摘要
在研究伊犁盆地黄土分布特征的基础上,分析了伊犁黄土的粒度、矿物和地球化学组成特征。粒度分析表明伊犁黄土以粉砂为主,含有一定量的细砂,粒径比黄土高原粗,分选性比黄土高原黄土差。在矿物组成上以石英、长石和碳酸盐类矿物为主,含一定量的绿泥石和云母。地球化学元素分析表明伊犁黄土以SiO2、Al2O3、CaO为主,比黄土高原黄土富Na2O和CaO,反映伊犁盆地黄土形成于较干冷、化学风化弱的环境。
The loess record of Central Asia provides an important archive of regional climate and environmental change. However, in contrast to the intensively investigated loess deposits in the Chinese Loess Plateau, Central Asian loess sediments are still insufficiently known and poorly understood. Based on satellite and topography, coupling with previous literature and field investigation, the authors investigate the distribution of loess sediments in the Yili Basin, central Asia. In order to identify the physical, chemical and mineral compositions, the authors carried out grain-size, geochemical and mineralogical analyses on collected surface soil and loess samples. Grain size measurements reveal that the loess in Yili Basin is dominated by silt and have minor sand, which is coarser than that of the Chinese Loess Plateau, indicating a close source. The mineral components of loess in this region are dominated by quartz, feldspar and carbonate with minor chlorite and muscovite. Geochemistry of loess in the Yili Basin are characterized by high contents of SiO2, Al2O3 and CaO, and by minor Fe2O3, MgO,K2O and Na2O. In contrast to the Chinese Loess Plateau, the loess in Yili Basin is rich Na2O and CaO, which indicates that loess in Yili Basin originated from a relative dry-clod and weak chemical weathering environment.
出处
《地理科学》
CSCD
北大核心
2010年第2期267-272,共6页
Scientia Geographica Sinica
基金
国家自然科学基金(40772116
40972230
40871018)
国家重点基础研究规划项目(2010CB833406)
中国博士后科学基金(200231234)资助
关键词
伊犁黄土
分布
粒度
矿物
地球化学
组成
Loess
Yili Basin
grain-size
geochemistry
mineral
composition
