Criteria for complete zeroing of ESR signals during faulting of the San Gabriel fault zone, southern California

In using electron spin resonance (ESR) to date the time of the last movement on a fault, it is essential to demonstrate that the ESR signal was fully zeroed at the time of faulting; if the signal was not completely reset, then the ESR age obtained will be too great. We have refined the criteria for complete zeroing of ESR signals at the time of fault movement. Samples of fault rocks were collected from surface outcrops of the San Gabriel fault …