Detailed Backstripping and Reassembly of the Architectural Elements of a Channel Complex Filling from Incised Valley in the Pennsylvanian East of Pikeville, Kentucky

Sumanta K. Chatterjee and Christopher G. Kendall
Geological Sciences, University South Carolina, Columbia, SC

The generalities of the expression of the architectural elements displayed by delta migration and channel incision have been well studied in the road and river cuts of the Pennsylvanian of Eastern Kentucky. This paper examines these elements from a new perspective of high frequency process modeling, using their detailed backstripping and reassembly to guide the results and predict their distribution out of section.

The focus of the study is a road cut on US 23 just east of Pikeville, Kentucky that exposes Pennsylvanian deltaic strata. The exposure, some 1.5 km long and 30 m high, captures several cycles of delta mouth bar switching subdivided by in situ coals. Incised into these features is a valley (over 1,200 m wide and 20 m deep) filled by a stacked and amalgamated channel and overbank complex that has responded to over ten cycles of base level changes. The basal channel elements are braided and contain detrital coal and slumped bank margin deposits. The episodes of channel migration, point bar, chute, and crevasse splay channel fill often have multiple orientations and migrate across the outcrop, from both east to west, and west to east. A transgressive coal layer followed by distal and then proximal bay fill and deltaic deposits overlies the valley fill.

The current study provides new insights into the relationship and contact between the architectural elements of fluvial and distributary channel fill and enables the depositional history of a channel complex to be inferred.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas