摘要:
提要：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。LA-ICP-MS锆石U-Pb同位素年龄测试表明，虎头崖Ⅴ矿带外围花岗闪长岩形成时代为(224.3±0.6) Ma，Ⅷ号矿带矿体下部正长花岗岩形成时代为(239.7±0.8) Ma，岩体形成时代为中—晚三叠世。岩石地球化学表明，花岗闪长岩富钾贫钠(K2O/Na2O为2.02~2.88)，无明显负Eu异常(δEu为0.68~1.06)，富集Rb、Th、U、K等大离子亲石元素，明显亏损Nb、P、Ti等元素，属I型花岗岩；正长花岗岩具高硅、富碱、低铁镁、贫钙磷钛的特征，负Eu强烈(δEu为0.08~0.26)，富集Rb、Th、U、K，亏损P、Ti、Ba、Sr，属高分异I型花岗岩；二者均形成于后碰撞构造背景；Hf同位素组成不均一，指示其经历了壳幔岩浆混合作用，幔源物质的加入可能带来了丰富的成矿物质。
Abstract:
Abstract: The Hutouya Pb-Zn polymetallic ore deposit is located in Qimantag, East Kunlun. Intermediate-acid intrusive rocks occur widely in this area, and are closely related to iron polymetallic mineralization. The results of LA-ICP-MS zircon U-Pb isotope dating reval that the granodiorite in the periphery of No. Ⅴore belt was formed at (224.3±0.6) Ma and the orthoclase granite in No. Ⅷ ore belt was formed at (239.7±0.8) Ma. Petrogeochemistry shows that the granodiorite is rich in K and poor in Na, with no strong negative Eu anomalies (δEu=0.68-1.06), and is enriched in Rb, Th, U, K, but depleted in Nb, P, Ti, thus belonging probably to I-type granite series. The orthoclase granite is characterized by high SiO2, high alkali, low TFeO, MgO, CaO, P2O5 and TiO2, strong negative Eu anomalies (δEu 0.08-0.26), enrichment of Rb, Th, U, K，and depletion of P, Ti, Ba, Sr, belonging probably to highly fractionated I-type granite series. Both of them were formed at the post-collision stage. Variable Hf isotopic compositions of zircon indicate that it experienced magma mixing, which provided large quantities of ore-forming meterials for large-scale polymetallic mineralization.
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