat as follows. The rocks composing the channels, was preserved by the hard sandstones The western division of the Appalachian river, which flows westward in a deep, narrow surface of the Cumberland plateau and the higher which formed its surface. During its elevation province embraces the Cumberland plateau and gorge through the Cumberland plateau into the portions of the Crab Orchard mountains are sand­ that portion of the Cretaceous peneplain within the Alleghany mountains, also extending from Ohio river. South of New river to northern stone and conglomerate, while in the coves lime­ and adjacent to the Kingston sheet was tilted New York to Alabama, and the lowlands of Ten­ Georgia the Great valley is drained by tributaries stone is exposed. The sandstone is underlain by towards the southeast, so that it is about 400 feet nessee, Kentucky, and Ohio. Its northwestern of the Tennessee river, which at Chattanooga the limestone, and it once extended over the areas higher at the northwest corner of the sheet than boundary is indefinite, but may be regarded as an turns from the apparently natural course and, en­ of the coves. Surface waters sinking down at the Cumberland escarpment. GEOLOGY. tion is taken from Apison, Tennessee, in the south­ thickness, where the strata represent the rapid the Tennessee river suggests that the formation eastern part of the Chattanooga sheet. and variable accumulation of sediment near the once covered the entire area of the sheet, but its STRATIGRAPHY. Home formation. Next above the Apison shale shore. original eastern limit is not known. It takes its The sedimentary record. All the rocks appear­ are the sandstones and shales of the Rome forma­ The formation takes its name from Athens, name from Fort Payne, Alabama. ing at the surface within the limits of the Kings­ tion. They are between 2,100 and 3,400 feet Tennessee, on the Cleveland sheet. Bangor limestone. The Bangor limestone is ton atlas sheet are of sedimentary origin, that is, thick, but the strata are so crumpled that it is im­ Rockwood formation. This formation, which from 800 to 1,100 feet thick at the head of Sequat­ they were deposited by water. They consist of possible to obtain accurate measurements. is the highest division of the Silurian in this chie valley and along the Cumberland escarp­ sandstones, shales, and limestones, presenting great The lower portion, 1,500 to 2,000 feet thick, is region, varies widely in character and thickness ment, where it forms the lower portion of the variety in composition and appearance. The composed of layers of sandstone and shale. Pass­ within the limits of the sheet. It forms a narrow mountain slopes. It also forms the coves* of materials of which they are composed were origi­ ing upward the proportion of the shale gradually strip about the head of Sequatchie valley, where Crab Orchard mountains. The limestone shows nally gravel, sand, and mud, derived from the waste increases, so that toward the top only a few thin it is 165 feet thick, and is composed of calcareous clearly the mode of its formation. It is often of older rocks, or the remains of plants and siliceous beds occur, which can scarcely be called shales interbedded with blue limestone. Along composed almost entirely of fragments of crinoids animals which lived while the strata were being sandstone. The shales are usually brown or dark the foot of the Cumberland escarpment it is about and calcareous coverings of other sea animals laid down. Thus some of the great beds of lime­ olive green, while the sandstone beds are reddish 600 feet thick, and consists of calcareous and which left their remains on the sea bottom. stone were formed largely from the shells of vari­ brown or purple, with an occasional thin layer of sandy shales. Still further east, in the ridge which Although in general a massive, blue, crinoidal ous sea animals, and the beds of coal are the re­ white quartzite. The sandstone beds are ripple extends from Iron Divide to Ten Mile Stand, the limestone, the upper 50 or 100 feet often weath­ mains of a luxuriant vegetation, which probably marked and were evidently deposited in shallow formation attains a thickness of from 850 to 1,000 ers to a brightly colored clay shale, and in Grassy covered low, swampy shores. water, but the succeeding formation contains lime­ feet, a considerable part of which is coarse sand­ cove there is a layer of sandstone about 70 feet These rocks afford a record of almost uninter­ stones and calcareous shales, probably formed on stone interbedded with sandy shales. Toward thick near the middle of the formation. rupted sedimentation from early Cambrian to late a comparatively deep sea bottom. the top are sandy shales and a few calcareous beds, Lookout sandstone. At the close of the period Carboniferous time. Their composition and ap­ Connasauga shale. This formation is composed with which is associated the iron ore that gives occupied by the deposition of the Bangor lime­ pearance indicate the nearness to shore and the at the base of thin limestones interbedded with the formation such great economic importance. stone there.was an uplift of the sea bottom, so depth of water in which they were deposited. shales, then yellow or greenish clay shales, and It takes its name from Rockwood, Tennessee, that the water became shallow over a wide area, Sandstones marked by ripples and cross-bedded at the top blue seamy or shaly limestone. The where the rocks are intermediate in character while an abundant supply of mud and sand was by currents, and shales cracked by the sun on limestone at the base is oolitic, being made up of between the western and eastern phases and washed in from the adjoining land. Under these mud flats indicate shallow water; while lime­ rounded or flattened grains, usually about a tenth where the ore is extensively mined. conditions a great mass of shale and sandstone stones, especially by the fossils they contain, of an inch in diameter. This oolitic limestone is The presence of the Athens shale on the eastern was deposited. The surface also stood above sea indicate greater or less depth of water and absence sometimes absent, and the boundary between the portion of the sheet only and the changes noted level at various times, long enough at least for the of sediment. The character of the adjacent land Rome and Connasauga becomes very indefinite. in the Chickamauga and Rockwood formations growth of a luxuriant vegetation, Avhich formed is also shown by the character of the sediments The blue, seamy limestone at the'top of the Conna­ indicate that while these formations were being coal beds. derived from its waste. Coarse sandstones and sauga is also locally wanting, especially on the deposited the land from which the sediment came The Lookout sandstone consists of strata of con­ conglomerates, such as are fonnd in the Coal- eastern edge of the sheet, and brown shales indis­ was toward the southeast and the deep sea toward glomerate, thin-bedded sandstone, sandy and clay measures, were derived from high land on which tinguishable from the Rome are found immedi­ the northwest. shale, and coal between the top of the Bangor stream grades were steep, or they may have re­ ately under the Knox dolomite. The thickness DEVONIAN ROCKS. limestone and the top of a heavy bed of conglom­ sulted from wave action as the sea encroached erate. The formation is about 260 feet thick in of the formation is about 1,500 feet at the south­ Chattanooga Hack shale. Overlying the Rock- upon a sinking coast. Red sandstones and shales, the Crab Orchard, mountains and increases to 510 ern edge of the sheet and decreases rapidly toward wood formation is a thin stratum of shale which such as make up some of the Cambrian and feet along the Cumberland escarpment. The bed the northeast till it wholly disappears or is rep­ appears to represent the whole of the deposition Silurian formations, result from the revival of of conglomerate at the top of the formation varies resented only by a thin bed of blue, seamy lime­ that took place in this region during the De­ erosion on a land surface long exposed to rock in thickness from 25 to 60 feet, and usually forms stone. vonian period. Typical exposures of this shale decay and oxidation, and hence covered by a deep a bold cliff. The formation takes its name from The Cambrian rocks are seen only in the south­ appear in the north end of Cameron hill, within residual soil. Limestones, on the other hand, if Lookout mountain. eastern half of the sheet, where they form long, the city limits of Chattanooga, from which locality deposited near the shore, indicate that the land Walden sandstone. This formation includes all narrow strips extending in a direction parallel to it takes its name. was low and that its streams were too sluggish to the rocks within the sheet above the Lookout con­ the Cumberland escarpment. Each of these strips The Chattanooga black shale has a remarkably carry off coarse sediment. Then the sea received glomerate. The conditions of its deposition were is limited by a fault along its western side, and uniform character wherever seen within the limits only fine sediment and substances in solution. similar to those of the Lookout, but were some­ there is a regular sequence in the order of the of this atlas sheet and for a long distance on either The sea in which these sediments were laid what more uniform and more favorable for the occurrence of the formation; the older lie next to side north and south. It varies in thickness from down covered most of the Appalachian province the fault and the younger in successive narrow accumulation of coal. The rocks are mainly thin- and the Mississippi basin. The area of the 15 to 35 feet. The upper portion of the shale, bedded sandstones and sandy shales, with some bands toward the east. three or four feet thick, is usually dark gray in Kingston sheet was near its eastern margin, and massive sandstones. The original thickness of The Rome sandstone forms ridges varying in color and often carries a layer of round concre­ the materials of which its rocks are composed height and continuity with its thickness, while the the Walden sandstone cannot be determined, as were therefore derived largely from the land to tions about an inch in diameter. The remainder it is probable that much of the formation has been upper part of that formation and the overlying of the formation is jet black, from an abundance the eastward. The exact position of the eastern Connasauga shale produce long, narrow valleys. removed by erosion. A thickness of about 1,300 shore line of this ancient sea is not known, but it of carbonaceous matter, and, when freshly broken, feet remains a short distance west of the escarp­ probably varied from time to time within rather SILURIAN ROCKS. it emits a strong odor resembling that of petroleum. ment. This shale, on account of its distinctive and wide limits. Knox dolomite. The lowest division of the The Lookout and Walden sandstones consti­ striking appearance, has attracted much attention Two great cycles of sedimentation are recorded Silurian consists of from. 3,300 to 3,500 feet of tute the productive coal-measures of this region. from miners, and has been prospected in many in the rocks of this region. Beginning with the massively bedded and somewhat crystalline, mag- They at present occupy the entire surface west of places for coal and for various ores, especially first definite record, coarse sandstones and shales nesian limestone. This limestone, or more prop­ the Cumberland escarpment, except at the head of silver and copper. Such exploitation, however, has were deposited in early Cambrian time along the erly dolomite, contains a large amount of silica in Sequatchie valley and in the coves of Crab Orchard always been attended by failure, since there is eastern border of the interior sea as it encroached the form of nodules and layers of chert or flint. mountains. It is probable that they formerly nothing of present economic importance in the upon the laud. As the land was worn down and Upon weathering, that part of the rock which extended over the whole area of the sheet, but shale. Although it contains a large proportion of still further depressed the sediment became finer, consists of the carbonates of lime and magnesia is the portions which covered the present Tennessee carbonaceous matter, which burns when it is placed until in the Knox dolomite of the Cambro-Silurian dissolved, and the chert remains, usually imbedded valley have been entirely removed by erosion. in a hot fire, the amount is not sufficient to con­ period very little trace of shore material is seen. in red clay. This residual material is often of The position and thickness of the various beds stitute a fuel, and no true coal is ever found asso­ Following this long period of quiet was a slight great depth and forms low, rounded hills and of coal which occur in these formations will be elevation producing coarser rocks; this became ciated with the shale. Small concretions of iron described under the Mineral Resources. irregular ridges. pyrites, which it often carries, have given rise to more and more pronounced until, between the The Knox dolomite occurs only in the south­ At the close of the Carboniferous period this the commonly accepted but wholly erroneous lower and upper Silurian, the land was much ex­ eastern half of the sheet, in long, narrow strips, region was elevated permanently above sea level, belief that the shale contains valuable ores. The panded and large areas of recently deposited alternating with the Cambrian rocks. Its out­ so that the constructive process of deposition formation is of economic importance only as a (Clinch) sandstones were lifted above the sea and crops are marked by the characteristic chert hills, ceased and the opposing, destructive process of starting point in prospecting for the red fossil eroded. Following this elevation, which com­ and the dolomite itself seldom comes to the sur­ erosion began. iron ore which occurs below it at a uniform depth pleted the first great cycle, came a second period, face. over considerable areas. STRUCTURE. during which the land was low, probably worn Chickamauga limestone. This formation shows down nearly to baselevel, affording conditions a decided change in character between its expos­ CARBONIFEROUS ROCKS. Definition of .terms. As the materials forming for the accumulation of the Devonian black shale ures on the western and eastern sides of the sheet. Fort Payne chert. This formation consists of the rocks of this region were deposited upon the and Carboniferous limestone, Avhich in general In the head of Sequatchie valley it is a hard, blue, from 75 to 150 feet of very siliceous limestone. sea bottom, they must originally have been in show very little trace of shore waste. A second flaggy limestone. In the narrow strip along the At the base, resting on the Chattanooga black nearly horizontal layers. At present, however, great uplift brought these rocks into shoal water foot of the Cumberland escarpment and in the shale, are usually heavy beds of chert, with only the beds are not usually horizontal, but are in­ and in some places above the sea, and upon them broader belt in Tennessee valley from Rockwood a small amount of limestone or greenish calcareous clined at various angles. When any particular were deposited, in shallow water and swamps, the landing southward, the Chickamauga is mainly shale. The lime increases toward the top, gradu­ bed is followed for a considerable distance it is sandstones, shales, and coal beds of the Carbon­ a blue limestone, but it also contains many mot­ ally replacing the chert, and the formation passes often found forming a series of arches and troughs. iferous. Finally, a further uplift at the close of tled, earthy and shaly beds. It is here about 1,500 upward into the Bangor limestone. East of In describing these folded strata the term syncline the Carboniferous stopped the deposition of sedi­ feet thick. In the belt which extends from near Emory river the Fort Payne chert is represented is applied to the downward bending troughs and ment in the Appalachian province except along Kingston southwestward to Decatur, the forma­ by a slightly cherty limestone, and beyond the anticline to the upward bending arches. its borders in recent times. tion, 1,500 to 1,800 feet thick, consists of blue and edge of the sheet it is not separable from the A synclinal axis is a line running lengthwise of mottled limestones, while above are yellow, calcare­ Bangor. The chert of this formation is readily the synclinal trough, at every point occupying its CAMBRIAN BOCKS. ous shales, probably equivalent to the upper beds distinguishable from that of the Knox dolomite by lowest part, towards which the rocks dip on either Apison shale. The oldest rocks exposed within of limestone farther west. the fossils which it contains. It is often made up side. An anticlinal axis is a line which occupies the limits of the sheet are slightly sandy or clay The formation is named from Chickaraauga of crinoid steins imbedded in a siliceous cement. at every point the highest portion of the anticlinal shales. Their most striking peculiarity is in the creek, on the Chattanooga and Rihggold sheets. On weathering, the cement remains as a porous arch, and away from which the rocks dip on brilliant coloring which they display, generally in Athens shale. East of the Tennessee river the chert filled with the fossil impressions. either side. These axes may be horizontal or in­ bands of red, purple, green, and yellow. The upper part of the Chickamauga limestone is re­ The formation occurs in a narrow belt around clined. Their departure from the horizontal is thickness of the formation is not known, since it placed by shales from 300 to 500 feet in thickness. the head of Sequatchie valley, over a small area called the pitch of the axis and is usually but a is always limited on one side by a fault, but it is Eastward beyond the edge of this sheet this in Grassy cove, and in a narrow strip along the few degrees. In addition to the folding, and as a not less than 1,000 feet. The name of the forma­ formation increases to several thousand feet in Cumberland escarpment. An occurrence east of result of the continued action of the same forces which produced it, the strata along certain lines province there is a regular increase of metamor­ D. On its eastern side the Knox dolomite and escarpment there is a narrow anticline, the axis of have been fractured, and the rocks have been phism toward the southeast, so that a bed quite on its western side the Rockwood and Chicka- which pitches toward the north. In the trough thrust in different directions on opposite sides of unaltered at the border of the great valley can be mauga have been thrust up onto the Look­ thus formed between the upturned rocks of the the fracture; this is termed a fault. The rocks traced through greater and greater changes until out sandstone. A similar wedge-shaped mass, escarpment and the anticline, coal is found in are also altered by production of new minerals it has lost every original character. bounded by faults with opposing dip, occurs at irregular masses. The coal yielded most readily from the old, or by metamorphism. The structures above described are manifestly Post Oak springs, shown in section B, and another as the strata were folded, and it was squeezed out Structure of the Appalachian province. These due chiefly to horizontal compression which acted at Rhea springs, shown in section E. from those parts of the folds where the pressure three methods of change which the rocks of the in a northwest-southeast direction, at right angles The strata lying southeast of Tennessee river was greatest, to accumulate where the pressure province have suffered are grouped very distinctly to the trend of the folds and cleavage planes. are divided into a number of similar belts parallel was relieved. In some places the coal is eighty to along the three geographical divisions. The compression apparently began in early Pale­ to the escarpment, each from two and a half to one hundred feet thick. Its original structure is In the plateau region and westward the rocks ozoic time and probably continued at intervals up four and a half miles in width. On the western almost obliterated, and it occurs in small rhom- are but little tilted from their original horizontal to its culmination, shortly after the close of the side of each belt are Cambrian rocks, the Apison boidal blocks, whose polished surfaces show that positions and are almost entirely unchanged; in Carboniferous, when the greater portion of the shale or Rome sandstone, while on the eastern much motion has taken place within the mass. the valley the rocks have been steeply tilted, bent folding was effected. side are Silurian rocks, and the younger strata of A second seam, also worked at Rockwood, oc­ into anticlines and synclines, broken by faults, and In addition to the horizontal force of compres­ one belt dip under the older strata of the belt curs about 620 feet above the conglomerate. -This to some extent altered into slates; in the moun­ sion, the province has been subjected to other next eastward. The belts are therefore separated is called the Richland seam at Dayton, where'it is tain district faults and folds are prominent, but forces, which have repeatedly elevated and de­ by faults, and the strata of each have been thrust about four feet thick. The strata high enough to the rocks have been changed to a greater extent pressed its surface. At least two periods of high up onto the strata of the zone next westward. contain this coal have been much eroded, but. it. by the minute breaks of cleavage and by the land near the sea and two longer periods of low Each of these belts represents a syncline in the still remains in the deeper portion of the Walden growth of new minerals. land are indicated by the character of the Pale­ originally folded strata, while the positions of the ridge syncline, a belt three or four miles broad* In the valley the folds and the faults developed ozoic sediments. And in post-Paleozoic time there intervening anticlines are occupied by the faults. west of the escarpment, and probably also in the from them are parallel among themselves and to have been at least three and probably more The arches of strata, which formed the anticlines, plateau west of the Crab Orchard mountains. the old land body, extending in a northeast-south­ periods of decided oscillation of the land, due to have usually been entirely removed by erosion, Without attempting strict correlations of in­ west direction for great distances. Some faults the action of some vertical force. In every case though the anticlinal structure is sometimes pre­ dividual beds it will thus be seen that there are have been traced for 300 miles, and some folds the movements have resulted in warping the sur­ served next to a fault in the oldest rocks. generally three horizons at which workable coal' have even greater length. The crests of the anti­ face, and the greatest uplift has occurred nearly Some peculiar faults are shown in sections D is likely to be found. The first is within 75 feet clines are very uniform in height, so that for long along the line of the great valley. and E, just east of Tennessee river. The Chick- below the top of the conglomerate, the second distances they contain the same formations. They /Structure sections. The six sections on the amauga and Rockwood formations lie in an open within 75 feet, and the third within 650 feet are also approximately equal to each other in structure sheet represent the strata as they would syncline, against which the Cambrian rocks are above the top of the conglomerate. Coal beds height, so that many parallel folds bring to the appear in the sides of a deep trench cut across faulted on the eastern side. This is the prevail­ occur at other horizons, and they may be locally surface the same formations. Most of the rocks the country. Their position with reference to the ing structure of the region, but it is further com­ workable, but less generally so than at the three dip at angles greater than 10°, and frequently the map is on the line at the upper edge of the blank plicated by a nearly horizontal fault, on which levels mentioned. sides of the folds are compressed till they are strip. The vertical and horizontal scales are the the Knox dolomite has been thrust over from the All the coals of this region are bituminous, and parallel. The folding is greater in thin bedded same, so that the elevations represeoted in the east so that it rests upon the syncline of younger all, so far as tested, are well suited for coking. rocks, such as shale and shaly limestone, because profile are not exaggerated, but show the actual rocks. Iron ore. The only iron ore sufficiently abun­ the thin layers were most readily bent, and slipped form and slope of the land. These sections repre­ MINERAL RESOURCES. dant to be commercially important is the red along their bedding planes. Perhaps the most sent the structure as it is inferred from the posi­ fossil ore of the Rockwood formation. This ore striking feature of the folds is the prevalence of tion of the strata observed at the surface. On The mineral resources of the Kingston sheet is very similar in appearance to that occurring southeastward dips. In some sections across the the scale of the map they cannot represent the consist of coal, iron ore, limestone, building stone, at the same horizon in such widely separated southern portion of the Appalachian valley minute details of structure; they are therefore road stone and brick clay. localities as Wisconsin, New York, and Alabama. scarcely a bed can be found which dips towards somewhat generalized from the dips observed Coal. The productive coal-bearing formations, It is a stratified bed of constant thickness and the northwest. near the line of the section in a belt a few miles consisting of the Walden and Lookout sandstones, with definite relations to other strata of the for­ Out of the close folds the faults were devel­ in width. occupy the entire surface of the sheet west of mation over considerable areas. Like any other oped, and with extremely few exceptions the fault Faults are represented on the map by a heavy, the Cumberland escarpment, except the head of rock stratum, however, it is not absolutely con­ planes dip toward the southeast. The planes on solid or broken line, and in the sections by a line Sequatchie valley and Grassy and Crab Orchard stant, so that while the map indicates within nar­ which the rocks broke and moved are often parallel whose inclination shows the probable dip of the coves. These formations have an area within the row limits the areas within which the ore may to the bedding planes, as the rocks slipped on the fault plane, the arrows indicating the direction in limits of the atlas sheet of about 370 square miles. occur, careful examination is required to deter­ beds in folding. Along these planes of fracture which the strata have been moved on its opposite The accompanying vertical sections show the mine whether at any particular locality its quan­ the rocks moved to distances sometimes as great sides. position and thickness of the various coal beds. tity and quality are such as to make it commer­ as six or eight miles. There is a progressive It will be seen from the sections that the region The sections are not generalized, but each rep­ cially valuable. increase in degree of deformation from northeast is divided by the Cumberland escarpment into resents the actual measurements made at a single The proportion of iron in the ore usually de­ to southwest, resulting in different types in differ­ two nearly equal divisions having entirely differ­ locality. It will be seen that the beds vary con­ creases with distance from the surface, and at con­ ent places. In northern Pennsylvania folds are ent types of structure. In the northwestern siderably in number, position, and thickness from siderable depths it becomes simply a more or less inconspicuous. Passing through Pennsylvania to­ division the strata are horizontal or gently undu­ one part of the field to another. The datum from ferruginous limestone. This is due to the fact ward Virginia they rapidly become more nume­ lating, while in the southeastern they are highly which their position is measured up or down in that near the surface the lime has been largely rous and dips grow steeper. In southern Vir­ inclined and intersected by numerous faults. the section is the top of the conglomerate. It is removed by percolating surface waters, leaving ginia the folds are closely compressed and often /Structure of the plateau. In the Crab Orchard not always possible to determine this point ex­ behind the insoluble iron oxide as the soft ore. closed, while occasional faults appear. Passing mountains the strata are bent upward, forming an actly, so that a slight uncertainty is thus intro­ Considerable quantities of this soft ore are fre­ through Virginia and into Tennessee the folds are anticline. If the rocks which have been removed duced into the correlation of coal beds in different quently obtained by trenching along the outcrops more and more broken by faults, until, half way from the top of the arch were restored, the moun­ parts of the field. of the bed where it is not of sufficient thickness through Tennessee, nearly every fold is broken tains would rise at least 1,500 feet higher than There is always one bed of coal contained in to make mining profitable at present. and the strata form a series of narrow, overlap­ they are at present. But erosion has been more the Lookout, and in some places there are as Along the foot of the Cumberland escarpment a ping blocks, all dipping eastward. This condition active on the arch than in the adjacent troughs. many as four. One bed immediately below the narrow strip of the Rockwood shale extends across holds nearly the same southward into Alabama, Thus Sequatchie valley has been eroded along the conglomerate is fairly constant in position, though the sheet, except at points where a number of short but the faults become fewer in number and their axis of the anticline toward the southwest, and it varies considerably in thickness. Lying next breaks are caused by faulting. The ore occurs in horizontal displacement much greater, while the within the sheet numerous coves have been formed to the rigid conglomerate, the coal has been much workable quantity along this whole strip, though folds are somewhat more open. along the same line. West of the Crab Orchard squeezed, especially along the escarpment, where it is thicker in the northern than the southern In the Appalachian mountains the structure is anticline the strata are nearly horizontal, while the strata are sharply folded. This bed is worked half. It has been worked at numerous points the same as that which marks the great valley; eastward they dip in a broad shallow syncline, on the south side of the Emory river at Harri- near Spring City, Sheffield, and Evansville, but there are the eastward dips, the close folds, the which extends toward the southwest, forming man. It is about ten feet thick at the outcrop, only by surface trenching. Between Rockwood thrust faults, etc. But in addition to these changes Walden ridge. Along the eastern side of this but this is probably only a local swell, produced and Emory gap there are two beds of ore, one of form, which took place mainly by motion on the syncline the strata are rather sharply upturned, by the bending of the rocks above and below the about 200 feet and the other 500 feet below the bedding planes, there were developed a series of forming the Cumberland escarpment. For a short coal. Coal beds below the conglomerate have Chattanooga black shale. Only the upper bed is minute breaks across the strata, producing cleav­ distance north of Emory river they are even over­ been opened at various points along the escarp­ worked at present, its thickness varying from age, or a tendency to split readily along these new turned, so that they dip steeply toward the east. ment, and also on both sides of the Crab Orchard three and a half to five feet. The workings have planes. These planes dip to the east at from 20° Sfructure of the valley. The complicated struct­ anticline, but sufficient information for their corre­ reached about 100 feet below the surface, and, to 90°, usually about 60°. This slaty cleavage ure of the southeastern half of the area is the re­ lation is not available, though in most cases the while the ore shows an increase in the proportion was somewhat developed in the valley, but not to sult of extreme compression in a northwest-south­ first bed below the conglomerate appears to be the of lime, it can probably be worked with profit to such an extent as in the mountains. As the east direction. The first effect of this compres­ one which is generally seen. The lower beds in much greater depths. breaks became more frequent and greater they sion must have been to produce a series of narrow, the Lookout sandstone, though worked on the The Rockwood formation thickens toward the were accompanied by growth of new minerals out parallel folds similar to the Crab Orchard anti­ Chattanooga sheet, appear to be either wanting or east, but the calcareous beds with which the iron of the fragments of the old. These consisted cline and Walden ridge syncline, except that they so thin as generally to escape notice over much of ore is associated are confined to its upper portion. chiefly of mica and quartz and were crystallized were probably not so broad. The force must this region. In the Tennessee valley, near the center of the parallel to the cleavage cracks. The final stage have acted very slowly through a long time, so The greater part of the workable coal of this sheet, it forms a strip about nine miles in length, of the process resulted in the squeezing and that the tops of the arches were eroded nearly as area is in the Walden sandstone. About sixty which is crossed four times by the Tennessee river, stretching of hard minerals like quartz, and com­ fast as they rose. When the folding had reached feet above the conglomerate is a bed which seems so that a large part of the area is not available plete recrystallization of the softer rock particles. a certain point, further compression resulted in to be quite uniform in position and character. It for mining. Notwithstanding the unfavorable All rocks, both those of sedimentary origin and the formation of faults. is worked at Dayton, just off the southwest corner conditions, considerable mining has been done in those which were originally crystalline, were sub­ The fault planes usually dip toward the south­ of the sheet, where it is about five feet thick. It this area, generally by surface trenching. jected to this process, and the final products from east, but there are some exceptions along the base has also been opened on the north bank of the A third belt of the ore-bearing rocks occupies the metamorphism of very different rocks are of the escarpment. Between Eockwood and Emory river near Harriman, but by far the most the top of the syncline which extends from near often indistinguishable from each other. E-ocks Spring City a narrow belt of rocks is bounded by extensive development has been made at Rock- Kingston to Ten Mile Stand. There are two containing the most feldspar were most thoroughly faults, which dip in opposite directions, so that wood. The rocks of the escarpment, through areas, separated by erosion, each about five miles altered, and those with most quartz were least the block of strata has the-form of a wedge with which the main entry is driven, there dip north­ in length, and from a quarter to a half mile in changed. Throughout the entire Appalachian the thin edge upward, as shown in sections C and west about 450. A short distance |)ack from the width. The ore has been worked only in the Kingston 3. ©f tlies& areas. On the western edge SOILS, the Kingston sheet into two nearly equal divis­ stones or easily eroded shales, which form clay dip eastward at an angle of ten degrees, ions, which differ widely in topographic features soils. The most productive of these are derived and' on the eastern edge they are nearly vertical. Throughout this region there is a very close and geologic structure. The difference in soils is from the Chickamauga limestone, and their dis­ The ore all lies above the level of the Tennessee relation between the character of soils and that also -marked. Northwest of the escarpment the tribution coincides with that of the formation as river, so that the lime has been thoroughly leached of underlying geologic formations. Except in rocks are sandstones and sandy shales, and, except shown on the geologic map. They have generally out;, 1 he-bed is from four to seven feet in thick­ limited areas along the rivers and the steep slopes in the coves which are underlain by limestone, a deep red color, but where the mantle of residual ness, wifch a few thin shale partings. of the Cumberland escarpment, the soils are de­ the soil is a sandy loam. At the surface it is material is thin, the soil is often dark bluish gray. In the same line with these two areas of iron- rived directly from the decay and disintegration gray, while the subsoil is generally light yellow, The clay soils derived from the Cambrian shales are bearikag rocks, a third occurs near the southern of surface rocks. Where these are sandstones or but varies to deep red. It usually contains suf­ somewhat less productive. The Connasauga and edge of the sheet. The ore is not so thick as sandy shales the resulting soil is sandy, where ficient clay to give the subsoil such coherence that upper part of the Rome make stiff, bluish gray further north, though it has been worked to some they are clay shales or limestones the soil is clay. a cut bank will remain vertical for some years. soils, thinner than that covering the limestone, the extent. As there are abrupt changes in the character of The depth of the soil on the plateau varies from shaly structure often .appearing- a few inches Limestone, Limestone suitable'for blast furnace the rocks, sandstones and shales alternating with a few inches to a dozen feet, depending chiefly on below the surface. ftax and; for lime is abundant and convenient of limestones, so there are abrupt transitions in the proximity to streams and the consequent activity Cherty soils. About half the area southeast of access. The Bangor limestone is used at Rock- character of the soil, and soils differing widely in of erosion. Almost the whole of the plateau the escarpment is underlain by the Knox dolo­ wood' on account of its freedom from impurities composition and agricultural qualities often occur retains its original forest growth, chiefly of oak, mite. The soil derived from this formation con­ andi it's< close proximity to the furnace. No lime side by side. The attitude of the strata and the chestnut, and hickory, while pines clothe the sists of clay, in which chert is imbedded. The fe< burned within the limits of the sheet. consequent breadth of outcrop of each formation steep sides of the stream channels. The practice proportion of chert to clay is variable; in some MuHding stone, Stone adapted to architectural determine the area of the derived soil. Where a of burning off the leaves each fall prevents the places only occasional fragments occur, while in u§es occurs in nearly all the formations of this formation is nearly horizontal at the surface, as accumulation of vegetable mold and has delayed others the residual material is made up almost region. That which has been most largely used the Walden sandstone of the plateau, the corre­ an appreciation of the agricultural possibilities of wholly of chert. Where the clay predominates is from the Chickamauga limestone. Sandstones sponding soil covers a broad area, but where its this region. the soil is deep red, but becomes lighter with the especially well adapted for foundations occur in outcrop is nearly vertical, as the Connasauga The sandy soils southeast of the escarpment are increase in amount of chert, and in extreme cases fehset Lookout and Walden formations, but these shale, its resulting soil covers only a narrow strip. confined to a few narrow strips coinciding with is light gray or white. Even when the propor­ have as yet been quarried only in a small way for The character of the soils derived from the vari­ the outcrop of the Rockwood and Rome sand­ tion of chert is very large this is a strong, produc­ focal use. ous geologic formations being known, their dis­ stones. These formations, however, produce sharp tive soil, especially adapted to fruit raising. The Hoad material. Tine hard blue Bangor and tribution may be determined from the map show­ ridges, so that their soils are not agriculturally soil derived from the Fort Payne chert is similar to Chickamauga limestones offer an abundant sup­ ing the areal geology, which thus serves also as a important. that from the Knox dolomite, but the areas of the ply of macadam, and the residual chert of the soil map. Since the sandstones of this region occupy the Fort Payne outcrops are so small that their soil is Fort Payne and Knox dolomite formations is an Classification. The soils of this region may con­ highest land, the sandy soil is often washed down relatively unimportant. ideal surfacing material. veniently be classed as (1) sandy soils, derived to lower levels and covers up the clay soil of ad­ Alluvial soils. These are confined to the flood Clays. The residual red or blue clays of the from the Walden and Lookout sandstones, some jacent valleys. This happens along the Cumber­ plains or bottoms of the Tennessee and Clinch B'angor and Chickamauga limestones are generally parts of the Rockwood formation, and the Rome land escarpment, so that the strip of Bangor lime­ rivers. Their areas are small, as the rivers are well adapted for making bricks. These clays, sandstone; (2}clay soils, derived from the Bangor stone at its base is covered by sandy soil instead usually bordered on one side or the other by steep as well as some from the Cambrian shales, are and Chickamauga limestones and the Connasauga of clay soil. bluffs. The soil is a rich, sandy loam, containing- a quite extensively used in adjacent areas for mak­ and Apison shales; (3) cherty soils, derived from Clay soils. In the coves of the Crab Orchard considerable proportion of fine mica scales derived ing drain tile. the Fort Payne chert and Knox dolomite; and | mountains the surface of the Bangor limestone is from the crystalline rocks far to the east. covered by a thin mantle of bluish gray clay soil, The beds of fire clay which are usually asso­ (4) alluvial soils, deposited by the rivers upon C. WILLARD HAYES, ciated with the coal probably contain material their flood plains. formed from its insoluble portions. Southeast of well? adapted for making fire brick, but they are Sandy soils. The Cumberland escarpment has the escarpment the many parallel valleys are due Geologist. yet wholly undeveloped. already been described as separating the area of to the presence of narrow belts of soluble lime­ May, 1894.