论文部分内容阅读
上宫金矿是典型的断控脉状造山型金矿床,成矿过程包括早、中、晚3个阶段。蚀变岩和矿石的δ18O明显高于未蚀变岩石,指示岩石在水岩作用过程中从流体中汲取18O。19件早阶段流体δ18OW变化于4.2‰～13.4‰(平均8.1‰),8件δDW介于-66‰～-88‰之间(平均-78‰),1件δ13C铁白云石=1.5‰,指示流体来源于含碳酸盐地层的变质脱水作用;晚阶段δ18OW为-2.0‰～-0.6‰,1件δDW=-56‰,3件δ13C铁白云石为-1.6‰～-2.2‰,指示流体以大气降水为主要成分;3件中阶段样品δ18OW为1.9‰～4.5‰,δ13为-1.2‰～0.5‰,均介于早、晚阶段之间,指示中阶段为变质热液与大气降水热液的CCO2混合流体作用。大量硫化物沉淀导致中阶段流体(δDW=-113‰～-94‰),显著低于早、晚阶段。28件中阶段硫化物δ34S为显著的负值(-19.2‰～-6.3‰),指示成矿流体系统中存在大量生物硫。理论分析表明,尽管熊耳地体的太华超群、熊耳群、燕山期花岗岩类和下伏地壳、地幔被前人解释为成矿流体的来源,但它们之一或其任意比例的混合物均不可能成为上宫金矿成矿流体的主导性物源,唯一可能是熊耳地体南侧的管道口群-栾川群CSC(含碳质碳酸盐-页岩-硅质岩)建造;在中生代华北与扬子板块的碰撞造山过程中,管道口群-栾川群沿马超营断裂A型俯冲到熊耳地体之?
The Shangong gold deposit is a typical fault-controlled vein-orogenic gold deposit. The ore-forming process includes three stages of early, middle and late stages. The δ18O of altered rocks and ores is significantly higher than that of unmodified rocks, indicating that the rocks draw 18O from the fluid during water-rock interaction. The δ18OW of 19 early-stage fluids varied from 4.2 ‰ to 13.4 ‰ (average 8.1 ‰), with 8 δDWs ranging from -66 ‰ to -88 ‰ (average -78 ‰) and 1 δ13C-iron dolomite = 1.5 ‰, Indicating that the fluids originated from the metamorphic dehydration of carbonate-bearing strata; δ18OW in the late stage ranged from -2.0 ‰ to -0.6 ‰, one δDW = -56 ‰ and three δ13C iron dolomites -1.6 ‰ -2.2 ‰, indicating The fluid is mainly composed of precipitation in the atmosphere. The δ18OW of the three middle-stage samples ranged from 1.9 ‰ to 4.5 ‰ and the δ13 ranged from -1.2 ‰ to 0.5 ‰, both between the early and late stages indicating that the metaphase was metamorphic hydrothermal fluid and atmospheric precipitation Hydrothermal CCO2 mixed fluid. Large amount of sulfide precipitation led to the mid-stage fluid (δDW = -113 ‰ ~ -94 ‰), significantly lower than the early and late stages. 28 mid-stage sulfides δ34S were significantly negative (-19.2 ‰ -6.3 ‰), indicating a large number of biological sulfur in the ore-forming fluid system. Theoretical analysis shows that although the overwhelming majority of the Xiong’er terrane, the Xiong’er Group, the Yanshanian granites and the underlying crust and mantle were previously interpreted as the source of ore-forming fluid, neither one of them nor a mixture of any of its proportions is possible It became the main source of ore-forming fluids in the Shangong gold deposit. The only possible formation was the CSC (carbonaceous carbonate-shale-silicalite) formation on the south side of the Xiong’er terrane. In the Mesozoic North China and During the collision of the Yangtze Plate with the orogenic process, the pipe mouth group - Luanchuan Group A subducted along the Machaoying fault to bear ear land.