格陵兰东部Jameson Land盆地Quensel Bjerg矿区铜铅锌多金属矿床成矿流体特征及成因探讨

摘要

格陵兰是世界上重要的巨型多金属成矿带之一,Jameson Land盆地位于该成矿带的东部,该区Cu、Pb、Zn等金属地表矿化特征明显、矿化强度大,分布范围广、厚度大.区内矿化点也较多,已发现近6～10个铜、铅或锌矿化层.Quensel Bjerg矿区位于Jameson Land盆地的东部.本文通过系统的野外地质调查、流体包裹体显微测温以及C-O、S稳定同位素分析,认为Quensel Bjerg矿区成矿流体性质为中低温、中低盐度流体,流体来源于大气降水和地层水(海水)的混合,碳来源于海相碳酸盐岩的溶解,成矿物质来源于Ravnefjeld组页岩、围岩(灰岩)及下伏地层,该矿床属于沉积岩容矿的沉积-改造型层状铜铅锌多金属矿床.%Greenland is one of the important huge polymetallic metallogenic belts in the world.The Jameson Land Basin is located in the east of the belt,in which Cu,Pb and Zn mineralization is characterized by distinctness,large intensity,wide distribution and great thickness on the earth's surface.Besides,there are more mineralized sites in the region;and about six to ten Cu,Pb or Zn mineralization beds have been found.The Quensel Bjerg ore district is situated in eastern Jameson Land Basin.Based on systematic field geological investigation work,microthermometry data of fluid inclusions and C-O,S isotopic analyses in this paper,it is suggested that metallogenic fluids with medium-low temperature and salinity are originated from mixing meteoric water and stratigraphical water (or seawater);carbon is derived from the dissolution of marine carbonate rocks;ore-forming materials are sourced from the Ravnefjeld Formation shales,wall rocks (limestone) and underlying strata.Thus,we have proposed that this deposit is a sedimentary-hosted sedimentary-reworked-type stratiform Cu-Pb-Zn polymetallic deposit.