雅鲁藏布江流域风成沉积空间格局、沉积模式及其环境效应  

Aeolian deposits in the Yarlung Zangbo River basin,southern Tibetan Plateau:Spatial distribution,depositional model and environmental impact

作　　者：夏敦胜[1] 杨军怀 王树源 刘鑫 陈梓炫 赵来 牛潇毅 金明[1] 高福元 凌智永[3] 王飞[1] 李再军[1] 王鑫[1] 贾佳 杨胜利[1] XIA Dunsheng;YANG Junhuai;WANG Shuyuan;LIU Xin;CHEN Zixuan;ZHAO Lai;NIU Xiaoyi;JIN Ming;GAO Fuyuan;LING Zhiyong;WANG Fei;LI Zaijun;WANG Xin;JIA Jia;YANG Shengli(Key Laboratory of Western China’s Environmental Systems(Ministry of Education),College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China;College of Urban Environment,Lanzhou City University,Lanzhou 730070,China;Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,China;College of Geography and Environmental Sciences,Zhejiang Normal University,Jinhua 321004,China)

机构地区：[1]兰州大学资源环境学院西部环境教育部重点实验室,甘肃兰州730000 [2]兰州城市学院城市环境学院,甘肃兰州730070 [3]中国科学院青海盐湖研究所盐湖资源综合高效利用重点实验室,青海西宁810008 [4]浙江师范大学地理与环境科学学院,浙江金华321004

出　　处：《地学前缘》2023年第4期229-244,共16页Earth Science Frontiers

基　　金：科学技术部第二次青藏高原综合科学考察研究项目(2019QZKK0602)。

摘　　要：青藏高原南部雅鲁藏布江(雅江)流域位于印度板块和欧亚板块碰撞产生的缝合带,是地球系统科学研究的热点地区。该区域中更新世以来的风成沉积物不仅是揭示青藏高原气候变化与大气环流演化的重要窗口,而且有助于深入认识构造、气候及地表景观之间的内在联系,然而我们对于该区域风成沉积物的空间格局、沉积模式及其环境效应至今仍然缺乏系统的认识。本文在大量野外考察和已有研究结果基础上,结合典型沉积物样品的综合分析,对雅江流域风成沉积体系进行了梳理,绘制了《雅江风成沉积空间分布图》,包括1幅序图和6幅区域分布图,其中风沙和黄土沉积呈斑块状分布,二者通常相伴而生。黄土与沙丘、河流砂等松散沉积物之间存在密切的物质联系,区域内的风成沉积以自循环过程为主,记录了区域气候的空间差异。河谷沉积物在接受有限的远源粉尘输入的同时,在高空西风的作用下向全球贡献粉尘物质。中更新世以来的粉尘活动受控于构造运动和全球气候变化的耦合,而全新世粉尘活动受河谷环境影响表现较为复杂,区域气候变化受中纬度西风和印度夏季风的协同作用影响。Situated in the suture zone formed by the India-Euroasia collision,the Yarlung Zangbo River(YZR)basin in the southern Tibetan Plateau is a hotspot for Earth systems research,where Middle-Pleistocene aeolian deposits not only provide an important window into the history of climate change and atmospheric circulation in the Tibetan Plateau,but also help us to gain a deeper understanding of the link between tectonics,climate and landscapes in general.However,a systematic understanding of the distribution,depositional model,and environmental effects of aeolian sediments in this region is still lacking.Here,we construct a new atlas and a depositional model of aeolian sediments in the YZR basin based on extensive field investigation as well as laboratory analyses of typical sediment samples collected across the region,combined with existing research results.In general,aeolian sand and loess are distributed in patches and usually occur together.A close provenance relation between loess and nearby loose sediments such as sand dunes and river sands indicates that aeolian sediments cycle locally,hence they record spatial changes of regional climate;in contrast,the valley sediments not only receive dust from distant sources but also contribute dust materials to the world via upper-level westerly winds.Middle-Pleistocene aeolian dust activity in the YZR basin was controlled combinedly by tectonic movement and global climate change;whereas aeolian dust activity during the Holocene was relatively complex under the river valley environment,and regional climate change was generally influenced by the synergistic effect of the mid-latitude Westerlies and the Indian summer monsoon.

关 键 词：青藏高原南部 雅鲁藏布江 沙丘 黄土 分布 物源 气候变化 全新世 

分 类 号：P532[天文地球—古生物学与地层学] P931[天文地球—地质学]