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Geologic Cross Section Through the Appalachian Basin from the Findlay Arch, Northwestern Ohio, to the Allegheny Structural Front, Eastern West Virginia

Ryder, Robert T., Christopher S. Swezey, Robert D. Crangle, Jr., and Michael H. Trippi
U.S. Geological Survey, Reston, VA

A new geologic cross section through the central Appalachian basin is presented here. The cross section is constrained by sixteen drill holes, twelve of which penetrate the Paleozoic cover rocks of the basin and bottom in Grenville-age crystalline basement rocks. A major objective for constructing the cross section is to provide a regional structural and stratigraphic context for better understanding prospective petroleum and coal systems and basinwide fluid-flow models.

Obvious styles of deformation interpreted on the cross section are (1) thin-skinned contractional structures of Alleghanian origin at the Allegheny structural front (Wills Mountain anticline) and in the adjoining foreland (Glady, Elkins Valley, and Burning Springs anticlines) and (2) basement-involved Middle Cambrian extensional faults that flank the Rome trough. At several localities, deeply rooted anticlines that involve basement rocks appear to have been caused by fault-block reactivation during the Alleghanian orogeny. Sedimentary rocks shown on the cross section span the entire Paleozoic Era, and their preserved thicknesses range from about 4,000 ft on the Findlay arch to about 25,000 ft near the Allegheny structural front. These rocks are broadly classified as follows: (1) Lower Cambrian to Upper Ordovician siliciclastic and carbonate shelf deposits (rift and passive margin); (2) Upper Ordovician to Lower Silurian foreland basin deposits (Taconic orogeny); (3) Lower Silurian to Middle Devonian carbonate shelf and evaporite basin deposits; (4) Middle Devonian to Lower Mississippian foreland basin deposits (Acadian orogeny); (5) Upper Mississippian carbonate shelf deposits; and (6) Upper Mississippian, Pennsylvanian, and Permian foreland basin deposits (Alleghanian orogeny).

AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004