摘要
共和盆地沉积物堆积过程较好的记录了亚洲季风和西风环流的变化信息,对揭示物源特征以及环境演变过程具有重要价值。文中选取共和盆地厚度为280cm的典型风成砂-古土壤剖面,对其粒度数据进行参数化端元分解,分析了沉积物搬运动力、搬运方式以及环境信息。得出以下结论:1)马四剖面的沉积物粒度组分可分解为3个端元:EM1代表高空气流搬运的远源粉尘物质,可间接作为夏季风的替代指标;EM2指示的是经短距离悬移或跃移搬运的近源粉尘,EM3为近源粗粒物质,共同指示区域冬季风的强弱变化。2)中晚全新世共和盆地的环境演化过程可划分为4个阶段:近8.0~4.78ka BP的气候温暖湿润、风沙活动较弱期,4.78~2.90ka BP的气候较为冷干、风沙活动频繁期,2.90~0.67ka BP的气候相对温湿期和0.67ka BP至今的气候冷干、风沙活动加剧期。
The sediment accumulation process in the Republican Basin is a good record of the changes in the Asian monsoon and westerly circulation,which is of great value in revealing the characteristics of the material sources and the environmental evolution.In this study,a typical aeolian-Paleosol profile with a thickness of 280cm in the Republican Basin was selected,and its grain-size data were parametrically endogenously decomposed to explore the sediment transport dynamics,transport modes,and environmental information.The following conclusions can be drawn:1)The sediment grain size component of the MS profile can be decomposed into three end members:EM1 represents remote source dust material transported by high altitude air currents and can be used indirectly as a proxy for summer monsoon.EM2 is indicative of near source dust transported over short distances by leaps or suspensions,and EM3 is a near source coarse-grained material,which together are indicative of changes in the strength of winter winds.2)The environmental evolution of the Republican Basin during the Middle and Late Holocene can be divided into four stages:About 8.0~4.78 ka BP period,the climate was warm and humid,with weak aeolian activities,4.78~2.90ka BP period,the climate was cooler and drier,with frequent aeolian activities,2.90~0.67ka BP period,the climate was relatively warm and humid,0.67ka BP to present,with a cooler and drier climate and increased aeolian activities.The dust accumulation process was also constructed based on environmental information to recognize that the dust accumulation process plays an important role in carrying out sand and dust management.
作者
胡梦珺
许澳康
白清竹
HU Mengjun;XU Aokang;BAI Qingzhu(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China)
出处
《干旱区资源与环境》
CSCD
北大核心
2024年第2期123-131,共9页
Journal of Arid Land Resources and Environment
基金
国家自然科学基金项目(41171018,41161036)资助。
关键词
端元分析
物源特征
中晚全新世
环境演变
共和盆地
end member analysis
material source characteristics
Middle to Late Holocene
environmental evolution
Republican Basin
