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通过对湖南骑田岭岩体芙蓉超单元南溪单元中粒斑状角闪石黑云母二长花岗岩、芙蓉矿田白腊水矿区的10号矿脉中蚀变花岗岩型锡矿石、19号矿脉中矽卡岩型矿石矿物、42号含矿花岗斑岩体和ZK801钻孔(80~90m)的细粒花岗岩的Rb-Sr、Sm-Nd和锆石SHRIMP U-Pb同位素年代学研究,分别获得南溪单元弱蚀变花岗岩全岩Rb-Sr等时线年龄为146±10Ma(95%可信度)和岩体锆石SHRIMP U-Pb年龄为155±6Ma(95%可信度),蚀变矿化花岗岩锆石SHRIMP U-Pb年龄为156±5Ma(95%可信度),10号蚀变花岗岩型矿脉矿石的Rb-Sr等时线年龄为137±5Ma(95%可信度),19号矽卡岩型矿脉的矿石—矿物Sm-Nd等时线年龄为133±15Ma(95%可信度);42号含矿花岗斑岩体锆石SHRIMP U-Pb年龄为146±5Ma(95%可信度);ZK801钻孔中细粒花岗岩全岩的Rb-Sr等时线年龄为140±7Ma(95%可信度)。上述精确的年代学研究结果表明,芙蓉超单元花岗岩侵位时间为燕山早期,而不是印支期。由此推测骑田岭芙蓉超单元花岗岩形成于早—中侏罗世,它的构造环境可能为地壳处于强烈剪切挤压晚期,而区内花岗斑岩和细粒花岗岩岩浆活动可能发生在140~145Ma之间,其构造环境可能为地壳由挤压剪切向拉张伸展转化的时期形成的;白腊水矿区不同类型矿床年代学研究结果(133~141Ma)清楚地表明,其成矿作用的时间与区内花岗斑岩和细粒花岗岩的岩浆活动时间有明显的耦合关系。据此推断,骑田岭芙蓉锡矿是在晚侏罗世,地壳由挤压剪切向拉张伸展转化的时期形成的。而与芙蓉花岗岩主体侵入岩浆活动无直接成生关系。
Through the alteration of the granite-type tin ore in No. 10 vein of the Furong orefield Bailaishui deposit in the Furong super-unit Nanxi unit of the Hutitailing rock mass in Hunan province, Rb-Sr, Sm-Nd and zircon SHRIMP U-Pb isotopic chronology of the kaolinite-type ore minerals, 42 ore-bearing granite porphyry and the fine grained granite ZK801 (80 ~ 90m) The Rb-Sr isochron age of the weakly altered granites in Nanxi unit is 146 ± 10Ma (95% confidence level) and the zircon SHRIMP U-Pb age is 155 ± 6Ma (95% confidence level) The SHRIMP U-Pb age of the altered mineralized granite is 156 ± 5Ma (95% confidence), and the Rb-Sr isochron age of the 10th altered granitic vein ore is 137 ± 5Ma (95% confidence) , The Sm-Nd isochron age of 133 ± 15Ma (95% confidence) of No. 19 skarn type veins, and SHRIMP U-Pb age of 146 ore-bearing granite porphyry was 146 ± 5Ma (95% confidence). The Rb-Sr isochron age of fine grained granite in ZK801 was 140 ± 7Ma (95% confidence). The above precise chronological study shows that the Habitat of the Hibiscus granitoid emplacement is early Yanshanian, not Indosinian. Therefore, it is speculated that the Qilianling Furong supra-unit granite was formed in the early-middle Jurassic. Its tectonic environment may be that the crust is in the late stage of intense shear crusting, whereas granitic porphyry and fine granitic magmatic activity may occur in the The tectonic setting may be formed during the period from extrusion shear to extensional extension and extension. The results of geochronology (133 ~ 141Ma) of different types of ore deposits in Baolashui area clearly indicate that the mineralization The time of interaction has obvious coupling relationship with magmatic activity time of granitic porphyry and granitic granite in the area. Based on this, we can conclude that the Furong Tin Mine in Qitianling was formed in the period of Late Jurassic with crustal transformation from extrusion shear to extension and extension. However, there is no direct relationship between intrusive magma activity and main body of Furong granite.