Tectonically influenced sedimentation in the Lance Formation eastern Wind River Basin, Wyoming
- South Dakota School of Mines and Technology, Rapid City (United States)
Facies analyses of the Maastrichtian Lance Formation in two areas of the Wind River Basin indicate deposition in fluvio-deltaic environments. The facies architecture of the fluvial deposits in the upper Lance Formation was strongly influenced by Laramide basin subsidence. The lower Lance in the basin axis contains strata deposited in a prograding delta along a low-energy shoreline. Delta-front deposits are overlain by cyclic interdistributary bayfill sequences, and distributary channels and floodplains representing lower and upper delta plain facies respectively. The upper Lance in the basin axis consists of thick layers of overbank deposits associated with highly aggradational, possibly anastomosing, river systems. Electric log cross sections indicate that these fine-grained facies are confined to the basin axis. This suggests that basin subsidence was directly affecting topography causing the streams near the basin axis to aggrade. Continued subsidence of the basin resulted in the accumulation of thick sequences of waterlogged floodplain sediments consisting of shallow lake and backswamp deposits in the basin axis. The Lance on the southern basin margin consists of strata deposited in a large, fine-grained, low-sinuosity river system. Crossbedding indicates that these rivers initially flowed east toward the Lewis Sea but were later diverted northward into the subsiding basin axis. Oil and gas is produced from the Lance Formation in several fields in the eastern half of the Wind River Basin. Reservoir geometry in these fields reflects the tectonic control of fluvial architecture noted above. Tectonic processes may also have influenced the type of kerogen present in the source rocks, making the Lance Formation more gas-prone along the southern basin margin and more oil-prone in the basin axis.
- OSTI ID:
- 5683756
- Report Number(s):
- CONF-8905393--
- Journal Information:
- Mountain Geologist; (United States), Journal Name: Mountain Geologist; (United States) Vol. 28:2-3; ISSN MOGEA; ISSN 0027-254X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sequence stacking and architecture, Cretaceous Foreland basin, Utah
Tectonic control on deltaic cyclicity in the Ridge Basin, California
Related Subjects
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
DEPOSITION
DEVELOPED COUNTRIES
ELECTRIC LOGGING
ENVIRONMENTAL TRANSPORT
FEDERAL REGION VIII
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GROUND SUBSIDENCE
KEROGEN
MASS TRANSFER
MATERIALS
MATTER
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NATURAL GAS FIELDS
NORTH AMERICA
OIL FIELDS
ORGANIC MATTER
PETROLEUM DEPOSITS
PRODUCTION
RESOURCES
SEDIMENTARY BASINS
SEDIMENTATION
SEDIMENTS
SOURCE ROCKS
STREAMS
SURFACE WATERS
TECTONICS
USA
WELL LOGGING
WYOMING