Emplacement of the Moxa Arch and related initiation of the ancestral prospect thrust, southwestern Wyoming

Conference · Mon Dec 31 23:00:00 EST 1984 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6456022

Kraig, D H; Wiltschko, D V; Spang, J H

North of the La Barge platform, recent seismic shows the western margin of the north-trending Moxa Arch (MA) as an east-dipping low-angle thrust (Moxa Thrust, MT) which carries Precambrian basement, Paleozoic and younger cover rocks in the hanging wall. The Paleozoic rocks form a ramp anticline over the footwall of the MT. During motion on the MT, the nose of the ramp anticline wedged westward along the basal Triassic detachment, peeling back the Triassic and younger rocks and thrusting them along the ancestral Prospect Thrust (PT) toward the crest of the ramp anticline. There, the PT cut up section in the footwall through the Triassic and younger rocks. This geometry yields a locally balanced cross section for both basement and cover rocks. The ancestral PT is interpreted as having been reactivated during a later interval roughly synchronous with movement on the Darby Thrust. Due west of Big Piney, Wyoming, the MA trends SE and is interpreted to be not a single thrust but rather a zone of steeply-dipping reverse faults restricted to basement. Shortening of the sedimentary rocks was accomplished by two west-dipping reverse faults, the upper flattens in the Triassic to the west and is the southernmost extension of the PT.

• Research Organization: Texas A and M Univ., College Station (USA)
• OSTI ID: 6456022
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Vol. 17; ISSN GAAPB
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
ANTICLINES
BASEMENT ROCK
FEDERAL REGION VIII
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOMETRY
GEOPHYSICAL SURVEYS
MATHEMATICS
NORTH AMERICA
PRECAMBRIAN ERA
SEISMIC SURVEYS
SURVEYS
TECTONICS
USA
WYOMING