Ouachita-Appalachian junction: a Paleozoic transpressional zone
The late Paleozoic collision of the Gondwana supercontinent with the trailing southern margin of North America created the Ouachita and Appalachian orogenic belts. Transecting these belts are several transpressional or wrench fault zones, including the Val Verde basin-Texas lineament system, the Ardmore-Anadarko basin trend, and the Reelfoot rift complex. Vertical movement within these wrench zones resulted in the emplacement of pop-block or flower structures. In Texas and Oklahoma these features are major structural traps for oil and gas. In this work, they propose that the (buried) juncture between the Ouachita and Appalachian foldbelts in Mississippi is a similar transpressional fault zone. Recent reconstructions of the collision between Gondwana and North America indicate a relative closure direction of southeast to northwest. Normal decollement thrusting occurred in the Appalachian and Ouachita foldbelts, where the structural grain of the North American margin was nearly perpendicular to the closure direction. Where the structural grain was oblique to closure direction, wrench faulting and high-angle thrust faulting occurred, due to the combined effect of both translational and compressional stress fields. In southwestern Alabama and Mississippi the trailing North American plate margin consisted of Mississippian and Pennsylvanian clastics draped over a thick Cambro-Ordovician carbonate shelf. This shelf trends northeast-southwest in Alabama but turns sharply to trend north-northwest in Mississippi, possibly reflecting changes in Precambrian basement relief. Transpressional stresses would have been generated near this sharp bend during the collision. This study identifies one such transpressional fault zone, on the basis of seismic data and well control, in east-central Mississippi.
- Research Organization:
- Amoco Production Co., New Orleans, LA
- OSTI ID:
- 6254888
- Report Number(s):
- CONF-870606-
- Journal Information:
- AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States), Vol. 71:5; Conference: American Association of Petroleum Geologists annual meeting, Los Angeles, CA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
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Evolution of Pre-Jurassic basement beneath northern Gulf of Mexico coastal plain
Related Subjects
ALABAMA
PETROLEUM DEPOSITS
MISSISSIPPI
EXPLORATION
CAMBRIAN PERIOD
CARBONATE ROCKS
GEOLOGIC STRUCTURES
ORDOVICIAN PERIOD
SEDIMENTARY BASINS
TECTONICS
FEDERAL REGION IV
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MINERAL RESOURCES
NORTH AMERICA
PALEOZOIC ERA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
020200* - Petroleum- Reserves
Geology
& Exploration