A High-Resolution Study of Depositional Facies and Architecture of Fords Branch Outcrop: A Middle Pennsylvanian Sedimentary Sequence Near Pikeville, Kentucky, U.S.A.
Sumanta K. Chatterjee, Arthur D. Cohen, Christopher G. St. C. Kendall, 2011. "A High-Resolution Study of Depositional Facies and Architecture of Fords Branch Outcrop: A Middle Pennsylvanian Sedimentary Sequence Near Pikeville, Kentucky, U.S.A.", Outcrops Revitalized: Tools, Techniques and Applications, Ole J. Martinsen, Andrew J. Pulham, Peter D.W. Haughton, Morgan D. Sullivan
Download citation file:
A Middle Pennsylvanian deltaic succession is exposed in the Fords Branch road cut located on US Highway 23, south of Pikeville, Kentucky, USA. The outcrop is 1.5 km long and 20 m in thickness and is oriented in an oblique strike orientation with respect to local paleoflow indicators and regional fluvio-deltaic drainage directed broadly to the west in a late Paleozoic Appalachian foreland basin.
Sedimentological analysis of the outcrop and interpretation of a panoramic photo montage establishes that the succession in the road cut accumulated in three depositional episodes bounded by sequence stratigraphic surfaces. A basal complex of distributary- mouth bars, channels and levees is cut by and overlain by an incised-valley fill. A capping unit of bay-fill and distributary-mouth-bars sediments completes the exposed succession.
Both the basal and capping depositional episodes are interpreted as lower-delta-plain settings. The incised valley is dominated by fluvial channel deposits and exhibits an upward increase in fluvial channel amalgamation.
The focus of the study presented here is twofold: (1) the nature of delta-front settings and how best analogs might be chosen, and (2) the evolution of fluvial channels in the outcrop panel, the architecture of which suggests a changing balance of sedimentation rate versus avulsion frequency over time.