萨尔布拉克金矿床位于准噶尔盆地北东缘之喀拉通克岛弧带,北邻呈北西西向展布的额尔齐斯构造挤压带,矿体受次级断裂萨尔布拉克韧性剪切带控制。据构造变形-热液蚀变-矿物共生组合特征,构造-成矿阶段划分为4个:Ⅰ韧性变形-黄铁矿化-硅化阶段;Ⅱ韧脆性变形-黄铁矿-毒砂-石英阶段;Ⅲ网脉状石英阶段(多金属硫化物阶段);Ⅳ石英-碳酸盐阶段。构造-成矿流体早、中阶段以富含CO2(CH4)的碳质流体包裹体和CO2/H2O高比值的H2O-CO2包裹体为特征,Ⅰ阶段均一温度集中在290~350℃和200~269℃两个区域;Ⅱ阶段均一温度集中在204~358℃和170~203℃,Ⅲ阶段均一温度215~310℃。原生水溶液包裹体与早中阶段CO2包裹体或碳质流体包裹体相伴,次生水溶液包裹体普遍存在于Ⅰ、Ⅱ和Ⅲ阶段中,可能为造山变质后由于地壳抬升大气降水和地层建造水加入所致。伴随着额尔齐斯碰撞造山带由压性、韧性转变为张性、脆性的演化,构造-成矿流体的演化也由富含CO2(±CH4)的碳质、CO2/H2O高比值、中温、低盐度的变质流体向低温、富含水的流体演化。萨尔布拉克金矿具有造山带型金矿的特点,其成矿作用主要发生在晚构造阶段,伴随构造由挤压向拉伸的转变。
The Sarbulake gold deposit,located in the Kalatongke's island arc zone in the northeastern margin of the Zhuigaer Basin,occurred in the Sarbulake shear zone,which is a secondary structure of the NWW-trending Erqisi compressive tectonic zone to the north.Based on deformation-hydrothermal alteration-mineral assemblages,the structural-mineralization process can be divided into four stages: 1) the ductile deformation-pyrite-silicification stage;2) the ductile-brittle deformation-pyrite-arsenopyrite-quartz stage;3) the stockwork quartz stage(polymetallic sulfide stage);and 4) the quartz-carbonate stage.The fluids in the early-and middle-stage were rich in CO2(CH4)(represented by the carbonic inclusions) and had high CO2/H2O ratios.The homogenization temperatures(Th) of inclusions in the stage 1 are concentrated in the ranges of 290-350 ℃ and 200-269 ℃,those in the stage 2 are mainly in the range of 204-358 ℃ and 170-203 ℃,whereas the homogenization temperatures in the stage 3 are concentrated in 215-310 ℃.Primary aqueous inclusions are associated with carbonic inclusions in the early and middle stages,while secondary aqueous inclusions also occurred widely in the stage 1,2 and 3.These secondary inclusions probably represent meteoric water during crustal uplift in the late metamorphism.The evolution from mesothermal,CO2(±CH4)-rich fluids to epithermal,aqueous fluids appears to have been accompanied by the transition from compressive,ductile regime to extensional,brittle regime along the Erqisi orogen.The Sarbulake gold deposit is similar to most orogenic gold deposits,with the mineralization process being mostly in the late-tectonic stage and accompanied by the transition from compressive to extensional stress regimes.