Reevaluation of the Bedford--Berea sequence on Ohio and adjacent states: New perspectives on sedimentation and tectonics in foreland basins
- Geological Survey of Alabama, Tuscaloosa, AL (United States)
- Univ. of Kentucky, Lexington, KY (United States)
The Late Devonian Bedford-Berea (BB) sequence provided an early basis for models of epeiric sedimentation, but controversy regarding its origin has arisen in recent years. This study was designed to resolve this controversy and to identify factors that control depositional architecture in foreland basins on the basis of outcrop and subsurface data. The BB is a siliciclastic succession that was deposited in the Appalachian foreland basin during a relaxational phase of the Acadian orogeny. Among the salient features of the BB are an eastern platform and a western basin. The platform was characterized largely by erosion of Catskill sediment and subsequent deposition of aggradational valley-fill sequences, whereas the basin was characterized mainly by progradational delta and shelf deposits that overlie conformably the distalmost part of the Catskill clastic wedge. BB depositional history and paleogeography is divided into two episodes: (1) basin filling and (2) delta destruction. Basin filling was characterized by regressive fluvial-deltaic systems that eroded the Catskill wedge and supplied prograding deltaic and shelf sediment to the western basin. Delta destruction began after the basin was full with sediment and was dominated by flexural relaxation, which gave rise to unusual facies patterns. Delta-front deposits in the western basin were uplifted and reworked, and a shelf silt blanket prograded back toward the incised valleys on the rapidly subsiding eastern platform where estuaries were forming. Reevaluation of the BB sequence demonstrates that the depositional architecture and paleogeographic history of foreland basins is much more elaborate than is commonly recognized. Tectonism, relict topography, differential compaction, and relative sea-level variation functioned collectively to determine the complex depositional history and paleogeography of the BB sequence.
- OSTI ID:
- 5806271
- Report Number(s):
- CONF-921058-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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