新疆伊犁地区黄土与古土壤的微结构及矿物成分分析

利用偏光显微镜对伊犁地区新源县则克台剖面黄土与古土壤进行分析，观察到黄土的微结构为粉砂细粒支架－镶嵌孔隙－斑状胶结类型，古土壤则属于砂粉土分散－镶嵌斑状－基底胶结类型。二者的矿物种类差异不大，只是相对含量有所变化。古土壤中原生矿物略有减少，次生、蚀变矿物含量相应增加，铁染较普遍，加外，溶解－再沉淀作用常使矿物细粒化，或形成粘土矿物和次生碳酸钙的微粒集合体和微晶充填在次生大孔隙中。这些特征在黄土中料

STUDY ON FABRICS AND MINERAL COMPOSITIONS OF LOESS AND PALEOSOIL IN YILI AREA OF XINJIANG

Based on the observation and analysis under the polarizing microscope, the difference of fabrics between the loess and paleosoil of the Zektai profile in Gongnaisi county of Yili prefecture in Xinjiang is distinct. The type of the loess fabric is fine silt, sand mosaic, porous porphyric cementation. The type of paleosoil fabric then belongs to fine silt clay, scattered mosaic, porphyric basal cementation. The kinds of their minerals have no evident different, then, the relative contents of minerals vary. The primary minerals in the paleosoil relatively decrease, and the contents of secondary and altered minerals increase. The dissemination of iron is commonly seen. On the other hand, solution precipitation makes mineral become more fine or form clay mineral and particle aggregate of secondary calcium carbonate and microcrystal which fill in secondary large porous. These characteristics of fabric and mineral composition, which are hardly seen in the loess, are the result formed by relative warm and wet environment. From that, the conclusion can be deduced that: the climate has the state of cold warm and dry wet alternation in the process of forming the Zektai loess.