Tectonic architecture of central Georgia Eastern Piedmont
- Univ. of Nebraska, Omaha, NE (United States). Dept. of Geography and Geology
- Univ. of South Carolina, Columbia, SC (United States). Dept. of Geological Sciences
- Univ. of Minnesota, Duluth, MN (United States). Dept. of Geology
Recent work suggests the following for the tectonic architecture of the central Georgia Eastern Piedmont. The Alleghenian-age, Modoc fault zone (MZ), first defined in S. Carolina, continues along strike (c. S60W) at least to the Ocmulgee R. (net length = 250 km), where it converges with the Ocmulgee (OF) and Goat Rock (GR) faults. Diverging to the S from the MZ is a sharp contact between migmatitic amphibolites and gneisses of the Sinclair Lake terrane (SLt) and lower grade metapelites and metapsammites of the Milledgeville terrane (Mt). Both are introduced by post-kinematic granites (likely Alleghanian). A previously undescribed, 10 km long ultramafite belt within SLt, the Shoulderbone zone (Sz), is concordantly foliated with respect to surrounding rocks--hence emplacement is considered as pre- or synkinematic. Numerous smaller ultramafite bodies exist within SLt, Metavolcanic rocks N of SLt and the intervening MZ are interpreted as Carolina slate belt (CSB) rocks extending farther SW than often depicted. Arc volcanism and plutonism, terrane amalgamation and subsequent Alleghanian plutonism, dextral shear zones (some with extensional components), and local tight folding contributed to the present architecture. Locally, accretionary wedge material may exist, but the authors find published views and maps describing the entire area as primarily an accretionary wedge thrust stack to be inappropriate.
- OSTI ID:
- 5689566
- 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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