继承性宇生核素在冰川地貌暴露测年中的研究进展  

Research progress of inherited cosmogenic nuclide in exposure dating of glacial geomorphology

作　　者：张梦媛 梅静 张志刚[1,2,3,4] 王建[1,2,3,5] 梁兴江 ZHANG Mengyuan;MEI Jing;ZHANG Zhigang;WANG Jian;LIANG Xingjiang(School of Geographical Sciences,Nanjing Normal University,Nanjing 210023,China;Key Laboratory of Virtual Geographic Environment (Nanjing Normal University),Ministry of Education,Nanjing 210023,China;Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application,Nanjing 210023,China;State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;School of Urban and Resource Environment,Jiangsu Second Normal University,Nanjing 210024,China;Geological Exploration Technology Institute of Jiangsu Province,Nanjing 210049,China)

机构地区：[1]南京师范大学地理科学学院,南京210023 [2]虚拟地理环境教育部重点实验室(南京师范大学),南京210023 [3]江苏省地理环境演化国家重点实验室培育建设点,南京210023 [4]中国科学院西北生态环境资源研究院冰冻圈科学国家重点实验室,兰州730000 [5]江苏第二师范学院,南京210024 [6]江苏省地质勘查技术院,南京210049

出　　处：《地球环境学报》2019年第4期325-334,共10页Journal of Earth Environment

基　　金：国家自然科学基金项目(41971009,41503054);中国博士后科学基金面上项目(2015M582728);江苏省高校优势学科建设工程项目(164320H116)~~

摘　　要：原地生成宇宙成因核素(in situ terrestrial cosmogenic nuclide,TCN)暴露测年技术已被广泛应用于全球冰川地貌的年代测定中。继承性核素(inheritance,核素残留)作为影响TCN暴露测年的重要因素之一,一直以来受到许多学者的关注。然而,继承性核素对暴露测年结果有无影响、影响程度有多大还存在争论。梳理该方面的研究将有助于进一步了解继承性宇生核素对TCN暴露测年的影响,进而提高测年的精确性。基于此,整理了2009—2017年共计54篇全球关于第四纪冰川宇生核素继承性文献,简述继承性核素的产生背景和研究进展,重点探讨核素残留对TCN暴露测年的影响程度以及在实际应用中如何降低其对测年数据的影响。结果表明:继承性核素会导致冰碛物出现异常老化和分散的暴露年龄,可通过选取合适的地貌部位及多样化的抽样和多样品方法,也可尝试采集现代冰川冰碛物定量化研究继承性核素的影响。Background,aim,and scope In situ terrestrial cosmogenic nuclide(TCN)has been widely used in the dating of glacier geomorphology.Inheritance is one of the important factors affecting the TCN exposure dating and has been the focus of many scholars.The research on this aspect will contribute to the quantitative analysis of TCN exposure dating error,and thus improve the accuracy of dating.Materials and methods In this paper,a total of 54 global literatures on quaternary glacial TCN inheritance were collected from 2009 to 2017,briefly describing the background and research progress of inherited nuclides,focusing on the influence of inheritance on TCN exposure dating and how to reduce its impact on dating data in practice.Results On the one hand,the complex exposure history of the sample and the reworking of geological features may lead to samples containing different degrees of inherited cosmogenic nuclide,which makes the age of glacial exposure significantly dispersible.On the other hand,in the study of TCN exposure dating,the true age of glacier landform is overestimated due to the inheritance of nuclide,which leads to the age of exposure of abnormal aging.Discussion Among the 1379 dating samples counted in this paper,glacial boulder is about 94%,and glacial boulder is the most common dating object in the study of TCN exposure dating.When a glacial boulder age than other boulder on the same moraine ridge is much older,the inheritance of nuclide is obvious,therefore,how to choose the glacial boulder to determine the formation of the moraine ridge appears very necessary.In addition,the sampling location and the number of collections of glacial boulder are also worth considering.Conclusions Research results indicate that the inheritance of nuclide can lead to the age of old and scattered exposure of moraine,by choosing appropriate landscape areas and diverse methods of sampling,also can try to collect modern glacier moraine quantitative research the effects of inheritance.Recommendations and perspectives The study of t

关 键 词：继承性核素 宇生核素 TCN暴露测年法 冰川地貌 测年误差 

分 类 号：P597.3[天文地球—地球化学] P931.4[天文地球—地质学]