Subsurface cross section of lower Paleozoic rocks, Powder River basin, Wyoming and Montana

Conference · Fri Jul 01 04:00:00 EDT 1988 · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)

OSTI ID:6126781

Macke, D L

The Powder River basin is one of the most actively explored Rocky Mountain basins for hydrocarbons, yet the lower Paleozoic (Cambrian through Mississippian) rocks of this interval remain little studied. As a part of a program studying the evolution of sedimentary basins, approximately 3200 km of cross section, based on more than 50 combined geophysical and lithologic logs, have been constructed covering an area of about 200,000 km/sup 2/. The present-day basin is a Cenozoic structural feature located between the stable interior of the North American craton and the Cordilleran orogenic belt. At various times during the early Paleozoic, the basin area was not distinguishable from either the stable craton, the Williston basin, the Central Montana trough, or the Cordilleran miogeocline. Both deposition and preservation in the basin have been greatly influenced by the relative uplift of the Transcontinental arch. Shows of oil and dead oil in well cuttings confirm that hydrocarbons have migrated through at least parts of the basin's lower Paleozoic carbonate section. These rocks may have been conduits for long-distance migration of hydrocarbons as early as Late Cretaceous, based on (1) the probable timing of thermal maturation of hydrocarbon-source rocks within the basin area and to the west, (2) the timing of Laramide structural events, (3) the discontinuous nature of the reservoirs in the overlying, highly productive Pennsylvanian-Permian Minnelusa Formation, and (4) the under-pressuring observed in some Minnelusa oil fields. Vertical migration into the overlying reservoirs could have been through deep fractures within the basin, represented by major lineament systems. Moreover, the lower Paleozoic rocks themselves may also be hydrocarbon reservoirs.

• Research Organization: Geological Survey, Denver, CO (USA)
• OSTI ID: 6126781
• Report Number(s): CONF-8808223-
• Conference Information: Journal Name: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States) Journal Volume: 72:7
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
CAMBRIAN PERIOD
CARBONATE ROCKS
DEVONIAN PERIOD
EXPLORATION
FEDERAL REGION VIII
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MINERAL RESOURCES
MISSISSIPPIAN PERIOD
MONTANA
NORTH AMERICA
ORDOVICIAN PERIOD
ORIGIN
PALEOZOIC ERA
PENNSYLVANIAN PERIOD
PETROLEUM DEPOSITS
POWDER RIVER BASIN
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SILURIAN PERIOD
USA
WYOMING