Bowen Formation
The Bowen Formation is an Ordovician-age geological formation in the Appalachian region of the eastern United States.[1] It occupies a thin stratigraphic range between the Wardell and Witten formations in some areas of southwest Virginia and northeast Tennessee.[2] It is particularly well-exposed in Tazewell County, Virginia. Unlike its encompassing strata, the Bowen Formation is mostly calcareous sandstone and mudrock rather than limestone. The thicker upper part of the formation is composed of layered red mudrock which is replete with mudcracks. The thinner lower part, which is not always preserved, is a coarser unit of dark grey stratified sandstone which weathers to a rusty-brown color. Fossils are rare, restricted to stromatolites and Tetradium fibratum (a coral-like colonial organism).[3][4][5]
| Bowen Formation | |
|---|---|
| Stratigraphic range: Late Ordovician | |
| Type | Formation |
| Underlies | Witten Formation |
| Overlies | Wardell Formation |
| Lithology | |
| Primary | mudrock, sandstone |
| Other | limestone, shale |
| Location | |
| Region |  Virginia |
| Country |  United States |
| Type section | |
| Named for | Bowen Cove, Tazewell County |
| Named by | Cooper & Prouty, 1943 |
The Bowen Formation was probably formed by a small lobe of a delta flowing northeast onto the carbonate platforms of the area. Mudcracks indicate that the sediments were partially exposed to the air. Shortly after deposition of the Witten Formation, similar conditions would return in force with the thick coastal red beds of the Moccasin Formation.[4][5]
References
- Read, J. Fred; Eriksson, Kenneth A. (2012). "Paleozoic Sedimentary Successions of the Virginia Valley & Ridge and Plateau" (PDF). Virginia Tech Scholarly Works, Department of Geosciences.
- Prouty, Chilton E. (1946). "Lower Middle Ordovician of southwest Virginia and northeast Tennessee". Bulletin of the American Association of Petroleum Geologists. 30 (7): 1140–1191. doi:10.1306/3D933854-16B1-11D7-8645000102C1865D.
- Read, J.F. (1980). "Carbonate Ramp-to-Basin Transitions and Foreland Basin Evolution, Middle Ordovician, Virginia Appalachians". American Association of Petroleum Geologists Bulletin. 64 (10): 1575–1612. doi:10.1306/2F9196CF-16CE-11D7-8645000102C1865D.
- Cooper, Byron N.; Prouty, Chilton E. (1943). "Stratigraphy of the lower Middle Ordovician of Tazewell County, Virginia". Bulletin of the Geological Society of America. 54 (6): 819–886. doi:10.1130/GSAB-54-819.
- Ruppel, Stephen C.; Walker, Kenneth R. (1984-05-01). "Petrology and depositional history of a Middle Ordovician carbonate platform: Chickamauga Group, northeastern Tennessee". GSA Bulletin. 95 (5): 568–583. doi:10.1130/0016-7606(1984)952.0.CO;2. ISSN 0016-7606.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.