Thermoluminescence dating of Quaternary red-sand beds: a case study of coastal dunes in Sri Lanka

Abstract

Red-sand beds, that occupy extensive tracts of coastal humid tropics have conventionally been considered undatable. Results of a first successful attempt to provide an absolute chronology to these sediments based on thermoluminescence dosimetry are presented along with a discussion on the importance of an understanding of ambient geochemistry in the application of the thermoluminescence technique. The results on the Sri Lankan coastal region indicate that the sea level in the region may have been affected by regional tectonics during the past 70,000 years. Based on in-situ finds of geometric microliths in the red-sands, a date of ca. 25,000 years is ascribed to them, suggesting them to be substantially older than believed so far.