We map and analyze 795 basement-rooted faults, expressed as high-angle reverse and near-vertical strike-slip faults. High-angle reverse faults that strike NNW-SSE define the eastern margin of the Central Basin platform and generate the greatest structural relief. East of the Central Basin platform, NNW-SSE and NNE-SSW striking reverse faults bound low-amplitude uplifts. Reverse faults are accompanied by WNW-ESE and WSW-ENE striking strike-slip faults, which limit the lateral length of reverse faults and associated uplifts, coinciding with a reversal in fault-bounded uplift vergence direction, and exhibit evidence for transpressional translation. These observations suggest that reverse structures initiated during Late Paleozoic orogenesis, but WNW-ESE and WSW-ENE striking strike-slip faults are the Late Paleozoic reactivation of a long-standing Proterozoic fabric.

Earthquakes have occurred on basement-rooted high-angle reverse and reverse–strike-slip faults, which are reactivated under present-day stress conditions as normal and normal–strike-slip, respectively. FSP analyses show that WNW-ESE and WSW-ENE striking faults are sensitive to reactivation under modest pore pressure increase. Our results provide a foundation to investigate causal behavior, characterize fault slip hazard, and can therefore be used to plan and regulate ongoing petroleum operations.