稻城冰帽库照日冰碛垄的宇生核素^(10)Be年代测定  

COSMOGENIC ISOTOPE ^(10)Be DATING FOR KUZHAORI MORAINE IN DAOCHENG ICE CAP

作　　者：张志刚[1] 王建[1,2] 徐孝彬[3] 赵志军[1] 白世彪[1,2] 

机构地区：[1]南京师范大学地理科学学院,南京210046 [2]南京师范大学虚拟地理环境教育部重点实验室,南京210046 [3]江苏教育学院,南京210024

出　　处：《海洋地质与第四纪地质》2012年第1期85-91,共7页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(40572097);江苏省优势学科项目

摘　　要：沙鲁里山南端的稻城冰帽在第四纪曾发生过大规模的冰川作用,然而,关于冰川作用的年代数据相对较少。选择稻城冰帽南缘库照日附近的3套冰碛垄进行宇生核素10Be的暴露年代测定,研究结果表明:(1)库照日最老冰碛垄(E)的暴露年代为(714±8.0)～(529±8.0)kaBP,D垄的暴露年代为(121±2.9)～(114±2.9)kaBP,DC垄的暴露年代为(47±1.3)～(43±1.3)kaBP。由于宇生核素暴露年代所反映的是冰川消退时的年代,因此,我们结合深海氧同位素的气候特征以及其他测年数据推断,E垄、D垄、DC垄可能是MIS16、MIS6以及MIS3b阶段冰川作用的产物;(2)冰川退却是一种逐步退却的模式。样品E的两次测验结果比较吻合,表明宇生核素10 Be暴露测年方法对冰碛垄形成年代的测定是可靠的,该方法在地貌学和第四纪年代学研究中有着巨大的潜力。The Daocheng Ice Cap which is on the southeast of Shaluli Moutain had appeared as a large-scale glacier in Quaternary. Howevrer, there are few dating data available in the study area. In this article, we chosed three samples form the Kuzhaori moraine in the southern margin of Daocheng Ice Cap and used Cos- mogenic Isotope ^10Be exposure dating methord to date the exposure age of the moraines. It is found that： （1） the exposure time of the oldest moraine at Kuzhaori is 714±8.0-529±8.0 kaBP. The exposure age of D moraine is 12±2.9-114±2.9 kaBP. and the exposure age of DC moraine is 47±1.3-43±1.3 kaBP. Exposure ages give an estimate of the timing of initial glacier retreat, so we can deduce that E mo- raine, D moraine and DC moraine are the results of glacier advance in MIS 16.MIS 16 and MIS 3b, accord- ing to the climate changes deduced from deep-sea oxygen isotope isotopic rec （2） The retreat of glacier is a gradual process. We double-Checked the dating data of sample E. It showsthat the cosmogenic isotopes dating technique is an effective method in dating moraine samples.

关 键 词：宇生核素 稻城冰帽 第四纪 冰碛垄 10Be 

分 类 号：P597.3[天文地球—地球化学]