新疆东天山康古尔金矿的两期热液成矿作用：来自年代学、地球化学的证据

Two Hydrothermal Mineralization Periods of Kangguer Gold Deposit of Eastern Tianshan, Xinjiang: Evidences from the Chronology and Geochemistry

康古尔金矿床受脆-韧性剪切带控制,热液成矿作用具有多期多阶段的特点。本文研究了不同成矿阶段的石英流体包裹体特征、元素垂向分带序列特征及成岩时代、成矿时代与区域构造演化之间的耦合关系,结果显示:第Ⅱ到第Ⅴ成矿阶段石英流体包裹体均一温度平均值分别为157.8℃、244.8℃、158.3℃、138.2℃,呈现降低→升高→降低的特点,成矿流体盐度和密度平均值分别为10.1%和0.97g/cm3,显示中等盐度和中等密度特征;As、Sb等前缘晕元素出现在元素垂向分带序列的中间或下部,呈明显的反分带特征;成矿时代集中于290.4Ma^282.3 Ma和263.8Ma^241Ma两个区间,分别与火山岩就位、次火山岩侵入和秋格明塔什-黄山韧性剪切带后期走滑剪切作用时间强烈吻合。综合研究,认为康古尔金矿具有两期热液成矿作用,为受韧性剪切带控制的与火山岩、次火山岩有关的中低温热液矿床。

Kangguer gold deposit is controlled by brittle ductile shear zone,and it experiences multi-period and multistage mineralizations.The characteristics of quartz fluid inclusions in different mineralization stages,the elements sequence of vertical zonation and the coupling connections among petrogenetic age,metallogenic age and regional tectonic evolution are studied.The results reveal that the average value of homogenization temperature of the quartz fluid inclusions in different mineralizations are 157.8℃,244.8℃,158.3℃and 138.2℃respectively,showing the variation characteristics of fall→rise→fall.The mean values of the salanity and density of ore-forming fluid are 10.1%and 0.97g/cm3,showing the future of moderate salanity and moderate density.The front halo elements such as As,Sb appear in the middle or lower part of the zoning sequence,indicating obvious“reverse zonation”.Mineralization ages are clustered in two intervals:290.4Ma^282.3 Ma and 263.8Ma^241 Ma,which are strongly coupling with the emplacement of volcanic and subvolcanic rocks and the latter strike-slip shear of Qiugemingtashi-Huangshan ductile shear belt respectively.In the synthesis,there are two periods of hydrothermal mineralization activities,and Kangguer gold deposit is a moderate-low hydrothermal deposit controlled by ductile shear belt and related to the emplacement of volcanic and subvolcanic rocks.