Precambrian control of Laramide faulting, Sheep Ridge anticline, western Owl Creek Mountains, Wyoming

Conference · · Mountain Geologist; (United States)

OSTI ID:5528896

Blundell, J S; Marrs, R W ^[1]

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1. Univ. of Wyoming, Laramie (United States)

Penetrative fabric data from a basement-involved Laramide fold and thrust structure on the north margin of the Wind River Basin were measured to investigate the role of Precambrian structural control on Laramide fault orientation. Three elements of the basement fabric were mapped along the crest and flanks of the Sheep Ridge anticline: (1) foliations; (2) fractures; and (3) mafic dikes. S-pole diagrams of the data show maxima for foliations and dikes that strike N40{degree}-45{degree}W and dip 45{degree}-50{degree} northeast. Fracture planes show two significant maxima: (1) N80{degree}-85{degree}W striking planes that dip 25{degree}-35{degree} northeast, and (2)N0{degree}-10{degree}E striking planes that dip 90{degree}. The northwest striking cottonwood Creek thrust fault dips northeast, and cuts the southwest flank of the anticline. The fault plane changes its orientation to an east-west striking high-angle reverse fault at the nose of the structure. Two mechanisms appear to accommodate this change in fault orientation: (1) the development of a footwall imbricate fault, and (2) the transfer of stress from northwest striking basement fabric elements to east-west striking basement fabric elements.

• OSTI ID: 5528896
• Report Number(s): CONF-8905393--
• Conference Information: Journal Name: Mountain Geologist; (United States) Journal Volume: 28:2-3
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ANTICLINES
BASEMENT ROCK
DEVELOPED COUNTRIES
DIKES
FEDERAL REGION VIII
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
MOUNTAINS
NORTH AMERICA
ORIENTATION
PRECAMBRIAN ERA
SEDIMENTARY BASINS
STRESSES
TECTONICS
USA
WYOMING