Impact of late Cenozoic extension on Laramide overthrust belt and Diablo Platform margins, northwestern Trans-Pecos Texas
- Univ. of Texas, Austin (United States)
Late Cenozoic basins and normal faults were superimposed upon preexisting Tertiary, Mesozoic and older structures of northwestern Trans-Pecos Texas. We analyzed the structural and stratigraphic framework of the region using borehole, seismic, outcrop, and aerial-photograph interpretations; regional cross sections were prepared to record Mesozoic and Cenozoic structural attributes. Laramide thrusting displaced Cretaceous rocks northeastward and produced northwest-trending thrust faults and related normal faults, folds, and monoclines. Cenozoic extension caused normal faulting that produced northwest- and north-northwest-trending, 3 to 30 mile-wide fault-bounded basins and adjacent mountain ranges. Tectonism continues to the present. The pre-late Cenozoic structural grain has at least partly controlled geometries of the late Cenozoic basins and associated faults. The deepest Cenozoic basin of this area developed along the leading edge of the Laramide thrust belt and the southwest margin of the Diablo Plateau, and has as much as 9800 ft of Cenozoic basin fill. The most active Quaternary faults vertically displace middle Pleistocene deposits by about 33 to 105 ft. The 56-mi-long Red Light Bolson, containing more than a 2000 ft of Cenozoic deposits, also formed near the leading edge of the older thrust belt. A northwest-striking Quaternary fault zone bounds this basin on its east margin. Two series of Cenozoic basins also have formed northeast of the overthrust belt. The 50-mi-long Eagle Flat-Green River basin system consists of three basins that contain 900 to more than 2000 ft of basin fill. Late Tertiary-Quaternary tectonism has not been as active there as in the other large basins. The 124-mi-long Salt Basin graben system comprises five basins and marks the east edge of Quaternary faulting in this region. Cenozoic fill is more than 2000 ft thick, and the most active Quaternary faults vertically displace middle Pleistocene deposits by at least 13 to 36 ft.
- OSTI ID:
- 6833219
- Report Number(s):
- CONF-9404148-; CODEN: AABUD2
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 78:3; Conference: American Association of Petroleum Geologists (AAPG) Southwest Section meeting, Ruidoso, NM (United States), 24-26 Apr 1994; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GEOLOGIC FAULTS
PETROLEUM GEOLOGY
GEOLOGIC STRUCTURES
CROSS SECTIONS
TEXAS
BOREHOLES
CENOZOIC ERA
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRATA
MESOZOIC ERA
QUATERNARY PERIOD
SEDIMENTARY BASINS
SEISMIC SURVEYS
STRATIGRAPHY
TECTONICS
TERTIARY PERIOD
CAVITIES
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGY
GEOPHYSICAL SURVEYS
NORTH AMERICA
SURVEYS
USA
020200* - Petroleum- Reserves
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