西藏北喜马拉雅马扎拉金锑矿床地质特征及成矿作用

来源期刊：黄金2011年第1期

论文作者：张建芳 郑有业 张刚阳 龚瑞君

文章页码：20 - 24

关键词：地质特征； 成矿作用； 马扎拉金锑矿床； 北喜马拉雅成矿带

Key words：geologic characteristic； mineralization； Mazhala gold-antimony deposit； Northern Himalaya metallogenic belt

摘    要：马扎拉金锑矿床位于西藏北喜马拉雅金锑成矿带。阐述了马扎拉金锑矿床矿床地质特征、金的赋存状态以及矿床地球化学特征,并对矿床成矿作用进行了探讨。研究结果表明,马扎拉金锑矿床严格受构造及层位的控制,金主要以裂隙金、包裹金和晶隙金3种形式赋存在黄铁矿、辉锑矿、石英及方解石中;流体包裹体类型主要为气液二相包裹体和含CO₂三相包裹体,成矿温度在180～350℃之间,峰值为270℃,w(NaCl)为2.90%～5.56%,成矿流体为中低温低盐度的岩浆水与地热水混合流体,成矿物质来源于深源闪长质岩浆及周围地层。因此,其成矿作用为早期断陷盆地沉积地层经区域变质作用使成矿物质初步富集,中新世岩浆热液带来成矿物质叠加成矿。

Abstract: Mazhala gold-antimony deposit locates in Northern Himalaya metallogenic belt.This paper not only reports the geological characteristics,gold occurrence and geochemistry characteristics of the deposit,but also discusses its mineralization.The deposit is strictly controlled by structures and layers.Gold mainly occurs in pyrite,stibnite,quartz and calcite in 3 forms of fissures,cracks and crystal gold.The main types of fluid inclusions are gas-liquid two-phase inclusions and three-phase inclusions with CO₂.The mineralizing temperature is in the range of 180-350 ℃ and the peak is 270 ℃;the value of w(NaCl) is between 2.9 % and 5.56 %.The mineralizing fluid is a commixed medium-low temperature low salinity fluid made up by magmatic water and geothermal water.The metallogenic material came from deep dioritic magma and its surrounding stratum.Therefore,its mineralizing function was that ore source sediment was enriched by metamorphosed in early rift basin and then superposed by ore-forming material which were brought by magmatic hydrothermal in later period.