中文摘要:江西大背坞金矿床赋存在中元古界双桥山群第二岩性组中，产于燕山期花岗岩体的旁侧，受韧性翦切带及其中的挤压破碎带控制。流体包裹体及氢、氧、碳、硫、铅、硅、锶同位素特征表明，参与成矿的碳以岩浆源为主，铅以壳源为主，锶源于上地壳，硫和硅来自地层，流体水以岩浆源为主，混有变质残留晶间水和一定数量的大气降水。矿床成因上应属与燕山期花岗岩浆活动有关的中温热液矿床。
Abstract:Located on the west side of a I)ate Mesozoic granitic intrusive (132×106～120×l06 a), the Dabeiwu gold deposit is hosted by the 2nd Lithologic Formation of metasedimentary rocks of the Mesoproterozoic Shuangqiaoshan Group. Orebodies occur as veins, lenses or beads within or outside the quartz viens, controlled by a ductile sheer zone and the compressional fracture zones in this ductile sheer zone. Au abundances are 6.90×10-9) in the 2nd Lithologic Formation of the Pt2~3 Shuangqiaoshan Group, and (40～42.99)×10-9 in the ductile shear zone of the same formation, Rb-Sr isochron ages of (118.08±1.26)×l06 a were obtained through the measurement of hydrothermal altered minerals such as chlorite, calcite, hydromica and moscovite from the orebodies. Fluid-inclusion studies of quartz yield homogenization temperatures of 180℃ t0 386℃, trapping temperatures 233℃ to 423℃, and fluid pressures of (224～826)×l05 Pa. Salinities of primary fluid inclusions range from 2. 7 to 5.1 wt%NaCl equivalent and densitics are 0.618 to 0.917 g/cm3. Isotope geochemical studies show that δ34S values of pyrite and of arsenopyrite range from -7.1 to -4.9 per mil and from -11.8 to -6.0 per milt respectively. δ13C volume of calcite from the ore is -5.3 per mil, and its δ18O is +15.9 per mil. δ18O and δD values of quartz are +14.8 to +16.9 per mil and -65 to -60 per mil, respectively. Volumes ofδ18Owater evaluated from fluid-inclusion trapping temperatures range from +8.63 to +10.78 per mil. δ30Si volumes of quartz from the ore vein and the Mesoproterozoic knotted slate are -0.5 and -4 per mil, respectively. Initial strontium isotope ratios of the altered minerals and of the granite are 0.711279 and 0.7162 ~ 0.7214, respectively. Sulfur* lead, carbon, silicori, oxygen hydrogen and strontium isotopic data indicate that the ore-forming substances of this deposit were derived mainly from the crust, and the ore-forming fluids were mainly magmatic fluids and subordinately metamorphic residual intercrystalline fluids. Mineralization was mainly associated with the I)ate Mesozoic granitic magmatism. Based on the study of its geology, geochemistry, metallogenic epoch and ore-control structures, it is concluded that the Dabeiwu gold deposit is a mesothermal to hypothermal type gold deposit related to the Yanshanian granitic magmatism and controlled by magmatitc and shattered zones. This conclusion is rather different from the previous genetic view that the deposit was of the shear zone type formed in Neoproterozoic.
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基金项目:地质矿产部定向科研项目
引用文本：
王平安, 董法先, 刘建民, 陈柏林, 沈廷远, 朱永余.1998.江西大背坞金矿床地质、地球化学特征[J].矿床地质,17(1):57~69.1998.Geology and geochemistry of the Dabeiwu gold deposit, Jiangxi Province[J].Mineral Deposits17(1):57~69
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