冰碛垄表面碎屑物质宇生核素暴露测年可行性研究

摘要

The method of in-situ Cosmogenic Nuclides 10Be and 26Al exposure dating has been widely used in dating of various landforms,especially in glacier dating.Most scholars usually choose glacier boulder which spread on the moraine surface as dating object.However,glacial boulders are existing exposed to late flip and unequal exposure problems in the exposure dating,and it not only affects the accuracy of glacial geomorphic dating,but also makes it difficult to obtain the older glacial geomorphic age.Moraine surface debris has been adhering to the "surface" of moraines which can avoid unequal exposure problem in glacial boulder dating,what' s more,it can reduce the amount of test samples and the cost of testing.Therefore,this paper attempts to explore the feasibility of using the fragmentary materials of moraine ridge for exposure dating studies,which may provide new ideas for the study of exposure dating of older glacial landforms.%原地生宇宙成因核素(宇生核素)10Be和26 A1暴露测年技术已广泛应用于各种地貌年代测定,尤其是在冰川地貌年代测定中备受青睐.多数学者通常选择冰碛垄表面散布的冰川漂砾作为测年对象.然而,冰川漂砾在暴露测年研究中存在暴露后期翻转、不等时暴露等问题,不仅影响冰川地貌测年的精度,而且难以获得较老的冰川地貌年代.冰碛垄表面碎屑物质,一直附着于冰碛垄“表面”,可以规避冰川漂砾测年存在的不等时暴露问题,而且可以减少测试样本量、降低测试费用.因此,本文尝试探讨利用冰碛垄表面碎屑物质进行暴露测年研究的可行性,可望为较老冰川地貌暴露测年研究提供新的思路.