An assessment of the luminescence sensitivity of australian quartz with respect to sediment history

Abstract

This study provides a preliminary systematic characterisation of OSL sensitivity, with re-spect to sediment history, of single grains of Australian quartz from a variety of source rocks and depositional contexts. Samples from two distinct lithologies and with relatively short modern sedi-mentary histories were compared in an examination of the influence of rock type on OSL sensitivity. Sediments derived from weathered sandstone were found to be brighter than those from metamor-phosed schists, suggesting that sensitivity may be inherited from the source rock and its earlier sedi-mentary history. Secondly, quartz from the same source, but different modes of deposition, was com-pared to assess the effect on sensitivity of nature of exposure to light during the most recent bleaching event. Quartz grain sensitivity appears not to vary depending on the mode of sediment deposition, suggesting that the nature of exposure to light during deposition is less important in the sensitisation process. This study highlights the complexity and variety of natural sedimentary quartz, demonstrat-ing the limitations of an investigation based solely on OSL sensitivity. Further systematic investiga-tion into the physical, geological and geomorphological characteristics of sediments is proposed to better understand the mechanisms of luminescence sensitisation in quartz. © 2011 Silesian University of Technology, Gliwice, Poland. All rights reserved.