This research is to develop a technique to date movements on faults by analysis of the distribution of cosmic-ray-flux- generated carbon-14 in calcite on exposed limestone fault scarps. The initial area of investigation will be in Pleasant Valley, Nevada, and in the Oquirrh-Stansbury Ranges, Utah. Carbon-14 production will be calibrated on surfaces of known age such as Bonneville and Provo Shoreline features which have previously been used to calibrate in situ produced cosmogenic isotopes. Future studies could be extended to use other minerals which will greatly extend the method's usefulness. The goal is to extend the record of earthquake occurrence on exposed faults into pre- historical times. This research is a component of the National Earthquake Hazard Reduction Program.