甘肃金山矿区金矿床成矿构造类型及成矿机制探讨

Metallotectonic Type and Metallogenic Mechanism of Jinshan Gold Deposit,Gansu Province

金山矿区有3个金矿床,矿体产于褶皱翼部或核部,构造控矿作用十分明显,对矿(化)体空间分布、矿化富集等均有明显的控制作用,主要有3种类型:层间断裂裂隙构造、切层断裂裂隙构造、成矿期后的断层裂隙构造。层间断裂构造控制着以充填地质作用形成的石英脉型矿体;层间断裂构造两侧并与之平行的层间裂隙构造、切层断裂裂隙构造控制着以交代地质作用形成的微细粒浸染型矿体;两组断裂裂隙交叉部位是成矿的有利部位;建立的构造控矿模式表明,矿区控矿构造由褶皱构造与岩体侵位构造共同控制。

There are 3 gold deposits at Jinshan area. Field observation shows that the ore bodies are hosted at the wing or the core of folded strata. They are apparently controlled by structures both in the terms of spatial distribution and mineraliza- tion enrichment. Three main types of structures are identified ： interlaminar fractures, cutting-bed fractures, and post-miner- alization fractures. Quartz vein type ore bodies are controlled by the first type, while at the both sides of the first type frac- tures, and in the second type fractures, there are disseminated ore bodies formed by alteration. The cross parts of two groups of fractures are favourable mineralization position. The established ore-controlling structure model shows that the ore bodies are controlled by both fold structure and magma emplacement structure.