摘要
爬坡沙丘是干旱半干旱区典型的风积地貌之一,其形成过程与物源备受关注。以共和盆地多石在沟爬坡沙丘为例,对其沉积物特征进行分析研究。结果表明:1)爬坡沙丘沉积物以极细砂和细砂为主,细砂的爬升能力最强,从河漫滩至谷坡,粒径变粗,分选变好;坡中上部受“风影效应”的影响,坡上部沉积物粒径偏粗,具有明显的风成特点。2)不同地貌部位沉积物的化学元素差异较小,常量元素以SiO_(2)、Al_(2)O_(3)、CaO和Fe_(2)O_(3)为主,微量元素主要集中于河漫滩中。物源和风力分选是造成沉积物粒度、化学元素空间差异的关键。3)多石在沟爬坡沙丘是在干冷的气候条件下形成,受木格滩沙漠侵袭和阶地面古风成砂就地起沙的影响,沉积物在坡麓地带下落、爬升往复交替,与河道沙丘共同构成多石在沟独特的地貌类型。
Climbing dunes are one of the typical wind-deposited landforms in arid and semi-arid regions,and their formation process and material sources are of great interest.We selected the climbing dunes in Duoshizai of Gonghe Basin as a typical research object and analyzed their sediment characteristics.The results show that:1)The grain size composition of climbing dunes is mainly very fine sand and fine sand,which becomes coarser and better sorted from the river floodplain to the slope foothills.The fine sand has the strongest climbing ability.Influenced by the“wind shadow effect”,the sediments on the upper slope are mainly coarse particles and have obvious aeolian characteristics.2)There is a smaller variation in different topography,and the constant elements are mainly SiO_(2),Al_(2)O_(3),CaO,and Fe_(2)O_(3),while the trace elements are mainly distributed in the river floodplain,and higher levels are found at the slope foothills.Mineral source and wind sorting are the key factors that cause the spatial variation in grain size and geochemical element.3)The climbing dunes at Duoshizai are formed under dry and cold climate conditions.Based on the expansion of Mug Desert and paleosand activation on the terraces,falling-climbing interactions of sediments exist on the slope foothills.Meanwhile,the unique geomorphological type in this area is constructed by both climbing dunes and the sand dunes in the river channel.
作者
董苗
严平
王晓旭
孟小楠
王一娇
王勇
纪欣然
DONG Miao;YAN Ping;WANG Xiaoxu;MENG Xiaonan;WANG Yijiao;WANG Yong;JI Xinran(School of Geography Science,Taiyuan Normal University,Jinzhong 030619;State Key Laboratory of Earth Surface Processes and Resource Ecology,Beijing 100875;Faculty of Geographical Science,Beijing Normal University,Beijing 100875;State Key Laboratory of Earth Surface Processes and Resource Ecology Zhuhai Base,Beijing Normal University,Zhuhai 519087;Institute of Geographical Sciences,Henan Academy of Sciences,Zhengzhou 450052,China)
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2022年第5期79-86,共8页
Journal of Arid Land Resources and Environment
基金
国家自然科学基金项目(41871010,42101013)
第二次青藏高原综合科学考察研究项目(2019QZKK0906)
中国林业科学研究院重点项目(CAFYBB2018ZE002)
山西省高等学校科技创新项目(2020L0502)资助。
关键词
爬坡沙丘
粒度
化学元素
物源
共和盆地
climbing dunes
particle size
chemical elements
material source
Gonghe Basin
