Description of the Geology of
Bradford County
Pennsylvania

 
Bradford.- Area, 1160 square miles; population in 1880, 58,541. An open, rolling country of nearly horizontal Catskill (IX) and Chemung (VIII) brown sandstone, red and olive shales, with some calcareous breccias, and one well-marked conglomerate (supposed to represent the Third Oil Sand of the western counties) is traversed from north to south by the wide meandering channel valley of the North Branch Susquehanna river. Three well-marked anticlinal rolls traverse its northern, middle, and southern districts. Between these lie two synclinal troughs, arranged in the same E.N.E. and W.S.W. direction. The southern trough, filled with Pocono sandstone (X) in mountain form, occupies most of Monroe, Barclay, Leroy, and Overton townships. Towanda creek flows along the north foot of the mountain; Shrader branch splits the mountain lengthwise into two, and the south branch cuts through its eastern end. A long plate of Pottsville Conglomerate, 100 feet thick and nearly solid, makes the broad flat top of the northern mountain, supporting isolated patches of the Lower Productive coal measures, one bed of which, from 6 to 10 feet thick, of excellent semi-bituminous coal, has been extensively mined for the markets of New York State. Although the coal lies so flat, the south dips become steeper descending to Towanda creek, until in the small gorges at Leroy the Chemung rocks stand nearly vertical, and have supplied the local cabinet of Mr. Lilley with a multitude of fossil forms - Spirifer, Productella, Strophomena, Grammysia, Ambocoelia, Pterinea, Loxonema, Bellerophon; beds containing these molluscs, Tentaculites, an Orthoceras, fish scales and crinoidal fragments together; with thin, solid, limestone layers; red and green shales; gray sandstone and conglomerated beds; 1855 feet in one consecutive section. (See Proc. A.P.S., Philadelphia, Dec. 7, 1883, page 304). At the west line of the county rises a similar synclinal mountain of X, which in Tioga County is crowned by XII and holds the Blossburg coal basin. In the space between the two mountains just at the south-west corner of the county, Towanda creek flowing east and Lycoming creek flowing south head together in a swamp in Chemung rocks, covered (as all the county is more or less) with glacial drift. The Mansfield fossil iron ore beds (VIII) of Tioga county range in two outcrops through this open space; and an exceptional limestone bed of Chemung age (VIII) becomes 40 feet thick in the quarries east of Burlington, a nearly solid mass of shells. Opposite Towanda is an outcrop of Chemung sandstone 300 feet thick crowded with carbonized plant stems. Where the Wysox-Standing Stone township line meets the river an interesting slip fault is exposed; and in the bend below Towanda a curious example of a single corrugated layer of rock between perfectly undisturbed strata above and beneath it. (See Report G.) 

From: A geological hand atlas of the sixty-seven counties of Pennsylvania :embodying the results of the field work of the survey, from 1874 to 1884. By J. P. Lesley. (Report of progress (Geological Survey of Pennsylvania), v. X ) Harrisburg, PA : Board of commissioners for the second geological survey, 1885.

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