Taconic collision in SE Penna and Delaware
Taconic metamorphism and tectonism in SE Pennsylvania and northern Delaware were a result of the collision of a volcanic arc with North America. The Wilmington Complex, the infrastructure of the arc, is presently the highest structural unit. It consists of granulite facies volcanogenic sediments intruded by gabbro and a ca. 500 Ma gabbronorite-charnockite suite. Latest Precambrian-earliest Paleozoic sediments of the Glenarm series were metamorphosed to conditions above the second sillimanite isograd beneath the overthrust hot (700-800/sup 0/C) Wilmington Complex. As the edge of the continent was depressed and heated under the advancing thrust complex, basement-involved nappes of Grenville age rocks (Avondale anticline, Woodville dome) with the Glenarm sedimentary cover were thrust over still rigid autochthonous basement (West Chester Prong). On the NW flank of the orogen, Grenville age gneiss-cored massifs (Honey Brook Upland, Mine Ridge, Trenton Prong), unconformably overlain by lower Paleozoic continental shelf sediments, were involved in the thrusting but metamorphosed only to the greenschist facies. Steep anticlines developed later in the Paleozoic, contributing to the present pattern of northeast trending Grenville basement massifs mantled by overlying units.
- Research Organization:
- Bryn Mawr College, PA (USA)
- OSTI ID:
- 6612677
- 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
DELAWARE
OROGENESIS
PLATE TECTONICS
PENNSYLVANIA
BASEMENT ROCK
GEOLOGIC FAULTS
GEOLOGIC HISTORY
IGNEOUS ROCKS
METAMORPHIC ROCKS
METAMORPHISM
PALEOZOIC ERA
PRECAMBRIAN ERA
FEDERAL REGION III
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
NORTH AMERICA
ROCKS
TECTONICS
USA
580201* - Geophysics- Seismology & Tectonics- (1980-1989)
580300 - Mineralogy
Petrology
& Rock Mechanics- (-1989)