青海省祁漫塔格地区牛苦头铅锌矿成矿流体特征

Metallogenic fluid characteristics of Niukutou lead zinc deposit in Qimantage area,Qinghai Province

青海祁漫塔格地区牛苦头铅锌矿床目前控制铅+锌金属储量达到大型。其主要金属矿物为闪锌矿、方铅矿、磁黄铁矿等,脉石矿物为石榴子石、阳起石、黑柱石、石英和方解石等,矿床成因类型为夕卡岩型。本次研究针对M1和M4矿区主要矿物开展流体包裹体的测温工作,获得石榴子石流体包裹体均一温度分布范围为384~600℃,盐度10.24%~23.18%,辉石中流体包裹体均一温度范围308~550℃,阳起石中流体包裹体均一温度346~458℃,石英中流体包裹体均一温度133~422℃。流体包裹体研究结果反映了成矿流体早阶段以岩浆热液为主,晚阶段加入了大量的大气降水引起温度、盐度的迅速降低,导致成矿物质的沉淀。

Niukutou lead-zinc deposit is located in Qimantage area,Qinghai Province.At present,it controls lead and zinc metal reserves to a large scale.The main metal minerals are sphalerite,galena and pyrrhotite,and the gangue minerals are garnet,actinolite,andalusite,quartz and calcite.In this research,the temperature measurement of fluid inclusions is mainly carried out for the main minerals in M1 and M4 mining areas.The uniform temperature distribution range of garnet fluid inclusions is 384℃~600℃,salinity is 10.24%~23.18%,The homogenization temperature of inclusions in pyroxene ranges from 308℃to 550℃.The homogenization temperature of inclusions in actinolite ranges from 346℃to 458℃.The homogenization temperature of fluid inclusions in quartz ranges from 133℃to 422℃.It reflects that the ore-forming fluid is mainly magmatic hydrothermal fluid in the early stage,and a large amount of meteoric water is added in the late stage,resulting in the rapid decrease of temperature and salinity,resulting in a large amount of precipitation of ore-forming materials.