西藏工布江达县亚贵拉铅锌矿床地质特征及成因分析

Geological Characteristics and Genesis of Yaguila Lead-Zinc Deposit in the Gongbujiangda County of Tibet Province

西藏工布江达县亚贵拉铅锌矿床位于狮泉河-纳木错-嘉黎结合带南侧,隆格尔-工布江达弧后断隆带内,矿体产于上石炭-下二叠统来姑组变石英砂岩与大理岩岩性转换部位,呈层状、似层状产出,其产状与地层一致。文章通过对矿床地质、地球化学特征和流体特征的研究,分析了矿床成因。矿区岩、矿石稀土元素地球化学特征及硫同位素分析表明,成矿物质主要来自深部物源区,氢、氧同位素资料证明成矿溶液为岩浆水和变质水组成的混合水,矿床既具有明显的热水沉积成因特征,又受后期岩浆热液的强烈叠加,属热水沉积-岩浆热液叠加改造型矿床。

Yaguila lead -zinc deposit in the Gongbujiangda county of Tibet is located in the back -arc fault uplift area of Longgeer- Gongbujiangda of the south part of Shiquanhe - Namucuo - Jiali belt. The deposit is occurred in the litbology transformation of ahered quartzose sandstone and marble of upper Carboniferous - lower Permian Laigu group. Orebodies, consistent oecurrence with the strata, exists as layer and stratabound. The authors analyzed its genesis through an integrated study of geological characteristics,geochemistry and ore forming fluid characteristics. The REE and S isotopic composition show that the ore - forming metallic materials were derived from depth, and the H - O isotopic data indicates that the ore - forming fluids were mixture flu- ids of metamorphic water and rnagmatic water. The deposits are of obvious genetic characteristics of submarine hot water deposition and also sustained intensely reformed by later magmatic solutions. The genesis of this deposit is a sedimentary exhalative - magmatic hydrothermal deposit superimposed and altered by later fluids.