Timing of compressional deformation in the southern Appalachian Blue Ridge
- Florida State Univ., Tallahassee, FL (United States). Dept. of Geology
Most southern Appalachian tectonic models have ascribed Blue Ridge ductile deformation and significant thrusting to be of Taconic age, overprinted by Alleghanian brittle thrusting. However, recent fossil discoveries in the crystalline cover sequence of the Blue Ridge and Tallagega belts indicate that major regional ductile deformation may be post-Ordovician and associated with the Acadian and/or Alleghanian orogenesis. The presence of extensive Ordovician or younger successor basin sequences nested within the Blue Ridge east of what was presumed to be the Taconic orogenic front brings into question earlier models which proposed Taconic thrusts and ductile deformation within the Blue Ridge, and which projected the Blue Ridge as a source terrane for Taconic foredeep clastic wedges. The presence of low angle unconformities at the base of successor basin sequences in the Blue Ridge and the apparent lack of regional metamorphic effects in rocks below the unconformities precludes significant deformation prior to successor basin formation. Significant internal Blue Ridge polyphase deformation can be dated as latest Paleozoic because of superposition of structural phases upon Carboniferous rocks of the foreland.
- OSTI ID:
- 5588618
- 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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