Stratigraphic significance and provenance of the Ordovician Walker Mountain Sandstone Member, Virginia and Tennessee
- Univ. of Georgia, Athens, GA (United States). Dept. of Geology
- Smithsonian Inst., Washington, DC (United States). Dept. of Mineral Sciences
The Ordovician (Mohawkian) Walker Mountain Sandstone Member of the Bays, Moccasin, and Eggleston Formations is a thin ([approx] 1--15 meters), widespread, conglomeratic sheet sand deposit in the Valley and ridge Province of Virginia and Tennessee. Recent work by the authors has shown that the Walker Mountain is laterally persistent across major regional facies changes, and marks an unconformity of regional extent in nearly all areas of occurrence. The basal bed of the Walker Mountain is commonly a conglomeratic quartz arenite, and is the most distinctive and recognizable bed of the unit. Where the conglomeratic basal bed is absent, the Walker Mountain consists either of a fine- to medium-grained, mature quartz arenite (southern sections) or a fine- to medium-grained quartz and sublithic arenite with appreciable clay matrix (northern sections). Petrologically, the basal conglomeratic bed of the Walker Mountain is compositionally very mature and in most areas has a bimodal texture; grains of the larger mode are extremely well rounded, and those of the smaller mode are subrounded to subangular. Preliminary field observations and petrographic analysis suggest that Walker Mountain sediments were derived from highlands to the present-day east, probably an accretionary wedge composed mostly of older Paleozoic passive margin sediments, and lesser plutonic igneous and low-grade metamorphic rocks.
- OSTI ID:
- 6886636
- Report Number(s):
- CONF-9404221--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 26:4; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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