江西冷水坑铅锌银矿田成矿系统与成矿模式

The metallogenic system and metallogenic model of the Lengshuikeng Pb-Zn-Ag orefield,Jiangxi province

江西冷水坑矿田具有浅部斑岩型矿体与深部层状矿体的复杂组合。深部的层状矿体曾被长期认为是受构造破碎带控制的"层控叠改型矿体",与斑岩型矿体同期形成。本文从矿床的基本地质特征入手,论述和分析了层状银铅锌矿体所具有的火山碎屑建造及成矿特点,认为矿床具有三期成矿特点,层状矿体属火山机构控制的以火山集块-角砾岩层为赋矿岩石的火山喷发-沉积成岩矿体。提出了该矿床火山构造-岩浆喷发成矿系统的主要成矿要素和成矿模式,斑岩岩浆就位及其流体活动,在产生大规模斑岩型矿化的同时,对早期的火山沉积碳酸盐层进行叠加改造而形成了与斑岩具有成因联系的层控铅锌银矿床。

The Lengshuikeng orefield owns a complex combination of a shallow porphyry orebody and a deep stratiform orebody. The deep layered orebody had been long regarded as'strata-bound orebody with later stack modifications'which was controlled by the fracture zone and generated with the porphyry orebody at the same period. This paper started from the basic geological characteristics of the deposit,discussed and analyzed the pyroclastic construction and mineralization characteristics of the layered Ag- Pb- Zn orebody. The result shows that the deposit has metallogenic features with thire different periods and the layered orebody belongs to the volcanic eruption-diagenesis orebody with ore-bearing rocks of volcanic block-breccia layer controlled by the volcanic edifice. We propose that the main ore-forming elements and the metallogenic model of the mineralization system. The porphyry magma emplacement and its fluid activity superimposed the early volcanic sedimentary carbonate layers and then formed the layered Ag- Pb- Zn deposit with a genetic link with porphyry as soon as they produced a large scale porphyry-type mineralization.