New COCORP profiling in the southeastern US: Major features and regional implications
COCORP recently collected 1100 km of new deep reflection data along two transects crossing the portion of the Appalachian orogen buried beneath the Georgia/Florida coastal plain, the superjacent Triassic/Early Jurassic South Georgia basin, and the southernmost Piedmont. On all profiles the base of the crust is marked by discontinuous patches of reflections at 11 to 12 s, which probably originate from Moho, implying a crustal thickness of about 35 to 38 km. Three crossings of the Brunswick magnetic low show that this feature coincides with a major crustal penetrating zone of dipping reflections and diffractions. Based on regional relations the authors argue that the dipping zone marks the Alleghenian terrane boundary (suture), flanking the N side of the African terrane underlying northern Florida. Continuation of the Brunswick anomaly offshore implies that this boundary continues NE across the Georgia/South Carolina continental shelf. In western Georgia deep-crustal reflections are sparse within Suwannee terrane basement and within Greenville basement to the N; however, in eastern GA numerous mid- and lower-crustal reflections are observed in the region bounded approximately by the Brunswick anomaly on the S and the Appalachian gravity gradient on the NW. It is not clear whether this regional deep-reflection fabric is a manifestation of Paleozoic accretionary structure, or Mesozoic extension. Data across the Pine Mountain belt and Inner Piedmont immediately to the N indicate approximately 9 km of structural relief across the Towaliga fault, much of which may be due to Mesozoic normal slip.
- Research Organization:
- Cornell Univ., Ithaca, NY (USA)
- OSTI ID:
- 6320019
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COASTAL REGIONS
SEISMIC SURVEYS
STRATIGRAPHY
FLORIDA
BASEMENT ROCK
PLATE TECTONICS
GEORGIA
APPALACHIAN MOUNTAINS
CONTINENTAL SHELF
EARTH CRUST
GEOLOGIC FAULTS
GEOLOGIC HISTORY
GEOLOGY
INCLINED STRATA
MAPPING
OROGENESIS
CONTINENTAL MARGIN
FEDERAL REGION IV
GEOLOGIC FRACTURES
GEOLOGIC STRATA
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
MOUNTAINS
NORTH AMERICA
SURVEYS
TECTONICS
USA
580100* - Geology & Hydrology- (-1989)
580201 - Geophysics- Seismology & Tectonics- (1980-1989)