作　　者： ; ; ;

机构地区： 嘉应学院地理科学与旅游学院

出　　处： 《核技术》 2013年第2期36-41,共6页

摘　　要： 在青藏高原东部硬普沟采集6个冰川沉积光释光测年样品(2个现代样、3个新冰期和1个末次冰期样品),运用SAR结合SGC技术,采用石英大测片、小测片BSL以及多矿物IRSL等3种方法进行了等效剂量(De)的测试,SAR和SGC技术测得的De值相近。3种方法的测试结果表明,De值IRSL>大测片BSL>小测片BSL。多矿物IRSL测得的De值比石英BSL偏高,表明长石比石英较难晒退,不适于该地冰川沉积测年。石英大测片适于晒退较好的样品。该地石英的释光敏感性较低,小测片的测试情况不理想,且不能完全区分不同晒退程度的颗粒。对于年代较老的、较明亮的冰川沉积样品,石英小测片甚至单颗粒技术可能是可行的。今后需要更多研究如何应对释光敏感性低的样品的测试问题。 Background： Absolute dating is the key technical issue of Quaternary glacial research. Optically stimulated luminescence （OSL） has been increasingly applied to Quaternary glacial dating in recent years. However, problems such as insufficient bleaching, low luminescence sensitivity, high thermal transfer effect, etc, still remain. Purpose： In order to investigate the applicability of equivalent dose （De） determination of glacial sediments by different OSL methods, six samples were collected from the Yingpu Valley of eastern Qinghai-Tibetan Plateau （two samples from modem glacial sediments, three from moraines and glacial terrace attributed to Neoglacial and one from a moraine attributed to the last glaciation）. Methods： The Des were determined by SAR combined SGC technique, using three methods： quartz large aliquot （6 mm） BSL, small aliquot （2/3 mm） BSL and polymineral IRSL. Results： Des determined by SGC are consistent with Des determined by SAR protocol. Comparison of three methods shows that IRSL De 〉large aliquot B SL De 〉small aliquot B SL De. Des of polymineral IRSL are obviously higher than quartz BSL. Conclusions： It is obviously that feldspar is more difficult to reset than quartz, thus is not suitable for dating glacial sediments in this region. Quartz large aliquot method is suitable for well bleached glacial samples. Due to the low luminescence sensitivity of quartz, small aliquot method showed poor luminescence characteristics. Moreover, this method cannot distinguish the poor bleached grains in this measurement. However, it is possible that quartz small aliquot, even single grain method could be used to date older or brighter glacial samples. More works are required to solve the problems we have encountered in dating low sensitivity glacial sediments.

关 键 词： 光释光 等效剂量 单片再生剂量法 标准生长曲线法 小测片 冰川沉积物

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