Late Pleistocene and Holocene Paleoearthquake Activity of the Olinghouse Fault Zone, Nevada

Paleoseismic trenching and fault surface trace mapping indicate that the Olinghouse fault zone, a northeast trending, left-lateral strike-slip fault located in the northern Walker Lane, Nevada, has been the source of multiple latest Pleistocene and Holocene surface-rupturing earthquakes. A trench exposure near the eastern end of the fault records two, and possibly three, earthquakes after 3360 190 cal. yr B.P. and two trenches at the western end of the fault contain evidence for two earthquakes after 19,800 630 cal. yr B.P., with the most recent earthquake occurring after 1935 70 cal. yr B.P. The apparent higher frequency of recent earthquakes at the eastern end of the fault may reflect triggered slip on the Olinghouse fault zone due to earthquakes on the conjugate northwest-trending, right-lateral Pyramid Lake fault. Repeated late Pleistocene and Holocene earthquakes on the Olinghouse fault zone demonstrate that northwest-directed, right-lateral shear of the northern Walker Lane is accommodated in part by northeast-trending left-lateral faults.