DESCRIPTION OF THE PISGAH QUADRANGLE

By Arthur Keith.

GEOGRAPHY. igneous rocks, such as granite and, diabase, which The position of the streams in the Appalachian slopes of the Blue Ridge. The cliffs around have solidified from a molten condition. Valley is dependent on the geologic structure. In Csesars Head are typical of the latter group, while GENERAL RELATIONS. The western division of the Appalachian prov­ general they flow in courses which for long dis­ Dunn Rock, near Brevard, and the many cliffs Location. The Pisgah quadrangle lies chiefly ince embraces the Cumberland Plateau, the Alle­ tances are parallel to the sides of the Great Valley, along Toxaway and Horsepasture rivers illustrate in North Carolina, but includes in its southeast­ gheny Mountains, and the lowlands of Tennessee, following the lesser valleys along the outcrops of the former class. A third class of cliffs is seen in ern portion about 150 square miles of South Caro­ Kentucky, and Ohio. Its northwestern boundary the softer rocks. These longitudinal streams empty Panthertail, Cedar Rock, and Lookingglass moun­ lina. It is situated between parallels 35° and 35° is indefinite, but may be regarded as an arbitrary into a number of larger, transverse rivers, which tains. (The two last-mentioned cliffs are shown in 30' and meridians 82° 30' and 83° and contains line coinciding with the eastern boundary of the cross one or the other of the barriers limiting the fig. 2.) These cliffs are situated on divides and about 975 square miles, divided between Hay- Mississippi embayment as far up as Cairo, and valley. In the northern portion of the province owe their great size to the spheroidal weathering of wood, Jackson, Transylvania, Henderson, and then crossing the States of Illinois and Indiana. they form Delaware, Susquehanna, Potomac, James, the granite which forms them. With these and Buncombe counties in North Carolina and Pick- Its eastern boundary is sharply defined along the and Roanoke rivers, each of which passes through similar exceptions, the even slopes of the weathered ens and Greenville counties in South Carolina. Appalachian Valley by the Allegheny Front and the Appalachian Mountains in a narrow gap and rocks are seldom broken and the cover of heavy In its geographic and geologic relations this the Cumberland escarpment. The Cumberland flows eastward to the sea. In the central portion forest is continuous on high and low ground alike. quadrangle forms part of the Appalachian prov­ Plateau, Allegheny Mountains, and associated of the province, in Kentucky and Virginia, these In all the illustrations the extent of the forest is ince, which extends from the Atlantic Coastal Plain plateaus are called the Appalachian Plateau. The longitudinal streams form New (or Kanawha) very noticeable. on the east to the Mississippi lowlands on the west, rocks of this division are almost entirely of sedi­ River, which flows westward in a deep, narrow Valleys and plateaus. The valleys intervening and from central Alabama to southern New York. mentary origin and remain very nearly horizontal. gorge through the Cumberland Plateau into Ohio between the mountain ranges are sharp, narrow, All parts of the region thus defined have a common The character of the surface, which is dependent on River. From New River southward to northern and V-shaped at their heads and have similar history, recorded in its rocks, its geologic structure, the character and attitude of the rocks, is that of a Georgia the Great Valley is drained by tributaries grades down to definite levels, at which they and its topographic features. Only a part of this plateau more or less completely worn down. In of Tennessee River, which at Chattanooga leaves widen out into rounded and plateaulike valleys. history can be read from an area so small as that the southern half of the province the plateau is the broad valley and, entering a gorge through the The plateaus consist near the stream heads of a represented on a single atlas sheet; hence it is neces­ sometimes extensive and perfectly flat, but it is Cumberland Plateau, runs westward to the Ohio. series of gently rolling and smoothly rounded sary to consider the individual area in its relations oftener much divided by streams into Large or small South of Chattanooga the streams flow directly to summits only slightly varied by shallow valleys. to the entire province. areas with flat tops. In West Virginia and portions the Gulf of Mexico. These characters are shown in fig. 4. The sum­ Subdivisions of the Appalachian province. The of Pennsylvania the plateau is sharply cut by mits rise to heights which are remarkably uniform DETAILED GEOGEAPHY OF THE QUADKANGLE. Appalachian province is composed of three well- streams, leaving in relief irregularly rounded knobs over large areas, and the plain which they once marked physiographic divisions, throughout each of and ridges which bear but little resemblance to the Mountain ranges. The Pisgah quadrangle is formed is readily recognized from any of the sum­ which certain forces have tended to produce similar original surface. The western portion of the Plateau included mainly in the Mountain division of the mits. Excellent illustrations of this are the views results in sedimentation, in geologic structure, and has been completely removed by erosion, and the sur­ Appalachian province. In the southeastern part around Brevard and westward from Caesars Head. in topography. These divisions extend the entire face is now comparatively low and level, or rolling. of the quadrangle there is a small area of the Pied­ (See fig. 1.) length of the province, from northeast to southwest. Altitude of the Appalachian province. The mont Plateau, at the foot of the Blue Ridge. The These plateaus are alike in origin and form, but The central division is the Appalachian Valley. Appalachian province as a whole is broadly dome relations of the two are shown in fig. 1 (illustration they vary considerably in altitude. They rise It is the best defined and most uniform of the shaped, its surface rising from an altitude of about sheet). Most of the quadrangle consists of moun­ gradually toward the heads of the rivers and each three. In the southern part it coincides with the 500 feet along the eastern margin to the crest of tain ranges, separated here by rolling plateaus and major stream has its set of plateau altitudes. The belt of folded rocks which forms the Coosa Valley the Appalachian Mountains and thence descending there by deep, narrow valleys. The longest chain plateau of Pigeon River near Waynesville and of Georgia and Alabama and the Great Valley of westward to about the same altitude on Ohio and is the Blue Ridge, which has a general east-west Sonoma is between 2700 and 2800 feet above sea; East Tennessee and Virginia. Throughout the cen­ Mississippi rivers. trend through the southern part of the quadrangle, that of French Broad River, about 2200 feet; the tral and northern portions the eastern side only is Each division of the province shows one or winding back and forth between the different river Piedmont Plateau surface south of the Blue Ridge, marked by great valleys such as the Shenandoah more culminating points. Thus the Appalachian basins and dividing the Atlantic from the Missis­ from 1100 to 1300 feet. An exception to this Valley of Virginia, the Cumberland Valley of Mountains rise gradually from less than 1000 feet sippi waters. On this is situated Great Hogback, variation from river to river is the plateau of the Maryland and Pennsylvania, and the Lebanon in Alabama to more than 6700 feet in western 4790 feet high. The greater portion of the Blue Blue Ridge, most of which is between 3200 and Valley of eastern Pennsylvania the western side North Carolina. From this culminating point Ridge in this quadrangle is between 3000 and 3300 3300 feet. Remnants of this pass entirely around being a succession of ridges alternating with narrow they decrease to 4000 or 3000 feet in southern feet in elevation and forms part of an ancient pla­ the French Broad valley along the heads of the valleys. This division varies in width from 40 to Virginia, rise to 4000 feet in central Virginia, and teau now deeply cut by the various streams. Most minor streams and continue southwestward across 125 miles. It is sharply outlined on the southeast descend to 2000 or 15QO feet on the Maryland- of the mountains between French Broad River and the headwaters of Toxaway and Horsepasture by the Appalachian Mountains and on the north­ Pennsylvania line. the Blue Ridge and along the upper parts of Tox- rivers, which flow into the Atlantic. The flat west by the Cumberland Plateau and the Alle­ The Appalachian Valley shows a uniform away and Horsepasture rivers also form parts of floor of the Pink Beds at the foot of Pisgah Ridge gheny Mountains. Its rocks are almost wholly increase in altitude from 500 feet or less in the same plateau. The view in fig. 1 is directly is a fine example of the original surface of the sedimentary, and are in large measure calcareous. Alabama to 900 feet in the vicinity of Chatta­ along the heads of all these streams. Another con­ plateau. The strata, which must originally have been nearly nooga, 2000 feet at the Tennessee-Virginia line, spicuous range is the Pisgah Ridge, which has a The plateaus of Pigeon and French Broad rivers horizontal, now intersect the surface at various and 2600 or 2700^ feet at its culminating point, northeasterly-southwesterly course, parallel to the belong to the same period of erosion. The Blue angles and in narrow belts. The surface features on the divide between New and Tennessee rivers. French Broad Valley. On this are situated Big Ridge plateau represents a much earlier and much vary with the outcrops of different kinds of rock, From this point northward it descends to 2200 Pisgah Mountain, 5149 feet; Chestnut Bald, 6040 longer period. Southeast of the Blue Ridge the so that sharp ridges and narrow valleys of great feet in the valley of New River, 1500 to 1000 feet feet; and numerous points of intermediate height. great Piedmont Plateau was.formed at a.still later -length follow narrow belts of hard and soft rock. in the James River basin, and 10()0 to 500 feet in Running northwestward from this are the cross period of erosion, whose action has not yet pro­ Owing to the large amount of calcareous rock the Potomac River basin, remaining about the ranges of the Balsams, including Richland Balsam, duced similar features on the streams which drain brought up on the steep folds of this district its same through Pennsylvania. These figures repre­ 6540 feet, the highest point in the quadrangle; into the Mississippi. The streams southeast of the surface is more readily worn down by streams and sent the average elevation of the valley surface, Cold Mountain, 6000 feet; and six other points Blue Ridge have shorter courses to the Atlantic is lower and less broken than the divisions on below which the stream channels are sunk from 50 more than 6000 feet in height. In fig. 5 are seen and have been able to establish lower grades clear either side. to 250 feet, and above which the valley ridges rise Big Pisgah Mountain, Cold Mountain, and various to their headwaters. Into all these plateaus the The eastern division of the province embraces from 500 to 2000 feet. minor ridges. Pisgah Ridge closely follows the rivers and creeks have sunk their channels in can­ the Appalachian Mountains, a system which is The Plateau or western division increases in trend of the rock formations. The other moun­ yons during the later periods of erosion. These made up of many minor ranges and which, under altitude from 500 feet at the southern edge of the tains have no such relation, however, except here have steep and rocky borders and are so narrow as various local names, extends from southern New province to 1500 feet in northern Alabama, 2000 and there for short distances. to be easily overlooked from a short distance. The York to central Alabama. Some of its prominent feet in central Tennessee, and 3500 feet in south­ The sides of the mountains are steep and usually Blue Ridge plateau is most deeply dissected, the parts are the South Mountain of Pennsylvania, the eastern Kentucky. Its height is between 3000 and made up of smooth, flowing slopes. The crests are streams of the French Broad plateau having cut Blue Ridge and Catoctin Mountain of Maryland 4000 feet in West Virginia, and decreases to about smooth and rounded, and as a rule are free from into it 1000 feet, and those of the Piedmont 2000 and Virginia, the Great Smoky Mountains of 2000 feet in Pennsylvania. From its greatest alti­ cliffs. A typical summit and an exception are seen feet. Tennessee and North Carolina, and the Cohutta tude, along its eastern edge, the* Plateau slopes in fig. 3. The abrupt slope or escarpment along the Drainage. The drainage of the quadrangle is Mountains of Georgia. The eastern division also gradually westward, although it is generally sepa­ southerly side of the Blue Ridge (see fig. 1) is one divided between the streams flowing toward the embraces the Piedmont Plateau, a vast upland rated from the interior lowlands by an abrupt of the notable features of the region. Large cliffs, Atlantic and those flowing toward the Gulf, about which, as its name implies, lies at the foot of the escarpment. which are noticeably rare in other parts of the one-fourth going toward the former. The waters of Appalachian Mountains, It stretches eastward Drainage of the Appalachian province. The mountains, are common here. The large bodies Davidson, Mills, and Little rivers and other tribu­ and southward from their foot from New York to drainage of the province is in part eastward into of mica gneiss which form the Balsam and Pisgah taries of the French Broad are joined by those of Alabama, and passes into the Coastal Plain, which the Atlantic, in part southward into the Gulf, and mountains are among the hardest rocks in the Pigeon River and flow through the Tennessee into borders the Atlantic Ocean. The Mountains and in part westward into the Mississippi. All of the quadrangle and cause lines of small cliffs and the Ohio and Mississippi. Saluda, Toxaway, and the Plateau are separated by no sharp boundary, western or Plateau division of the province, except ledges. In Big Pisgah Mountain and Cold Horsepasture rivers are tributary to Savannah but merge into each other. The same rocks and a small portion in Pennsylvania and another in Mountain extensive cliffs appear in the mica River, which flows into the Atlantic. From their the same structures appear in each, and the form Alabama, is drained by streams flowing westward gneiss. These are due in large part, however, heads, high up on the mountains, the streams fall of the surface varies largely in accordance with the to the Ohio. The northern portion of the eastern to the recent removal of the soil cover. On with heavy,grades down to the levels of the plateaus. ability of the different streams to wear down the or Appalachian Mountain division is drained east­ Shining Rock (see fig. 3) is to be seen a rare For considerable distances near those levels the rocks. Most of the rocks of this division are more ward to the Atlantic, "while south of New River all form of cliff consisting entirely of massive vein grades are, light, until the heads of the second­ or less crystalline, being either sediments which except the eastern slope is drained westward by quartz. ary canyons are reached. Thence downstream have been changed to slates, schists, or similar tributaries of the^ennessee or southward by tribu^ Similarly the granites make enormous cliffs the currents descend Swiftly, with many waterfalls rocks by varying degrees of metamorphism, or taries of the Coosa. whe,re they are near drainage lines or along the and rapids. Thus Mills River, for instance, goes through this cycle twice, as do all the streams which Upon these once deep-seated rocks now rest phic, igneous, and sedimentary. The sediments greenish gray. Layers of white granitic material traverse the 3200-foot ; plateau. Starting at eleva­ lavas which poured forth upon the surface in are found in a narrow band passing.up the French are not .uncommon, and lenses and veins of pegma­ tions of 5000 to 6000 feet the waters, of Mills River pre-Cambrian time. Thus there are in contact Broad Valley and across the heads of Toxaway and tite are frequent. Much the greater part of the descend with rapidly lessening grades to the Pink two extremes of igneous rocks those which con­ Whitewater rivers. They cover barely 3 per cent formation consists of mica gneiss and mica schist. Beds plateau at 3200 feet. Along this they flow for solidated at a considerable depth, and those which of the quadrangle. Igneous rocks are very gen­ In most of the formation the minerals are segre­ 2 or 3 miles with very little fall. As the newly cooled at the surface. The more ancient crystal­ erally distributed throughout the quadrangle, occu­ gated into layers, either singly or in combinations, cut canyon is entered the river drops rapidly line complex had therefore undergone uplift and pying about 50 per cent of its area. Southeast of thus producing rocks with a marked banded appear­ through a narrow gorge to 2200 feet in about 13 long-continued erosion before the period of vol­ the sedimentary strata practically all the rocks are ance. These rocks usually have more feldspar than miles. Near this level, that of the Asheville plateau, canic activity began. The complex may safely be of igneous origin. The remaining area, about 45 the schists. The granitoid layers contain quartz and it descends slowly to French Broad River, at a little referred to the Archean period, being immeasura­ per cent of the quadrangle, is underlain by the feldspar, with muscovite and biotite in small less than 2100 feet. A similar course is followed bly older than any rocks of known age. Whether metamorphic rocks of the Carolina gneiss. amounts; in the light-colored layers the biotite and by other branches of the French Broad. Toxaway these ancient lavas represent a late portion of the The sediments consist of a group of black and most of the muscovite are wanting. The schists are and Whitewater rivers and similar streams have the Archean or are of Algonkian age is- not certain. gray slates and schists. These contain thin beds composed of quartz, muscovite, a little biotite, and same characters as Mills River, but the fall from the The latter is more probable, for they are closely of limestone and marble at many points in this a very little feldspar. They have a fine grain and upper plateau to the Piedmont is nearly twice as associated with the Cambrian rocks. Yet they are quadrangle. The age of the sediments is not well a strong schistosity, but their texture is even and great. Accordingly, the country which they trav­ separated from the Cambrian strata by an uncon­ determined, but they are probably Cambrian and the minerals are uniformly distributed. erse is exceedingly steep and rugged and the formity, and fragments of the lavas form basal are so considered in this discussion. A few thin layers in the mica schist have a streams show continuous rapids and falls for miles. conglomerates in the Cambrian. Of the igneous rocks, granites are found in one bluish-gray or black color, largely due to grains of The plateau characters at their heads are well pre­ Next, after a period of erosion, the land was large, irregular area in the southeastern part of the iron oxides. These are most numerous in those served and have made possible, by means of a dam submerged, and sandstones, shales, and limestones quadrangle and in several other and smaller areas portions of the formation near the Brevard schist. about 50 feet in height, the flooding of a large area were laid down upon the older rocks. In these west and north of Brevard. Other igneous rocks They strongly resemble the coarser portions of the in Lake Toxaway. sediments are to be seen fragments and waste from are diorite, hornblende gneiss, and dunite, which Brevard schist; the component minerals are about the igneous and metamorphic rocks. The different occur in a large number of narrow bands with no the same, and the dark color given by the iron GEOLOGY. sedimentary formations are classified as of Cam­ definite grouping. The width and frequency of oxides is the most prominent characteristic of each. brian or later age, according to the fossils which the bands increase somewhat toward the north. The similarity in appearance near the contacts sug­ GENERAL GEOLOGIC RECORD. they contain. Remnants of these strata are now The Carolina gneiss, which underlies most of the gests that part of the Carolina is of sedimentary Nature of the formations. The formations which infolded in the igneous and metamorphic rocks, quadrangle, consists mainly of mica schist and mica origin. The possible origin of the Carolina is dis­ appear at the surface of the Pisgah quadrangle and and the portions thus preserved from erosion cover gneiss throughout its extent. The gneiss masses cussed under the heading " Metamorphism." adjoining portions of the Appalachian province large areas of the mountains. The submergence which form the Balsam and Pisgah mountains con­ The gneisses and schists alternate in beds from a comprise igneous, ancient metamorphic, and sedi­ which caused their deposition began at least as tain much cyanite and garnet, to whose greater few inches to 50 feet thick. Layers similar in com­ mentary bodies, all more or less altered since their early as the beginning of Cambrian and extended resistance to weathering is due much of the height position and from one-tenth to 1 inch in thickness . materials were first brought together. Some of them at least into Silurian time. It is possible that the of those mountains. Garnetiferous bands are also compose the banded gneisses. That part of the are very ancient, going back to the earliest known beginning was earlier and the end not until the numerous in the formation, near the borders of the formation which is adjacent to the Roan gneiss con­ period. They are found mainly in two groups, of close of Carboniferous time; the precise limits are Roan gneiss areas. tains some thin interbedded layers of hornblende widely different age and character. These are (1) not yet known. Practically all the igneous and metamorphic schist and hornblende gneiss precisely like the igneous and metamorphic rocks, including gneiss, These strata comprise conglomerate, sandstone, rocks are of Archean age. There are, however, Roan gneiss. The areas of the formations thus schist, granite, diorite, and similar formations; and slate, shale, limestone, and allied rocks in great a few exceptions to this. The Brevard schist is merge somewhat, so that the boundary between (2) sedimentary strata, of early Cambrian age, variety. They were far from being a continuous regarded as Cambrian, for reasons given in the them is seldom definite. including conglomerate, sandstone, shale, limestone, series, for the land was at times uplifted and areas description of the formation. Dikes and small Cyanite gneiss. In the Balsam and Pisgah and their metamorphosed equivalents. The older of fresh deposits were exposed to erosion. The sea bodies of fine-grained granite are found in the mountains and the area drained by West Fork of these groups occupies the greater area, and the gradually advanced eastward, however, and land Carolina and Roan gneisses near the northern bor­ of Pigeon River, the gneiss shows a marked younger the lesser. The materials of which the areas which furnished sediment during the early der of the quadrangle. These seldom exceed a few increase in cyanite. This mineral is distributed sedimentary rocks are composed were originally Cambrian were covered by later Paleozoic deposits. feet in thickness and are not of sufficient size to along distinct layers of the gneiss and occurs in gravel, sand, and mud, derived from the waste of The sea occupied most of the Appalachian prov­ be represented on the map. That they are much crystals an inch or less in length, giving the rock older rocks, and the remains of plants and animals. ince and the Mississippi basin. The area of the younger than the other granites of the region is a decided porphyritic appearance. These are All have been greatly changed since their deposition, Pisgah quadrangle at first formed part of the east­ shown by the almost entire absence of the schis­ usually parallel with the foliation and the other the alteration being so profound in some of the older ern margin of the sea, and the materials of which tosity which appears in the other formations of minerals of the inclosing gneiss. In areas north­ gneisses and schists as to destroy their original the rocks are composed were derived largely from the mountains. The latest time at which this east of this quadrangle the cyanite is seen to be of nature. the land to the southeast. The exact position of the schistosity was produced was post-Carboniferous. a later age than most of the other minerals compos­ From the relations of the formations to one eastern shore line of this ancient sea is known only The granite dikes, therefore, are clearly later ing the gneiss. The cyanite forms stubby, flat another and from their internal structures many here and there, and it probably varied from time to than Carboniferous, although they may have been crystals or blades of a light-gray or dark-gray color. events in their history can be deduced. Whether time within rather wide limits. produced during the later part of the deformation On weathered surfaces these stand out prominently the crystalline rocks were formed at great depth or Cycles of sedimentation. Four great cycles of period. from the rest of the rock. Associated with these at the surface is shown by their structures and tex­ sedimentation are recorded in the rocks of this In the southern half of the quadrangle are found cyanite layers in many places are prominent large tures. The amount and the nature of the pressure region. The first definite record now remaining large bodies of granite which are probably younger patchy crystals of muscovite. These are distributed sustained by the rocks are indicated in a measure was made by coarse conglomerates, sandstones, and than the Archean. They show much less meta­ through the rocks just as the cyanite crystals are, by their folding and metamorphism. The com­ shales, deposited in early Cambrian time along the morphism than the Henderson granite or the Caro­ and, like them, probably have a secondary origin, position and coarseness of the sediments show the eastern border of the interior sea as it encroached lina gneiss, through which they cut. Considerable Where they are frequent they give a noticeable depth of water and the distance from shore at which upon the land. As the land was worn down and portions of their mass have little or no metamor­ silvery appearance to the schist or gneiss. Small they were produced. Cross-bedding and ripple still further depressed the sediment became finer, phism, but retain their original structures. Since garnets are often found in the same layers with the marks in sandstones indicate strong and variable until in the Cambro-Ordovician Knox dolomite the rocks in the same areas which are known to be cyanite and coarse muscovite. currents. Mud cracks in shales show that their very little trace of shore material is seen. After Archean have very great metamorphism, it is prob­ Garnet gneiss. Garnet schist and garnet gneiss areas were at times above and at times below this long period of quiet came a slight elevation, able that these granites are of considerably later are a conspicuous part of the Carolina gneiss. water. Red sandstones and shales were produced producing coarser rocks; this uplift became more age. It can not be stated from present knowledge The garnets are small, seldom exceeding one- when erosion was revived on a land surface long and more pronounced, until, between the Ordo- how young they are, but the fact that they are fourth of an inch in diameter. They are rather subject to decay and covered with a deep residual vician and Silurian, the land was much expanded altered considerably in places shows that they are evenly distributed through the rock and but soil. Limestones show that the currents were too and large areas of recently deposited sandstones Carboniferous or older. seldom restricted to bands in the gneiss. These weak to carry sediment or that the land was low and were lifted above the sea, thus completing the first In the columnar sections are shown the character rocks are most prominent in the northwestern por­ furnished only fine clay and substances in solution. great cycle. After this elevation came a second and probable age of the different formations, and tion of the quadrangle, in the Balsam and Pis­ Coarse strata and conglomerate indicate strong cur­ depression, during which the land was again worn these will be described in order of age as nearly as gah mountains, and extend as far northeast as rents and wave action during their formation. down nearly to base-level, affording conditions for it is known. Sky land. Thus in this quadrangle they charac­ Principal geologic events. The rocks themselves the accumulation of the Devonian black shale. terize bodies of gneiss from 1 to 4 miles in width thus yield records of widely separated epochs from After this the Devonian shales and sandstones AECHEAN EOCKS. and 25 miles in length, and extend far into the the earliest age of geologic history through the were deposited, recording a minor uplift of the CAROLINA GNEISS. adjoining quadrangles. Some occurrences accom­ Paleozoic. The entire record may be summarized land, which in northern areas was of great impor­ pany the contacts of the Roan gneiss and are as follows, from the oldest formation to the latest, tance. The third cycle began with a depression, Distribution. The northwestern half of the apparently due to them. In most of the large as shown in this general region: during which the Carboniferous limestone accu­ quadrangle is nearly covered by the Carolina areas, however, there is no apparent connection Earliest of all was the production of the great mulated, containing scarcely any shore waste. A gneiss, which is so named because of its extent in between eruptive beds and the production of gar­ bodies of Carolina gneiss. Its origin, whether third uplift brought the limestone into. shallow North and South Carolina. Most of the large nets, many of the garnets being miles from' any igneous or sedimentary, is buried in obscurity. water portions of it perhaps above the sea- and areas of this formation are connected with one outcrop of the Roan gneiss. If the igneous rocks It represents a complex development and many upon it were deposited, in shallow water and another and in reality form one large mass pene­ caused the growth of all the garnets, it must have processes of change, in the course of which the swamps, the sandstones, shales, and coal beds of trated by many bodies of the different igneous been by inducing an extensive circulation of min­ original characters have been largely obliterated. the Carboniferous. Finally, at the close of the rocks. In addition to being the principal forma­ eralizing waters. The gneiss is, however, distinct from and much Carboniferous, a further uplift ended the depo­ tion of this quadrangle, it is also the oldest, since Granite gneiss. The granitoid layers of the older than any other formation yet identified in sition of sediment in the Appalachian province, it is cut by the igneous rocks and overlain by the gneiss * contain quartz and feldspar, with small the province, and the time of its production is the except along its borders in recent times. sediments. Inclosed within its areas are numerous amounts of muscovite and biotite. In the light- earliest of which we have record. The columnar section shows the composition, igneous and secondary rocks. Although these are colored layers the biotite and the muscovite are During succeeding epochs masses of igneous name, age, and, when determinable, the thickness too small to be shown on the map, they can read­ sparse. The granitoid layers and the schists alter­ rock were forced into the gneiss. The lapse of of each formation exposed in the quadrangle. ily be assigned to formations which are elsewhere nate in beds ranging in thickness from a few inches time was great; igneous rocks of many different mapped in larger bodies. to a foot or two. Beds of such size are rather rare kinds were intruded, and later intrusive masses DESCRIPTION OP THE FORMATIONS. General character. The formation consists of an in this quadrangle. Layers similar in arrange­ immense series of interbedded mica schist, garnet ment, varying in thickness from one-tenth of an were forced into the earlier. The granitic texture EOCKS OF THE QUADRANGLE. of some of the formations and the lamination and schist, mica gneiss, garnet gneiss, cyanite gneiss, inch to an inch, compose the banded gneiss. schistosity of others were produced at great depths The rocks exposed at the surface in" the Pisgah and fine granitoid layers. Most "of them are light Toward the north and east in this quadrangle below the surface. quadrangle comprise three great classes metamor­ or dark gray in color, weathering to dull gray and the granitoid layers increase in amount. In them the minerals are much less distinctly parallel than however, since it fails to account for the parallel schist,, garnet schist, and gneiss. The hornblendic and closely folded in many places to an extent in the schists and gneisses. The parallel arrange­ layers and banding. Many parts of the formation beds are dark greenish or black in color and the equal to all the folding of the later formations. ment is usually seen more or less roughly, how­ in areas adjoining on both the northeast and the micaceous beds are dark gray. The mica schist Thus the Roan gneiss has passed through two ever, and its prominence depends largely on the southwest are doubtless of sedimentary origin. The and gneiss beds range in thickness from a few deformations, one producing the foliation, and a amount of mica in the rock. apparent transition of the Carolina into the sedi­ inches to 100 feet, and are numerous only near the second folding the foliation planes and minerals. Pegmatite. Included in the area of the formation mentary Brevard schist indicates that other parts Carolina gneiss, into the areas of which they merge. During or before the second deformation the bands are numerous veins and dikes of pegmatite. One of the Carolina are sedimentary. It is very likely In composition the. mica schist and gneiss are of quartz and feldspar of the gneiss appear to have group of these occurs in the shape of lenses that still other sedimentary masses have not been exactly like the micaceous parts of the Carolina been formed. The total alteration is extreme. ranging from 1 foot to 25 feet in thickness. distinguished from the Carolina because of their gneiss, and are composed of quartz, muscovite, Weathering. In reducing the surface of the for­ Some of the largest of the lenses can be readily total metamorphism and similarity to the latter. a little biotite, and more or less feldspar. The mation, the first stage is the decomposition of the followed for 2 or 3 miles. The smaller ones, how­ Whatever their original nature, one deformation hornblende schists make up most of the forma­ hornblende and feldspar. The more siliceous lay­ ever, can not be traced surely beyond the imme­ produced a foliation of these rocks. A subsequent tion and are interbedded with hornblende gneisses ers and many of the harder hornblende schists and diate outcrops. For the most part, they lie parallel deformation folded and crushed the earlier planes throughout. The schist beds consist almost entirely mica schists are extremely slow of disintegration, to the foliation of the gneiss. In places they have and structures. Before the latter period pegmatites of hornblende, in crystals from one-tenth to one- however. Their outcrops form cliffs and heavy the form of veins or dikes and cut the gneisses were formed. These were thoroughly mashed by half inch long, with a very small amount of biotite, ledges near the streams and greatly retard the abruptly, with nearly parallel walls. The pegma­ the second deformation and retain in many places feldspar, and quartz; the gneisses contain layers or reduction of the surface. As a whole, the forma­ tites are most conspicuous near the contacts of the only a fraction of their original coarseness. In seams consisting of quartz and feldspar interbed- tion is somewhat less resistant than the Carolina Carolina and Roan gneisses, but are not closely most of the formation excessive metamorphism has bed with layers of hornblende schist. In places gneiss and far weaker than the Cranberry or limited to those localities. They are also found destroyed the original attitudes and most of the these are regularly disposed and give a marked Henderson granites. Consequently its areas are in great numbers near the Whiteside granite mass, original appearance of the rocks. The rocks of the banding to the rock. Here and there the horn­ reduced to plateaus in the large stream valleys which itself has pegmatitic portions. These latter formation are now composed entirely of the meta- blende, feldspar, and quartz appear with the mass­ and form gaps and depressions in the high ground pegmatites are closely associated with that granite, morphic minerals. These are usually arranged ive structure of diorite. Some of these beds are away from the rivers. The rise of the mountains cut the foliation of the gneisses, and are of the with their longer dimensions nearly parallel to one very coarse and massive, with crystals half an inch beyond its areas is very noticeable in most cases. nature of dikes. They vary greatly in form, from another and to the different layers. Where the long. Many of the beds of this formation consist In this respect the formation differs much from its narrow masses to irregular patches, or even scattered layers have been bent by the later deformation the almost entirely of hornblende and are so basic habit farther northeast in the Roan and Cranberry crystals. Many of the smaller lenses can be seen minerals are bent into corresponding curves. In that they appear to have been derived from gabbro. quadrangles. The clays accumulating on this for­ to be surrounded on all sides by mica gneiss, and places where by the second deformation a second So thorough is the alteration, however, that such an mation are always deep and have a strong dark-red apparently were deposited from aqueous solutions. schistosity was produced, this schistosity cuts in origin is not certain. In many localities the dio- color; the soils are rich and fertile and well repay The pegmatites consist chiefly of very coarsely parallel planes across the older schistose layers. rites contain large crystals of garnet, due to alter­ the labor of clearing. The hilly surfaces keep the crystalline feldspar, quartz, biotite, and muscovite; Since the schistosity is evidenced more strongly ation induced by intrusive granite. soil well drained, and yet the clayey nature of the crystals of orthoclase feldspar rarely attain dimen­ by the micas than other minerals, the coarse and In composition the mica schist and the mica latter prevents serious wash. Hence, the soils are sions of 2 feet, and mica 2 feet. In them are also granitoid layers are least schistose and the mica gneiss beds are exactly like the micaceous parts of extensively cultivated in situations remote from found many rare or valuable minerals, including schists most so. the Carolina gneiss and contain quartz, muscovite, the principal settlements. beryl, emerald, tourmaline, garnet, and cyanite. Decomposition. The schistose planes of the biotite, and more or less feldspar. The hornblende The pegmatites associated with the granite contain various layers afford easy passage for water and schists make up a large share of the formation and SOAPSTONE, DUNITE, AND SERPENTINE. fewer minerals than the others and are more feld- are deeply decayed. After decomposition has are interbedded with hornblende gneiss throughout. Distribution. Many areas of these rocks are spathic. Much merchantable mica is procured from destroyed the feldspar the resultant clay is filled The schists are most prominent north and west of found within the quadrangle. While most of them the pegmatites of lenticular and veinlike shape, and with bits and layers of schist, quartz, and mica. Burnsville, near the Cranberry granite masses. are less than half a mile in length, one exceeds that the Balsam and Pisgah mountains form one of the Solid ledges are seldom found far from the stream The schist beds consist almost entirely of horn­ considerably. The largest area is on Pigeon River best mica districts of the State. cuts and the steeper slopes. Near the Blue Ridge blende, in crystals from one-tenth to one-half an at Three Forks, with a length of about a mile. Many of the minerals of the pegmatite have been many large ledges and cliffs appear. The cyanite inch long, with a very small amount of biotite, feld­ Here most of the masses are lens shaped and three crushed and folded by the second deformation gneiss and garnet gneiss of the Balsam and Pisgah spar, and quartz. The gneiss is composed of layers or more times as long as they are wide. This area which folded the gneisses. The pegmatites, there­ mountains, especially, form big cliffs and rocky or sheets of quartz or feldspar interbedded with is nearly all in contact with Carolina gneiss, but fore, are older than this deformation. Their con­ slopes. In fact, these mountains owe their height sheets of hornblende schist. In places these are there is a small body of Roan gneiss at its eastern nection with the contacts of the Roan and Carolina to the superior resistance of these gneisses. The very regularly disposed and give a marked banding end. In this respect this area differs considerably gneisses is not sufficiently marked to prove that cover of clay on the decayed rocks is thin, and the to the rock. An accessory mineral frequently seen from most others of the formation, the association contact action caused the pegmatites. The smaller soil is light on account of the large proportion of is garnet. As already stated, this occurs in the Caro­ of which with the Roan gneiss is usually close and lenses appear to have been formed by deposition quartz and mica that it contains. Accordingly, its lina gneiss near the contacts of the Roan gneiss, marked. There are in this quadrangle only six from mineralized waters, after the manner of veins. natural growths are poorly sustained, even in the and it is common also in the Roan gneiss in simi­ exceptions to this rule, out of sixty-two areas of the Those of veinlike form also show a banded arrange­ areas of gentle slope where the formation has been lar positions. The garnets are seldom larger than formation. ment in places. Owing to the considerable altera­ well decomposed. These soils, however, are sus­ a quarter of an inch in diameter and as a rule are Relations. The rocks of this group break tion of the pegmatite contacts, however, it is difficult ceptible of great improvement by careful tillage. much smaller. through and across the beds of Roan gneiss and to determine their origin with precision. As stated In the mountain areas, where slopes are steep and In the northeastern part of the quadrangle many are thus seen to be distinct from and later than above, much of the pegmatite is plainly igneous. fresh rock is nearer the surface, the soils are richer lenses and patches of epidote, hornblende, and the gneiss. From the constant association of the Intrusive granites. Inclosed within the gneiss and stronger and produce good crops and fine quartz are to be seen in the gneiss. These are of two formations, however, and the rarity of the and schist areas are many bodies of intrusive granite. timber. The greater amount of soluble matter late origin and replace the older hornblende more soapstone group in other situations, the difference These vary in thickness from a few inches up to a and clay in the gneiss renders its areas somewhat or less thoroughly. They are associated with veins in age can not be considered great. Its alteration few feet, and, on account of their small size and more productive than those of the schist. The of epidote, and neither variety has been deformed. is as great as or greater than that of the Roan the difficulty in tracing them, they are not repre­ garnet and cyanite gneiss a,reas are somewhat less Seldom are they more than 3 feet long or over a gneiss, so that it appears to have shared in that sented on the map. They cut the gneisses at every productive than those of the ordinary gneiss. few inches thick. earlier period of metamorphism which involved conceivable angle. The granite is fine grained and Here and there the hornblende, feldspar, and the Roan and Carolina gneisses. very uniform in texture, and has a light-gray or ROAN G-XEISS. quartz are found with the structure of diorite or Character. The group comprises many different whitish appearance. The smaller dikes are some­ Distribution. Areas of this formation are found gabbro. A few of these beds are very coarse and rocks, such as soapstone, dunite, and serpentine, what lighter colored than the large ones on account generally throughout the quadrangle, usually in massive. About 3 miles west of Sitton is a small and many other combinations of minerals derived of the larger proportion of quartz and feldspar. long, narrow bands. In the northwestern half of body of massive diorite with crystals of feldspar and from the original rocks by metamorphism. The The component minerals are quartz, orthoclase and the quadrangle the Roan forms dikelike bands in hornblende nearly an inch long. Massive rocks variety most common in this quadrangle is an plagioclase feldspar, biotite, and muscovite, the the Carolina gneiss. In the southeastern half, how­ of medium grain are found here and there in the impure soapstone containing chlorite, hornblende, micas being subordinate in amount. As a rule ever, the Roan lies in very irregular bodies inclosed Roan gneiss with no special geographic distribution. and silicates of magnesia. There are also two or these beds are massive and fairly free from the by the eruptive masses of Henderson or Whiteside Many of the beds of the formation which consist three bodies of dunite composed almost entirely of schistosity which marks all of the adjoining for­ granite. The formation receives its name from almost entirely of hornblende are so basic that they olivine. These are found in the basins of Wolf mation. For this reason it is concluded that they Roan Mountain, on the boundary of Tennessee appear to have been derived from gabbro. Of this and Tennessee creeks. The soapstones are white were intruded into the gneisses after the principal and North Carolina, north of this qua.drangl'e. kind are the hornblende schist and many layers less and light gray, while the other varieties of the for­ part of the deformation of the region had been Relation to Carolina gneiss. The Roan gneiss strongly schistose. So thorough is the alteration, mation have a greenish color, either bright or dull. accomplished. They are accordingly later than the appears to cut the Carolina gneiss, but the contacts however, that such an origin is not certain. At In some localities the soapstone contains little but Carboniferous in age. In approaching the White- are so much metamorphosed that the fact can not many points in the Roan gneiss there are found talc and is fit for industrial uses, but, as a rule, side granite areas, these dikes are found more often. well be proved. Moreover, the rocks included in veins and lenses of pegmatite of secondary growth, it contains much chlorite and crystals of enstatite, Since both dikes and granite masses have the same the Carolina are entirely metamorphosed ; some of precisely similar to those described under "Carolina tremolite, actinolite, or magnesian silicates. The relations and composition, it is probable that they the Roan is less altered, however, and thus appears gneiss." They seldom, however, equal the latter in bodies of talc and pure soapstone are usually found came from the same magma. to be younger. Narrow, dikelike bodies of Roan size and importance. Dikes and small masses of around the borders of the formation, but the large Metamorphism. The Carolina gneiss covers in the Carolina support this view, for some of these granite like the Whiteside granite are found in the mass at Three Forks is nearly all made up of greater areas than any other formation in this narrow beds are plainly of an igneous nature. In Roan gneiss, just as in the Carolina, too small to be schistose talc. All the varieties of the formation region. On account of the uniform aspect of its fact, the shape and continuity of many of the nar­ mapped. may be present in a single ledge, or one variety beds over large areas, no true measure of its thick­ row sheets of Roan gneiss can be explained only on Metamorphism. Deformation and recrystalliza- may occupy the whole of an area. The latter rela­ ness can be obtained; even an estimate is idle. the theory that they represent original dikes cutting tion have extensively changed the original rocks of tion is most common where soapstone alone is seen. The apparent thickness is enormous, having been the Carolina gneiss. In still other areas the Roan this formation into schist and gneiss. The exact The dunite is usually more or less altered to ser­ increased many times by the folding and the enor­ gneiss consists of large numbers of lumps or lenses measure of the alteration is usually unknown pentine. This change may appear in considerable mous metamorphism to which the gneiss has been of hornblende gneiss surrounded by mica gneiss. because the original character of the rock is uncer­ masses of the rock, or in small patches or seams, subjected. The original nature of this gneiss is These undoubtedly represent original dikes of the tain. It is probable that most of the mass was and is very irregular in its distribution. uncertain. It is possible that much of the mass Roan disconnected by folding and faulting. The originally diorite and gabbro of much the same Many minor mineral deposits of later origin are was once a granite. Some of the material has a frequent development of garnets in the Carolina mineral composition as now. A few of the coarse found in the formation. Nickel ores form thin granitic character now, and its local metamorphism near the borders of the Roan gneiss seems to masses still retain much of their original texture. seams and coatings between portions of the dunite, to schist can be readily seen. Other and similar indicate contact metamorphism. The minerals in most of the formation are sec­ and corundum occupies small veins and patches in material might easily have been altered into the Character. The Roan gneiss consists of a great ondary, however, and are arranged as a whole in dunite and soapstone. Here and there small veins great body of mica schist. Such an origin can less series of beds of hornblende gneiss, hornblende parallel layers, causing the schistosity. These of asbestos are found in the dunite. They occur easily be attributed to the beds of banded gneiss, schist, and diorite, with some interbedded mica minerals and schistose planes were afterward bent in the shape both of small veins and of irregular Pisgah. rounded crusts between portions of the dunite. the phenocrysts are drawn out into lenses (or that the Brevard and the Hiwassee formations are occurs in extremely small scales and flakes, which Small veins of this kind are found near Tennessee augen) more than twice their original length. equivalent. lie nearly parallel to one another and cause the and Wolf creeks, but are of no importance. The Where they retain their original shape they are Character. As it is displayed in this quadrangle schistosity of the rock. The iron oxides and gar­ alteration proceeds along cracks into the mass of seldom over an inch in length. the formation consists mainly of schist and slate. net are undoubtedly secondary. the rock, replacing the dunite more and more near Northeast of Brevard and near the Carolina Most of it is schist, of a dark bluish-black, black, Weathering. The rocks of the formation disin­ the surface. gneiss the granite is finer grained and the porphy-^ or dark-gray color. At several points considerable tegrate more readily than most of the others of the Metamorphism. In their original form these ritic feldspars are fewer and smaller. Many finer bodies of marble are interbedded with the schist. region, but the formation occupies ground only rocks were peridotite and pyroxenite, composed of beds have there been metamorphosed into dark In some of the lower layers of the formation along slightly lower than the Carolina gneiss. Decay olivine, with more or less feldspar and pyroxene. schists resembling the Carolina schists. Boylston Creek the schistose character is less pro­ makes its way down the schistose partings, and the The change from these to the soapstone group is The massive granite which appears here and nounced and the rock is a banded mica slate. All rock breaks up into slabs and flakes, largely by the enormous far greater in appearance than that of there in small bodies is usually of fine or medium the strata are fine grained except a few siliceous action of frost. Red and brown clay soils are left any of the other formations. The minerals which grain and contains very little biotite. The feld­ layers, which represent original sandy strata, and when the rock is complete^ disintegrated. These now appear, however, are closely related in chem­ spars make up a large portion of the rock and some thin layers of quartzite and fine conglomerate. are shallow and contain many flakes of the black ical composition to those of the original rock. The give it a much lighter color than that usual in the The rocks are composed mainly of very fine quartz schist. Ledges are usually near the surface, but intermediate stages of alteration are obscure or absent porphyries. and muscovite, through which are scattered count­ seldom outcrop far from the stream cuts. The soils in this region. These changes seem to have easily Metamorphism. The formation has been greatly less minute grains of the iron oxides, producing the are light and fairly productive on the lowlands, but affected the peridotites and pyroxenites. Unlike affected by metamorphism. This is best shown by dark color. Another constituent commonly found on the slopes and summits of the mountains sup­ the other metamorphosed rocks, these show only the porphyritic portions, where the change in the is graphite. This is disseminated in minute grains port only a scanty growth of timber. moderate schistosity. Near their borders the soap- form of the mineral particles can often be measured. through large masses of the rock and is only here stones are often schistose in consequence of the The rock has been squeezed and mashed until large and there concentrated in some layers. Graphite is POST-CAMBRIAN (?) INTRUSIVE ROCKS. parallel arrangement of the talc and chorite scales. portions have a pronounced gneissoid structure. also found associated with quartz in small secondary WHITESIDE GRANITE. This condition prevails throughout many of the Results of this kind are prominent throughout this lenses. In the adjoining Mount Mitchell quad­ The Whiteside granite lies in two general areas smaller bodies and even of the large mass at Three area and especially near the French Broad Valley. rangle the graphite is so abundant as to have led to in this quadrangle. The principal mass occupies Forks. In a few places in this quadrangle a schis­ The change is manifest in the growth of the new mining operations. The base of the formation is the southeast corner of the quadrangle and is part tose nature is given to the rock by parallel crystals micas and in the elongation of the porphyritic the most regularly graphitic and has many strikingly of a much larger body to the south and east. Also, of tremolite. This result, although common in feldspars. The latter have increased in places to black beds. In a few localities garnets are found in a wedge-shaped area running southwestward from adjoining regions on the west, is rare in this quad­ two or three times their original length. During in these rocks. They are disseminated through the the Pink Beds there are many irregular bodies of the rangle, for the usual alteration is to soapstone. the squeezing and slipping under pressure large schist in small crystals, usually less than one-tenth granite. They do not extend far northeast of the Entirely different is the arrangement of the actino- crystals were cracked and their fragments rotated of an inch in diameter. They are more numerous Pink Beds, but pass southwestward considerable lite and enstatite crystals in many localities, for until they were nearly parallel with the schistose in the northeastern parts of the formation, but are distances into Georgia and South Carolina. In they form bunches and radiating clusters in the planes. The mica flakes were turned into similar nowhere conspicuous. Where the garnets are the southeastern area the granite contains many soapstone. planes and the small grains of quartz and feldspar present it is sometimes difficult to distinguish the enormous inclusions of the older gneisses, which An exception to the general altered aspect of were broken and recomposed into quartz, feldspar, schist from garnet schists in the Carolina gneiss. lie with various positions and directions. In the these rocks is the dunite, for it appears to be one of and mica. Large bodies of a very gneissoid rock This is particularly true where they are much northwestern area the granite appears for the most the least metamorphosed rocks of the region. The (or augen gneiss) were thus produced, in which weathered. The schists of this formation, however, part in dome-shaped masses uplifting the gneisses, serpentine, which is a common alteration product many porphyritic crystals were cracked and pressed are usually finer grained. The garnets are of sec­ and from them many sheets and dikes are sent off. of the dunite, is not due to such metamorphism as out into eyes or strings. The amount of distortion ondary origin, and probably were developed by the The formation is named from Whiteside Moun­ the schistose rocks, but to hydration. In this pro­ can be plainly measured in the least extreme cases same agencies in each of the formations during tain, in the Cowee quadrangle, where it forms a cess the water worked in through the cracks and by the interval between the fragments of one crystal. their metamorphism. series of enormous cliffs. joints of the original dunite and united chemically The large feldspars retain their shape better than The most unusual part of the formation in this Relations. This granite is intrusive in all the with the olivine to form serpentine. the finer groundmass, however, and the mica flakes quadrangle is the series of limestone lentils which rocks of this quadrangle with which it comes into Weathering. Few rocks are slower to disintegrate in the latter are bent and wrapped around the large are found at intervals throughout its extent. They contact except the Triassic diabase. The ends of than those of this formation, and its areas invari­ feldspars almost as if fluid. are most numerous and largest northeast of Brevard, some of the granite bodies pass under the surround­ ably show many ledges. Wherever the formation Weathering. As the formation is attacked by and consist of finely crystalline limestone or marble. ing gneisses and are shaped like anticlines. The contains much tremolite or enstatite huge ledges weathering agencies its surface is slowly lowered. This is usually white, but contains also beds of blue, schistose planes of the gneiss arch over and dip come to the surface and large bowlders are scattered Its siliceous composition and its great mass unite buff, and banded blue and white colors. Southeast away from the granite as if pushed up by the gran­ everywhere. The rock is not much affected by in maintaining the relative altitude of its areas. It of Lake Toxaway the carbonate of lime is largely ite from below. This is excellently shown east of solution, but breaks down under the direct action forms a high plateau south of the French Broad, replaced by silica and the rock has a cherty aspect. Lake Toxaway and around the Pink Beds. This of frost and usually occupies low ground. Final deeply cut by the smaller creeks., The summits of In the quarries near Fletcher the total thickness of relation is characteristic of those masses of the decay leaves a cover of stiff yellow clay of little this are broad and rounded, with steep faces toward the marble lentil is about 250 feet and its length granite which lie northwest of the Brevard schist. depth and much interrupted by rock. Soils the streams. The granite causes many ledges and over a mile. The quarries at the head of Boylston The smaller granite bodies in that region appear derived from this are of almost no value. cliffs, which are conspicuous features of the land­ Creek show about 50 feet of marble, with a prob­ to lie between the layers of gneiss, both formations scape near French Broad River. The bowlders able length of 1^ miles. The other lentils are both having moderate dips in the same direction. The HENDERSON GRANITE. and waste from the formation are carried for long thinner and shorter. Owing to the soluble nature great granite mass in the southeastern part of the Distribution. The rocks of this formation lie distances over the adjoining formations. Upon of the limestone, outcrops of it are very scarce, and quadrangle shows none of the anticlinal arrange­ in a band 6 or 8 miles wide running diagonally complete decay the formation produces a yellow­ it is possible that it extends considerably farther ment. Within this general granite area are many through the quadrangle. Northwest of this gran­ ish or reddish clay, which is frequently leached than shown on the map. The contacts of the extremely irregular inclusions of the gneisses. ite lies the Brevard schist and southeast of it the out nearly white. This is mixed with sand and limestone and the adjoining black schist are sharp These extend in many directions and dip at all Whiteside granite. The extensive areas and expo­ fragments of rock on the mountain sides and is wherever they are visible, and there is no inter- angles. The general position of these included sures of the granite in Henderson County give the of no great depth. In the valleys the rock is bedding. The materials composing the limestone masses is monoclinal between the different parts of formation its name. often decomposed and soft to depths as great as 30 are entirely different from those of the black schist, the granite, and they appear to represent the rem­ Relations. This granite is intrusive in all the feet, and the overlying clay is 6 or 8 feet in thick­ except for a little silica, which is probably of sec­ nants of the original gneiss cover. The large granite Archean rocks with which it comes into contact. ness. Except in coves and hollows the soil is ondary origin. The change in the conditions mass extends both southeastward and southwestward Northeast of this quadrangle the ends of some of infertile and is subject to drought. which produced limestone instead of the black schist for considerable distances into the adjoining quad­ the granite bodies ' pass under the surrounding must, therefore, have been abrupt and complete. rangles, and the rocks now at the surface evidently CAMBRIAN ROCKS. gneiss with shapes like anticlines. The schistose The limestone deposits extend only about 4 were once deep down within the granite body. planes of the gneiss arch over and dip away BREVARD SCHIST. miles northeast of Fletcher, but they are found The granite domes represent the upper portions from the granite as if pushed up by the granite Age, name, and relations. The strata of this for­ southwestward at intervals through South Carolina of a similar great mass. from below. In this quadrangle the contacts with mation are the only sedimentary rocks recognized and far into Georgia; so the conditions which they Only a small amount of metamorphism is to be the Carolina gneiss are much obscured by meta­ within the quadrangle. They are named from their represent were widespread. seen in this granite, some of its masses appearing morphism. The granite cuts the Roan gneiss and occurrence near Brevard, in Transylvania County. An exception to the usual fine grain of the Brevard to be entirely free from it. For this reason it is carries large included masses of gneiss near the The evidence thus far obtained is insufficient to schist is to be seen in the thin beds of quartzite concluded that the granite was forced into the Blue Ridge. The granite passes out of this quad­ determine their age. They form the first sedimen­ found in the schist near Cherryfield and Rosrnan. gneisses after most of the deformation of the region rangle into the adjoining quadrangles for 50 miles tary deposit upon the Archean rocks, holding a These occur interbedded with the black schist 700 had been accomplished. Accordingly the granite both northeastward and southwestward. position which is occupied in this region only by or 800 feet above the base of the formation. They may be as late as the Carboniferous in age. Character. The granite is composed mainly of Cambrian strata. The rock types found in this consist of feldspathic quartzite, usually fine, but in Included within the areas mapped as Whiteside orthoclase and plagioclase feldspar, quartz, musco- formation can be precisely duplicated in the Cam­ places conglomeratic. They are only a few feet granite are numerous outcrops and small bodies of vite, and biotite, enumerated in order of their brian rocks farther north and northwest. In fact, thick and seldom outcrop. By their waste they the older formations. There are also many dikes importance. The latter mica varies a great deal the resemblance between this and the Hiwassee can be traced for considerable distances, but they are of the granite beyond the borders of the principal in amount, but is usually subordinate. The usual slate is very marked. Each consists in the main too small to be indicated separately on the map. masses. Near the contacts of the formations the color of the rock is gray, becoming lighter after of bluish-black and dark banded slates or schists, They represent local activity in erosion, in contrast beds vary from a few inches up to many feet in weathering. The general aspect of the rock is the color varying according to the degree of meta­ with the uniformity which preceded and followed thickness and alternate with great frequency. In strikingly uniform through this area. Porphyritic morphism. Interbedded with these are sandy lay­ them. comparatively few cases do the boundaries shown crystals of orthoclase feldspar are a prominent fea­ ers and lentils of blue limestone. The Hiwassee Metamorphism. While the effects of metamor­ on the map represent a single contact between two ture of the rock. The porphyritic varieties are not formation, which is a slate in its northwestern out­ phism are not conspicuous in this formation on large masses, but rather they indicate a narrow limited to any particular position in the granite crops, is metamorphosed toward the southeast into account of its fine grain, they are in reality pro­ zone beyond which one rock or the other predom­ mass, but are irregularly distributed through it. schists which are identical in varieties and in found. Only near the base of the formation and inates. Unless the included bodies of other for­ The porphyries grade into granites of uniform appearance with the Brevard schist. The fre­ in a few districts can the original sedimentary mations were found to prevail over considerable grain, and the two varieties may be present in a quency of limestone lenses in the Hiwassee slate bands be seen; usually they are entirely destroyed areas they were disregarded in the mapping. single ledge. In this quadrangle the porphyritic and the absence of limestone from thousands of feet by the secondary minerals. The original argilla­ Character. The granite is composed mainly of feldspars are a decided characteristic of the rock of strata above and below it give added interest ceous or feldspathic materials of the slate developed orthoclase and plagioclase feldspar, quartz, musco­ and the massive variety is rather uncommon. to the presence of these limestone lenses in the new quartz and muscovite. It is probable that some vite, and biotite, enumerated in order of impor­ This is most strikingly to be seen near French Brevard schist. The latter is not now known to be of the latter seen in the less-altered slates is an origi­ tance. Minor accessory minerals are magnetite, Broad River, in numerous cliffs and ledges. The connected in area with the Cambrian strata lying nal mineral. The quartz is in very small grains, ilmenite, pyrite, and garnet. Most of the rock rock has a general gneissoid aspect and most of farther northwest, so that there is no definite proof sometimes lenticular in shape. The muscovite is made up of the feldspars. The biotite varies a great deal in amount and is sometimes entirely agencies. There is considerable variety in the of the blank space. The vertical and horizontal becomes the most prominent of the Mountain struc­ absent. The granite has least biotite in the dikes topographic forms caused by the granite. All var­ scales are the same, so that the actual form and tures. Formations there whose original condition and small bodies, and they are nearly white. ieties give rise to ledges and great cliffs, and all are slope of the land and the actual dips of the layers is unchanged are extremely rare, and frequently There is also little biotite in the granites of the found worn down into plains. The cliffs of White- are shown. These sections represent the structure the alteration has obliterated all the original char­ southeastern mass. The Toxaway granite mass side Mountain, in the adjoining Cowee quadrangle, as it is inferred from the position of the layers acters of the rock. Many beds that are scarcely contains the most biotite and its color is, accord­ are the largest in the Appalachians, and the same observed at the surface. On the scale of the map altered at the border of the Valley can be traced ingly, darker than any of the others. All the granite forms similar cliffs in Lookingglass Moun­ they can not represent the minute details of struc­ southeastward through greater and greater changes rocks of the formation, however, have a generally tain, Table Rock (see figs. 1 and 2), and many ture, and they are therefore somewhat generalized until every original feature is lost. light color, varying from white to gray. other localities. In these positions the granite also from the dips observed in a belt a few miles in In most of the sedimentary rocks the bedding Most of the granite is of fine or medium grain. forms plateaus adjoining the cliffs. The difference width along the line of the section. Faults are planes have been destroyed by metamorphic action, This is especially true of the dikes and small bodies seems to be due to the action of the acids in the represented on the map by a heavy solid or broken and even where they are distinct they are usually and of the great southeastern mass. At various soils, by which the feldspars are decomposed wher­ line, and in the section by a line whose inclination less prominent than the schistosity. In the igneous places near the borders of the granite, porphyritic ever soil is allowed to accumulate. A ledge once shows the probable dip of the fault plane, the rocks planes of fracture and motion were developed, feldspar crystals are found. These are most prom­ bare of soil is kept so by rain and frost and if situ­ arrows indicating the relative direction in which the which, in a measure, made easier the deformation of inent near Lake Toxaway and east of Brevard. At ated on a steep slope becomes a cliff. Decay works strata have been moved. the rocks. Along these planes or zones of localized the latter place it is difficult to distinguish between down into the granite by the decomposition of the motion the original texture of the rock was largely the porphyritic forms of the Whiteside and Hen- feldspars, leaving the quartz and mica grains free. GENERAL STRUCTURE OF THE APPALACHIAN destroyed by the fractures and by the growth of derson granites. In the Whiteside granite, how­ The final product is a light-red or yellowish clay PROVINCE. the new minerals, and in many cases this alteration ever, the massive form is much more common and often strewn with fine white sand. In coves and Types of structure. Three distinct kinds of struc­ extends through the entire mass of the rock. The the porphyritic phase is usually localized near its hollows the soil is fairly fertile, but elsewhere is ture occur in the Appalachian province, each one extreme development of this process is seen in the borders. In those parts of the formation which thin, easily worn out, and subject to drought. prevailing in a separate area corresponding to one mica schists and mica, gneisses, the original textures are much metamorphosed the phenocrysts are some­ of the geographic divisions. In the Cumberland of which have been entirely replaced by the schis­ what drawn out into lenses or augen of slightly TRIASSIC (?) ROCKS. Plateau and the region lying farther west the rocks tose structure and parallel flakes of new minerals. more than their original length. Where they DIABASE. are generally flat and retain their original composi­ The planes of fracture and schistosity are inclined retain their original shape they are from a half Distribution and relations. In the southeastern tion. In the Valley the rocks have been steeply toward the southeast through most of the Moun­ to three-fourths of an inch in length. Akin to part of the quadrangle are found three areas of this tilted, bent into folds, broken by faults, and to tains, although in certain belts, chiefly along the this are the small dikes and patches of pegmatite rock. They form practically one narrow dike, being some extent altered into slates. In the Mountain southeastern and southern portions, northwesterly found at many points in the granite. Some of but slightly separated and lying in a single line. district faults and folds are important features of dips prevail. The range of the southeasterly dips these are massive and others porphyritic, and the Their most distinctive feature is the absence of the structure, but cleavage and metamorphism are is from 10° to 90°; that of the northwesterly dips, varieties grade into one another. The pegmatite dynamic metamorphism, although the adjoining equally conspicuous. from 30° to 90°. patches grade into the granite and range in size rocks are all metamorphosed, in places extremely. Folds. The folds and faults of the Valley Earth movements. The structures above described from single crystals of feldspar up to bodies 2 or Rocks of the character of diabase and gabbro are region are about parallel to one another and to are chiefly the result of compression which acted 3 feet across. especially subject to metamorphism, so that its the northwestern shore of the ancient continent. most effectively in a northwest-southeast direction, Another variety of the Whiteside granite is absence here indicates that the diabase was formed They extend from northeast to southwest, and sin­ at right angles to the general trend of the folds and marked by a decided flow banding. This is due after the general period of metamorphic action. gle structures may be very long. Faults 300 miles of the planes of schistosity. Compression was also to the arrangement of the minerals in rudely par­ Inasmuch as rocks of precisely this character are long are known, and folds of even greater length exerted, but to a much less extent, in a direction allel layers when the granite was forced in a molten of frequent occurrence among the rocks of the Tri- occur. The crests of most folds continue at the about at right angles to that of the main force. To condition into the other rocks. This can be seen assic period and are found at intervals in the older same height for great distances, so that they pre­ this are due the cross folds and faults that appear at many points in the various granite bodies, but rocks of other areas, and as there are no other for­ sent the same formations. Often adjacent folds are here and there throughout the Appalachians. The is best shown near Lake Toxaway, Lookingglass mations of this character known in the Appala­ nearly equal in height, and the same beds appear earliest known period of compression and deforma­ Mountain, and along Saluda River east of Cassars chians, this rock is considered to be of Triassic age. and reappear at the surface. Most of the beds dip tion occurred during Archean time, and resulted in Head. The rock marked by wavy flow bands Character. The diabase is a dense, hard rock at angles greater than 10°; frequently the sides of much of the metamorphism of the present Carolina merges into the massive variety in the same ledge. of prevailing black or dark color, and on weathered the folds are compressed until they are parallel. gneiss. It is possible that later movements took Metamorphism. During the deformation of the surfaces has a reddish-brown or rusty appearance. Generally the folds are smallest, most numerous, place in Archean time, producing a portion of the rocks the granite suffered changes both by folding It is composed chiefly of plagioclase feldspar, horn­ and most closely squeezed in thin-bedded rocks, metamorphism that appears in the other Archean and by metamorphism. The folding is the most blende, and pyroxene, in crystals of medium size. such as shale and shaly limestone. Perhaps the rocks. In the course of time, early in the Paleozoic prominent and is best shown in the dome-shaped Additional constituents are magnetite and pyrite most striking feature of the folding is the preva­ era, compression became effective again, and a series masses north of the Blue Ridge. It is probable in small grains and crystals. The texture of the lence of southeastward dips. In some sections of movements took place that culminated soon after that some of the folding and upheaval of the sur­ rock is sometimes massive and granular like gab­ across the southern portion of the Appalachian the close of the Carboniferous period. The latest rounding gneiss was accomplished during the intru­ bro, but usually has the ophitic structure of dia­ Valley scarcely a bed can be found which dips of this series was probably the greatest, and to it is sion of the granite. Similar folding is shown near base. Near the contacts with other formations the toward the northwest. chiefly due the well-known Appalachian folding Marietta, in the southeastern part of the quadran­ grain of the rock grows perceptibly finer, but it is JFaults. Faults appear on the northwestern sides and metamorphism. This force was exerted at two gle, where the granite and gneiss bodies describe a seldom coarse in this quadrangle. In places the of anticlines, varying in extent and frequency with distinct periods, the first deformation producing semicircle. Metamorphism is comparatively small contact variety is an extremely fine whitish or the changes in the strata. Almost every fault great overthrust faults and some metamorphism, in most of the granite, but locally is of impor­ gray rock without visible grain and resembling plane dips toward the southeast and is approxi­ the second extending farther northwestward and tance. Its chief development is near Lake Tox­ chert. mately parallel to the beds of the upthrust mass. deforming previous structures as well as the away, where schistose and gneissoid granites are Weathering. This rock withstands weathering The fractures extend across beds many thousand unfolded rocks. The various deformations com­ common. Some of these are as much deformed as most effectively. Decay works gradually in along feet thick, and sometimes the upper strata are bined have greatly changed the aspects of the the Henderson granite. The coarse varieties and joints, and spheroidal masses and bowlders are pushed over the lower as far as 10 or 15 miles. rocks so much so, in fact, that the original nature those containing most biotite show the alteration formed, which are characteristic of the surface of There is a progressive change from northeast to of some of the oldest formations can be at present best, while the fine-grained and light-colored granites the formation. Ledges are seldom far from the southwest in the results of deformation, and dif­ only surmised. have practically no metamorphism throughout large surface and the cover of brown clay is usually ferent kinds prevail in different places. In south­ In addition to the force that acted in a hori­ masses. When the rock was folded planes of frac­ thin. The rounded bowlders readily find their ern New York folds and faults are rare and small. zontal direction, this region has been affected by ture and motion were found in the rock mass along way downhill and block the stream channels. Through Pennsylvania toward Virginia folds forces that acted vertically and repeatedly raised become more numerous and steeper. In Virginia or depressed the surface. The compressive forces which metamorphism took place. As the process STRUCTURE. went on the quartz was broken and recemented, the they are more and more closely compressed and were tremendous, but were limited in effect to a feldspar developed into mica, quartz, and new feld­ INTRODUCTION. often closed, while here and there faults appear. relatively narrow zone. Less intense at any point, spar, and chlorite replaced part of the biotite. These The rocks of this quadrangle that were depos­ Through Virginia into Tennessee the folds are but broader in their results, the vertical movements minerals crystallized in general parallel to planes ited upon the sea bottom must originally have more broken by faults. In the central part of the extended throughout this and other provinces. of motion in the rock; inasmuch as these were the extended in nearly horizontal layers. At pres­ Valley of East Tennessee folds are generally so It is likely that these two kinds of movement were result of broad general stresses the planes of schis- ent, however, the beds or strata are seldom hori­ obscured by faults that the strata form a series of combined during the same epochs of deformation. tosity are fairly uniform in position over large areas. zontal, but are inclined at various angles, their narrow overlapping blocks of beds dipping south­ In most cases the movements have resulted in a The change is most manifest in the porphyritic edges appearing at the surface. Folds and faults eastward. Thence the structure remains nearly warping of the surface as well as in uplift. One feldspars, which have increased somewhat in length. of great magnitude occur in the Appalachian the same southward into Alabama; the faults result of this appears in overlaps and unconformi­ They were cracked and broken and their fragments region, their dimensions being measured by miles, become fewer in number, however, and their ties of the sedimentary formations. were rotated until nearly parallel. The mica flakes but they also occur on a very small, even a micro­ horizontal displacement is much greater, while . As was stated under the heading "General geo­ were turned into similar planes and thus was pro­ scopic scale. Many typical Appalachian folds are the remaining folds are somewhat more open. logic record" (p. 2), depressions of this kind took duced a gneissoid rock or augen gneiss with many to be seen in the region. In the folds the rocks Metamorphism. In the Appalachian Mountains place at the beginning of Paleozoic time, with porphyritic crystals pressed out into eyes. The have changed 'their forms mainly by adjustment the southeastward dips, close folds, and faults that several repetitions later in the same era. They large feldspars retained their shape better than the and motion on planes of bedding and schistosity. characterize the Great Valley are repeated. The alternated with uplifts of varying importance, the finer groundmass, and the inica flakes in the latter There are also countless planes of dislocation inde­ strata are also traversed by the minute breaks of last of which closed Paleozoic deposition. Since are bent and wrapped around the large crystals. pendent of the original layers of the rocks. These cleavage and are metamorphosed by the growth of Paleozoic time there have been at least four, and Other results effected by the deformation are the are best developed in rocks of an originally mass­ new minerals. The cleavage planes dip eastward probably more, periods of decided uplift. How stripes and striated surfaces which mark the granite ive texture and are usually much nearer together at angles ranging from 20° to 90°, usually about many minor uplifts or depressions have taken place here and there. These are due to linear growths and smaller than the planes on which the defor­ 60°. This phase of alteration is somewhat devel­ can not be ascertained from this region. of new minerals with parallel arrangement. The mation of the stratified rocks proceeded. In these oped in the Valley as slaty cleavage, but in the LOCAL STRUCTURES. dark stripes are composed in the main of fine biotite more minute dislocations the individual particles Mountain region it becomes important and fre­ and fibrous hornblende and the light stripes of of the rocks were bent, broken, and slipped past one quently obscures all other structures. All rocks General features. The rocks of this area have quartz and feldspar. This phenomenon is well another or were recrystallized. were subjected to this process, and the final prod­ undergone many alterations in texture and position shown along the southern border of the quadrangle Explanation of structure sections. The sections ucts of the metamorphism of very different rocks since they were formed, having been bent, broken, and in the fresh sections along Toxaway and Horse- on the structure-section sheet represent the strata are often indistinguishable from one another. and metamorphosed in a high degree. The struc­ pasture rivers. as they would appear in the sides of a deep trench Throughout the southern part of the Appalachian tures which resulted from these changes extend in Weathering. The surface of the formation is cut across the country. Their position with refer­ province there is a great increase of metamorphism a general northeast direction. Exceptions to this slowly lowered as it is attacked by weathering ence to the map is on the line at the upper edge toward the southeast, until the resultant schistosity are seen south and east of Caesars Head and in Pisgah 6 the basin of Pigeon River. In these areas the The northwestern uplift is composed of many oid or schistose as the result of previous metamor­ the Henderson granite. In this rock the dip of the structure planes swing into a northwest course, axes, the most conspicuous being those which expose phism the existent schistose planes served to schistosity as a rule is very small from 10° to 20° nearly at right angles to their prevailing direction. the Henderson granite. At four places near Lake facilitate flexure, as did the bedding planes of the toward the southeast. Similarly light dips prevail Many minor changes of this kind are to be found Toxaway, around Panthertail Mountain, Looking- sediments. In the massive igneous rocks there in the adjoining Whiteside granite around and at various localities in the quadrangle. glass Mountain, and the Pink Beds the doming of were no planes already formed, but these were northeast of Caesars Head. Strongly in contrast Structures in the sedimentary rocks are readily these masses and their anticlinal arrangement is developed by fracture and mashing, and the with these are the dips in the gneisses of the deciphered. In the igneous and metamorphic for­ very well shown. The same attitudes are to be change of form expressed in folds was less than Pigeon River basin, where for mile after mile the mations, however, while it is easy to see that the seen in the rocks overlying the main granite in the laminated rocks. These schistose partings rocks scarcely diverge from the vertical, even in rocks have been greatly disturbed and the details of masses, comprising the Roan and Carolina gneisses are in a general way parallel to one another for spite of extreme crumpling. the smaller structures are apparent, it is difficult to and smaller sheets and masses of the granite. All long distances and over large areas. This is con­ Vertical movements. The latest form in which discover the larger features of their deformation. these axes pitch toward the northeast, so that the spicuously true of the gneissoid portions of the yielding to pressure is displayed in this region One reason for this is that the original shape of granite disappears in that direction and higher Henderson granite. They sometimes diverge con­ is vertical uplift or depression. Evidence of such most of the formations is unknown, because they rocks form the surface. The crescent-shaped out­ siderably for short distances around harder por­ movements during the deposition of the sediments are intrusive and consequently irregular. Another lines of the various formations on the pitching folds tions of the rock, which have yielded less under can be found in this quadrangle, as at the begin­ reason is that the masses of one kind of rock are so are very striking. Around Lake Toxaway the compression, but the influence of these portions is ning of the deposition of the Brevard schist. In great and distinctive beds are so rare that structures anticlinal arrangement of the foliation planes is only local. Near the boundaries of formations, post-Carboniferous time, after the great period of of large size can seldom be detected. finely shown well down into the granite mass. also, the schistose partings are usually about par­ Appalachian folding just described, such uplifts While folds are numerous throughout the quad­ Similarly, the sections northeast of Lookingglass allel to the general contact of the formations, the took place again and are recorded in surface forms. rangle, especially where they are defined by the Mountain show the arching of the overlying yielding to pressure having been directed by differ­ While the land stood at one altitude for a long sedimentary rocks and the uplifted granite masses, gneisses. The remainder of the great anticlinal ences in strength between the formations. Thus, time, most of the rocks were worn down to a their importance is much less than that of the uplift is characterized by very steep dips. Enor­ while the strike of the different formations may nearly level surface. Over a large part of this multitude of slips that accompany the metamor- mous bodies of the rocks stand on edge and are vary considerably in adjoining areas, yet the schis­ region one such surface was developed, but only phism, which combined equal the larger structures. very highly contorted. This condition is brought tose planes swing gradually from one direction to its worn remnants are now to be seen, at the heads It is possible, also, that other faults occur in addi­ out somewhat by the thin bands of Roan gneiss another, and there is seldom an abrupt change. of the main streams, .where secondary cutting has tion to the few faults that are shown, but for lack northwest of Big Pisgah Mountain. As was stated in the description of the Carolina not yet reached. Along the Blue Ridge are found of distinctive or regular beds they can not be deter­ The folds, both anticlines and synclines, range in and Roan gneisses, the foliation evident in them the largest areas of this plateau, from 3000 to 3200 mined. By far the greater part of the deformation size from mere wrinkles up to arches and basins was produced at an exceedingly early date. In feet above sea. There are many smaller remnants of the rocks in the region has taken place through with breadths of miles. Folds of all intermediate the later or post-Carboniferous compression these here and there in the high mountains, the most metamorphism. It is very probable that the folds dimensions are to be observed. A few of them are foliation planes were deformed by folding. Thus perfectly preserved being the Pink Beds. Over are complicated with faults along their borders; for open, especially near the ends of the granite domes. were produced the larger folds, such as appear much of this region another such surface was instance, in the synclines of Brevard schist. No Sections C-C and D-D exhibit these moderately in the Balsam and Pisgah mountains, the minor developed, which is still visible in the plateaus sharp line can be drawn, however, between the folded rocks. The majority of the folds, however, folds, and the wrinkles which are seen in scores in along French Broad River at elevations of 2200 to dislocation shown in faults and in metamorphism are nearly or quite closed. Thin beds, like those of every large outcrop. The conditions of deforma­ 2300 feet. Actual profiles of small parts of these without displacement. the Brevard schist and portions of the Carolina tion were such as to fold and mash rather than plateaus are shown in sections A-A, B-B, and C-C. In the structure sections it is not possible, on gneiss, are bent and crumpled in an extreme degree break the layers, and the bands of the gneisses are Southeast of the Blue Ridge another plain was account of the small scale, to show the minor folds without breaking. This is best seen in sections twisted and grow thicker and thinner in the great­ extensively developed after further uplift and ero­ and wrinkles, so that the structure is generalized A-A and B-B. Sections B-B and C-C also cross est variety. Bending of the beds was largely sion had taken place. This, the Piedmont Plateau, and represented as comparatively simple. Nor is it masses of highly contorted gneisses with closed accommodated by motion along the foliation planes. now stands at heights of 1100 to 1200 feet above possible to represent the granite and gneiss occur­ folds. Other large masses of gneiss with steep or In the granites during the same period of fold­ sea. ring beneath the surface, since they have no known vertical dips undoubtedly contain many closed folds ing there were no existing foliation planes. Under After the formation of each of, these plains, methods of disposition or occurrence, such as char­ which can not be detected. the great stresses, however, planes and zones of uplifts of the land gave the streams greater slope acterize the sediments. In many places the granite Faults. Faults are very rare in this quadrangle, shearing and mashing were produced and changes and greater power to wear; they have therefore bodies can be seen protruding through the gneisses and the only situation in which they are probable of form took place on them. These planes dip for cut into the old surfaces to varying depths and from below. In other places the same relation can is along the southeast side of the Brevard syncline. the most part toward the southeast and are nearly produced canyons or later plains, according to their be deduced from a study of the topography. There It is difficult to explain the change from Carolina uniform over large areas. They vary in amount power and the nature of the waste they carried. are also instances in which the bodies of Roan and gneiss to Henderson granite on the opposite sides from 5° or 10° up to vertical, averaging about 40°. The amounts of the uplift can be estimated, from Carolina gneiss and soapstone rest at various dis­ of the syncline without faulting. Usually there is Along the contacts of the formations the planes of the vertical intervals between the plateaus, at nearly cordant angles within and upon the bodies of the perfect conformity of all the formations in dip, so schistosity are roughly parallel to the contact in both 1000 feet after the first period of reduction, 1100 granite. As a general principle, moreover, it is that a fault can not be detected by that means. At dip and direction. Within the body of each for­ feet after the second, and perhaps 1000 feet after evident that the granites were intruded into the Davidson River the granite near the schist is mation, however, there are considerable divergences the last period. Other uplifts and pauses undoubt­ gneisses from larger bodies of granite lying deeper highly brecciated and undoubtedly faulted. It is from the direction of the contact. Around more edly occurred in this region, but their traces are in the earth. For these reasons the granite masses not probable, however, that the contact between massive and resistant portions of the rocks, also, the obscure; and probably there were still others which have been represented as growing larger downward. the Henderson granite and the schist is usually one schistose planes swing gradually. In places where were not of sufficient length to allow plains to be From a similar course of reasoning, the bodies of of faulting. Except in that situation no faults of the motion was especially localized the minerals of formed and record the movement. Roan gneiss, being probably eruptive in the Caro­ any note have been determined. Small faults of a the granites were elongated into thin sheets and lina gneiss, have been treated as enlarging beneath few inches throw are to be seen at many points in strings or striated forms. In the porphyritic gran­ ECONOMIC GEOLOGY. the surface. the gneisses, especially where large ledges have ites, like the Henderson, the large feldspar crystals MINERAL RESOURCES. Folds. In a broad way the structure of the rocks been swept bare by streams, but such displacements were cracked, rotated, flattened, and elongated into of the Pisgah quadrangle is that of a synclinal are local and unimportant. eyes. Around these harder portions the secondary The rocks of this region yield materials of value, basin between two broad areas of uplift. The basin, Metamorphism.- Metamorphism of the rocks was micas of the granite are closely bent. such as soapstone, talc, mica, corundum, kaolin, which is marked by infolded sedimentary rocks, the extreme, as well as the folding. In the description There is great variety in the direction of the gold, graphite, copper, lime, building stone, and Brevard schist, has a nearly straight course from of the individual formations its detailed effects on structure planes in the region. Their average trend brick clay. The soils they form produce timber and northeast to southwest, almost from corner to cor­ the rocks were described. In general it consisted is between N. 30° E. and N. 45° E. Locally there are crops, and the grades they cause furnish abundant ner of the quadrangle. The principal syncline of a mashing of the rocks under the overwhelming groups running north and south, and also north­ water power. is composed of from two to five minor synclines, pressure and a production of planes of fracture and west and southeast. Some of the latter are brought SOAPSTONE. along which in places the underlying granites are motion through the body of the rock as .well as out by the Roan gneiss bands in the Pigeon River exposed. This fold, which begins in the adjoining along the sedimentary planes. Along these planes basin. Local curves due to anticlinal structures are Soapstone is found here and there through the Mount Mitchell quadrangle, extends with a singu­ of fracture and to a less extent in other parts of the to be seen around the ends of the Whiteside gran­ Archean formations. With allied rocks it occurs larly straight course south westward through South rock new minerals were developed, lying about ite areas north of the French Broad Valley, both in at frequent intervals through the entire length Carolina and far into northern Georgia. Its extent parallel to planes of motion. To this arrangement the granite and in the surrounding gneisses. Similar of the Appalachians. Although soapstone is thus and straightness make it one of the most striking is due the schistosity of the rocks. For the most curves without trace of anticlinal origin are seen in very widespread, few of its areas are over a mile in folds in this part,of the country. Toward it the part the new minerals were quartz and muscovite the southeast corner of the quadrangle, where the length. Some of the bodies are to be measured by structure planes of the gneisses on the north developed from the recirvstallization of the old schistose planes describe a semicircle in both gneisses a few feet, and most of them cover only a few acres. approach in succession. Local twists and turns in quartzose, feldspathic, and argillaceous material. and granite. In practically every case where the Soapstone is derived from the metamorphism of the individual beds can be found in almost any These results are such as characterize metamorphism pitch of a large fold can be determined it is toward very basic igneous rocks and is associated with large outcrop. These are accommodated to one throughout the Appalachian Mountains. In this the northeast. dunite, serpentine, chlorite schist, and other prod­ another, however, so that the average course of the region there is also seen an enormous development In the dips of the schistose planes of this quad­ ucts of that metamorphism. It is customar^ to formations is very regular for long distances. of secondary garnet and cyanite during metamor­ rangle there is great variation. Throughout most find several of the metamorphic varieties together The synclines in other portions of the quadrangle phism. Similar metamorphic products are found of the area the dip of the schistose planes and sed­ in each area. South of the Blue Ridge only one are recognized as such chiefly because they separate in tracing these structures southwestward into imentary beds is toward the southeast at angles soapstone body is known and practically all of it definite anticlines. Minor exceptions to this are Georgia. Northeastward the garnet-cyanite phases ranging from 10° to 90°. In certain belts there are is found in the district north of Brevard and Lake seen in the contorted gneisses northwest of Pisgah extend for 40 or 50 miles and southwestward for usually distinct groups of dips. An exceptional Toxaway. More than twenty areas of the forma­ Mountain. 10 to 25 miles, while the other products continue feature in this respect is the series of northwestward- tion show a considerable amount of soapstone, in The two areas of uplift are marked both by the throughout the Appalachians. dipping beds and schistose planes seen along the addition to those bodies pure enough to be classed foliation planes and by the masses of granite which The processes of metamorphism were along headwaters of French Broad River. This is best as talc. ;; have forced the gneiss upward from below. Of the the same lines in both sediments and crystallines. defined in the region lying south of Tennessee Bald, In places the soapstone is sufficiently pure for two uplifts the southeastern is far the simpler and The mineral particles were changed in position in which locality most o£ the dips are northerly at economic use. As a rule, however, the talc, the compares in this respect with the principal syncline. and broken during the folding of the rock. angles of 20° to 60°. These northwesterly dips are hydrous silicate of magnesia forming the basis of This is especially true of a belt 5 or 6 miles wide In folding, the differential motion in the sedimen­ caused by the anticlinal domes of Whiteside gran­ soapstone, is too much mixed with other silicates, adjoining the syncline. The southeastern portion tary 'strata was to a large extent along bedding ite, which run from the Pink Beds in a southwest especially of the hornblende family, to be valuable. of this uplift, however, is very irregular in the planes. As deformation became extreme, however, course. The anticlinal form taken by the granite The special uses of ;soapstone demand a rock which direction of the foliation planes. Just west of Mari­ other planes of motion were formed through the indi­ masses is followed also by ;the schistosity, where it is readily cut and sawed and which contains no etta, dn particular, the included masses of gneiss vidual layers, as in the case of the massive igneous is developed, and by the foliation of the gneiss. An material that is affected by fire. Some of the horn- and the foliation planes describe a semicircle. rocks. In rocks which had already become gneiss- exceptional area of another character is found in blendic minerals fuse readily, and others which fuse 7

less easily are hard and injure the texture and the either were not originally of workable size or have At Retreat corundum was first found in the gravel account of the thick cover of soil. It is certain working of the stone. The igneous rocks from been crushed or distorted during the deformation bed of a small stream. During later search for its that there are many other deposits not discovered, which the soapstone was formed vary much in of the rock. In this quadrangle the pegmatites source a small amount of corundum was encountered of equal or greater value than those mentioned here. composition, so that the bodies of soapstone are which carry large mica are usually of lenticular in a small tunnel in the mica schist a few rods The pegmatite bodies are universally found in this equally variable in quality. Metamorphism of the shape and lie in general parallel to the inclosing northeast of the stream. It was evident, however, region, and on the uplands are frequently seen to be original rock was not always complete and did not gneisses. Some can be traced for miles, while that the main source of the corundum was not dis­ of large size. always produce a soapstone, even when complete. others extend only a few rods or a few feet. In covered, because the corundum was found in the The two instances cited are scarcely developed at Accordingly, in this quadrangle large bodies of some places the pegmatite has the form of a vein gravels above the tunnel. The corundum float was all and barely more than their presence is known. soapstone are rare, the mass at Three Forks of or dike, with nearly parallel walls; this variety traced for perhaps 200 yards. Most of the corun­ Near Retreat the kaolin has been exposed in three Pigeon River being much the greatest. The soap- cuts across the schistosity of the gneiss at high dum was of a light-grayish color. Small fragments small pits on opposite sides of a little ridge, and it stone usually occurs in seams or layers in serpen­ angles. Still other pegmatites are replacements of of a clear sapphire blue were found, and some of is probable that it is a single body. One pit is tine and dunite, a few inches or a few feet thick, the Whiteside granite and are entirely inclosed in the light-colored pieces contained sapphire streaks. nearly north from the other, a direction which and in larger bodies at the ends and borders of it. These are more feldspathic than the other Some of the larger pieces are deeply pitted, as if crosses the foliation of the mica gneiss. The kaolin their inclosing masses. In this quadrangle an forms and are closely connected with the granite the corundum had filled in spaces between other near Sonoma appears to have a similar north-south unusual number of bodies of the formation are in origin; they seldom or never carry merchant­ minerals. In the tunnel the corundum crystals direction, which is there more nearly coincident entirely made up of soapstone or talc. On the able mica. Pegmatite in the Henderson granite is were reported to be embedded directly in the mica with the strike of the inclosing mica gneiss. At economic geology map are indicated twenty-one comparatively rare and the mica is small. schist. Small veins of vermiculite, usually asso­ this locality a single pit about 15 feet deep has areas of the formation where soapstone is found in The mica which is mined is the variety musco- ciated with corundum, are found in the schist. been sunk on the top of a hill. In each case the sufficient purity and body to be valuable. The vite, and it is crystallized with quartz and feldspar, These schists are somewhat garnetiferous and are kaolin has a clear white color and is very little sur­ most promising localities are at Three Forks, 5 forming the pegmatite. In many localities biotite just northeast of a narrow dike of the hornblende face stained. It is mixed with a moderate amount miles west of Fletcher, and 2 miles southeasterly also occurs, and beryl, garnet, chlorite, and numer­ gneiss which lies in the Carolina gneiss. Aside of fine quartz and but little mica. Although no from Lake Toxaway. At Three Forks the soap- ous other minerals are found. From a texture from this suggestion of a contact relation between considerable deposit has been revealed, the prospects stone body is about a mile long, much of it being like -that of granite the coarseness of the pegmatite the corundum, and the igneous rock, there is no are worth further testing; owing to the steep dips nearly pure talc, while at the other two localities varies until the mica, crystals attain a diameter as evidence in this region as to the origin of the of the country rocks, they would probably descend its bands are from 100 to 1500 feet long. Thus great as 20 inches. Crystals of this size are rare, corundum. No deposit of note was developed in to considerable depths. Near Retreat the kaolin far, however, only loose blocks and bowlders have having been found only in the mine at the head of the hard rock, nor is the amount of corundum in deposit has a length of about 200 feet, and may been sawed and used for building fireplaces, and Pigeon River. The average crystals mined are the gravels or the amount of gravel itself sufficient be much longer; the length of the other deposit is nowhere has the rock been quarried to any extent. from 3 to 8 inches in diameter. to justify much work to recover it. unknown. In places the mica apparently follows rather The deposits near Great Hogback are typical of TALC. GOLD. irregular planes, which are termed the " vein." The most of the southern Appalachian corundum. Deposits of pure talc are found in connection distribution in the vein of the crystals or "blocks" They are closely associated with the dunite forma­ Vein gold is found at only one place within the with the dunite-soapstone rocks. The talc has the of good mica is very irregular. They can not be tion. The principal occurrence here is at the Burnt Pisgah quadrangle, at the Boylston mine, on the same origin as the soapstone bodies, both being predicted or traced far with a definite position in the Rock mine, a mile northeast of Great Hogback. southeast slope of Forge Mountain. In addition to derived from the metaniorphism of peridotite, and pegmatite. Consequently, the success of any mica The dunite there forms a lenticular mass at the this occurrence of gold in the ledge, gold has been is, in fact, only the purest form of those deposits. mine is uncertain at the start. Large mica may be contact of the hornblende gneiss and mica gneiss. washed from the gravels along the head of Toxaway On the economic geology map ten talc localities found at once or barren rock may continue There is a minor lens of the dunite formation below River, now occupied by Lake Toxaway. Similar are shown. The principal ones are 4 miles north­ throughout. Large mica at one point may become the principal one and separated from it by a thin gravels at the western foot of Great Hogback were east of Lake Toxaway, at Three Forks of Pigeon, smaller in a few feet, or the crystals may be crushed band of mica gneiss and pegmatite. The main washed for gold with considerable success before and just south of Waynesville. In these three and cut into ribbons. Even when the mica is body of the mica gneiss is above the dunite, while they were covered by the present lake at Fairfield. localities the talc forms substantially the entire large, most of it may be "A" mica with poor cleav­ below it is chiefly hornblende gneiss. The rocks The gravels occupy valleys of streams which head outcrop of the formation. No tests have been age. Generally, however, one class of mica prevails as a whole have a dip of about 30° NW. The within 2 miles of the deposit. The basins above made of the depth of the talc bodies. Since, how­ for considerable distances. dunite formation here consists of a rock character­ the gravels are mainly underlain by granite with ever, they replace the dunite the depth of the talc Many of the crystals do not furnish sheets across ized by large amounts of enstatite and chlorite. narrow bands of hornblende and mica gneiss. is probably similar to that of the dunite. The shape their entire diameter, for seams and cuts divide These are secondary replacements of the minerals These gravels at Lake Toxaway are associated closely of the dunite bodies is lenticular and their depth is them into strips and angular pieces. Such crystals, of an original peridotite or pyroxenite. with the plateau of the Blue Ridge, and are a little doubtless as great as their length on the surface. however, are suitable for ground mica. Impurities Corundum is found there in two situations. A over 3000 feet above sea. Similar gravels derived At Three Forks the talc crops out in an irregular in the form of dendrite figures, stains, and spots little is embedded in the kaolin of the pegmatite from the same group of rocks are found in a nar­ area about a mile long. Near Waynesville and render much of the mica worthless for any purpose, lenses; the major part, however, is derived from row belt running northeastward across the head­ east of Lake Toxaway the talc forms small lenses and clay penetrates between the sheets where the veins along the border of the dunite and filling small waters of French Broad River near Balsam Grove, 10 to 50 feet thick and from 50 to 150 feet long. rock is decayed near the surface. Clayey impuri­ cracks between its blocks. These veins or seams of Davidson River, and of Mills River in the Pink Some uses of talc demand that the product shall ties can be, for the most part, taken out by careful are seldom more than a foot or two thick, and con­ Beds. While it is not known that these'gravels are be absolutely free from grit; others, that it shall washing, but the spots of dendrite can not be wholly sist mainly of chlorite, actinolite, vermiculite, and auriferous, there is reason to suppose that they are. contain no fusible minerals; still others, that the removed, existing as they do between the thinnest corundum. The corundum occurs in nodules and At the Boylston mine operations have been car­ minerals shall be massive and capable of being sheets. These spots are unimportant in mica where small lumps in the other minerals. They form a ried on at several times during a period of thirty sawed into small sections. All of the talc shown transparency is not required, or where used for closely felted mass in which most of the crystals years. The deposits are quartz veins carrying gold here is sufficiently free from grit and fusible sub­ insulation of low-tension electric currents. are arranged at right angles to the walls of the vein. and pyrite. The country rock is bluish-gray and stances. A few small grains of iron oxides are Pits and shallow openings have been made at The corundum has for the most part a dull gray gray mica schist and mica gneiss, cut by narrow found in most of the talc, but these can readily be scores of places in this region during many years, color, but now and then sapphire-blue or ruby-pink beds of white biotite granite. There are four or five separated when the rock is pulverized. Except but they have usually been sunk in the decayed crystals were found. Corundum also occurs spar­ quartz veins in the property with a general strike for these oxides there are no fusible impurities. rock and soon exhausted. Later work in the solid ingly in the pegmatite lenses cutting the gneisses. of N. 30° E., the same as the country rock. The All of the talc, however, is schistose to some degree. rock is difficult, on account of the hardness of the It there forms crystals inclosed in feldspars and is one on which the most work has been done lies This structure renders it unfit for the manufacture quartz and feldspar. not of commercial importance. About 10 tons of near the foot of the mountain. This varies in of pencils, on account of the easy splitting which At present the only work carried on is at the corundum was taken out from this locality in 1892, thickness from 2 to 8 feet. It is lenticular in it produces; but it does not affect the use of the Big Ridge mine and 2 miles north of Balsam Grove but the work was discontinued the following year. character, but in places the lentil is so long as to talc in larger forms, such as linings for fireplaces on the head of French Broad River. The Big Ridge Several times since then the deposits have been resemble a fissure vein. The dip of the lentils and furnaces. In this way considerable use has mine is the most important and has been worked prospected. The work consists only of open cuts and of the containing rocks is the same. Along been made of the material from these localities. for many years. At that point inclines go 'down and pits following the contacts and irregularities of the surface in shallow cuts they all dip toward the None of the talc is translucent or massive. The for 70 or 80 feet, at angles of 10° to 30° to the the veins, and no systematic exploration has been northwest, while in the hard rock of the tunnel the portions now available are the surface materials, northeast, following the pitch pf the pegmatite and made. dip is steep toward the southeast. Inasmuch as all however, and the deeper rock would doubtless be the inclosing mica gneiss. The mine lies just on a At the Brockton mine, about a mile southwest of the rocks of that, region dip toward the southeast better. In no case would the schistose character small anticlinal fold in the mica gneiss which pitches Great Hogback, the associations are practically the when in place, it is probable that the northwest­ be absent. northeast. The pegmatite is composed of feldspar, same as at Burnt Rock. A much larger amount of ward dips are due to creeping of the decayed rock quartz, muscovite, and biotite, with a little beryl, corundum was taken out, however, at the same time down the mountain. Some of the quartz is very MICA. apatite, garnet, and chlorite. The amount of bio­ that operations were carried on at Burnt Rock. rich in pyrite, while the greater part of it carries In the pegmatites of the Archean rocks, mica tite is unusually large in this pegmatite. The feld­ The origin of the corundum is doubtful. All a very little. It is probable that the great range in occurs in crystals large enough to be of commer­ spar is mainly plagioclase, some of which is clear the rocks in which it is inclosed are marked by reported values is due to very unequal distribution cial value. Pegmatites are found in the various and glassy. Its crystals are large, occasionally schistosity which results from metamorphism. The of pay ore. Most of the quartz is vitreous, but a? granites and gneisses throughout a large portion exceeding a foot in length. The largest mica corundum and associated minerals in the veins do considerable part is saccharoidal. The principal of their areas, but they contain mica of workable "blocks" are nearly a foot across the sheets, but not display this feature. It is most probable, developments consist of a long line of open cuts size chiefly in a belt about 8 miles wide and run­ most of them are much smaller. Most of the mica therefore, that the corundum-bearing veins were in the weathered rock and quartz. These extend ning 20 miles southward from Waynesville. The has good cleavage and but little figuring. The formed later than the inclosing rock. along the foot of the mountain for half a mile. largest mica has been produced from the Big Ridge product is used chiefly for insulating work in Below these openings a tunnel has been driven to KAOLIN. mine, on the southwestern side of Lickstone Bald. electric construction. a reported length of 700 feet. The original devel­ All of the mines are in the Carolina gneiss, as are There are two localities in the quadrangle at opments included a 10-stamp mill, which remains; COBUNDUM. most of the good mica mines of this region. The which kaolin has been found in Quantity at the last work was done by a 40-stamp mill, which principal developments in mica mining have been Corundum is an aluminum oxide and is found in Retreat and near Sonoma, 2^ miles nearly northeast has been removed. in the Big Ridge mine and also within a distance association with the Archean rocks. Within this of Retreat. The kaolin has resulted from disinte­ GRAPHITE. of 4 miles from Tennessee Bald. The mica region area three localities where it occurs are known and gration of pegmatite lenses, which are very common also extends westward into the Cowee quadrangle. it is reported to have been found in numerous in that region. Those which contain a large pro­ Graphite is found here and there in many of the The group of mica-bearing pegmatites passes others. There are two distinct kinds of occurrence : portion of feldspar have decomposed most and form layers of the Brevard schist, disseminated through northward into the Asheville quadrangle, but does Near Great Hogback, a mile northeast, and also workable deposits. Rock decay has been most the body of the schist in extremely fine particles. not there contain mica of workable size. In gen­ about a mile southwest, corundum is found in con­ thorough and deepest near the old plateau sur­ While the deposits of this mineral have been mined eral, however, outside of the mica district above nection with the dunite formation. At Retreat it faces, and in those regions also it is most difficult to on the extension of the schist in the Mount described the crystals of mica in the pegmatites also occurs in mica 'gneiss. determine the nature of the underlying rock on Mitchell quadrangle, no work has been attempted in Pisgah. 8

this quadrangle. 3 _The black schists are graphitic The Whiteside granite yields excellent stone of a being thickest in the bottoms of the hollows and trated into falls and rapids by hard beds of rock. in many parts of the formation, especially near its more massive texture than the Henderson. Its thinner on the hill slopes. In many places these This is notably the case in the Whiteside granite base. In fact, graphite might be said to be a reg­ color is light gray or white, and its grain is medium have been burned into bricks for local use. areas near the Blue Ridge, where its hard and ular constituent of the schist in some areas. As to and very uniform through large bodies. It splits massive character causes enormous cliffs and ledges. WATER RESOURCES. the cause of the presence of the graphite in some out in thick sheets and dresses very well. Its dur­ Similar but smaller falls are made by the Hender­ places and its absence in others there is no good ability i3 shown by its enormous cliffs in Table WATER POWER. son granite. The various gneisses are not widely evidence, nor is it known whether the graphitic Rock and Lookingglass Mountain. Along the Within this quadrangle there are abundant different in their influence upon the immediate material was introduced into the schists as an orig­ Blue Ridge are found the best natural outcrops, but resources in the form of water power. In nine- stream grades. inal or as a secondary constituent. Its presence in quarries could be developed readily at nearly any tenths of the area the streams, both great and The enormous water powers thus at hand in the the Mount Mitchell quadrangle in veins, the quartz locality in its areas. The cover of soil is seldom small, flow rapidly. Since they are fed from mul­ quadrangle have received scarcely any development. of which is secondary, indicates a secondary origin heavy over the rock and weathering is not deep. titudes of springs and drain well-forested areas, A few sawmills and gristmills have been turned by for the graphite. The schist itself is composed of The stone has been used for dams, chimneys, and their flow is very steady from season to season. the small streams, but nothing more. With the very fine quartz and muscovite scales with black abutments. The stream grades are divided into three general coming of railroads and the possibilities of electric iron oxides in extremely minute grains. These Marble. Beds of marble are found in the Bre­ groups, according to their relations to the large transmission the energy of the various streams various minerals are distributed uniformly through vard formation at several points. While the areas topographic features. These are above, below, or should prove very valuable. *the schist. Another mineral sometimes found in underlain by the marble are large, outcrops of the on the old plateau surfaces. As was explained the graphitic schists is garnet. rock itself are very scarce. The marble is much under the heading "Geography," plateaus now are WATER SUPPLIES. In some respects the outlook for successful more rapidly dissolved by circulating waters than found at three heights above sea level and cover The various sources of water in the Pisgah quad­ recovery of the graphite is better in this than in the the adjoining rocks, so that its surface is low and about two-thirds of the quadrangle. Above them rangle furnish an unusually large supply. The Mount Mitchell quadrangle, where both cyanite overspread with wash from the harder formations. stand large mountain masses never reduced to the region is covered, for the most part, with heavy tim­ and garnet were abundant in the graphitic schist Most of it is white or light colored, but associated levels of the plateaus. ber growth and is almost altogether mountainous, and were a serious hindrance to the separation of with this variety are beds of white marble with blue Since the formation of the plateaus as plains the no part of it being more than 8 miles distant from the graphite. In this quadrangle the schists appear bands and numerous dark-blue beds. An analysis streams have acquired fresh power and recut their high mountains. The fall of rain and snow is to be as graphitic, while cyanite is absent and garnet of the marble near Fletcher gives 95 per cent of channels to greater depths. The new cuts are heavy and the natural advantages for storage are uncommon. carbonate of calcium and 5 per cent of carbonate deepest in the lower portions of the main streams very great. The rocks of the mountain district, of magnesium. The marble is finely crystalline, and are progressively shallower toward their heads. particularly the gneisses in the northwestern part COPPER. and some of it has almost the texture of limestone. The streams are only beginning their work in recut- of the quadrangle, have large numbers of schistose Copper ore is known to exist along the western The lower beds of marble shown near Fletcher are ting the Piedmont Plateau, and their channels are planes and are not dense. Accordingly, they are border of the quadrangle at a number of places not suitable for ornamental use, since silica is less than 200 feet below the plateau tops. The able to hold large quantities of water. The granites shown on the economic geology map. The copper present in the form of small grains which impair French Broad plateau is only from 2 to 6 miles are less schistose and more compact, and thus are occurs as chalcopyrite mixed with pyrite and pyr- the polish of the stone. The upper 200 feet, how­ wide in this quadrangle. On this the channels of able to store up less water. The result is seen in rhotite. These minerals are found in three forms ever, are suitable for ornamental stone. The great­ the streams still flow for 5 or 6 miles below Brevard, the more frequent droughts which affect the granite as concentrations in layers of mica schist and est thickness of the marble shown in this region at which point recent cutting is well under way. regions. In the granites, also, the schistose planes mica gneiss, as vein deposits with quartz, and as is near Fletcher, about 250 feet. At all other Where the stream leaves the quadrangle it is about over large areas dip at small angles and do not con­ vein deposits with epidote and quartz. No deposits points the thickness is much less. 200 feet below the plateau surface. The plateau of duct the rainfall readily into the inferior of the of value have been discovered where minerals were No attempts have been made to utilize the mar­ Pigeon River extends only a few miles into the rock. The gneisses, on the other hand, stand at disseminated in mica gneiss. In this form, how­ ble for building stone, but large amounts have been quadrangle and has not been appreciably lowered very steep angles over nearly all the areas, and thus ever, when weathered, they cause a great deal of taken out for burning into lime. The locality near by recent cutting. The Blue Ridge plateau was the the water is carried into the earth most readily. iron-ore float and limonite stains, forming small Fletcher affords the most available places for quar­ most extensive of all in this region. Its height is Ample time is allowed for this transfer, for evapo­ gossans. These have led to considerable prospect­ rying. The marble there lies along the bottom lands from 3100 to 3200 feet above sea and it was prin­ ration is checked by the forest growth and by the ing work, but without success. Of this character of a small stream, and hard rock comes within 4 cipally developed in the basin of French Broad lower temperatures due to the height of the moun­ are the localities near Lavinia. On Dick Creek or 5 feet of the surface. This would necessitate River, and the basins of Saluda, Toxaway, and tains. In times of flood the streams rise and fall about east of Retreat and on Pigeon River a mile considerable pumping. The dip of the strata at Whitewater rivers on the south side of the Blue quickly, but the usual flow is steady and full. south of Retreat small openings have been made in that point is southeastward at angles ranging from Ridge. Innumerable, springs maintain this flow in spite of quartz veins cutting the mica gneiss. These strike 65° to 75°. At this angle the quarrying of definite During the formation of the French Broad occasional droughts. In the mountains, where rock about N. 30° W. and dip at steep angles toward the beds of marble would not involve handling a great plateau the streams cut down into the Blue Ridge comes close to the surface, most of the springs issue southwest. Small amounts of pyrrhotite and pyrite deal of rock. The rock is usually massive and plateau about 1000 feet and formed a network of directly from the rock. In the valleys and plateaus and traces of chalcopyrite were found, but no deposit fairly free from joints, so that large blocks could be deep canyons. Stream grades in these are usually the residual soils are from 6 to 50 feet thick. The of any value. On Wolf Creek a few miles west of quarried. heavy and small waterfalls are common. Typical water of the springs is largely absorbed by this and Pinhook Gap chalcopyrite occurs in an epidote- seeps out from the clay into hollows. Actual springs LIME. of this is the course of Mills River. This heads on quartz vein associated with pyrite, plagioclase feld­ Pisgah Ridge over 5000 feet above sea, descends are very much fewer on surfaces of this kind, spar, and lime garnet. The vein, about 20 feet Lime for building and agricultural purposes can rapidly to the plateau of the Pink Beds at 3200 which are practically limited to the remnants of the wide, cuts the mica gneiss and runs northeasterly be obtained in this quadrangle only from the mar­ feet, and descends in a narrow canyon to the French plateaus. As was stated under the heading "Geog­ for a considerable distance. Numerous other occur­ ble beds in the Brevard schist. For many years Broad plateau at 2200 feet in about 8 miles. South­ raphy," these plateaus are found chiefly around rences of the epidote-quartz rock are found in that this lime was used, even before the advent of rail­ ward from the Blue Ridge plateau the streams French Broad River and the streams which flow region, but in no case does it constitute an ore. roads. Large quantities have been burned and the descend a little more than 2000 feet to the Pied­ southward from the Blue Ridge. About a mile northeast of Tennessee Gap lies a product has been found excellent. The kilns on mont Plateau. The fall from the upper to the The only use made of the enormous outflow of considerable series of gossans. In one pit 2 feet Boylston Creek furnish material for local use, while lower plateau is extremely heavy in most of the water from this region is for domestic purposes. of iron ore were found, which is the greatest thick­ those at Fletcher ship their product by railroad. streams, many of the smaller creeks accomplishing The houses were built within easy reach of springs, ness shown at any point. Several prospects extend Outcrops of the marble are scarce and are usually it in 4 or 5 miles. Typical of this is South Saluda which was usually possible. On the uplands of the the gossan lead northeastward about a mile, mainly found near streams, so that disposal of waste mate­ Creek. Horsepasture and Toxaway rivers flow 5 plateaus and on the flood plains of streams shallow in the Roan gneiss. Although almost no work has rial and water requires extra expense. or 6 miles along the upper plateau surface and wells were sunk in the clay and gravel. A few been done on this deposit, the indications are better descend with many waterfalls and rapids to the wells have been cut in decomposed and solid rock than anywhere else in the quadrangle. BRICK CLAYS. lower plateau in 8 or 9 miles, an average grade of for depths of 50 or 60 feet, but none have been bored All of the formations in this region form clays considerably more than 200 feet per mile. The to any considerable depth. The town of Waynes­ BUILDING AND ORNAMENTAL STONE. on decomposition. These are of various kinds streams of the Piedmont Plateau are comparatively ville secures its water by damming a small creek Most of the formations of this quadrangle yield pure, sandy, or micaceous and they extend over sluggish and descend in this quadrangle only about about 3 miles northwest of the town. A far better stone suited for building. The best is found in the most of the valleys and lower portions of the quad­ 200 feet in 10 miles. supply can be secured from the head of Alien Creek, Henderson granite, Whiteside granite, and Brevard rangle. In the mountains the amount of clay on The streams which flow northward from Pisgah distant about 6 miles, while from West Fork of schist. the slopes is very small. In the smaller valleys Ridge and Balsam Mountains start at heights of Pigeon River, 13 miles distant, an ample supply of Granite. The two granite formations contain throughout the area, however, more or less clay 5000 and 6000 feet above sea and fall with great the best quality can be obtained. The latter could by far the best and most abundant building is always found. In the'more level portions of rapidity to about 3000 feet, where the beginnings be taken through Davis Gap and delivered to the stone. Neither is very variable in texture, and the region the cover of clay and decomposed of the Pigeon plateau are to be seen. The courses town under a head of about 200 feet. These large quantities of massive, uniform stone can be rock is from 3 to 50 feet thick. The best clay is of these streams lie in V-shaped gorges and the supplies are of the very best quality. The water procured. The Henderson granite yields the found in two situations on the flood plains and amount of water is considerable in each, although is seldom turbid, even after the heaviest rain, and most workable and accessible stone in this region. terraces of the larger rivers and in the small valleys the drainage areas are small. a good flow is maintained by the stream, however Extensive outcrops of the formation are common and hollows on the various plateaus. On the small Thus, there are two situations in which extremely severe the drought. The situation of each catch­ throughout its course, especially near French Broad streams of this quadrangle, except those some dis­ high grades are typical of all the streams. These ment basin is excellent, since it includes a compact

River. »The formation consists mainly of the por- tance southeast of the Blue Ridge, the grades are are the unreduced masses of the Balsam and Pisgah area of mountains from 5000 to 6500 feet in- height,O 7 phyritic granite, which is usually schistose or too heavy to permit the accumulation of clay. Along mountains and the canyons intersecting the Blue where the forest cover is very heavy and the pre­ gneissoid. The rock is gray for the most part, the rivers and larger creeks there are extensive de­ Ridge plateau. Most of the streams thus located are cipitation unusually great. Similar supplies are to either light or dark. The porphyritic feldspar posits in flood plains and terraces. These clays have small, but they drain heavily forested and well- be found in East Fork of Pigeon River, West Fork crystals give a striking aspect to the rock and been used principally near Waynesville, Brevard, watered regions, so that their flow is considerable of French Broad River, Mills River, and Davidson render it suitable for ornamental work. The stone and Fletcher. At the latter point a good-sized and steady. Their extremely high grades concen­ River, all flowing from the Pisgah Ridge. For can readily be opened along the schistose planes, plant is using the clays along the bottom lands of trate the water power within narrow limits and example, the town of Brevard is now supplied from and split into beds of any desired thickness. It Cane Creek. The deposit is 8 or more feet in thick­ render it available at little expense. Kings Creek, a small branch dammed 2 miles from dresses well, and is exceedingly hard and durable. ness and covers many square miles. Its size is even The water power developed in thjs. region is thus the town. A much better supply could be secured The best localities for quarrying are along and exceeded by similar deposits along Mud Creek and obtained, for the most part, by the elevation and from the head of Davidson River, at a distance near French Broad River. In these situations French Broad and Saluda rivers. Into the small cutting of the Blue Ridge plateau. Since the large of about 11 miles. Similar supplies are to be had many large outcrops and cliffs of granite reach the hollows of the old plateau surfaces, also, the finest streams are nearly all below the plateau level those from Toxaway and Horsepasture and various creeks surface and the slopes are steep. Considerable portions of the decomposed rock were washed and water powers which are above the plateau are in flowing southward and eastward from the Blue stone has been quarried at three places shown there e'xcellent clay beds were formed. The total most cases on small streams and of no great Ridge. on the economic map and local use made of it in amount of this kind of material in the quadrangle amount. The heavy grades are due to the back­ bridges and buildings. is enormous. These clays are from 1 to 6 feet deep, ward cutting of the streams, here and there concen­ July, 1906.