新疆中天山马鞍桥铅锌矿床脉状矿石成矿流体的性质  

Characteristics of metallogenic fluids of vein ore in Maanqiao Pb——Zn deposits in middle Tianshan,Xinjiang

作　　者：张志斌[1,2] 黄超义[3] 兰晓东[1] 李朝阳[2] 

机构地区：[1]四川省核工业地质局二八一大队,四川西昌615000 [2]中国科学院广州地球化学研究所成矿动力学研究室,广州510640 [3]紫金矿业集团东北亚有限公司,长春130021

出　　处：《世界地质》2009年第2期179-186,198,共9页World Geology

基　　金：国家973重点基础研究发展规划项目(2001CB409805)

摘　　要：新疆中天山地区热水沉积形成的马鞍桥铅锌矿床在成矿后期形成了穿插早期层状、似层状矿体的脉状紫色萤石-闪锌矿矿石。紫色萤石和闪锌矿中气液相L—V型流体包裹体的均一温度呈双峰式分布，主要分布在140℃～260℃和260℃～442℃两个区间内，且有少量高于470℃的流体包裹体存在，指示其成矿流体由中高温和低温两个端员组成。同时，测得脉状矿石的成矿流体盐度为1．91～6．30Wt％（NaCl）和11．93～21．82Wt％（NaCl）。激光Raman光谱分析显示紫色萤石中气液相L—V型流体包裹体的气相组分主要为CH4、C2H6和C3H8等低分子烷烃及少量的H2S和N2，指示形成这种脉状矿石的热液由中高温的岩浆气液与低温、高盐度的油田热卤水混合而成。The hydrothermal sedimented Maanqiao Pb-Zn deposits in middle Tianshan of Xinjiang formed purple fluorite-sphalerite veins which cut through the earlier bedded ore bodies in late metallogenic stage. The homogeneous temperature of the vapor-liquid L-V type fluid inclusions in purple fluorite and sphalerite shows the characters of bimodal distribution and mainly distribute in 140 - 260℃ and 260 - 442℃, and some inclusions＇ temperatures are higher than 470℃, which indicates the metallogenic fluids composed of two temperature ends including medium-high and low temperatures. The salinity of these vein ore metallogenic fluids is fall into two groups of 1.91 -6.30Wt% （NaCl） and 11.93 -21.82Wt%（NaCl）. The study of laser Raman spectra reveals the main compositions of the gaseous phases in vapor-liquid L-V type of purple fluorite are some low molecular alkanes （CH4, C2H6, C3H8 ） , as well as little H2S and N2. The fact shows the hydrothermal fluids forming the vein type ores are the mixed by the medium-high temperature magrnatic vapor-liquid and the oilfield hot brine with low temperature and high salinity.

关 键 词：新疆中天山 马鞍桥铅锌矿床 成矿流体 地球化学 

分 类 号：P618.4[天文地球—矿床学]