ESR dating of aeolian sediments from Pleistocence desert environments

电子自旋共振（ESR）光谱将用于估计更新世沙漠环境中风成层序的沉积年龄。最近的研究表明，石英中与钛相关的杂质缺陷具有利用ESR建立风成沉积年表的巨大潜力（Beerten和Stesmans， 2005）。ESR测年最重要的前景在于其测年范围有望超越其他广泛使用的风成沉积测年方法（如光激发发光测年法或热释光测年法）的上限。过去曾多次尝试用ESR测定这类矿床的年代，但至今缺乏系统的研究。然而，与其他年龄控制相比，ESR测年结果的广泛数据库是评估ESR测年方法的重要因素。从澳大利亚、埃及、苏丹和纳米比亚的风成环境中，跨越晚更新世和中更新世的几个序列将使用多个谷物样品的x波段ESR光谱进行研究。这些层序目前正在其他项目的框架内进行研究，后者提供（独立的）基于发光方法的年龄控制，以及来自区域地层学的间接年龄控制。预计本研究成果将是扩大ESR测年范围的重要一步，超出了用于风成沉积物测年的其他技术（如OSL）。

Electron spin resonance (ESR) spectroscopy will be used to estimate depositional ages of aeolian sequences from Pleistocene desert environments. Recent investigations have shown that Ti related impurity defects in quartz have a great potential for establishing chronologies of aeolian deposits using ESR (Beerten and Stesmans, 2005). The most important prospect of ESR dating lies in the expected extension of the dating range beyond the upper limit of other widely used dating methods for aeolian deposits such as optically stimulated luminescence (OSL) or thermoluminescence (TL) dating. In the past, several attempts have been made to date such deposits with ESR, but a systematic study is lacking so far. An extensive database of ESR dating results against other age control however is an important element in the evaluation of the ESR dating methodology. Several sequences from aeolian environments in Australia, Egypt, Sudan and Namibia, spanning the Late and Middle Pleistocene, will be investigated using X-band ESR spectroscopy of multiple grain samples. Such sequences are currently being studied in the framework of other projects, the latter providing (independent) age control based on luminescence methods, and indirect age control from the regional stratigraphy. It is expected that the output of this study will be an important step in extending the dating range of ESR beyond that of other techniques (i.e. OSL) used for dating aeolian deposits.