By William Clifton Phalen
United States Geological Survey
Government Printing Office, Washington, D. C., 1908
Please note that only a small portion of this book has been reproduced here - only the sections that pertain to the stone industry and related subjects. Also, the page numbers will be included in the "Contents" and "Index" sections for your information, but the book has been re-typed, so the page numbers will not be relevant for this document.
|Importance of the area||9|
|Location and area||9|
|Previous field work||9|
|Present field work||10|
|Roads and farming||12|
|Locks and dams||13|
|General geology of surface rocks||13|
|Character of rock||21|
|Age and relationship||22|
|Mode of representing structure||23|
|Detailed description of structure||23|
|(The sections on coals, clays, and shales, and limestone ores will not included.)|
|(Glass sand, salt, metallic elements, diamonds, oil and gas will not be included.)|
|(Triangulation stations and spirit-level work will not be included.)||130|
|Bibliography (The bibliography will not be included as it pertains mainly to coal.)||151|
By William Clifton Phalen.
Importance of the area.-The Kenova quadrangle is of interest on account of its valuable deposits of coal and fire clay. Of less value are its iron ores, limestones, and building stones. It forms part of a much larger area in which during the last three or four decades there has been much activity in the mining of coal and in the mining and smelting of iron ores. The latter industry has been discontinued, but coal is still being mined. The clay industry in this region is small at present, but should have an important future on account of the amount of available raw material. (See Pl. I, in pocket. This plate is not included with in this document.)
Location and Area.-The Kenova quadrangle includes parts of Kentucky, Ohio, and West Virginia, the name Kenova being coined by combining abbreviations of these State names. Its exact position is shown on the accompany key map (Pl. II). Far the greater part of its 938 square miles is within Kentucky, including the whole of Boyd County, the larger part of Lawrence, and parts of Carter, Greenup, and Elliott counties, Ky. A small part of Wayne County, W. Va., and the south end of Lawrence County, Ohio, make up the remainder. The quadrangle takes its name from a small town, Kenova, lying at the confluence of Big Sandy and Ohio rivers.
The portions of Kentucky and Ohio in this locality are sometimes known as the "Hanging Rock" region, from an outcrop of massive sandstone at Hanging Rock on Ohio River, a few miles below the city of Ashland.
From a geographic as well as a physiographic point of view, this area is a part of the western edge and just north of the center of the great coal field comprised within this province, which extends from north-central Alabama to the southern boundary of New York.
Previous field work.-This area was studied by the geologists of the Kentucky Geological Survey during the latter half of the past century. Most of the work on the coals and general geology in this particular area was done by Prof. A. R. Crandall. Mr. P. N. Moore examined more particularly the geology, distribution, and technology of the iron ores. Dr. I. C. White, director of the West Virginia Geological Survey, has measured sections in that part of the quadrangle which lies in Wayne County, W. Va., and the State Survey of Ohio has worked on the Ohio portion.
In addition to the work of these men special areas have been examined for private parties by geologists and mining engineers.
Literature.-The publications containing the most information on this area are the following:
Crandall, A. R., and Moore, P. N., Report on the eastern coal field: Geol. Survey Kentucky, vol. C, 1884, 77 pp.
The chapter on coals in this publication is also contained in Geol. Survey Kentucky, vol. 2, pt. 1, new ser., 1877, pp. 1-77; the discussion relating to the iron ores of Greenup, Boyd, and Carter counties, or the Kentucky division of the Hanging Rock iron district, is found in the same report, pt. 3, vol. 1, 1876, pp. 59-136.
Shaler, N. S., and Crandall, A. R., Report on the timber growth of Greenup, Carter, Boyd, and Lawrence counties: Kentucky Geol. Survey, new ser., vol. 1, pt. 1, 1876, pp. 1-58.
Survey of Big Sandy River, West Virginia and Kentucky, including Levisa and Tug Forks; House Doc. No. 326, 56th Cong., 1st sess., 1900, 62 pp.
Hoeing, J. B., Oil and gas: Kentucky Geol. Survey, Bull. No. 1, 1905, 233 pp.
White, I. C., Coal report: West Virginia Geol. Survey, vol. 2, 1903, 725 pp.
Stevenson, J. J., Lower Carboniferous of the Appalachian Basin: Bull. Geol. Soc. America, vol. 14, 1903, pp. 36 et seq., 80 et seq.
Steven J. J., Carboniferous of the Appalachian Basin: Bull. Geol. Soc. American, Vol. 15, 1904, pp. 92-114.
Ohio Geol. Survey, vol. 3, p. 1; vols. 5 and 7.
The reader will also get much information from the four volumes of reports of the first Kentucky Geological Survey, made by Dr. David Dale Owen in the years 1854 to 1860, inclusive. These early reports are somewhat discursive, and the information can most easily be found by reference to the indexes under the names of the various counties.
Present field work.-The field work on which this paper is based was done by W. C. Phalen in 1905, from the last of May to the first of November. George H. Ashley spent about two months in the field, visiting with the writer most of the critical areas and doing some independent mapping. David White also visited the field and spent somewhat less time making numerous careful and complete connections, which have furnished in part the basis for the separation of the formations chosen in geologic mapping. Numerous references to the work of Doctors Ashley and White will be found scattered through the text, and an expression of thanks is herewith extended to these geologists for courtesies both in the office and in the field.
Relief.-The part of the Appalachian Plateau included in this region has been greatly dissected, until there is now scarcely any level land within the quadrangle, except the flood plains of the larger streams, like Ohio, Big Sandy, and Little Sandy rivers. This extensive erosion has resulted in sharp ridges, in many caves barely wide enough for wagon roads, and rather narrow valleys with small flood plains reaching well up to their heads. From the tops of the highest hills the remnants of the Appalachian Plateau may still be recognized in the even sky line (Pl. III, A). In a general way this ancient surface, or rather what remains of it, is highest at the south edge of the area, where the highest knobs reach an elevation of 1,200 feet. It slopes gradually northwest, and in the divide between the waters of Tygarts Creek and Little Sandy River only a few of the knobs rise about 1,000 feet. The lowest points in the area are those farthest downstream in Ohio and Little Sandy rivers and on Tygarts Creek. The flood plan of the Ohio ranges from about 530 feet above sea level where it enters it from the east. The flood plain of Big Sandy has an elevation of about 597 feet at the south edge of the quadrangle and 550 feet at the mouth of the stream, showing a gradient of about 1.1 feet per mile. This is slightly less than the gradient of Little Sandy. On Big Sandy the flood plain, though it may in places reach a mile in width, averages between one-half and three-quarters of a mile. The plain of Little Sandy from Grayson to Argillite has a greater average width, but in the upper portion of the river flood plains are wanting, the stream flowing through a gorge formed in the Sharon conglomerate.
The badly dissected character of the region has an important bearing on the exploitation of the natural resources. The railroads were confined during the early part of their history to the main river valleys and had to leave untouched for some time the more remote workable coal and clay beds; on the other hand, the flood plains, which are almost everywhere developed along the streams, are favorable to the construction of spur tracks that will materially lessen the haulage from mine breast to tipple.
Points of equal elevation are represented on the map by contour lines in buff, which are really the intersections of hypothetical plains with the surface of the country. These contour lines are placed 100 feet apart and, when carefully studied, enable the mind to grasp fairly well the general "lay of the land."
Drainage.-The drainage of this quadrangle is either directly or indirectly into Ohio River, which crosses its northeastern corner. The chief tributaries of Ohio River are Big and Little Sandy rivers and Twelvepole and Tygarts creeks, the last named flowing across the extreme northwestern corner. Twelvepole Creek, entering from the Huntington quadrangle on the east, flows about 10 miles in a circuitous course in West Virginia and empties into Ohio River at Kellogg. Practically all the smaller streams flow into Big and Little Sandy rivers. Of these streams Big Blaine, a tributary of Big Sandy with an estimated length of about 70 miles almost wholly included within this quadrangle, and East Fork of Little Sandy are the most important. The Big Sandy, which in conjunction with Ohio River is the main drainage course of the area, is formed by the confluence at Louisa of Levisa and Tug forks. After flowing northward for 27 miles, it empties into Ohio River at Catlettsburg. Levisa Fork is often called Big Sandy.
Roads and farming.-Though from the farmer's point of view this area is rough, it is completely intersected by fairly good country roads, and the construction of which is facilitated by the fairly soft character of the rocks. The roads of Boyd County are notably well kept.
Notwithstanding the comparatively rugged character of the country, it is under general cultivation. The flood plains of the streams, which are subject to periodical overflow, are on this account very fertile. Along the valleys of the larger streams some wheat is grown, but corn is the principal crop. In Carter County many of the hillsides are given to the cultivation of tobacco. These crops, with the usual garden truck, constitute the principal products of the soil. The timber resources of this area are of little or no importance. Most of the big timber was removed during the days of the old charcoal iron furnaces, which flourished during the seventies and early eighties.
Railroads.-Most of the railroads are confined to the larger stream valleys. The main line of the Chesapeake and Ohio Railway enters the area from Huntington, W. Va., and crosses Big Sandy River at Hampton, keeping along the south bank of Ohio River. The Big Sandy division of this line, formerly known as the Chatteroi Railroad, follows the west bank of Big Sandy River. During the summer of 1905 the old wooden railroad bridges were being replaced by substantial stone culverts, curves were being straightened, and general improvements were under way in preparation for an expected increase in the freight traffic from the Elkhorn and other coal areas near the headwaters of Levisa Fork. The Louisville and Lexington division of this railroad crosses the area diagonally from northeast to southwest, leaving the main line at Ashland. The coal mined at Straight Creek, Grant, Rush, Princess, and Winslow is carried by this line or by the Ashland Coal and Iron Railway, which is that portion of it between Rush and Ashland. The Norfolk and Western Railway has recently built a line down the eastern bank of Big Sandy connecting it with Twelvepole division and crossing Ohio River at Kenova. The new line is so much superior to the old in grade and general character that much of the coal from the headwaters of Tug Fork is now hauled over the new division. The Baltimore and Ohio Railroad has a terminus at Kenova. The Eastern Kentucky Railway, a short line constructed several years ago, has its southern terminus at Webbville, Lawrence County, and its northern terminus at Riverton, Greenup County, where it joins the Chesapeake and Ohio Railway. It carries staves, ties, etc., from the Blaine country and coal from its mines at Partloe, Boghead, and Hunnewell, as well as clay from the mines at Willard.
Locks and dams.-Big Sandy River has been under improvement by the United States Government since 1878. The plan of improvement adopted by Congress on March, 1899, contemplates carrying slack water as far as Pikeville on Levisa Fork, and to the mouth of Pond Creek on Tug Fork by the construction of 22 locks and dams. Within the limits of the Kenova quadrangle there have been built already three locks on Big Sandy below Louisa, one on Tug Ford at Saltpeter, and one on Levisa Fork on Chapman. By the aid of the dams the river will be navigable the whole year, instead of only about eight months, and the present commerce, chiefly in saw logs, cross-ties, staves, etc., will be largely augmented as a result of the cheaper water transportation. The development of the thinner coals within the Kenova area and in larger measure the thicker beds near the headwaters of the river will be aided. The navigable season of the smaller streams is so short that it will probably not aid materially in the development of the mineral wealth of this area. These streams are used chiefly in transporting logs and ties.
All the rocks appearing at the surface within the limits of this quadrangle, with but a single exception, are of sedimentary origin and were laid down in or by water. They consist of sandstones, shales, limestones, coal beds, and iron-ore deposits, and have a total thickness of between 1,100 and 1,200 feet. All of these sedimentary rocks belong to the Carboniferous system, except the imperfectly consolidated gravels of the river terraces, which are of Pleistocene age, and the alluvium of the flood plains. The subdivision of the Carboniferous in the northwest portion of the Appalachian coal field, which was proposed by Henry D. Rogers in the reports of the First Geological Survey of Pennsylvania, has been accepted and followed at least in its main features, by all the geologists who have subsequently worked in the territory to which this subdivision applies. The coal-bearing rocks have been followed from Pennsylvania into Ohio, and then southward in Ohio to Jackson County, and from this county into Scioto and Gallia counties, and through them into and across Lawrence County to Ohio River. Thus the stratigraphy of the "Coal Measures" of western Pennsylvania is brought into the northeastern corner of the Kenova quadrangle. The carboniferous system, as developed in this quadrangle, consists of parts of the Pennsylvania and Mississippian series. The former contains the workable coals of this area. The rocks will be described in descending order, beginning with the youngest.
Recent deposits.-The alluvium of the streams of this area is the youngest bedded deposit and has considerable commercial importance. It makes up the flood plains of both the large and the small streams, extending well up to their heads. The larger streams, like Ohio, Big Sandy and Little Sandy rivers, have deposits of this material fully 50 feet thick. Along Ohio River the width of this flood-plain deposit ranges from three-fourths of a mile to a mile, but on Big Sandy and Little Sandy rivers these deposits are not quite so wide. The material is being constantly cut out and redeposited by variations in the currents at each period of high water. The mode of utilization of these flood-plain deposits will be indicated in connection with the description of the clays (p. 120).
Pleistocene deposits.-None of this region lies within the glacial boundary, but there are deposits within the area which are considered of Pleistocene age. Just back of the city of Ashland is a district known as the Flatwoods, where the hills are flat and do not rise to an altitude of over 700 feet. These flat lands are covered with deposits of sand, gravel, quartz, and chert bowlders, some of which are 12 inches in diameter. These represent residual material from the remains of older crystalline rocks of the Blue Ridge to the east. This deposit may be traced fairly distinctly up Big Sandy River to the south of Louisa, maintaining its general elevation of about 150 feet above the present flood plain of the stream. These gravel deposits may, and do in places, represent the valleys of streams which long ago ceased to flow through them. The proof of this statement lies in the rounded character of the bowlders and in certain topographic features usually associated with streams. Among the more conspicuous features of the remnants of these old, high-level valleys are their well-graded walls and the maturity indicated by their flat-bottomed floors. This floor in the Flatwoods area is nearly a mile wide. The old drainage channel represented by the Flatwoods is regarded by W. G. Tight as a continuation of the preglacial Teys River.
Similar deposits have been found on the Little Sandy at elevations closely approximating those of the Big Sandy, and though the correlation of the two deposits has not been attempted, it is probable that the benches and their associated gravels on Little Sandy, when traced up Ohio River, will merge into those on Big Sandy. Silt associated with quartz pebbles has been discovered at lower elevations on Little Sandy, indicating a quiescent condition of the water with periods of deposition while these ancient streams were probably subsiding. Since these deposits, as developed in the Kenova quadrangle, have no economic significance, they will not be considered further.
Plate III - A. Ohio Topography,
showing level sky line.
Plate III - B. Mahoning Sandstone,
Little Ice Creek, Lawrence County, Ohio.
Monogahela formation.-The Monogahela in Pennsylvania was first termed the "Upper Productive Measures," since it marks an epoch in which several workable beds of coal were deposited. The base of the formation is marked by the Pittsburg coal. In accordance with Dr. I. C. White's correlation, the coal at the top of the hills east of Lett, near the mouth of Gragston Creek, West Virginia, is accepted for the time being as the Pittsburg coal and as marking the base of the Monongahela formation. The area underlain by the coal does not exceed a few acres, and the formation is represented by 100 feet of shales with a massive sandstone at its base. No important coals are found in it except the Pittsburg bed.
Conemaugh formation.-The Conemaugh includes the rocks lying below the Pittsburg coal and above the Upper Freeport coal. What is regarded as the Upper Freeport coal with its overlying massive Mahoning sandstone is well exposed below Louisa in the vicinity of Zelda, and on Blaine Creek near Fallsburg. Above the sandstone which forms the roof of the Upper Freeport coal, and which varies in thickness from 20 to 30 or more feet, the rocks are in marked contrast with the rocks below, both in character and in the number and importance of the coal beds. The massive sandstone is probably the same as that which overlies the Waterloo, Bayleys Run, No. 7, or Upper Freeport coal of the Ohio geologists, and which makes such a striking appearance along the banks of Big Sandy River near its mouth. The coal at its base in Lawrence County, Ohio, is regarded by the geologists of that State as higher than the Hatcher or No. 8 coal of the Kentucky reports.
The position of the coal under consideration, which north of Louisa is immediately below a massive sandstone, the Mahoning of Owen, is strong evidence that it corresponds more probably with the coal above the Hatcher bed. Crandall, however, in his report on the geology of Greenup, Carter, and Boyd counties, explicitly states that coal No. 8 of the Kentucky survey is the first coal below the Mahoning sandstone of Owen, and follows the statement with the words that this coal is commonly known as the Hatcher seam. In another place he states that above the shales containing coals Nos. 7 and 8 occurs a coarse ferruginous sandstone, the Mahoning of Owen and Lesquereaux. In this sandstone and its overlying rocks are found coals Nos. 9, 10, 11, 12, etc. However, J. J. Stevenson, in his description of the Allegheny formation in Kentucky, interprets Crandall's generalized section of Greenup, Boyd, and Carter counties as placing coal bed No. 9 below the Mahoning sandstone.
In view of the evidence outlined above, the coal which has been opened below the massive sandstone exposed near Zelda and Fallsburg is regarded as the Upper Freeport and as the first bed above the Hatcher coal or No. 8 of the Kentucky reports. Normally, therefore, it would be No. 9 of the Kentucky series, and instead of coming within the Mahoning sandstone would occur just below it, as in Pennsylvania.
The minimum thickness of the Conemaugh formation is between 300 and 400 feet. It is almost entirely exposed only in a small area near the center of the basin in the hills east of Lett, W. Va. This may be due to a possible local thinning of the formation, for at other points near the center of the basin, west of Big Sandy River, where the hills rise as high, nothing is apparently known of the existence of the Pittsburg coal. If the thickness of the Conemaugh formation, 300 to 400 feet, obtained under the assumption that the coal in the hilltops near the mouth of Gragston Creek, West Virginia, is the Pittsburg bed, is compared with the thickness of that formation at Charleston and Huntington given by I. C. White, some question may be raised as to the correctness of the identification of the Pittsburg bed. White makes the Conemaugh 800 feet thick at Charleston and 660 feet at Huntington. However, the correctness of his identification of the Upper Freeport coal at Charleston has been questioned, both David White and J. J. Stevenson placing the Upper Freeport well above the black flint, thus reducing the thickness of the Conemaugh formation to a little over 600 feet. G. H. Ashley has been inclined to reduce it to 530 feet or less. The section of the Conemaugh formation obtained by the Ohio geologists in Lawrence County, Ohio, is only 420 feet thick, suggesting a westward thinning of the formation, which is in full accordance with the westward thinning known to take place in going from Pennsylvania across the panhandle of West Virginia into Ohio. If the coal in the Kenova quadrangle is the Pittsburg bed, the thickness of the Conemaugh is much less than it is to the northeast at Huntington and slightly less than the Ohio geologists make it.
The rocks of the Conemaugh are mainly red or greenish shales, with beds of limestone and iron ore and in some localities important beds of sandstone. The fact that it contains no workable beds of coal, together with the sharply defined character of its rocks as contrasted with those of the formations above and below, serve in part as a basis for making it a separate formation. The members of the formation in this area are generally irregular in their development and are on this account poor guides in unraveling the stratigraphy. The basal member, however, which is the Mahoning sandstone, is very persistent and hence a valuable guide in tracing this formation. (See Pl. III, b.) Above this sandstone at variable intervals occurs a rather persistent limestone, one of the Cambridge limestones, which is usually capped by a cliff-making sandstone. These two massive sandstone members occurring near the base of the Conemaugh serve to clearly demark it in most localities from the underlying rocks, the more so because the succeeding higher rocks are usually red shale. In some parts of the quadrangle, notably near the mouth of Big Sandy River, the basal sandstone is unusually thick and massive, attaining near Kenova a thickness of 70 feet, and is continuous, with but a few irregular intercalations of shale, east of Ceredo, south of which it becomes even more massive and attains a thickness of 100 feet. Above this sandstone there is usually a small coal, which may be the Brush Creek coal of Pennsylvania. This is an unimportant bed, though it has been worked in the hills opposite Louisa. It will probably not be of any great commercial importance in the near future. The Cambridge limestone overlying the Brush Creek coal is a very persistent member and is a most valuable guide in tracing the rocks of the Conemaugh. In many places it consists of two members, an upper and a lower, as shown by the section obtained near the bed of Whites Creek, about 1 mile west of Potomac (p. 131).
In the western part of the quadrangle, near Willard, this limestone usually occurs as a single layer. At Willard it is found near the hilltops 180 feet above coal No. 7, but the interval above this coal is in some places slightly less than that. This limestone has a very characteristic appearance, and, owing to the fact that it is highly siliceous, it withstands weathering, and can usually be found at its proper horizon. Almost directly above it occurs a small bed of coal, locally workable. Overlying this coal at a varying interval is a massive sandstone. The distance between the base of this sandstone and the limestone ranges from 10 to 40 feet, but averages about 35 feet. This sandstone is rarely more than 25 to 30 feet thick, but is usually massive and coarse grained, and makes prominent outcrops. Capping this sandstone is a mass of red shale, near the base of which occurs a small bed of coal. The remainder of the Conemaugh is prevailingly red, and for the most part the rocks are shales or shaley sandstones with a few bands of Massive sandstone. (See Pl. III, B.) The formation contains practically no workable coal.
Allegheny formation.-The Allegheny formation underlies the Conemaugh and is about 180 feet thick in the northern part of the quadrangle, but in places it varies considerably from this thickness, as in the southern part of the area, where the thickening of the Homewood sandstone seems to have interfered with the normal development of the Allegheny. The top of this formation is the top of the Zelda coal, which is believed to correspond to the first bed above the true Hatcher coal of Ohio, and hence to be the Upper Freeport coal Ohio and normally No. 9 of the Kentucky series. The base of the formation is demarked from the underlying rocks both on paleontologic and lithologic grounds. It is the base of coal No. 5 of the Kentucky series, which according to Stevenson corresponds to the Brookville coal of Pennsylvania. This coal lies practically at the top of a massive sandstone in the Kenova quadrangle, which is regarded as the equivalent of the Homewood sandstone at the top of the next lower (Pottsville) formation. In the western part of the quadrangle, though all the more constant members of the Allegheny are present, the formation seems to be thinner than in the region around Ohio River and to show considerable variation. On one side of the hill west of Willard it is about 130 feet thick, but on the other side it is less than 100 feet. It should be noted that in this district the Homewood sandstone thickens to 100 feet, and in general it may be said that throughout the area the Allegheny formation tends to become thin as the underlying Homewood sandstone thickens. This formation was known in Pennsylvania as the "Lower Productive Measures," from the fact that it is the lower of the two groups of rocks containing valuable coals. It also contains a valuable clay deposit in this part of Kentucky. In addition it contains beds of sandstone, shale, iron ore, and limestone. Unlike the formation on which it rests, it is, as a rule, not decidedly sandy, and the character of its fossil plants is so distinct from that of the plants in the Pottsville as to warrant its separation as an independent formation.
The number of coals present in the Allegheny formation is usually not more than six, and in many places not more than four. The lowest coal, No. 5 of the Kentucky Survey, lies directly on the Homewood sandstone. It is locally of workable thickness.
An important member in this formation has been called the "Ferriferous" limestone by Andrews in the reports of the Ohio Geological Survey, and the "Hanging Rock" limestone by Orton. It is the equivalent of the Vanport ("Ferriferous") limestone of western Pennsylvania, and that name will be used in this report.
It usually lies from 10 to 20 feet above the top of the Homewood sandstone, and is found at its top in many places where coal No. 5 is absent. It is generally associated with an important clay bed, and on this account has an economic interest. This clay ranges in thickness from 4 to 6 feet. The next higher economic member in this formation is the No. 6 coal of the Kentucky section, known in the region about Ashland as the "Limestone coal" and in Ohio as the "Newcastle coal." It is commonly found 20 feet above the Vanport "Hanging Rock") limestone.
The next higher coal is the Coalton, or the No. 7 of the Kentucky Geological Survey, or the No. 6 or Sheridan coal of Ohio. This is the celebrated Nelsonville coal of the Hocking Valley. It is the most important bed in this area at present and is found from 25 to 45 feet above coal No. 6 and from 40 to 50 feet below coal No. 8, the next higher bed in the formation. This coal No. 8 is workable in parts of the quadrangle, but is as yet comparatively unimportant. From 40 to 50 feet higher in the scale is coal No. 9, which like the coal below it, is generally a thin bed and only locally workable.
Besides the coals and fire clays of economic importance in this formation, various beds of iron ore occur. These formerly had considerable importance, but at present have little or no value, as the cheaper ores of Lake Superior and Alabama have entirely replaced them in the market. The general sections (Pl. IV and fig. 20) show the beds of economic interest and the intervals between them.
Pottsvilleformation.-The Pottsville formation is the lowest in the Pennsylvanian series. Its base is the top of the Mississippian series, on which it rests unconformably, and it comprises all the rocks to the top of the Homewood sandstone. This formation is separated from that lying below and from that above on both lithologic and fossil evidence. The entire formation is exposed in the northwestern part of the quadrangle, where it has a thickness of between 350 and 400 feet. In the southeastern part of the area it has a thickness of at least 600 feet, and along the southern edge it must be fully as thick. General sections showing the character of the rocks of this formation, as exposed at different points of the area, are given in Pl. IV. The rocks of this formation are decidedly sandy, but contain occasional beds of shale, iron ore, limestone, and coal. Owing to its thickening in the southeastern part of the area and the introduction of coal beds not represented in the section in the western part of the field, the lowest coals in the area are believed to appear in the section along Levisa Fork near Gallup. There are three or four of these beds, and the thickest of them is not over 2 feet at any point. The higher coals in this formation are all locally workable and have been numbered by Prof. A. R. Crandall (Pl. IV). There are usually four fairly thick coal beds in this formation, but at some points this number may be increased to five or even six. Detailed descriptions of these coals, together with the intervals which separate them, are given under the headings of the various districts.
The Pottsville formation also contains some very valuable beds of fire clay. Most noteworthy of all is the bed occurring only a few feet above the top of the Maxville limestone. This is the celebrated Sciotoville fire clay of Ohio. Though it outcrops over a very small area in this particular quadrangle, it has considerable economic importance to the west, and it is being mined at present on a large scale in the vicinity of Olive Hill. Other beds of fire clay in this formation are locally workable, notably the bed associated with coal No. 4, which has been worked in the eastern part of Ashland and on Catletts Creek. Nearly one-half of the entire surface of this quadrangle is covered by rocks belonging to the Pottsville.
The Mississippian series is represented by a massive limestone, called in the Kentucky reports "Sub-Carboniferous limestone," and in those of Ohio the Maxville limestone. About 100 feet of the Waverly group is also present. The outcrops of the limestone are confined to the western part of the area and are limited in extent. West of Tygarts Creek, in Greenup County, this rock is present in the hills. Here it does not exceed a thickness of 25 feet, being underlain by 100 feet of sandstone and shale belonging to the Waverly. A small outcrop of limestone is found at the bend in Everman Creek, Carter County, just above the mouth of Wolfpen Branch, and again farther up the creek, just at the edge of the quadrangle. The limestone in this part of the field does not exceed 15 or 20 feet in thickness. It is usually overlain by a thin band of iron ore. This limestone is encountered in all the deeper borings for oil, in both the eastern and western parts of the quadrangle, and reaches in places a thickness of several hundred feet. The total thickness of the Mississippian rocks outcropping in the western part of the area does not exceed 150 feet.
Occurrence.-Igneous rocks in this quadrangle were noted by Professor Crandall many years ago. They are found in the hills on each side of Ison Creek west of Stephens, Elliott County, and about 8 miles southwest of Willard. The region was visited by J. S. Diller, of the United States Geological Survey, in 1884, and as a result of this trip a very detailed account of the occurrence and petrography of these rocks was published. The rock is peridotite, and owing to this fact is of more than usual interest, first, because it bears a resemblance to the peridotite of South Africa, the mother rock of the diamond, in the Kimberley district; and second, owing to the relative scarcity of this type of igneous rock and to a possible relationship to the mica peridotite of western Kentucky. In another publication Mr. Diller has applied the name of kimberlite to this rock from its resemblance to the South African rock.
Extent.-The area covered by the rock is very small, not more than a few acres. The outcrops of the solid ledge are not numerous, but their original extent is not difficult to trace, owing to the characteristic minerals resulting from weathering. There is no apparent reason why the various isolated masses should not be considered parts of a single intrusion, as all appear identical in mineral composition.
Character of rock.-The groundmass of this rock is compact, grayish black in color, and porphyritic. It is plentifully specked with phenocrysts of olivine, which appear to be very fresh and unaltered and give a grayish tinge to the rock. Garnet (pyrope) and titanic iron ore (ilmenite) are also easily detected and in the field were found to be of great assistance in tracing the boundaries of the decayed ledges. Sections of biotite are not uncommon. Besides these constituents, which are readily detected in the hand specimens, the chief remaining minerals are enstatite and a small amount of apatite. In places the olivine has been altered to serpentine, which may be readily seen in hand specimens, and which in thin section is associated with magnetite and some carbonate, presumably dolomite resulting from the alteration of the olivine. This rock has been so thoroughly described by Diller, and its peculiar characteristics are so well pointed out in his publication, that it will not be further considered here.
Age and relationship.-The sedimentary rocks through which the igneous rock has forced its way are traceable and practically up to the contact and strangely enough do not appear to have been even flexed upward along this zone. Though the igneous rock has broken off masses of shale, which are now found embedded in it, this is surprisingly fresh and unaltered, like the ordinary black shale of the Pennsylvania series. Only in a few cases are metamorphic effects markedly visible. In some of the baked shale secondary mica was seen in considerable quantity. The color of the shale had been somewhat reddened and the sandstone and limestone fragments, which were inclosed by the igneous rock, had been baked and the latter converted to quicklime.
The sedimentary rocks in which the bulk of the igneous rock is found belong to the Pottsville formation, but as some of the igneous rock is found in the Allegheny, the intrusion is Allegheny or post-Allegheny in age. It was forced into the carbonaceous shale and coal beds found in this formation, and, owing to the fact that the Kimberley diamonds occur in peridotite penetrating carbonaceous shale, more than ordinary interest attaches to the Elliott County occurrence of Peridotite. This interest has led to the prospecting of streams in the neighborhood, and also to the sinking of a shaft 70 feet deep, which at the time of the writer's visit (October, 1905) was filled with debris. During the spring of 1906 it was reported that another prospect shaft was being sunk. As to the presence of diamonds the writer has no authentic information.
Mode of Representing Structure.
The inclination of the beds to a horizontal plane, or the dip of the beds, as it is commonly called, is measured in the field by means of a clinometer when the inclination is great enough to be susceptible to this method. In but few localities, however, in the Kenova quadrangle are the dips sufficient to allow this mode of measurement. Where this method is not applicable continuous road sections are run and the beds are correlated from hillside to hillside. When the elevation above mean sea level of a given sandstone, coal, or limestone on one hill and its elevation a mile or so away have been found, the rise or fall of this particular bed in feet per mile is at once obtained. By connecting points of equal elevation on any selected bed the contour lines of that bed are drawn. On the map, Pl. I, the contour interval is 50 feet and all points having altitudes that are multiples of 50 were connected by black lines. For instance, in drawing the 600-foot contour line those points in the area where the datum selected (the top of the Homewood sandstone) reached this elevation were connected, and likewise for the other contour lines.
The top of the Homewood sandstone was selected in this area, on account of the ease with which this bed may be followed, owing to its persistence and relations to other well-known horizons. Where it failed to appear above drainage, its distance below other known beds were used, assuming, of course, that the distance was constant within the limited area where this means was employed. Conversely, when the dips were such as to carry the top of the Homewood above the hilltops its distance above known beds was applied. However, great precision was not obtainable, as such intervals are subject to variation all over the region, and especially in the areas covered by the formations above the Homewood. Furthermore the elevations were obtained by means of aneroid barometers, which are liable to sudden variations and have to be constantly checked against spirit-level elevations. In spite of these sources of error, it has been though advisable to draw structure contour lines. These show the generalized surface formed by the top of the Homewood sandstone, and, less precisely, the lay of the overlying and underlying beds. The limit of error may generally be considered a contour interval, but where the beds vary in thickness as they do in this area it may be more. This mode of presentation, in addition to showing the structure of the beds, enables us to estimate the elevation of the top of the Homewood sandstone when it is below drainage. For instance, near Zelda the 400-foot contour line was drawn. The elevation of Zelda is 580 feet above mean sea level; therefore, the top of the Homewood sandstone should be at a depth of 180 feet. The distance of various coal beds above or below the top of this sandstone being known, their depth below the surface may in turn be estimated at this point.
Detailed Description of Structure.
This quadrangle lies at the southwest end of the great trough formed by the coal-bearing rocks of the Appalachian field. The axis of the trough extends southwest from near Pittsburg, Pa., and the trough reaches its maximum development near central West Virginia. From this point southwestward the axis slowly rises, crossing Ohio River a little east of the quadrangle and reaching Big Sandy River from 8 to 10 miles above its confluence with the Ohio. The axial line follows Big Sandy River southward for 2 miles and gradually curves to the west, pitching upward along a line practically coincident with the boundary between Carter County and Elliott and Lawrence counties. The beds south of the axial line dip north and northwest, and northwest, and those on the northern side dip southeast. The dips over most of the area are not very steep. In the northern two-thirds of the quadrangle the dips, with a few exceptions, do not average as high as 50 feet per mile. Near Catlettsburg the upper part of the Pottsville formation is exposed at railroad level, but across Big Sandy River the lowest rocks exposed in the cliffs along the Norfolk and Western Railway are the lower sandstone members of the Conemaugh formation; thus a dip of more than 50 feet per mile is involved between these points. Near Willard and southwest of this town in Carter County the dips are above the average, being close to 100 feet per mile. The steepest dips are confined to the southern third of the area. This belt of sharp dips is about 6 miles broad south of Louisa, but it narrows westward until at Blaine it is not more than a mile in width. West of this town the beds curve gently northwestward around the head of the basin. The dips in the ridge south of Louisa are fully 100 feet per mile. Near Adams and on Right Fork of Blaine Creek the rocks in places dip 300 feet per mile. The steepest dips in the area are near the mouth of Hood Creek in the eastern part of the town of Blaine. At the bridge over Hood creek the beds are inclined 11 degrees, and near this point two small faults were discovered by Mr. Ashley, but their throws are probably not great enough to materially affect the structure contours.
A few minor flexures are involved in the main syncline. In the region near Irad and Osie, Lawrence County, the Homewood sandstone thickens toward the west very rapidly, causing a slight arch in the overlying beds, but west of this district the sandstone is somewhat thinner and causes a slight depression. West of Cherokee Creek, approaching Elliott County, the structure seems to be rather irregular. This may be more apparent than real, and the irregularity in the contours may be due to the fact that they are based on but few outcrops and that the underlying sandstones, which might serve as a guide, thicken and cut out the coal beds. The flattening of the beds to the west is due to the dying out of the Appalachian folds as the Cincinnati arch is approached. West of this quadrangle the beds gradually rise to the apex of this arch, and this gradual rise is indicated in the contours west of Little Sandy River.
In an area of sedimentary rock, like the Kenova quadrangle, in which the chief deposits are sandy or clayey, it is useless to attempt to find such metals as gold, silver, and lead in paying quantities. Small amounts of lead, zinc, and iron sulphides do occur in the clay-limestone concretions in the shales of the Carboniferous system, but the amount of such material is so small as to be entirely negligible, and time devoted to the search for the previous and base metals will be fruitlessly spent. On the other hand, the coal and fire-clay beds may repay more careful prospecting than has heretofore been given them, and perhaps to a less extent this is also true of the alluvium of the stream beds, the shale, the limestone, and the sandstone beds.
(The sections on coal, clays and shales, and iron ores are not included in this document.)
Brief descriptions have been given of two limestones, the Vanport ("Hanging Rock") limestone near the base of the Allegheny formation and the Maxville limestone underlying the Pottsville. The Conemaugh contains higher beds of limestone, a few of which are persistent and are hence of value in unraveling the stratigraphy. Some of these beds are also of local economic importance.
The lowest limestone in the Conemaugh is the most persistent of all. It usually lies very near the top of the Mahoning sandstone, or, rather, the group of sandstone lying at the base of the Conemaugh formation. It is very widespread, but not everywhere a typical limestone in its development. Along Big Sandy River it may be traced rather continuously from the mouth of Dock Creek to Roundbottom. At some points along this stretch it is a calcareous sandstone 4 to 5 feet thick, containing abundant crinoid stems and other fossils. About one-eight of a mile below Lockwood on the Kentucky side it has much the same character, but here it is weathered and dark in appearance and crumbles easily under the hammer. In the hills back of Cassville it is a fossiliferous shale and is closely underlain by a thin bed of coal, called the Mason coal by I. C. White, and probably correlating closely with the Brush Creek coal of western Pennsylvania. Throughout the southern part of Boyd County it is very persistent, but much of it is too sandy to burn for fertilizer. In the hills east and west of Willard and on most of the streams flowing into Little Fork from the east it is 4 to 5 feet thick. In this region it is siliceous and does not react with acid on the weathered surface, but on being broken it is found to contain much lime. At Willard it occurs 180 feet above the Coalton coal and about 230 feet above the Vanport limestone. When burned this limestone will probably yield a fairly satisfactory fertilizer. This limestone is probably the representative of one of the Cambridge limestones of the Ohio Geological Survey. The horizon is in many places characterized by two calcareous beds lying a small distance from one another, as indicated in the following section:
|Section of Cambridge limestone 1 mile west of Potomac on Whites Creek.|
A short distance away, near the residence of J. L. Bowling, the following section was measured:
|Section of limestone near residence of J. L. Bowling, west ofPotomac, Ky.|
The fossiliferous sandstone and the limestone lying from 14 to 23 feet below may represent the upper and lower Cambridge limestones of Ohio.
About 80 to 100 feet above the Cambridge limestone is another limestone, also largely siliceous, which probably corresponds to the Ames of the Ohio and Pennsylvania surveys. It is seen at many places on the headwaters of East Fork of Little Sandy and is rather persistent in the hills east and southeast of Cassville, W. Va. In the latter region much of it is characterized by calcareous pebbles on its outcrop. This limestone is possibly valuable for fertilizer and may repay careful prospecting. Other limestones have been observed higher in the Conemaugh at 70 and 120 feet above the Ames. These higher Conemaugh limestones are generally characterized on their outcrops by the presence of a few limestone pebbles. Like the lower limestones, they may prove locally valuable.
The only rock suitable for building stone in this area is sandstone, and of this there is a great abundance. As a rule this rock will not bear the cost of transportation, but as a local building stone it has proved of value in the construction of culverts for the railroads which pass through the area and also in the construction of chimneys, fireplaces, etc., all through the country. Some of this sandstone has also been used in the construction of dwellings. Very little of it, if any, can be cut into blocks of any considerable dimensions, but for rougher purposes it serves as a cheap and very accessible source of supply.
Most of the sandstone in this area is micaceous, much is feldspathic, and as a rule it contains iron oxide. It ranges from very fine-grained to conglomeratic, in which few of the quartz pebbles exceed an inch in their largest dimension. A large amount of this sandstone is friable, disintegrating readily to fine sand. Such rock was used in the construction of a residence and of a building Ashland, and so far as known proved satisfactory. It would appear, therefore, that freshly cut blocks, even of this friable sandstone, season fairly well and become resistant.
In the Conemaugh formation the most important sandstone lies at its base and is known as the Mahoning sandstone. This sandstone is well exposed along Big Sandy River near its mouth, in both Kentucky and West Virginia. Near Kenova it appears to be thick bedded enough to supply dimension stone. At this point, besides being very massive, it is very coarse grained and locally conglomeratic. It has been used by the Norfolk and Western Railway in this locality. To the south, up Big Sandy River, it is above drainage level nearly to the mouth of Dock Creek in West Virginia and to Savage in Kentucky. In building the Norfolk and Western Railway and in the recent changes in grading the Chesapeake and Ohio Railway much of this rock has been used. A higher sandstone in the Conemaugh formation has been quarried for local purposes on Whites Creek, near Egypt. The Conemaugh also contains other sandstone beds which, though suitable for local purposes, are not sufficiently valuable to export.
Sandstone from the Allegheny formation has been used along Ohio River opposite Ashland. At this point the sandstone above the Coalton coal thickens abnormally and has been quarried by the Norfolk and Western Railway for use along its line. It has furnished much rock of fair dimensions.
The Pottsville formation contains many sandstones of considerable thickness, much of which has been used in the construction of the Norfolk and Western Railway along Tug Fork, and by the Chesapeake and Ohio Railway on Levisa Fork. The Homewood or upper sandstone member of this formation outcrops near Ashland and occurs as a very massive cliff between the eastern limits of the city and Cliffside Park. The rock has been used with very satisfactory results in the construction of dwellings. Lower sandstone of the Pottsville have proved locally valuable.
 Economic Geology of the Kenova Quadrangle, Kentucky, Ohio, and West Virginia, 1908, pg. 14 footnote: Vol. 2, pt. 1, 1858, p. 16, et seq.
 Ibid., pg. 15 footnote: Prof. Paper U. S. Geol. Survey No. 13, 1903. For a very complete description of Teays River to the east of this area see M. R. Campbell, Description of Huntington quadrangle; Geologic Atlas U. S., folio 69, U. S. Geol. Survey, 1900, pp. 2-3.
 Ibid., pg. 15 footnote: West Virginia Geol. Survey, vol. 2, 1903, pp. 191-192. See also pp. 16-17 of this bulletin.
 Ibid., pg. 15 footnote: Kentucky Geol. Survey, vol. C, 1884, p. 60.
 Ibid., pg. 16 footnote: See section by E. McMillan, Ohio Geol. Survey, vol. 5, 1884, p. 122.
 Ibid., pg. 16 footnote: Kentucky Geol. Survey, vol. C, 1884, p. 24.
 Ibid., pg. 16 footnote: Idem. pp. 9, 10.
 Ibid., pg. 16 footnote: Bull. Geol. Soc. America, vol. 17, 1906, p. 128.
 Ibid., pg. 18 footnote: Bull. Geol. Soc. America, vol. 17, 1906, p. 128.
 Ibid., pg. 19 footnote: Ohio Geol. Survey, vol. 3, pt. 1, 1878, pp. 885 et seq., 892 et seq.
 Ibid., pg. 21 footnote: Bull. U. S. Geol. Survey No. 38, 1887.
 Ibid., pg. 21 footnote: Williams, G. H., Am. Jour. Sci. 3d ser., vol. 34, Aug. 1887, p. 137.
 Ibid., pg. 21 footnote: Bull. U. S. Geol. Survey No. 150, 1898, pp. 290-294.
 Ibid., pg. 130 footnote: West Virginia Geol. Survey, vol. 2, 1903, p. 280.