Current topics in ESR dating

摘要

After over 25 years, the use of electron spin resonance (ESR) is well-established in dating sites of geological, paleontological and archaeological interest. Like any scientific technique, there have been changes in understanding and in methodology. Improvements have not, however, changed the observation that external dose calculations are still a significant source of uncertainty in ages. Examples from Europe, Africa and the Americans illustrate this point. For Pradayrol Cave (France), the occupation age, 330 ka, is unchallenged, making this the oldest known Neanderthal site in France. For Roc de Marsal, also in France, on the other hand, discrepancies between TL and sedimentary dose rates imply substantial differences in interpretation. In the Western Egyptian Desert, where artifacts and datable material are not well-correlated, the dating results show consistency with expectations based on global climate change, even in deflated sites. Climate change is also the question in geological studies in the Bahamas where, despite concerns about cosmic dose history, ESR dates confirm other evidence for sea level changes. We show that an uncertain age is not the same as an impossible one.