Abstract
The Upper Mississippian Hinton, Princeton, and Bluestone formations of southern West Virginia constitute a westward-thinning wedge of strata that filled the central Appalachian basin over approximately 7 m.y. Up to 17 transgressive-regressive sequences comprise the study interval in the basin depocenter. High-frequency, fourth-order (~400 k.y.) sequences vary with regard to the degree of basal incision, the overall thickness, and the character of the dominant facies. Five sequence types are recognized in the outcrop belt: (1) major incised valley fill to coastal plain, (2) major incised valley fill to deltaic, (3) minor incised valley fill, (4) coastal plain, and (5) marine-dominated sequences. Sequence development is ascribed to glacioeustasy during the early stages of the Permian-Carboniferous Gondwanan glaciation.
Regional well log correlation indicates that the high-frequency sequences stack into two composite sequences. These composite sequences consist of (1) a major incised valley-fill-dominated sequence and a set of coastal plain-dominated sequences that together constitute the transgressive systems tract, (2) a marine-dominated sequence that demarcates maximum flooding, and (3) (where preserved) a progradational set of minor incised valley-fill-dominated sequences that comprise the highstand systems tract. The composite sequences are interpreted to reflect third-order (2-4 m.y.) changes in accommodation as a result of tectonically driven eustasy.