PRINCIPLES AND POTENTIAL OF OSL THERMOCHRONOLOGY

Optically stimulated luminescence (OSL) has been applied as a sediment dating technique since the late 1980s. Significant technical developments associated with improved precision and accuracy in the last 15 years have led to much wider application recently. The basic principles for extending OSL for use as a low temperature thermochronometer are relatively straight forward. However, there are additional technical requirements for thermochronological application that go beyond the basic assumptions that must be met for successful OSL dating. I will examine the underlying physical basis of OSL dating and the related technique of IRSL (infra-red stimulated luminescence), along with both theoretical and practical considerations for applications to thermochronology. Possible pitfalls associated with naive application of the technique will be examined, besides means to negotiate these potential limitations. This is a hugely exciting new technique with real potential to answer pressing questions regarding rates and patterns of erosion and exhumation, but a clear understanding of the underlying physical basis and possible limitations is very important.