Abstract:
Upper Devonian Hampshire and Lower Mississippian Pocono sandstones were correlated over a 370-mi2 area in north-central West Virginia using 400 gamma-ray logs. Isolith maps show the geometry, position, trend, and distribution pattern of the sandstones. Sandstone belts occur in north-south (strike) trends particularly in the western part (Lewis County), whereas east-west (dip) trending sandstone belts and dendroids generally occur in the eastern part (Upshur County) of the study area. The north-south-trending sandstone belts are interpreted as barrier islands, and their adjacent eastward facies consisting of some plant-rich black shales and thin sandstones are interpreted as lagoonal. Tidal inlets are associated with barrier islands along the strike trend. Sands probably were supplied to the ancient barrier islands by east-trending distributary channels that were affected by both tidal and fluvial processes. East-west cyclic shifting of the barrier islands and the north-south shifting of the feeder systems were strongly influenced by the paleotopography of the next lower sandstone unit. The nearly 5-mi (8-km) shoreline shift east-west within sand intervals (Fourth, Thirty-foot, Fifty-foot) of these shoreline sandstones probably resulted from combinations of changes in sea level, sediment supply, and differential compaction. The interpreted “feeder systems” of tidal and fluvial channels trending east-west indicate a history of distributaries shifting with time also. The Hampshire Formation and Pocono Group of north-central West Virginia are interpreted facies of coastal plain-nearshore environments in which marinedominant deltas characterize the shoreline.
