The general east-west trend of the regional-scale, fault-related Casper Mountain uplift in central Wyoming reflects a preexisting Precambrian fabric along which there was Laramide compressional reactivation. Initial fault displacement on the south-dipping Casper Mountain fault zone probably predates displacement on the intersecting, northwest-trending, northeast-dipping Casper arch thrust that forms the northeastern border of the Wind River basin. Later phase, incremental, Laramide displacements occurred along both fault zones: left-oblique slip on the Casper Mountain fault zone, dip slip on the crosscutting Casper arch thrust. Basement-involved thrust generation of the subsidiary Laramide, northwest-trending Iron Creek and Emigrant Gap anticlines along the north (footwall) side of the Casper Mountain fault zone also occurred during this later phase Laramide deformation.

Perturbation of far-field, northeast-southwest, Laramide maximum horizontal paleostress trajectories (σ1) to local, nearly fault-normal orientation at Casper Mountain, together with strain partitioning, is proposed to explain the apparent coeval development of divergent hanging-wall and footwall, basement-involved, fault-related structures. This kinematic and dynamic interpretation may be applied conditionally to other east-west-trending Laramide uplifts in the central Rocky Mountain foreland province.

You do not have access to this content, please speak to your institutional administrator if you feel you should have access.