甘肃省徽县郭家沟铅锌矿床特征及矿石特征浅析

A Brief Analysis of the Characteristics of Lead-Zinc Deposit and Its Ore in Guojiagou,Hui County,Gansu Province

郭家沟铅锌矿床含矿地层为中泥盆统安家岔组焦沟层上部层位(D2a^2-2),矿体主要赋存在(D2a^2-2b)层绢云千枚岩中的灰岩透镜体和(D2a^2-2b)层绢云千枚岩与(D2a^2-2a)厚层灰岩接触带的灰岩一侧。该矿床矿石均为硅质岩型硫化铅锌矿石,矿石中矿物组成较为简单,主要为闪锌矿、方铅矿等,呈自形-半自形、它形粒状结构,不规则网(脉)状构造常见。通过大量钻孔岩芯观察和光薄片等岩相学研究,大致将郭家沟铅锌矿床成矿期分为热水沉积期和改造期。

The ore-bearing strata of the Guojiagou lead-zinc deposit is the upper layer of the jiaogou layer(D2a^2-2)in the Anjiacha formation of the middle devonian,and the ore body mainly occurs in the limestone lens of the(D2a^2-2b)layer sericite and the limestone side of the contact zone between the(D2a^2-2b)layer sericite and the(D2a^2-2a)thick layer limestone.The ore of this deposit is all siliceous rock type lead-zinc sulfide ore,the mineral composition in the ore is relatively simple,mainly is sphalerite,galena,etc.,the ore is self-shaped-semi-self-shaped,other shaped granular structure,irregular net(vein)structure is common.Based on the observation of a large number of borehole cores and lithographic studies such as photolithography,the metallogenic period of Guojiagou Pb-Zn deposit can be divided into hydrothermal deposition period and modification period.