柴达木盆地第三系粘土矿物横向分布规律及控制因素研究

本文根据粘土矿物的类型、含量和组合特征了柴达木盆地第三系粘土矿物横向分布规律，发现上、下第三系尽管伊/蒙间层粘土、伊利石这两类主要粘土矿物从湖盆的边缘向中心分别呈现减小和增大的趋势，但其含量对比及矿物组合显然不同，下第三系以伊利石为主，主要有Ｉ＋有序Ｉ/Ｓ＋Ｃｈ＋Ｋ组合，其次为不含高岭石的组合；上第三系，湖盆边缘相带以Ｉ/Ｓ间层为主，并主要呈现无序Ｉ/Ｓ间层＋Ｉ＋Ｃｈ＋Ｋ组合，湖盆中心相区则与下第三系类似，但Ｉ/Ｓ间层的含量却要高一些。上述分布规律的控制因素主要有干旱-半干旱的古气候状况、不同的母岩类型、沉积环境和成岩作用强度等。

The Transverse Distributive Regularity and its Controlling Factors of Clay minerals in Tertiary System,Qaidam Basin

In this paper, the transverse distributive regularity and its controlling factors of clay minerals inTertiary System in Qaidam Basin was carried out. From the marginal facies to the centeral facies of theBasin, the ralative content of interstratified illite/smectite has a tedency of decrease and the ralative con-tent of illite increases obviously. In Neogene system, there are two types of combination of the clay min-erals. The one of them is the combination of randomly interstratified illite/smectite→illite→ chlorite→kaolinite in the marginal facies of the Basin. The other is the combination of ordered interstratified illite /smectite →illite → chlorite→ kaolinite in the central facies of the Basin. In Eogene System have two typesof combination. The one is the composition of ordered interstratified illite/smectite→ illite→ chlorite→kaolinite.The other is the combination without kaolinite. The distributive regularity of clay minerals in NeogeneSystem was controlled chiefly by arid-semiarid peleoclimate, composition of source rock and peleosedi-mentary environment. In Eogene System, because the sediments were buried very deep, it was controllednearly completely by digenesis, but the sedimentary environment still was a its important controlling fac-tor.