桂北地区锡矿床锡石主要、微量及稀土元素特征及其地质意义

本文较系统地研究了桂北地区锡矿床锡石的产状、主要、微量及稀土元素特征。研究结果表明本区锡矿床在时间、空间和成因上与基性超基性岩存在着密切联系,同时受花岗岩和四堡群变质岩的影响,具明显的多期多阶段、多物质来源和多成因特征,提供了矿床成因类型、成矿作用演化和成矿环境等方面的信息,具有重要的成因意义。锡石的微量元素含量、比值及稀土配分参数可作为找矿标志,并可指示隐伏矿床类型。

COMPOSITIONAL CHARACTERISTICS AND GEOLOGICAL SIGNIFICANCE OF MAJOR,TRACE AND RARE-EARTH ELEMENTS IN CASSITERITE IN NORTH GUANGXI REGION

Systematically described in this paper are the compositional characteristics of cassiterites from tin deposits in north Guangxi region, involving its natural occurrence,major,trace elements and REE,a(?)d their geological significance.It is suggested that the cassiterites are closely related to the basic-ultrabasic rocks both in time-space and in genesis,and they are affected by the biotite granites in this region and metamorphic rocks of the Sibao Group.The cassiterites have an apparent feature of multiperiod and multistage,the multisubstance and the mul- tigenesis.The compositional characteristics of major,trace elements and REE in these cassiterites may provide some information of the genesis, matalloginic evolution and metalloge-nic conditions of tin deposits,and so they are of important genetic signifi-cance.The contents and ratios of trace elements and REE distribution parameters of cassiterite can be regarded as effective guides to prospecting and as indicators of the type of concealed ore deposits.