西昆仑塔木—卡兰古铅锌铜矿带含矿岩系的地质地球化学特征

CHARACTERITICS OF GEOLOGY AND GEOCHEMISTRY OF ORE-BEARING FORMATION IN TAMU-KALANGU LEAD-ZINC- COPPER ORE BELTS IN WESTERN KUNLUN MOUNTAIN

新疆塔木—卡兰古铅锌铜成矿带位于西昆仑与塔里木盆地的结合带 ,是近年来新发现的一个大型矿带。通过对含矿岩系的岩石化学、成矿元素、硫同位素、稀土元素的研究 ,并结合流体包裹体成分及H、O同位素的综合研究分析 ,认为该成矿带可分为两种矿床类型 ,即砂砾岩型铅铜 (钴 )矿和碳酸盐岩型铅锌矿。二者为同一热卤水成矿系统的不同成矿阶段的产物 ,两类矿床可互为找矿标志。下部砂砾岩型矿床的成矿元素组合为Cu Co Pb Ag As(Ni Zn Cd) ,硫同位素组成表明富集轻硫 ,海底热液活动不强烈 ;上部碳酸盐岩型矿床的成矿元素组合为Pb Zn Cd As Ag Ba ,硫同位素分布具塔式结构 ,显示具海水还原硫和深源硫的混合来源 ,有强烈的海底热液活动。提出该成矿带的找矿目标应以上部碳酸盐岩型铅锌矿为主 ,同时应当注意下部砂砾岩型铅铜矿及其含铜砂页岩中钴的综合评价和工业利用。

Tamu-Kalangu lead-zinc-copper ore belt located at the boundary between western Kunlun and the Tarim basin is a large metallogenic belt.With the study of compositions of ore-bearing formations,metallogenic elements,sulfur isotopes,REE compositions and H,O isotopes of fluid inclusions for ore-bearing formations,the deposits in the belt can be divided into the lead-copper(cobalt)deposits of sandstone type and the lead-zinc deposits of carbonate type.They were formed at different stages in the same metallogenic system.The metallogenic element assembles in sandstone type deposits are Cu-Co-Pb-Ag-As(Ni-Zn-Cd),sulfur isotope is rich in light sulfur,and the contents of Ba show the thermal activity in seafloor is delicacy.The metallogenic element assembles in carbonate type deposit are Pb-Zn-Cd-As-Ag-Ba,and the feature of sulfur isotopic distribution shows that the metallogenic material was derived from deoxidation of seawater and seafloor hydrothermal.The lead-zinc deposits of carbonate type should be a main prospecting goal.At same time,the lead-copper deposits of sandstone type and the cobalt in copper-bearing sand-shale should be noticed.