摘要
粘土是铝土矿的主要伴生矿物,本文论述了中国红土型及古风化壳型铝土矿床中粘土的类别、产出状态和垂向及侧向演化规律。认为铝土矿中的粘土矿物主要是风化壳中继承性粘土,它经历了风化剥蚀、搬运沉积、成岩及后生或表生作用的长期地史演化。是铝土矿成矿的直接物源,大量事实证明1:1型粘土可以转化为三水铝石或一水硬铝石及勃姆矿;同时也可见到2:1型粘土→1:1型粘土→铝土矿的证据。
Clay, a mainly associated mineral of bauxite, makes up about 50 percent of ore-earing rock groups. It not only occurred as an associated mineral in bauxite, but also
formed high-alumina clay and hard-refreetory clay layer which have special industry significance. The types and occurance states of clay and its vertical and horizontal evolutionary law can provide important information for revealing the bauxite's origin, forming environment and ore-forming material sources.
Most of the clay minerals which appear in the ore-bearing rock groups are mainly of kaolinite with unit layers ( 1 : 1 type) of double-layer type strutures and illite or chlorite with single-layer ( 2 : 1 type) of three-layer type structures. In China's bauxite, kaolini.te, a mainly associated clay mineral, is widely distributed, with both kaolinite
of ordered structures and kaolinite of disordered structures found everywhere.
The occurance states of clay and its vertical and horizontal evolutionary law indicate that clay minerals in bauxite are mostly derived from weathered crust. These clay minerals have undergone a long period of the earth's historical evolution of weathering, disintegrating, transporting, accumulating, depositing, diagenesis and epigenesis or epi-. 'diagenesis, and they are products of multistages and multi-actions and are direct ore-forming material sources of bauxite.
A great number of facts have proved that the 1 : 1 type clay can change into gib-bsite and diaspore, and the evidence can be seen of 2 : 1 type clay→ l : l type clay bauxite deposits.
出处
《贵州地质》
1989年第4期303-312,共10页
Guizhou Geology
基金
国家自然科学基金资助项目
