科尔沁沙地地表沉积物特征及其气候意义  

Characteristics and climate significance of surface sediments in the Horqin Sandy Land

作　　者：张悦仪 迟云平[1,2] 谢远云[1,2] 康春国 刘若男 孙磊 吴鹏 魏振宇 Yueyi Zhang;Yunping Chi;Yuanyun Xie;Chunguo Kang;Ruonan Liu;Lei Sun;Peng Wu;Zhenyu Wei(College of Geographic Science,Harbin Normal University,Harbin 150025,China;Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions,Harbin Normal University,Harbin 150025,China;School of Geography and Tourism,Harbin University,Harbin 150086,China)

机构地区：[1]哈尔滨师范大学,地理科学学院,黑龙江哈尔滨150025 [2]哈尔滨师范大学,寒区地理环境监测与空间信息服务黑龙江省重点实验室,黑龙江哈尔滨150025 [3]哈尔滨学院地理与旅游学院,黑龙江哈尔滨150086

出　　处：《中国沙漠》2024年第4期223-235,共13页Journal of Desert Research

基　　金：国家自然科学基金项目(42171006,41871013);哈尔滨师范大学博士启动基金项目(XKB201418);哈尔滨师范大学学术创新项目(HSDSSCX2023-51)。

摘　　要：沙漠作为干旱气候的产物,记录着气候与环境变迁的丰富信息,在不同区域条件下沙漠风成沉积物特征指示的气候环境存在差异。本研究在科尔沁沙地自东向西共选取25个样点,进行色度、漫反射光谱和磁化率分析,探讨沙地地表风成沉积物的空间变化特征,并结合区域的现代气候因子探讨各代用指标的气候意义。结果表明:科尔沁沙地地表风成沉积物的色度特征与区域降水关系密切,亮度(L*)、红度(a*)与黄度红度比(b*/a*)能够作为指示区域气候的代用指标;地表沉积物中针铁矿(Gt)和赤铁矿(Hm)的相对含量均处于较低水平,Gt/Hm的变化能够指示气候干湿条件的总体趋向;地表风成沉积物的χ_(fd)%值能够作为区域降水情况的代用指标,沉积物的磁性增强主要源于降水强度增加导致的风化成壤作用加强,进而产生大量细颗粒亚铁磁性矿物。总体而言,科尔沁沙地地表风成沉积物色度、磁化率和Gt/Hm能够有效指示区域气候环境。As a product of arid climate,deserts record rich information about climate and environmental changes.The climate environment indicated by the characteristics of desert aeolian sediments varies under different regional conditions.In this study,we selected a total of 25 sample points from east to west in the Horqin Sandy Land,and the chromaticity index,DRS and magnetic susceptibility were analyzed to explore the spatial variation characteristics of aeolian sediments on the sandy surface.At the same time,the climate significance of various proxy indicators in the context of regional modern climate factors is discussed.The results show that the chromaticity characteristics of surface wind-sand sediments in Horqin Sandy Land are closely related to regional precipitation.L*,a*and b*/a*can be used as proxy indicators to indicate regional climate.The goethite and hematite in surface sediments are at low levels,and changes in Gt/Hm can indicate the overall trend of dry and wet climate conditions.Theχ_(fd)%value of surface wind-sand sediments can be used as a proxy indicator of regional precipitation.The magnetic enhancement of sediments is mainly due to the strengthening of weathering and pedogenesis caused by the increase of precipitation intensity,which leads to the production of a large number of finegrained ferromagnetic minerals.Generally speaking,the chromaticity,magnetic susceptibility and goethite to hematite ratio of surface aeolian sediments in Horqin sandy land can effectively indicate the regional climate and environment.This study deepens the relationship between surface sedimentation and climatic parameters in Northeast China from the perspective of modern process,and provides an important reference for the reconstruction of paleoclimate change history in Northeast China.

关 键 词：地表沉积物 色度 针铁矿赤铁矿比值(Gt/Hm) 磁化率 气候意义 

分 类 号：P512[天文地球—地质学]