Geological Society of America

T345 Tectonics, Geohazards, and Morphodynamics from High-Resolution Topography and Imagery

Wednesday, 25 October 2017
1:30 PM - 5:30 PM
Tahoma 4

A NEW GEOLOGICAL SLIP RATE ESTIMATE FOR THE CALICO FAULT, EASTERN CALIFORNIA: IMPLICATIONS FOR GEODETIC VERSUS GEOLOGIC RATE ESTIMATES IN THE EASTERN CALIFORNIA SHEAR ZONE

Paper number: T345-12
Program: Technical Sessions
Time: 4:30 PM – 4:45 PM

Authors

Surui Xie
University of South Florida, Tampa, FL
Elisabeth Gallant
University of South Florida, Tampa, FL
Paul Wetmore Presenting Author
University of South Florida, Tampa, FL
Lewis A. Owen
University of Cincinnati, Cincinnati, OH
Timothy Dixon
University of South Florida, Tampa, FL

Abstract

Fault slip rate is fundamental to accurate seismic hazard assessment. In the Mojave Desert section of the Eastern California Shear Zone previous studies have suggested a discrepancy between short-term geodetic and long-term geologic slip rate estimates. Understanding the origin of this discrepancy could lead to better understanding of stress evolution, and improve earthquake hazard estimates in general. We measured offsets in alluvial fans along the Calico fault near Newberry Springs, California, and used exposure age dating based on the cosmogenic nuclide ¹⁰Be to date the offset landforms. We derive a mean slip rate of 3.6 mm/yr, representing an average over the last few hundred thousand years, significantly faster than previous estimates.

Considering numerous faults in the Mojave Desert and limited geologic slip rate estimates, it is premature to claim a geologic versus geodetic “discrepancy” for the ECSZ. More data are needed to provide a statistically meaningful assessment of the geologic rates for each of the faults comprising the ECSZ.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-300595

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