An Integrated Geological and Geophysical Analysis of Thrusting in the Hoback Range, Sublette and Teton Counties, Wyoming

STERNE, E. J., and M. C. WILLIAM, Amoco Production Company, Denver, CO

Recent seismic acquisition and drilling in the Hoback Range of the Wyoming thrust belt have focused on the buried Granite Creek thrust sheet. To date, four wells have penetrated the thrust sheet and have yielded some encouraging results without establishing production. Wells, seismic control, and surface geology help define the southern extent of the Granite Creek thrust package as well as the lateral and subsurface geometry of other thrust packages in the area.

The Hoback Range provides an excellent view of a frontal thrust zone with several unique attributes. In contrast to most parts of the Cordilleran thrust belt, the regional layer dips east, reflecting the convergence of the northern Moxa arch and the thrust belt. Typical eastward younging of thrusting is not followed, and the order of thrusting can be shown to break back to the west. Unlike other parts of the Wyoming thrust belt, a west-vergent thrust bounds the eastern limit of thrusting and forms a possible triangle zone. The Cache Creek fault merges into the northern end of the range and offers an excellent opportunity to study thrust-belt and foreland interactions.

This study illustrates many of the problems typically encountered in areas of complex structure and demonstrates how they may be solved using an integrated geological and geophysical approach.

AAPG Search and Discovery Article #91010©1991 AAPG Rocky Mountain Section Meeting, Billings, Montana, July 28-31, 1991 (2009)