Evidence for 65 km of dextral slip across Owens Valley, California,since 83 Ma

Abstract

The Golden Bear dike in the Sierra Nevada and the Coso dikes in theCoso Range crop out on opposite sides of Owens Valley, California, andstrike roughly perpendicular to it. Neither dike reappears alongstrike across the valley. New data demonstrate that the dike sets areca. 83 Ma in age, share nearly identical mineralogy and petrography,and intrude similar wall rocks including distinctive 102 Maleucogranite. Dike bulk-chemical and Sr and Nd isotope compositionsare nearly indistinguishable. These data suggest that the dike setswere originally continuous and were offset dextrally by approximately65 km. This displacement estimate is consistent with other recentestimates of total slip across Owens Valley. If faulting began duringthe Pliocene, the average slip rate was significantly faster than thecurrent rate. Alternatively, motion could have been episodic and havebegun as early as the Late Cretaceous.

47 samples from this reference