黔北习水县桑木场铅锌矿岩相学、矿相学特征及与MVT型铅锌矿床的对比

Petrography,Mineragraphy Characteristics of Sangmuchang Lead-zinc Deposit in Xishui County and Comparison with MYT Type Zn-Pb Deposits

习水县桑木场铅锌矿,容矿层为震旦系灯影组白云岩,属于局限台地相的碳酸盐盆地;铅锌矿受断层与裂隙控制,属于开放式空隙充填,矿石与容矿层呈脉状、网脉状接触。矿石矿物为闪锌矿及方铅矿,脉石矿物为重晶石、方解石、白云石、萤石、黄铁矿及石英。样品表现出两期成矿特征,根据矿物穿插关系可判定与流体活动相关的矿物生成顺序。本文结合习水县桑木场区域地质特征及样品岩相学、矿相学特征,初步判定研究区铅锌矿属于密西西比河谷型(MVT)铅锌矿,并以此典型矿床的成矿模式为指导,尝试在研究区内寻找较大型铅锌矿床。

A batch of lead-zinc deposit samples are collected from Sangmuchang,Xishui County.They are produced in a certain horizon called the restricted platform in the sedimentary rock basin.The deposits are hosted in Late Proterozoic,especially in dolostone and formed by open-void filling.Collected by faults and fracture,lead-zinc mines have shown discordant,for instance phlebitic and diktyonitic and the characteristic of post-metallogenic.Lead-zinc mines consist of metal mineral and gangue mineral.In upwards,they are(1)sphalerite,galena and pyrite,(2)dolomite,barite,calcite,fluorite and quartz.This paper combines the characteristic of regional geology,petrography and mineragraphy.Preliminary determination of lead-zinc mines in the study area belong to Mississippi Valley-type(MVT) lead-zinc deposits.Following this pattern,we will look for others mineral deposits in our study area.