南极洲拉斯曼丘陵及其邻近地区冰盖演化历史研究进展  

Research advances of the ice sheet history in the Larsemann Hills and adjacent regions,East Antarctica

作　　者：陈麓名 张志刚[1,2,3] 赵丹 张红梅 林怡 CHEN Luming;ZHANG Zhigang;ZHAO Dan;ZHANG Hongmei;LIN Yi(School of Geography,Nanjing Normal University,Nanjing 210023,China;National Demonstration Center for Experimental Geography Education(Nanjing Normal University),Nanjing 210023,China;Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application,Nanjing 210023,China)

机构地区：[1]南京师范大学地理科学学院,江苏南京210023 [2]地理科学国家级实验教学示范中心(南京师范大学),江苏南京210023 [3]江苏省地理信息资源开发与利用协同创新中心,江苏南京210023

出　　处：《冰川冻土》2024年第4期1414-1422,共9页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41971009)资助。

摘　　要：东南极冰盖的演化能够显著影响全球气候变化,因此,对该地区冰盖演化历史的研究是理解第四纪全球气候变化的关键。近年来,陆地宇生核素(in-situ Terrestrial Cosmic Nuclides,TCN)暴露测年逐步应用于拉斯曼丘陵地区冰川地貌年代测定。对该区第四纪冰川地貌年代数据的梳理可以进一步了解南极冰盖的变化。本研究归纳整理了拉斯曼丘陵及其邻近地区1997—2022年发表的15篇文献共196个10Be暴露测年数据,结果显示拉斯曼丘陵的最小暴露年龄为(4.05±0.81)ka,最大暴露年龄为(147.01±11.80)ka,其邻近地区最小暴露年龄从(0.32±0.20)ka至(4096±2404)ka不等。对不同来源和地区的数据进行对比,得到以下结论:(1)17.86%暴露年龄小于11 ka,83.16%样品暴露年龄小于600 ka,98.47%的样品暴露年龄小于2.8 Ma,部分地区^(10)Be暴露年龄确定的冰退时间仍存在争议。(2)侵蚀速率达到0.007 mm·a^(-1)时,对测年结果的影响达到了51.57%,该影响因素不可忽略。(3)暴露年龄有随海拔的降低有减小的趋势,需进一步研究来解释其原因。The evolution of the East Antarctic Ice Sheet can significantly affect global climate change since deglaciation could contribute much to sea-level dynamics.Thus,studying ice sheet history in this region is the key to understanding the Quaternary global and regional climate change.In recent years,in-situ Terrestrial Cosmic Nuclides(TCN)exposure dating has been gradually applied to the dating of glacial dynamics in the Larsemann Hills area.The data of Quaternary glacial chronology in this area can be employed further to understand the changes in the Antarctic Ice Sheet,and the dating results from this method currently require further refinement.This study summarized and homogenized 196^(10)Be exposure dating data from 1997 to 2022 of the Larsemann Hills and adjacent areas.These areas include the Larsemann Hills,Vestfold Hills and Rauer Group,Prince Charles Mountains,and Grove Mountains.The sampling information such as sample type,altitude,latitude,elevation,shielding factors,thickness,erosion rate,density,and AMS results were also counted.Based on distinguishing erratic and bedrock samples,we applied the newest model to all of the sample data and recalculated them.Meanwhile,the onset of biogenic sedimentation in the Larsemann Hills has been recorded with bedrock exposure data for further discussion.The results showed that the minimum exposure age of the Larsemann Hills was(4.05±0.81)ka,and the maximum exposure age was(147.01±11.80)ka.The minimum age of exposure in its adjacent areas ranged from(0.32±0.20)k a t o(4096±2404)ka.The earliest date reaches the mid-Pleistocene,specifically MIS Gi24,spanning the entire Quaternary period.Among all the samples discussed,17.86%have an exposure age of less than 11 ka,83.16%have an exposure age of less than 600 ka,and 98.47%have an exposure age of less than 2.8 Ma.We divided the chronology into the Holocene(approximately 11 ka,MIS 1),the mid to late Pleistocene(approximately 11 ka to 600 ka,MIS 1 to MIS 15),and the early Pleistocene to late Pliocene(600 ka to 4000 ka,MIS 15

关 键 词：东南极 拉斯曼丘陵 暴露年龄 冰川演化 

分 类 号：P343.6[天文地球—水文科学]