Elastic flexure with compressive thrusting of the Green River Basin, Wyoming, U.S.A.

Abstract

An inverse elastic flexural model with compressive thrusting is applied to the northern Green River Basin, Wyoming. A combination of six parameters in the model determines the deformational processes of basement due to sediment load and compressive thrusting: flexural rigidity, lateral stress, bending moment, initial load, dip angle of the basement, and length. The results suggest that the northern Green River Basin develops dominantly as an elastic flexural response to the deformation of basement due to compressive thrusting of the Wind River Mountains. From the unloaded basement configuration we estimate that by latest Cretaceous time the thrust fault activity of the Wind River Mountains led the basement to uplift about 7 km above the hinge point at the margin of the basin and to form a complex faulted mountain system. The maximum uplift rate is about lOOm/Ma at the Wind River Mountains. Also we predict the sedimentary pattern, and provenance of sediments of Tertiary units, from the unloaded basement geometry. Thus the inverse elastic flexural model can be used to assess the evolutionary processes involved in a basin under compressive thrusting.