科尔沁沙地的元素、粘土矿物与沉积环境

The Element, Clay Mineral and Depositional Environment in Horqin Sand Land

湿润气候型元素(Fe,Mn,Cr,V,Co,Ni)和干旱气候型元素(Ca,Mg,K,Na,Sr,Ba)的迁移与分配规律,均与古气候密切相关。依据古气候指数C值概念:古气候指数C值=∑(Fe+Mn+Cr+V+Co+Ni)/∑(Ca+Mg+Sr+Ba+K+Na)对古气候变化给出定量分析。研究沙物质中元素分配的状况,粘土矿物的组合类型,推断晚更新世以来科尔沁沙地的气候状况和沙漠化进程。

The author has researched the migration and distibutional laws of the elements (Fe, Mn, Cr, V, Co, Ni) of humid climatic type arid the elements (Ca, Mg, K, Na, Sr, Ba) of dry climatic type, and the introduced the concept of palaeoclimatic index: Palaeoclimatic index C=Σ(Fe+Mn+Cr+V+Co+Ni)/Σ(Ca+Mg+Sr+Ba+K+Na) Based on the Quantitative analysis of paleaoclimatic changes, the author inferred the climatic conditions and the desertification processes in the Horqin Sand Land since late pleistocene. It has been found from the element distribution in sandy mass that the elements of first transitional element series varied regularly in the desertification processes, which is helpful to predict the desertification development. The clay mineral assemblage in the Horqin Sand Land is dominated by montmorillonite, and the accompanied clay minerals are illite and chlorite. They are all clay minerals of dry type.