Master of Science (MS)
First Committee Member
Wanda J. Taylor
Number of Pages
The River Mountains are the eroded remnants of a mid-Miocene stratovolcano complex located between Henderson, Nevada and western Lake Mead. This study addresses the tectonic and societal significance of (1) a 13.5-9 Ma initial stage and (2) a late-Pliocene(?)-present stage of extension. Multiple slip histories were recorded on NW-, N-, NE-, and E-striking conjugate fault sets, in addition to numerous orthorhombic faults. Multiple corrugations on the Saddle Island detachment (SID) during 13.5-9 Ma extension are interpreted to have produced localized zones of triaxial strain and orthorhombic faulting. Conjugate faults occurred where the SID was planar. The multiple kinematics suggest that 13.5-9 Ma tectonism in the River Mountains was controlled by transient slip gradients on the Las Vegas Valley shear zone and the Lake Mead fault system. Active faults of the second period of extension may impact present day Las Vegas. An earthquake rupturing the combined 38 km length of the Ithaca Avenue Fault-Frenchman Mountain Fault could produce a MW 6.9 +/- 0.3 earthquake.
Cenozoic; Extension; Frenchman; Mountain; Mountains; Nevada; River; Southern
University of Nevada, Las Vegas
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Rittase, William Michael, "Cenozoic extension in the River Mountains and Frenchman Mountain, Southern Nevada" (2007). UNLV Retrospective Theses & Dissertations. 2148.