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
张悦仪 1迟云平 2谢远云 2康春国 3刘若男 1孙磊 1吴鹏 1魏振宇1
作者信息
- 1. 哈尔滨师范大学地理科学学院,黑龙江哈尔滨 150025
- 2. 哈尔滨师范大学地理科学学院,黑龙江哈尔滨 150025;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
- 折叠
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xfd％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.
Abstract
As a product of arid climate,deserts record rich information about climate and environmental chang-es.The climate environment indicated by the characteristics of desert aeolian sediments varies under different re-gional 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 varia-tion characteristics of aeolian sediments on the sandy surface.At the same time,the climate significance of vari-ous proxy indicators in the context of regional modern climate factors is discussed.The results show that the chro-maticity characteristics of surface wind-sand sediments in Horqin Sandy Land are closely related to regional pre-cipitation.L*,a*and b*/a*can be used as proxy indicators to indicate regional climate.The goethite and hema-tite in surface sediments are at low levels,and changes in Gt/Hm can indicate the overall trend of dry and wet cli-mate conditions.The xfd％value of surface wind-sand sediments can be used as a proxy indicator of regional pre-cipitation.The magnetic enhancement of sediments is mainly due to the strengthening of weathering and pedogen-esis caused by the increase of precipitation intensity,which leads to the production of a large number of fine-grained ferromagnetic minerals.Generally speaking,the chromaticity,magnetic susceptibility and goethite to he-matite ratio of surface aeolian sediments in Horqin sandy land can effectively indicate the regional climate and en-vironment.This study deepens the relationship between surface sedimentation and climatic parameters in North-east 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Key words
surface sediment/chromaticity/goethite to hematite ratio/magnetic susceptibility/climate signifi-cance引用本文复制引用
基金项目
国家自然科学基金项目(42171006)
国家自然科学基金项目(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)
出版年
2024
NETL
NSTL
万方数据