西秦岭凤太矿集区八方山－二里河铅锌（铜）矿床成矿地质特征与矿床成因探讨

八方山-二里河铅锌(铜)矿床位于西秦岭凤县-太白(简称凤太)矿集区西北部.本次工作详细研究了该矿床成矿地质特征,依据矿石的矿物组合、结构构造、围岩蚀变,以及矿脉的相互穿插关系等特征,将成矿阶段划分为早期富闪锌矿硫化物阶段、中期石英-多金属硫化物阶段和晚期石英-碳酸盐阶段.结合前人在成矿时代、构造样式和演化、岩浆活动等方面的研究成果,认为八方山-二里河铅锌(铜)矿床是印支期构造-岩浆-热液活动的产物,是一个后生的流体充填交代矿床.这一认识对理解西秦岭凤太矿集区中发育的成矿地质特征与八方山-二里河铅锌(铜)矿床相似的其它铅锌矿床具有一定的借鉴意义.

Geological Characteristics and Genesis of the Bafangshan-Erlihe Pb-Zn (-Cu) Deposit in the Fengxian-Taibai Ore Concentration Area, West Qinling

Abstract: The Bafangshan-Erlihe Pb-Zn (Cu) deposit is located in the northwest of the Fengxian-Taibai (Fengtai in short) ore concentration area, West Qingling. This paper studies in detail its ore-forming characteristics, and divides the ore-forming process into three stages: the early stage sphalerate-rich sulfide, middle stage quarz-polymetallic sulfide, and the late stage quarz-carbonate based on the mineral combination of the ores, textures and structures, wall rock alteration, and the interpenetrating relationships of the ore veins. Integrated with previous research results about the mineralization epoch, structural styles and evolution, magmatism, it is suggested that the Bafangshan-Erlihe Pb-Zn (Cu) deposit is the product of the regional tectono-magmatic-mineralization processes, and it is an epigenetic deposit formed by hydrothermal filling and metasomatism. This insight would provide enlightenment for understanding the deposits which have similar ore-forming characters to the Bafangshan-Erlihe Pb-Zn (Cu) deposit in the Fengtai ore concentration area, West Qinling.