内蒙古河套地区第四纪地球化学研究

Research on Quaternary geochemistry in the Hetao area of Inner Mongolia

第四纪地球化学是介于第四纪地质学和地球化学之间的边缘研究领域,研究第四纪时期化学元素及其同位素在地壳中的分布与演化规律,侧重研究元素及其同位素在不同成因类型的第四纪沉积物中的分布、分配、迁移和富集的特征。在第四纪地球化学研究中,除常用某些元素的比值和烃类化合物的成分,作为海、陆和过渡相的划分标志外,微量元素和同位素成分也越来越多地被用作环境指示标志。研究区处于华北地台北缘,主体河套平原属中新生代断陷盆地,以第四系为主;研究区北部属大青山、狼山,南部属鄂尔多斯高原,分布白垩系、侏罗系、三叠系、寒武系、太古代地层,局部有岩浆岩出露。本次研究利用河套地区表层土壤元素与指标分析数据,计算了干湿系数、冷暖系数、土壤风化淋滤系数、干旱系数、Rb/Sr比值等环境指示意义的参数进行恢复河套地区古气候环境。

Quaternary geochemistry is the marginalized research field between the Quaternary Geology and geochemistry, researching on the distribution and evolution of Quaternary period＇ s chemical elements and their isotopes in the earth＇s crust. Quaternary geochemistry focused on study the characteristics of the distribution, migration and enrichment of the elements and their isotopes in the different genetic types of Quaternary sediments. In Quaternary geochemical studies, trace element and isotopic compositions are also increasingly being used as environmental signage ,beside use some commonly used element＇ s ratio and the composition of the hydrocarbons as the sea, the land and transition division sign. The study area in North China margin, the main Hetao plain case of Mesozoic-Cenozoic rift basin, mainly Quaternary; the northern part of the study area belongs to Daqing Mountain, Wolf Mountain, the southern part belongs to Ordos plateau, the strata is Cretaceous, Jurassic, Triassic, Cambrian, Archean, magmatic rocks exposed in some area.This research used the surface soil elements and analysis data in the Hetao area to calculate the parameters which has environmental implica- tions ,such as wet coefficient, heating coefficient, soil weathering and leaching coefficient, drought coefficient and Rb / Sr ratio, in order to restore the ancient climate in the Hetao area.