M. Zreda, University of Arizona, J.S. Noller, Vanderbilt University

Science 282 (1998) 1097-1099

Cosmogenic chlorine-36 reveals dates of the multiple prehistoric earthquakes that have produced a scarp on the Hebgen Lake fault. Apparent chlorine-36 ages are stratigraphically correct, follow a predicted theoretical pattern, and produce geolocially resonable model ages of 24,20,7.0,2.6,1.7, and 0.4 thousand years ago. This result demonstrates the feasability of using cosmogenic chlorine-36 to extract paleoearthquake records from bedrock fault scarps.