青海省茫崖地区滑石矿地质特征及成因初探

Geological characteristics and genesis of talc deposts in Mangya area,Qinghai Province

青海省茫崖地区目前有两处滑石矿床,为野马滩滑石矿及茫崖石棉伴生滑石矿,两处滑石矿床的赋存地层及成矿类型不同。野马滩滑石矿赋存于古元古代金水口岩群片麻岩组的大理岩段中,主要含矿岩性为白云石大理岩,由于构造多期叠加、热液活动强烈,滑石矿床具有层控后期热液变质的特征,属区域变质叠加热液交代型;茫崖石棉矿床中的滑石矿体集中产于岩体中下部的蛇纹岩中,受超基性岩体及控岩构造的控制,成因为超基性岩热液蚀变型。通过对成矿地质背景、含矿岩性及矿体特征和矿石质量进行对比,了解区内滑石成矿类型,为寻找高品质滑石矿提供一定的参考。

At present,there are two deposits containing talc in Mangya area of Qinghai Province,namely,Yemantan talc deposit and Mangya asbestos deposit associated with talc.The occurrence strata and mineralization types of the two deposits with talc are different.The talc deposit occurs in the marble section of gneisses Formation of the Paleoproterozoic Jinshuikou Group,and the main ore-bearing lithology is dolomite marble.Due to the multistage superposition of structure and strong hydrothermal activity,the talc deposit has the characteristics of late stage of hydrothermal metamorphism with layer-controlled characteristics,which belongs to the regional metamorphic overlying hydrothermal metasomatism type.The talc ore bodies in the Mangya asbestos deposit are concentrated in serpentinite in the middle and lower part of the rock mass,which is controlled by ultrabasic rock mass and rock controlling structure,resulting in hydrothermal alteration of ultrabasic rock.Through the comparison of metallogenic geological background,ore-bearing lithology,ore body characteristics and ore quality,we can understand the talc mineralization types in the area,and provide a certain reference for seeking high-quality talc deposits.