Restraining bend tectonics in the Santa Cruz Mountains, California, imaged using 10Be concentrations in river sands

Reverse faults frequently generate large and destructive earthquakes, their seismic hazard remains diffi cult to assess with traditional tools because their surface expressions are often and subtle. This contribution assesses the utility of millennial- denudation rates derived from in-situ cosmogenic 10Be for the spatial patterns and magnitudes of rock uplift produced slip along reverse faults. We present seventeen basin-averaged rates from rivers draining the Santa Cruz Mountains the San Andreas fault (California, USA) which closely reproduce uplift rate patterns associated with a restraining bend the fault. An additional component of vertical deformation to be superposed on the uplift due to the restraining bend; may result from regional transpression, further irregularities in fault trace, or interactions with neighboring faults. Our results that 10Be-derived denudation rates can reveal patterns of uplift adjacent to reverse faults over length-scales relevant for their seismic hazard potential.