The Overthrust Belt of Western North America

Conference · Mon Feb 01 04:00:00 EST 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6066580

Verrall, P

The Overthrust Belt extends for 5000 mi (8000 km) from the Brooks Range in Alaska to the Sierra Madre Oriental in Mexico. It consists of northeastward vergent thrust and fold structures involving late Precambrian to early Tertiary sedimentary section. These sediments represent deposition off the western rift margin, formed in late Precambrian time, of the North American Precambrian craton. The northeastward thrusting continued throughout the Mesozoic as a response to the convergence of the East Pacific Plate with the North American Plate. This convergence resulted in subduction beneath the North American Plate except at the northwest end (the Brooks Range) where the result was obduction. Convergence ceased when the west edge of the East Pacific Plate reached the subduction zone. The sedimentary section involved in the Thrust Belt contains good Devonian to Cretaceous hydrocarbon source rocks, and Ordovician to traps related to the thrusting (simple thrust sheets, imbricate thrust sheets, folded thrust sheets, step anticlines, footwall cutoffs, footwall anticlines, etc.). Field methods involved in exploration for hydrocarbons include field geological mapping, remote sensing (aerial photography and Landsat imagery), various seismic refraction and seismic reflection techniques (including modern detailed three dimension surveys) and potential field methods such as gravity and magnetic surveying. Studies of the field data include paleontology, source rock and hydrocarbon migration studies, structural and stratigraphic analyses, and the processing of geophysical data. This work has succeeded in two major areas: the Western Canadian Rocky Mountain Foothills, a major gas province producing mainly from Paleozoic reservoirs; and the Wyoming-Idaho-Utah portion of the thrust belt, also a major gas producer from Paleozoic reservoirs and, in addition, a major oil producer from the Jurassic Nugget Sandstone.

• OSTI ID: 6066580
• Report Number(s): CONF-930306--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 77:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALASKA
DEPOSITION
DETECTION
DEVELOPED COUNTRIES
DEVELOPING COUNTRIES
EXPLORATION
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
GEOPHYSICAL SURVEYS
HYDROCARBONS
LATIN AMERICA
MAGNETIC SURVEYS
MAPPING
MEXICO
MIGRATION
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
ORGANIC COMPOUNDS
ORIGIN
PALEONTOLOGY
PETROLEUM DEPOSITS
REMOTE SENSING
RESOURCES
SEDIMENTS
SEISMIC DETECTION
SOURCE ROCKS
SURVEYS
USA
WESTERN US OVERTHRUST BELT