SEQUENCE STRATIGRAPHIC ANALYSIS OF TRANSGRESSIVE-REGRESSIVE CYCLES IN THE UPPER HINTON FORMATION (UPPER MISSISSIPPIAN), CENTRAL APPALACHIAN BASIN

Cyclothemic facies successions in the upper Hinton Formation were deposited during the onset of Late Paleozoic icehouse conditions. This study aims to establish a sequence stratigraphic framework for these cycles. The study interval extends upward from the base of the Little Stone Gap (Avis) Member of the Hinton Formation to the unconformity associated with the base of the Princeton Formation. Data for this study were derived from 15 outcrop sections across southern West Virginia and southwestern Virginia. The upper Hinton Formation attains a maximum thickness of about 150 m, and primarily consists of shallow marine and tidally influenced marginal-marine facies with subordinate alluvial facies. Three regionally extensive marine zones are present. The lower marine zone comprises the Little Stone Gap Member. The middle and upper marine zones are informally termed the "Five Mile" and "Eads Mill" marine zones, respectively. A maximum flooding surface that records peak transgression (Galloway-type sequence boundary) has been identified in each marine zone. Two fluvial entrenchment surfaces (Vail-type sequence boundaries) also are recognized, contradicting previous reports of five such surfaces in the upper Hinton Formation. The lower Vail-type sequence boundary occurs between the Little Stone Gap Member and the Five Mile marine zones, and the upper one occurs between the Five Mile and Eads Mill marine zones. Cyclothems are best packaged as Galloway-type genetic sequences because maximum flooding surfaces are generally more robustly expressed than fluvial entrenchment surfaces. The upper Hinton cycles analyzed in this study record a history of relative sea-level change that is consistent with the glacioeustatic hypothesis for Upper Paleozoic cyclothems. A correlation panel with detailed sedimentological logs and inferred hiatal surfaces will be presented in order to engage discussion of sequence stratigraphic interpretations.