Two large gravity slide blocks moved up to 5 mi southwestward off the Lemhi Range during the latest stages of basin-range uplift. Both detachment faults coincide in part with folded thrust faults along which 1 to 3 mi of eastward displacement occurred during the Mesozoic Sevier orogeny. The detachment faults, which dip 9° to 12° southwest, are not offset by the normal fault zone at the range margin. Sliding was localized by the interception of west-dipping folded thrust surfaces by the range front normal fault zone.

First Page Preview

First page PDF preview
You do not currently have access to this article.