Tectonic history of the Illinois basin

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6935608

Kolata, D R; Nelson, J W ^[1]

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1. Illinois Geological Survey, Champaign (USA)

The Illinois basin began as a failed rift that developed during breakup of a supercontinent approximately 550 Ma. A rift basin in the southernmost part of the present Illinois basin subsided rapidly and filled with about 3,000 m of probable Early and Middle Cambrian sediments. By the Late Cambrian, the rift-bounding faults became inactive and a broad relatively slowly subsiding embayment, extending well beyond the rift and open to the Iapetus Ocean, persisted through most of the Paleozoic Era. Widespread deformation swept through the proto-Illinois basin beginning in the latest Mississippian, continuing to the end of the Paleozoic Era. Uplift of basement fault blocks resulted in the formation of many major folds and faults. The timing of deformation and location of these structures in the forelands of the Ouachita and Alleghanian orogenic belts suggest that much of the deformation resulted from continental collision between North America and Gondwana. The associated compressional stress reactivated the ancient rift-bounding faults, upthrusting the northern edge of a crustal block approximately 1,000 m within the rift. Concurrently, dikes (radiometrically dated as Early Permian), sills, and explosion breccias formed in or adjacent to the reactivated rift. Subsequent extensional stress, probably associated with breakup of Pangea, caused the crustal block within the rift to sink back to near its original position. High-angle, northeast- to east-west-trending normal faults, with as much as 1,000 m of displacement, formed in the southern part of the basin. These faults displace some of the northwest trending Early Permian dikes. Structural closure of the southern end of the Illinois basin was caused by uplift of the Pascola arch sometime between the Late Pennsylvanian and Late Cretaceous.

• OSTI ID: 6935608
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CAMBRIAN PERIOD
CARBONIFEROUS PERIOD
CRETACEOUS PERIOD
FEDERAL REGION V
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
ILLINOIS
MESOZOIC ERA
NORTH AMERICA
PALEOZOIC ERA
RIFT ZONES
SEDIMENTARY BASINS
TECTONICS
USA