山东三山岛金矿床流体包裹体特征及其地质意义

三山岛金矿床位于莱州市三山岛—仓上断裂带内,矿石主要为蚀变岩和含金石英脉2种类型。随着胶东金矿床研究的深入和三山岛金矿资源的不断减少,对三山岛金矿床的成矿作用及深部开发前景问题研究具有更重要的意义。针对上述问题,对三山岛金矿床2种类型矿石的成矿流体特征进行对比研究,认为代表成矿早—中期的蚀变岩型矿石形成于中温(均一温度为325～240℃)、低盐度(2.07%～6.88%)、低密度(0.720～0.868g/cm3)、酸碱性不均匀(pH=3.27～10.43)、以氟化物和氯化物为成矿物质载体的还原性流体;代表成矿中—晚期的含金石英脉型矿石形成于中—低温(均一温度为306～160℃)、低盐度(1.05%～9.73%)、低密度(0.739～0.962g/cm3)、碱性(pH=9.25～9.85)、以氯化物和硫化物为成矿物质载体的还原性流体。成矿流体性质的转变反映了成矿流体处于由比较封闭到比较开放的构造环境的转变期,且成矿流体早期以原生岩浆水为主,后期有变质水、大气降水以及海水的参与作用。三山岛金矿成矿深度为2.5～5km,根据目前的开采深度推算其深部还有一定的资源量可供开发。

Study on the Fluid Inclusions Characteristics of the Sanshandao Gold Deposit, Shandong Province, China and Its Geological Significance

The Sanshandao gold deposits,located in Sanshandao-Cangshang fault zone,Laizhou city,mainly develop the orebodies of the altered rock type and quartz vein type.As the genesis research in gold deposit of Jiaodong peninsula advance further and the resources of the Sanshandao gold deposit reduce gradually,investigation for the metallogenic process and resource potential in the Sanshandao gold deposit is more and more significant.The results show that the ore-forming fluid of altered rock type orebodies is mainly middle-low temperature with homogenization temperature from 325 to 240 ℃,low salinity(NaCl eqv.)from 2.07% to 6.88%,low density with density from 0.720 to 0.868 g/cm3,heterogeneous alkalescence with pH from 3.27 to 10.43,and deoxidized.The gold is transported by gold fluoride and gold chloride complexes.The ore-forming fluids of quartz vein type orebodies mainly in low temperature with homogenization temperature from 306 to 160 ℃,low salinity(NaCl eqv.)from 1.05% to 9.73%,low density with density from 0.739 to 0.962 g/cm3,alkalescence with pH from 9.25 to 9.85,and deoxidized.The gold is transported by the gold chloride and gold bisulfide complexes.The transform of ose-forming fluids' characteristics suggests the change of structure condition from the close one to the open one,and the variety of ore-forming fluids from the principal magmatic water in the early stage to a complex origin from metamorphic water,meteoric water and sea water in the late stage.The metallogenic depth of the Sanshandao gold deposit is from 2.5 to 5 km,suggesting that there are respectable resources in the deep part.