Award Date

1-1-2007

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Geoscience

First Committee Member

Wanda J. Taylor

Number of Pages

269

Abstract

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.

Keywords

Cenozoic; Extension; Frenchman; Mountain; Mountains; Nevada; River; Southern

Controlled Subject

Geology

File Format

pdf

File Size

7976.96 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Permissions

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Identifier

https://doi.org/10.25669/ntnu-6nkj


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