Upper Devonian outcrop stratigraphy, southwestern Virginia and southeastern West Virginia
- Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Geology
- Coll. of William and Mary, Williamsburg, VA (United States). Dept. of Geology
- Univ. of North Carolina, Wilmington, NC (United States). Dept. of Earth Sciences
Ongoing outcrop studies are resulting in the extension of existing formal lithostratigraphic units and revision of previously less refined subdivisions of Upper Devonian strata in southwestern Virginia and southeastern West Virginia. A 425 km (263 mi) long stratigraphic cross-section has been constructed primarily from the outcrop belt along the Allegheny Structural Front, supplemented by sections from nearby outcrop belts. This NE-SW striking cross-section is oblique to the nearly due N-S depositional strike of the Upper Devonian Acadian orogenic wedge. To the southwest, the Upper Devonian section thins from 2,100 meters (6,900 feet) to 230 meters (756 feet) as progressively more distal deposits are encountered. An integrated approach has been taken to establish chronostratigraphic control within the cross-section. The best time markers include particularly regressive parasequences which can be identified across facies boundaries (especially the Pound and Briery Gap Sandstones and their equivalents), volcanic ashes, and an organic-rich shale zone marking the base of a major transgression (equivalent to the base of the Huron Shale in Ohio and the Dunkirk Shale of New York). These tools provide chronostratigraphic correlation through the undivided Brallier Formation. Supplemental control includes biostratigraphic markers as well as marine dull redbeds within the Foreknobs which parallel other time lines and may represent partially reduced influxes of oxidized coastal plain sediments during minor parasequence scale regressions.
- OSTI ID:
- 6924857
- Report Number(s):
- CONF-9404217--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 26:5; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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