作　　者： ; ; ; ; ; ; ; ;

机构地区： 中国地质大学北京地球科学与资源学院地质过程与矿产资源国家重点实验室

出　　处： 《地质与勘探》 2012年第3期449-459,共11页

摘　　要： 豫西铝土矿是我国喀斯特型铝土矿的典型代表。本文选取豫西典型的喀斯特型铝土矿为研究对象,通过XRD分析、扫描电镜-能谱分析、电子探针分析和差热分析多种手段,探测铝土矿的物质组成及其赋存状态,并且分析其矿物成因,总结矿物演化序列。研究显示,豫西铝土矿的主要矿物成分包括硬水铝石、伊利石、锐钛矿、高岭石、针铁矿、赤铁矿、金红石等。硬水铝石主体为简单结晶成因。伊利石主体为风化过程中产物,部分为后期硬水铝石硅质交代的结果。锐钛矿和硬水铝石同期结晶形成于还原环境下。大部分高岭石形成于陆源期风化阶段,少部分为后期硬水铝石硅化转变形成。针铁矿和赤铁矿形成于两个阶段,第一阶段为成矿前风化作用形成的铁质风化壳;第二阶段为铝土矿成岩晚期出现了一期铁质流体活动形成了大量的赤铁矿和针铁矿。重砂矿物金红石和锆石等主要是母岩风化作用的残留物。豫西铝土矿中矿物形成演化可归纳为如下五个阶段:陆源期、同生期、成矿期、成矿后期和表生期。 The bauxite deposits in western Henan are the typical ones representative of karstie bauxite deposits in China. Some typical bauxite deposits in western Henan were chosen to conduct researches of mineral composition, occurrence, genesis and evolutionary sequence through analyses using XRD, SEM-EDS, EPMA and DTA techniques. The results show that the major minerals in the bauxite deposit in western Henan include diaspore, illite, anatase, kaolinite, goethite, hematite and futile. Diaspore is of a simple diagenetic genesis. Illite was mainly transformed from mica during the weathering process, and a few are silica replacement products. Most of the kaolinites were formed during the weathering process ; a few of them were formed by silica replacement. Both goethite and hematite fm^aed at two stages. The first stage is before the formation of the bauxite, abundant weathering crns＇ts were formed. The second stage is at the later stage of the diagenetic process, abundant Fe-rich solutions circulate in the bauxite ores and abundant goethite and hematite were formed. Zircon and rutie arc mainly relic minerals. The evolutionary sequence of minerals in bauxite deposits in western Henan include continental, syngenetie, diagenetic, post diagenetic and supergene five stages.

关 键 词： 豫西 铝土矿 矿物组成 矿物成因 演化序列

领　　域： [天文地球] [天文地球]