作　　者： ; ; ; ; ; ; ; ;

机构地区： 南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室

出　　处： 《地质论评》 2013年第5期983-992,共10页

摘　　要： 在详细的野外地质工作基础上,本文测定了河南省新县大银尖钼矿床的矿石硫、铅同位素,含矿石英脉中石英的氧同位素、石英中包裹体的氢同位素组成,以及辉钼矿的铼含量,参照前人的研究成果,探讨大银尖钼矿床成矿物质来源和形成机制。矿石硫同位素δ34S V-CDT介于3.90‰~10.70‰之间,均值为7.44‰。矿石铅同位素n(206Pb)/n(204Pb)介于17.0411~17.3188之间,均值为17.1388;n(207Pb)/n(204Pb)介于15.3968~15.4166之间,均值为15.4041;n(208Pb)/n(204Pb)介于37.7322~38.2360之间,均值为37.9100。含矿石英脉中石英的δ18O SMOW值在11.20‰~13.20‰之间,均值为11.90‰;石英中包裹体的$D SMOW介于-79.00‰^-76.90‰之间,均值为-78.28‰;利用流体包裹体均一温度的平均值和Clayton平衡分馏方程计算与石英平衡共存流体的δ18O H2O,SMOW介于-0.26‰~3.70‰之间,均值为1.82‰。辉钼矿中的Re含量介于8.28×10-6~54.74×10-6之间。矿石硫同位素组成研究表明成矿物质与岩浆作用有关,但混有地壳物质。铅同位素组成和辉钼矿的铼含量研究表明,大银尖钼矿床的成矿物质主要来自地壳。含矿石英脉的氢和氧同位素组成研究显示,氧同位素飘离岩浆水范围,表明成矿流体早期为岩浆水,晚期混入大气降水,也进一步证实混合作用是大银尖钼矿形成的一种重要机制。 After a detailed field geological investigation, writers analysed the sulfur and lead isotopic compositions of the ores, oxygen isotopic compositions of quartz and hydrogen isotopic compositions of the inclusions in the quartz from the ore-bearing quartz veins, and rhenium content of the molybdenite in the Dayinjian molybdenum deposit, Xinxian County, Henan Province; discussed the ore-forming material resource and ore- forming mechanism. The δ34Sv_cDT values of the ores range from 3.90%0 to 10. 70%e, with an average value of 7.44%0; n（206pb）/n（204pb）, n（207pb）/n（204Pb） and n（20spb）/n（204pb） ratios of the ores range from 17.04 to 18 17.32, 15.40 to 15.42 and 37.73 to 38.24, respectively. The 81SOsMow, δDsmow, and 8 On：o.smow of the ore- bearing quartz precipitated in the main mineralization stage are 11.20‰- 13.20‰（with an average 11.90‰） , -79.00‰- -76.90‰ （with anaverage value of -78.28‰）, and -0.26%e- 3.70‰（ with an average value of 1.82‰）, respectively, which show the characteristics of oxygen isotope drift. The contents of rhenium in the molybdenite range from 8.28 x 10-6 to 54.74 x 10-6. The sulfur isotopic compsition indicates that the ore sulfur mainly came from magma in deep source and contaminated by the crustal substances; lead isotopic composition of ores and rhenium content in the molybdenites showed that ore-forming materials come from the crust; and hydrogen, oxygen isotopic compositions suggests a mixing between magmatic hydrothermal and meteoric water in the late mineralization stage. Therefore, the composite action is proved to be the Dayinjian molybdenum deposit formed an important ore-foreming mechanism.

关 键 词： 同位素 成矿物质 成矿机制 钼矿床 河南新县

领　　域： [天文地球] [天文地球]