Patterns and timing of Late Quaternary faulting in the Great Basin Province and relation to some regional tectonic features

Abstract

Large‐scale surface faulting events, each tens of kilometers long and involving more than a meter of displacement, of late Quaternary age have not been uniformly distributed but have been concentrated in subprovincial and smaller belts and areas within the Great Basin province. Furthermore, faulting apparently has not been uniformly distributed over time. The average recurrence interval of large‐scale faulting events on individual faults in the province is measured in thousands or tens of thousands of years. In contrast to such long recurrence intervals, in the central Nevada and eastern California seismic belts, large‐scale faulting events have occurred during the last 111 years in an apparently coherent, sequential belt‐filling pulse of activity in which events were separated by only a few years or a few decades. The questions are, where are other pulses of large‐scale faulting likely to occur and what controls the localization of such belts and areas characterized by higher rates of faulting? Two examples of tectonic subprovinces that may play a role in delimiting smaller zones of faulting are the Black Rock‐Carson Sink zone of extension and the central Nevada downwarp. The central Nevada seismic belt lies along the dividing line between these two subprovinces, and the northwest margin of the Black Rock‐Carson Sink zone of extension coincides with the margin of a fingerlike belt of dense faulting in northwestern Nevada.