The Owens Valley fault zone (OVF) is one of the primary structures accommodating dextral shear across the Eastern California shear zone (ECSZ). Previous estimates of the Holocene slip rate along this structure rely on paleoseismic data and yield rates 2-3 times lower than those implied by geodetic velocities. Using displaced lava flows along the flank of Crater Mountain, we present the first estimate of slip rate along the OVF during the late Pleistocene. Subsurface characterization of the flow margin using a ground-penetrating radar (GPR) allows for relatively precise determination of dextral displacement, and terrestrial cosmogenic 36Cl exposure ages of samples from the flow surface yield slip rates between ∼2.8 - 4.5 mm/yr over the past 55-80 kyr. Our results suggest either that paleoseismic slip-rate estimates underestimate the long-term slip rate or that rates of strain release have not been steady during the latter part of the Quaternary.
All Science Journal Classification (ASJC) codes
- Earth and Planetary Sciences(all)