Grain size and surface micro-texture characteristics and their paleoenvironmental significance of Holocene sediment in southern margin of the Gurbantunggut Desert,China  

作　　者：MA Yunqiang LI Zhizhong TAN Dianjia ZOU Xiaojun TAO Tonglian 

机构地区：[1]School of Geographical Sciences,Fujian Normal University,Fuzhou 350117,China [2]Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350117,China [3]Institute of Geography,Fujian Normal University,Fuzhou 350117,China

出　　处：《Journal of Arid Land》2024年第5期632-653,共22页干旱区科学（英文版）

基　　金：the National Natural Science Foundation of China(42071011);the 2023 Annual Postgraduate Research and Innovation Foundation of Fujian Normal University,China.

摘　　要：The southern margin of the Gurbantunggut Desert,China,is characterized by alternating layers of aeolian and alluvial deposits.Investigating the characteristics of arenaceous sediment in this area is of significant importance for understanding the interactive processes of wind and water forces,as well as the provenance of sediment.However,there are relatively few investigations on the characteristics of such sediment at present.In this study,we researched three aeolian-alluvial interactive stratigraphic profiles and different types of surface sediment on the desert-oasis transitional zone of southern margin of the Gurbantunggut Desert.Based on the optically stimulated luminescence(OSL)dating of aeolian sand and analyses of quartz sand grain size and surface micro-texture,we explored the aeolian-alluvial environmental change at southern margin of the desert in Holocene,as well as the provenance of sediment.The results indicated that the grain size characteristics of different types of sediment in the stratigraphic profiles were similar to those of modern dune sand,interdune sand,muddy desert surface soil,and riverbed sand.Their frequency curves were unimodal or bimodal,and cumulative probability curves were two-segment or three-segment,mainly composed of suspension load and saltation load.The quartz sand in the sediment at southern margin of the desert had undergone alternating transformation of various exogenic forces,with short transportation distance and time,and sedimentary environment was relatively humid.In Holocene,southern margin of the desert primarily featured braided river deposits,and during intermittent period of river activity,there were also aeolian deposits such as sand sheet deposits,stabilized dune deposits,and mobile dune deposits.The provenance for Holocene alluvial deposits at southern margin of the desert remains relatively constant,with the debris of the Tianshan Mountains being the primary provenance.Aeolian sand is mainly near-source recharge,which is formed by in situ deposition of fluvial

关 键 词：aeolian-alluvial deposition grain size surface micro-texture sedimentary environment HOLOCENE 

分 类 号：P512.2[天文地球—地质学] P534.632