光释光测年法——综述及进展

光释光(OSL)测年是对沉积物最后一次曝光(或热)事件年代的测定,其测试对象主要为石英和长石。自20世纪80年代该方法提出以来,在国内外得到了广泛的应用。但国内不少地学工作者对该技术的原理与测年方式了解十分有限,为了使应用者能更好、更全面地了解和使用这一方法,对OSL测年法及其近年来的国内外主要研究进展进行了回顾,重点对OSL测年法的基本原理、样品采集及实验室前处理过程、等效剂量(De)值的测定方式、环境剂量率的计算,以及影响测年结果可靠性的重要因素等进行了全面介绍、分析和探讨。同时,对近年来国内外关于De值测定方法与技术上的进展及已经获得较可信年龄的相关方法等进行了总结分析,并对OSL可能测年的范围和影响结果可靠性的一些潜在因素,以及对获得100ka~1Ma间的年龄新的释光信号研究方法等进行了介绍和探讨。

Review and progress of OSL dating

Optically Stimulated Luminescence (OSL) method dates the last bleached or thermal event of the sediments. Since its development in the 1980s, OSL dating has been improved significantly. Quartz and feldspar are mainly applied to conduct such dating. This paper aims to provide an overview of the OSL dating method for geoscientists who intend to use OSL dating for chronological control in which the sampling in the field can satisfy OSL chronologists. The general principles of the method are described, and the procedures of OSL dating from the field sampling to the age interpretation in the luminescence dating laboratory are recounted, which include sampling, pretreatment, equivalent dose (De) and dose rate determination. Recent methodical and technological progress and the development of new laboratory measurement procedures for obtaining the De have resulted in more widespread and more confident use of OSL for dating, and new luminescence signals are being investigated in order to extend the age range back by an order of magnitude from 100ka to 1Ma.