Presented by Title Before the Society, December £9, 1906)
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BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA Vol. 18, pp. 29-178 April 9,1907 CARBONIFEROUS OF THE APPALACHIAN BASIN * BY JOHN J. STEVENSON (Presented by title before the Society, December £9, 1906) CONTENTS Page Monongahela formation ............................................................................................... 30 Correlation ............................................................................................................... 30 East from the Alleghenies................................................................................... 45 Broad Top ........................................................................................................ 46 Maryland ......................................................................................................... 46 West from the Allegheny mountains, in Pennsylvania............................ 47 The First and Second bituminous basins............................................. 47 The Blairsville-Conncllsville basin............................................................ 60 The Greensburg basin.................................................................................. 64 The Lisbon-Irwin basin................................................................................ 54 The Waynesburg basin................................................................................ 58 The western basins in Pennsylvania....................................................... 60 The northern panhandle of W est Virginia..................................................... 64 Ohio ............................................................................................................................ 66 West Virginia ......................................................................................................... 81 The Dunkard formation................................................................................................ 95 Correlation ............................................................................................................... 95 East from the Alleghenies.................................................................................. 112 East from Monongahela river, in Pennsylvania........................................... 113 West from Monongahela river, in Pennsylvania..................................... 115 The northern panhandle of W est Virginia.................................................... 129 Ohio ............................................................................................................................ 131 West Virginia ........................................................................................................ 138 Geographical changes during the Pennsylvanian............................................... 142 Notes on the Paleontology of the Pennsylvanian................................................. 164 The fauna ................................................................................................................. 164 The flora ................................................................................................................... 168 Table of formations ..................................................................................................... 178 * The earlier papers of this series, now closed, are in this Bulletin, volume 14, page» 15-96; volume 15, pages 37-210; volume 17, pages 65-228. The writer desires to ac knowledge his obligations to Doctor I. C. White and Mr David White, who throughout the whole period of his study have been unreserved in giving information and criticism. At the same time it must be understood that these observers are committed in no wim to conclusions .offered by the writer. Manuscript received by the Secretary of the Society January 5, 1907. IV—Bull. Geol. Soc. Am., Vol. 18, 1906 (29) 3 0 J. J. STEVENSON— CARBONIFEROUS OF APPALACHIAN BASIN T h e M o n o n g a h e l a F o r m a t io n CORRELATION The practically continuous area of Monongahela is confined to the southwest four counties of Pennsylvania, a narrow strip in eastern Ohio, and central West Virginia. Small outlying patches remain east from the Alleghenies, in the First and Second basins of Pennsylvania, and, at the south, beyond the Kanawha river in West Virginia. The area in which this formation remains is far within that of the Cone- maugh, except at the east. The formation, as limited by Doctor I. C. White, has the Pittsburg coal bed as the lowest and the Waynesburg coal bed as the highest stratum. The thickness varies from somewhat more than 400 feet in central West Virginia to about 140 feet at the most northerly exposure in Jefferson county of Ohio. This formation is characterized by notable variation in thickness of intervals and in composition of the rocks, as well as by local irregularities of deposit, whereby every student in the several parts of the area has been led into serious errors of correlation. These have made study of the Monongahela more perplexing than that of any earlier Carboniferous formation. In ascending order, the important members of the formation are: Pittsburg coal bed. Pittsburg sandstone. Redstone limestone. Redstone coal bed. Fishpot limestone. Lower Sewickley coal bed. Sewickley sandstone. Upper Sewickley coal bed. Benwood limestone. Tyler red beds. Ritchie red beds. Uniontown limestone. Uniontown coal bed. Uniontown sandstone. Waynesburg limestone. Little Waynesburg coal bed. Waynesburg coal bed. The Pittsburg coal bed...............Maryland: Cumberland, Elkgarden, Great H. D. Rogers, 1839. vein, Pittsburg. Pennsylvania: Pittsburg, Connellsville, I. Ohio: Federal creek, Pomeroy, Lower Bamesville, VIII, Pitts burg. West Virginia: Pittsburg. MONONGAHELA FORMATION 31 At one time this bed was thought to be a practically continuous sheet underlying the whole remaining area of Monongahela, somewhat less than 20,000 square miles; but studies by Professor E. B. Andrews dur ing the Second Geological Survey of Ohio proved its absence from a con siderable part of the field in that state and Doctor White’s study of oil well records in West Virginia, almost 20 years later, led to a similar conclusion for much of that state. The northern boundary of this bar ren area is in Guernsey county of Ohio and the coal is to all intents wanting in Noble, Monroe, east Morgan, and most of Washington in Ohio, most of Wetzel, Tyler, Pleasants, Wood, Eitchie, Doddridge, Gil mer, Boane, Calhoun, Jackson, Clay, Kanawha, Putnam, and Mason counties of West Virginia, all within the area in which formerly the bed was supposed to exist. Yet, even when thus restricted, the coal underlies a vast area, 7,000 or 8,000 square miles, in which it exhibits for the most part such regularity in variation as to both quantity and quality as to render it, from an economic point of view, the most im portant member of the formation and probably of the whole bituminous coal measures. Within the barren area itself it is represented frequently by black shale and occasionally it reappears abruptly as a bed of work able thickness. The Pittsburg coal bed in the ordinary condition, as seen in most of Pennsylvania and Ohio, is double, showing a “roof” division separated by an “over-clay” from the “Main” coal below. The “roof,” varying in thickness from a few inches to 10 or 12 feet, is composed sometimes of laminations of coal and clay; at others, the coal and clay are segre gated into beds, each 6 inches to a foot, while again it is almost wholly coal or almost wholly carbonaceous shale. At the best the coal is in ferior and is not mined. This division is wanting in the Salisbury basin of Somerset county, Pennsylvania, and is seen rarely along the eastern outcrop in West Virginia; but it reappears suddenly on the Kanawha, where at one locality it attains to almost the extreme thick ness. The “over-clay,” varying from a few inches to 2 feet, is thoroughly persistent, though sometimes so carbonaceous as to be almost a bony coal; even in West Virginia it seems to be present always, though the "roof” is wanting. The “Main” coal may be regarded as in three benches—“Breast,” “Bearing-in,” and “Bottom”—but in a great part of the field the “Breast” as well as the “Bottom” is divided by a thin parting, so that five benches are distinct. The parting slates are ordinarily very thin, rarely exceeding half an inch, often much less, and in considerable areas 3 2 J. J. STEVENSON— CARBONIFEROUS OP APPALACHIAN BASIN some of them contain much mineral charcoal. The persistence of these filmy layers throughout thousands of square miles is not the least re markable feature of this bed. The “B earing-inknow n in some locali ties as the “Bands,” is not persistent in West Virginia, where along the eastern outcrop the bed is often only double, with a mere parting, there being no deposit between the benches. The coal is not the same through out the bed, and each bench is apt to show its own type, distinguishing it as sharply from the others as though the partings were many feet thick. The coal differs in volatile, in ash, in coking qualities, and in sulphur; that from one bench is “brick;” from another, prismatic; from a third, hard, with more or less of semicannel. Like other beds, the Pittsburg occasionally carries some cannel; but this is unusual, occur ring only on the border of the field. The proportion of volatile shows variation geographically, as was indicated long ago by Professor H. D. Rogers. Along a line passing westnorthwest from Maryland to Ohio,