摘要
为了解黄土高原东南缘临汾盆地黄土沉积物粒度分布特征及其气候意义,运用参数化端元分析模型对临汾盆地黄土沉积物粒度数据进行分析,提取对气候变化反映敏感的粒级组分。通过对临汾盆地黄土-古土壤序列运用谢帕德三角分类法,发现黄土主要由粉砂和黏土质粉砂组成,分布较为集中;对临汾盆地黄土粒度进行Gen.Weibull函数分布的参数化端元模型反演得出了3个端元,EM1可能是黄土在夏季风作用下的风化和成壤过程中形成的,EM2可能代表的是高空西风搬运的远源沉积物,EM3可能代表的是较强的冬季风所搬运的近源沉积物以及冬季短时间尘暴所带来的物质。结合OSL测年结果,临汾盆地黄土粒度端元组分、磁化率与深海氧同位素对比分析,发现临汾盆地与深海氧同位素一致,说明临汾盆地气候演化受全球冰量控制,但在每个阶段的内部波动上又表现出一定的区域特征。
In order to understand the grain size distribution pattern of the loess sediments and its bearing on climatic changes in the Linfen Basin on the southeastern margin of the Loess Plateau,the method of Parametric End-member Modeling was used to analyze the grain size data of the loess sediments through extraction of the grain-size fraction sensitive to climate changes.According to Shepard’s classification,the Loesspaleosol sequence in the Linfen Basin is mainly composed of silt and clayey silt.Three general Weibull distribution end members(EM)are recognized.Our results suggest that the EM1 may indicate the product of weathering and pedogenesis of loess under the influence of summer monsoon in the East Asia,while the EM2 indicate the remotely sourced dust by the high-altitude airflow under the control of the westerly belt.The EM3 represents near source dust brought by the East Asia winter monsoon and short-term dust storms in winter.Through the correlation with OSL results,grain size end-member of the loess,magnetic susceptibility and SPECMAP data,it is found that the oxygen isotope of Linfen Basin is consistent with that of SPECMAP,indicating that the climate evolution of the Basin is controlled by global ice amount.However,the internal fluctuation within each stage shows regional features.
作者
赵格格
田庆春
杜五喜
裴瑜
鄂崇毅
ZHAO Gege;TIAN Qingchun;DU Wuxi;PEI Yu;E Chongyi(College of Geography Science,Shanxi Normal University,Linfen 041000,China;Key Laboratory of Qinghai-Tibetan Plateau Environmental and Resource(MOE),Qinghai Normal University,Xining 810008,China;Qinghai Institute of Salt Lake,Chinese academy of sciences,Xining 810008,China)
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2021年第2期192-200,共9页
Marine Geology & Quaternary Geology
基金
国家自然科学基金项目“临汾盆地高分辨率黄土记录的MIS3阶段气候变化过程”(41701223)。
关键词
粒度
黄土
端元分析
临汾盆地
grain size
loess
End member analysis
Linfen Basin
