Abstract: Controls on Foreland Basin Filling and Erosion: Subsurface Stratigraphic Analysis of the Mississippian to Middle Pennsylvanian Interval of the Central Appalachian Basin

Chaoqing Yang, Alan C. Donaldson

A three-dimensional stratigraphic framework has been constructed for the Mississippian to Middle Pennsylvanian interval in southwest West Virginian with subsurface isopach, isolith and subcrop maps, as well as a network of well cross sections. Stratigraphic response to tectonic activities on the continental margin was regulated by the Cambrian-aged basement structures, the Rome trough and the Burning-Mann lineament, which is expressed in the depositional and erosional patterns of the studied interval in the central Appalachian foreland basin. Compartmentalization of the region by the structural elements formed several subblocks with different stratal geometries. Structural inversion occurred on the east margin faults of the Rome trough during active tectonic loading and t e loading-type relaxation. Sedimentary records of different tectonic stages are dominated by the deposits of unloading-type and loading-type relaxation, while the records for active tectonic loading are usually quite thin or even absent. The sub-Berea and the sub-Greenbrier (centered on the West Virginian Dome) unconformities are considered to have been formed by unloading-type relaxation, whereas the Mississippian/Pennsylvanian unconformity by loading-type relaxation, based on their position and erosional patterns. Eustatic sea level lowering is considered to be responsible for the minor erosional unconformities on the top of the Mississippian Greenbrier Limestone and the Avis Limestone. Bounded by these unconformities are four depositional sequences which are usually dominated by highs and systems tract.

AAPG Search and Discovery Article #90954©1995 AAPG Eastern Section, Schenectady, New York