古尔班通古特沙漠南缘沉积记录的全新世环境演变  

Holocene environmental evolution recorded by sedimentation on the southern edge of the Gurbantunggut Desert

作　　者：马运强 刘瑞 李志忠[1,2,3] 靳建辉[1,2,3] 邹晓君 谭典佳 陶通炼 MA Yunqiang;LIU Rui;LI Zhizhong;JIN Jianhui;ZOU Xiaojun;TAN Dianjia;TAO Tonglian(College of Geographical Sciences,Fujian Normal University,Fuzhou 350117,Fujian,China;State Key Laboratory of Subtropical Mountain Ecology,Fujian Normal University,Fuzhou 350117,Fujian,China;Institute of Geography,Fujian Normal University,Fuzhou 350117,Fujian,China)

机构地区：[1]福建师范大学地理科学学院,福建福州350117 [2]福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福建福州350117 [3]福建师范大学地理研究所,福建福州350117

出　　处：《干旱区地理》2023年第10期1663-1679,共17页Arid Land Geography

基　　金：国家自然科学基金(42071011);福建师范大学研究生科研创新基金项目资助。

摘　　要：古尔班通古特沙漠南缘处在风、水两相营力作用的交汇区域,沉积环境独特,对气候变化响应敏感,是研究中国西北沙区全新世环境演变的理想区域。选取古尔班通古特沙漠南缘荒漠-绿洲过渡带3个风积-冲积交互地层剖面,在实地观察岩性特征、沉积序列的基础上,通过光释光(OSL)测年建立年代标尺,结合粒度参数、磁化率和石英颗粒表面微形态特征的对比分析,综合判别研究区全新世以来的沉积环境演化过程。结果表明:研究区地层序列主要反映了河流过程和风沙过程的消长,并且表现出同期异相特征。约11.8~10.2 ka,天山北麓冲积作用活跃,辫状河深入沙漠,局部发育河流沉积;约10.2~6.0 ka,研究区进入全新世适宜期,沙漠北退,河湖、湿地广泛发育;约6 ka至今,研究区冲积作用减弱,风沙活动频繁,沙漠环境与河流环境交替出现。近千年以来,研究区沉积环境表现出风沙活动增强、河流冲积萎缩的特点,古尔班通古特沙漠总体上有南侵扩张趋势。本区全新世湿润环境的出现主要受制于西风环流的强弱变化和位置变动,此外,北半球夏季太阳辐射与天山冰川的耦合作用及北大西洋冷事件引发的气候波动可能也是影响本区全新世沉积环境变迁的重要因素。The southern margin of the Gurbantunggut Desert is located in the intersection area of wind-water forces with a unique sedimentary environment and sensitive response to climatic change.This makes the area ideal to study the Holocene environmental evolution of the northwest desert of China.Three aeolian-alluvial interactive stratigraphic profiles in the desert-oasis transitional zone of the southern margin of the Gurbantunggut Desert were selected.Based on field observation of the lithological characteristics and sedimentary sequences,the age scale was established using optically stimulated luminescence dating.Herein,combined with the comparative analysis of particle size parameters,magnetic parameters,and surface micromorphology characteristics of quartz particles,the sedimentary environmental evolution process since the Holocene in the study area was comprehensively discriminated.The result showed that the stratigraphic sequences in the study area mainly reflect the prevalence and recession of river and wind-sand processes,exhibiting obvious characteristics of contemporaneous heterogeneity.Moreover,alluvial deposits were dominant in the northern piedmont of the Tianshan Mountains from 11.8 ka to 10.2 ka,and braided rivers penetrated the desert with local fluvial deposits.From 10.2 ka to 6.0 ka,the study area entered into the Holocene optimum,and the desert retreated northward with widespread lakes and wetlands.Furthermore,the study area has experienced weak alluvial deposits and frequent wind-sand activities from 6 ka to the present,and the desert environment alternated with the river environment.In the past millennium,the sedimentary environment of the study area has exhibited the characteristics of increased wind-sand activity and river alluvial atrophy,along with the Gurbantunggut Desert showing an overall trend of southward invasion and expansion.The change of strength and position of westerly circulation mainly controlled the emergence of the Holocene humid environment in the study area.Additionally,the cou

关 键 词：全新世 沉积环境变迁 气候演化 风-水两相沉积 古尔班通古特沙漠 

分 类 号：P512.2[天文地球—地质学] P534.632P532