西藏仲巴县天宫尼勒矽卡岩型铜金矿床锆石U-Pb年代学和岩石地球化学特征: 对成因及其成矿构造背景的指示 |
点此下载全文 |
引用本文:黄瀚霄,李光明,刘波,董随亮,石洪召,张智林,范安辉.2012.西藏仲巴县天宫尼勒矽卡岩型铜金矿床锆石U-Pb年代学和岩石地球化学特征: 对成因及其成矿构造背景的指示[J].地球学报,33(4):424-434. |
DOI:10.3975/cagsb.2012.04.04 |
摘要点击次数: 3568 |
全文下载次数: 5817 |
|
基金项目:国家重点基础研究发展计划(编号: 2011CB403100);青藏专项“西藏铜铅锌国家级接替基地综合研究”(编号: 1212011121239);“西藏大型矿床成矿专属性研究”(编号: 1212011221073);“班公湖-怒江成矿带铜多金属成矿规律综合研究” (编号: 1212011086074) |
|
中文摘要:天宫尼勒铜金矿床位于冈底斯成矿带北部, 是与花岗闪长岩关系密切的矽卡岩型矿床。花岗闪长岩锆石ICP-MS U-Pb年龄加权平均值为102.6±1.8 Ma, 指示该矿床形成于早白垩世。元素地球化学数据表明, 花岗闪长岩具有高Al2O3, 富Na2O, 低TiO2等特点, 属于准铝质、钙碱性岩石系列, 微量元素富集大离子亲石元素(LILE), 亏损高场强元素(HFSE)和重稀土元素, 显示Nb和Ta的负异常, 具有明显的岛弧型岩石的地球化学特征, 岩石成因可能与班公湖-怒江洋壳板片俯冲所诱发的岩浆活动有关。结合区域构造演化, 天宫尼勒铜金矿床形成于班公湖-怒江洋向南(即冈底斯地块)俯冲碰撞闭合之前的岛弧环境。 |
中文关键词:锆石U-Pb年代 岩石地球化学 成矿构造背景 铜金矿 冈底斯成矿带 天宫尼勒 |
|
Zircon U-Pb Geochronology and Geochemistry of the Tiangongnile Skarn-type Cu-Au Deposit in Zhongba County, Tibet: Their Genetic and Tectonic Setting Significance |
|
|
Abstract:The Tiangongnile Cu-Au deposit located in the northern part of the Gangdise metallogenic belt is a skarn-type deposit closely related to granodiorite. Zircon ICP-MS U-Pb weighted average age of the granodiorite is 102.6±1.8 Ma, indicating that the deposit was formed during the Early Cretaceous period. Element geochemical data indicate that the diorite is characterized by high Al2O3, rich Na2O and low TiO2, thus belonging to metaluminous calc-alkaline series. Trace elements are characterized by enrichment of large ion lithophile elements(LILE) and depletion of high field strength elements (HFSE) and heavy rare earth elements, with Nb and Ta negative anomalies, suggesting that the diorite has geochemical features of island arc rock and its petrogenesis may be related to magmatic activity induced by the subduction of Bangong Co–Nujiang River oceanic crust plates. In combination with regional tectonic evolution, it is held that the Tiangongnile Cu-Au deposit might have been formed in an island-arc environment before southward subduction and closure of Bangong Co-Nujiang River oceanic crust plates. |
keywords:zircon U-Pb age rock geochemistry tectonic setting Cu-Au deposit Gangdise Tiangongnile |
查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|