The Sou Hills: A barrier to faulting in the central Nevada Seismic Belt

Abstract

Bedrock zones transverse to regional structures may indicate barriers at depth that inhibit the propagation of fault ruptures in the Basin and Range Province. The Tertiary bedrock of the Sou Hills separates Dixie and Pleasant valleys and is transverse to the trends of physiography and historic surface faulting in central Nevada. Four lines of evidence indicate that the Sou Hills are a barrier to faulting in the seismic belt. First, total late Cenozoic vertical displacement on range‐bounding faults decreases toward the Sou Hills. Second, analyses of landforms that reflect rates of relative uplift show that Quaternary uplift decreases where range‐bounding faults meet the Sou Hills. Third, the most recent prehistoric faulting south of the transverse zone is several thousand years younger than faulting to the north. Fourth, patterns of late Quaternary fault scarps in the Sou Hills are similar to rupture patterns observed at the termination of faults elsewhere.