冷水坑矿田层状富铅锌矿赋矿围岩——铁锰碳酸岩角砾岩物质来源及成因分析

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,深部层状矿体赋存于上侏罗统打鼓顶组晶屑凝灰岩所夹的(铁锰)碳酸岩角砾岩层中。从(铁锰)碳酸岩角砾岩的基本地质特征入手,论述和分析了(铁锰)碳酸岩角砾岩的主要物质成分组成、分布、产状及与矿体关系等特点,结合矿物X-射线粉晶分析、碳-氧同位素和氢-氧同位素佐证,认为(铁锰)碳酸岩角砾岩为深水湖泊相火山-沉积成因,与层状矿体形成密切相关,后期斑岩岩浆就位及其流体活动对早期火山沉积碳酸岩层叠加改造,从而形成了与斑岩具有成因联系的层状富铅锌银矿床。

Material sources and genetic analysis of the iron-manganese carbonatite breccia host rock of the stratiform Pb-Zn-rich orebodies in the Lengshuikeng orefield

The Lengshuikeng orefield has a complex combination of shallow porphyry type orebody and deep stratiform orebody. The stratiform orebody is hosted in (Fe, Mn) carbonatite breccia layer which is sandwiched in crystal tuff of the Upper Jurassic Daguding Formation. This paper has discussed and analyzed the characteristics of Fe-Mn carbonatite breccia in the aspects of main material composition, trace elements composition, distribution, attitude and its relationship with the orebody on the basis of basic geological features of the Fe-Mn carbonatite breccia. In combination with X- ray powder analysis of minerals, carbon- oxygen isotopes and hydrogen-oxygen isotopic evidence, the authors have reached the conclusion that the Fe-Mn carbonatite breccia is of the deep lake facies volcanogene sedimentary origin closely associated with the formation of stratiform orebody, and the early volcanogene sedimentary carbonatite rock had been subjected to the superimposed reformation of later porphyry magma emplacement and fluid activity, which formed Zn-Ag-rich deposits genetically associated with porphyry.