Local and basin analyses were integrated into a regional depositional and tectonic model for hydrocarbon migration and entrapment for the Lower Mississippian Pocono Formation sandstones for a study area located in the Appalachian Plateau of West Virginia and Virginia.
Subsurface mapping on a local scale led to the recognition of a suite of depositional facies corresponding to the Pocono Formation sandstones and the tectonic effects exerted on them. The Pocono depositional sequence consists of sediments deposited in wave-dominated linear clastic shorelines. These features include the corresponding facies of barrier islands and strand plains. Structural elements observed from local mapping on Pocono horizons include northeast-southwest strike, northwest dip, high-angle reverse faults, low-relief folds, and northwest-southeast cross-strike structural discontinuities (tear faults).
Basin analysis generated a basin history model, which was described using the following parameters: basin-forming tectonics, depositional sequences, and basin-modifying tectonics.
Placing the local Pocono Formation study area within the framework of the generated basin history model yielded a tracing for the movement of the study area through time relative to basin evolution. This permitted identification of the genetic relationships among the observed local depositional and tectonic features and the mechanisms responsible for their generation, thus providing a basis for exploration and field extension.
For the study area, we place the Pocono Formation sandstones at the wedge top of a Middle Silurian through Lower Mississippian depositional sequence deposited within an interior sag basin situated immediately west of a westward-converging mobilized fold belt.