摘要
本文通过对广西南丹芒场锡—多金属矿田的82个钻孔1000余件岩石标本研究,根据特征变质矿物及其组合将矿田热变质岩划分出角岩化、透闪石角岩、透辉石—石榴石角岩和黑云—红柱石角岩具有同心环状四个热变质带与绿帘—钠长石角岩、角闪石角岩、辉石角岩三个变质相;并对各相带的厚度(深度)、岩石组合、热变质矿物、化学成分与微量元素及其与原岩关系进行论述,探讨了各变质相带、成矿元素组合等与隐伏岩体的时、空关系,指出了热变质带中心即隐伏花岗岩体高突位置,为隐伏岩体定位预测进而寻找隐伏矿床、矿体提供了依据。
Based on the studies of 1,000 rock specimens from 82 drill holes in Mangchang tin-polymetallic ore field in Nandan county, Guangxi and based on characteristic metamorphic minerals and their associations, the thermally metamorphosed rocks in Mangchang ore field can be divided into four concentrical metamorphosed zones: hornfelsization zone, tremolite hornfels zone, diopside-garnet hornfels zone and biotite-andalusite hornfels zone, and three metamorphic facies: epidotealbite hornfels facies,amphibole hornfels facies and pyroxene hornfels facies. The thickness or depth, association of rocks thermally metamorphosed minerals relation of chemical composition trace elements and original rocks are expounded. The time and space relation between each metamorphic zone and facies association of ore-forming elements, etc. and concealed rock body has been probed into. It is pointed out that the center of thermally metamorphosed zones is the locality where the concealed granite body is in high position. This provides evidences for locating and forecasting concealed rock bodies and then searching for concealed deposits and ore bodies.
