Single quartz grain electron spin resonance (ESR) dating of a contemporary desert surface deposit, Eastern Desert, Egypt

摘要

Signal resetting by sunlight prior to burial is a crucial assumption in electron spin resonance (ESR) dating of sediments. This resetting process is expected to be completed to a greater extent in and than in fluvial environments. The present paper investigates the natural and artificially irradiated signal intensity of Ti related centres in single quartz grains collected from the desert surface (Eastern Desert, Egypt) in order to test this hypothesis. The results suggest that in most grains both the Ti-Li and Ti-H signal are completely reset to zero. Additive dose curves based on the sum of both Ti centres show an anomaly in the low dose region. Possible causes for this behaviour are briefly discussed. Three fitting procedures are conducted and each of them shows a different palaeodose distribution with a rather large spread in D-E values. It is concluded that similar fossil deposits would be datable by single grain ESR using Q-band measurements of the Ti-Li or Ti-H signals in quartz. (C) 2004 Elsevier Ltd. All rights reserved.