摘要
通过粒度和元素地球化学分析研究方法,对伊犁盆地昭苏剖面黄土和古土壤形成环境的差异性进行了对比研究。结果发现,伊犁古土壤层中>30μm、>40μm和>63μm等粗粒径组分含量较黄土层稍高,尤其是>63μm组分更为显著;伊犁古土壤形成时期,西风环流较强,导致古土壤层中存在大量粗颗粒的近源堆积物,气候存在突变性,是一个环境变化不稳定的时期;而黄土堆积时,西风较弱,气候变化相对稳定;古土壤形成时期虽降水相对较多,但气候较冷,导致其风化成壤作用并不强,而黄土堆积时降水与古土壤形成时期相当或者较少,但由于气候总体较为温暖,风化成壤作用相对较强。不同时期水热组合形式及其各自权重不同均会对伊犁黄土和古土壤风化作用产生不同程度的影响。
Based on grain size and geochemical analysis data, we compared the formation environment of lo- ess and paleosol at the Zhaosu section in Ili, Xinjiang, China. Results indicate that the contents of coarse grain-size of 〉30 μm, 〉40 μm and 〉63 μm at the paleosol layer is higher than that of at the loess layer, especially the 〉63 μm component. A lot of near source coarse components accumulation in the paleosol layer resulted from the enhanced westerly circulation during the paleosol formation process, which indicated that there was a climate mutation and environmental change in this period. The westerly wind was weak when loess deposited, so the climate change was relatively slight. During the period of paleosol formation, the weathering process was not strong due to an enhanced westerly wind and a cold climate, although the rain- fall was much. When loess deposited the precipitation equaled to or less than that during the paleosol forma- tion process, but the weathering pedogenesis was relatively strong because of a warm climate. The combina- tion of water and heat and their different weights in different periods had different impacts on the weathe- ring process of loess and paleosol in Ili.
出处
《中国沙漠》
CSCD
北大核心
2012年第5期1256-1262,共7页
Journal of Desert Research
基金
国家重点基础研究规划项目(2010CB833406)
国家自然科学基金项目(41172166
40972230)
中国科学院知识创新工程重要方向项目(KZCX2-YW-Q09-04)共同资助
关键词
伊犁盆地
黄土
古土壤
粒度
地球化学
形成环境
Ili basin
loess
paleosol
grain size
geochemistry
formation environment
