东昆仑祁漫塔格虎头崖铅锌多金属矿成矿时代及其地质意义——黑云二长花岗岩地球化学特征和锆石U-Pb年龄证据

发布时间：2018-06-14 15:01

  本文选题：LA-ICP-MS锆石U-Pb测年 + 黑云二长花岗岩　； 参考：《地质通报》2017年06期

【摘要】：虎头崖铅锌多金属矿床位于东昆仑祁漫塔格地区,矿区内中酸性侵入岩体广泛发育,且与成矿关系密切。通过高精度LA-ICP-MS锆石微区原位U-Pb同位素测年,获得与矿化、矽卡岩化关系密切的黑云二长花岗岩锆石的~(206)Pb/~(238)U年龄加权平均值为234.2±1.5Ma。地球化学分析表明,黑云二长花岗岩具有高Al_2O_3、K_2O,低TiO_2、Na_2O的特征,稀土和微量元素显示其富集轻稀土元素、Rb、Th和部分高场强元素,Nb、Sr、Zr相对亏损,稀土元素表现为LREE/HREE明显分离的配分模式,总体表现为I型花岗岩的特征。在(Y+Nb)-Rb图解中落入后碰撞花岗岩区,在R1-R2因子判别图上落入造山晚期和同碰撞花岗岩重叠区,显示其可能形成于碰撞-后碰撞构造阶段。虎头崖铅锌多金属矿区Ⅵ矿带具有强烈的矽卡岩化,结合矿石组构、脉石矿物、围岩蚀变等特征,认为其具有矽卡岩型矿床的特征,形成于234.2±1.5Ma(中—晚三叠世)。
[Abstract]:The Hutouya Pb-Zn polymetallic deposit is located in the Qimantage area of East Kunlun Mountains. The intermediate-acid intrusive rocks are widely developed in the ore area and are closely related to mineralization. Based on the in situ U-Pb isotopic dating in the LA-ICP-MS zircon microregion, a weighted average of 234.2 卤1.5 Ma for zircon zircons from the black cloud monzonitic granite, closely related to mineralization and skarn mineralization, is obtained, and the weighted average age of zircon is 234.2 卤1.5 Ma.The zircon of the La-ICP-MS zircon is closely related to mineralization and skarn mineralization. Geochemical analysis shows that the bifeldite has the characteristics of high Al2O3K _ 2O and low TiO-2 ~ + Na _ 2O. Rare earth and trace elements show relative depletion in the enrichment of light rare earth elements (RbTh) and some high-field strength elements (Nb-Sr-Zr), and the REE is characterized by an obvious separation pattern of LREE / hree. It is characterized by I type granite in general. It falls into the post-collision granite area in the Y Nb-Rb diagram, and falls into the late orogenic and syncollisional granite overlapping areas on the R1-R2 factor discriminant diagram, indicating that it may have been formed in the collision-post-collision tectonic stage. The 鈪，

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