| 郭周平.北祁连浪力克铜矿镁安山质岩石年代学及地球化学特征[J].地质与勘探,2015,51(2):253-265 |
| 北祁连浪力克铜矿镁安山质岩石年代学及地球化学特征 |
| Geochronology and geochemistry of magnesian andesites in the Langlike cooper deposit, North Qilian ShanMountain, China |
| 投稿时间：2013-11-18 修订日期：2014-09-06 |
| DOI： |
| 中文关键词: 镁安山质岩石 锆石U-Pb年龄 地球化学 浪力克 北祁连 |
| 英文关键词: Mg andesite,zircon U-Pb geochronology, geochemistry, Langlike, North Qilian |
| 基金项目:中国地质调查局地质调查项目“青海省门源县银灿-浪力克1:5万成矿预测”(1212011221043)资助 |
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| 中文摘要: |
| 浪力克铜矿床位于北祁连造山带中段的冷龙岭复式背斜内，铜矿体主要赋存于火山通道内的闪长玢岩及其邻近的安山岩中，本文对矿区内赋矿的安山岩和石英闪长玢岩进行岩石学、地球化学研究，对安山岩进行锆石U-Pb年代学研究，以探讨矿区火山岩的岩石成因与形成环境，并对成矿时代进行约束。岩石地球化学数据显示，安山岩和石英闪长玢岩的化学特征十分相似，均具有高镁的特点，以大离子亲石元素（Rb、Ba、Th、U、K）强烈富集和高场强元素相对亏损及出现明显的Nb、Ta、P、Ti谷为特征，Cr和Ni含量较高，稀土元素配分曲线呈平坦型，∑REE较低，轻重稀土元素分馏不明显，略微富集轻稀土，基本无Eu异常，为一套高镁安山质岩石组合，其特点可以和世界某些高镁安山岩相对比，属于岛弧构造环境岩浆作用的产物，很可能为俯冲洋壳脱水熔融产生的熔体与地幔楔反应形成的。 |
| 英文摘要: |
| The Langlike cooper deposit is located in the middle of the North Qilian Shan with mineralization occurring in quartz diorite porphyrite and andesite. This paper presents the study on the geochemistry and petrology of these rocks. Using zircon U-Pb dating of the andesite, we explored the genesis and context of the volcanic rocks and constrained the age of mineralization in this deposit. Geochemical data show that both the rocks have very similar geochemical characteristics, all bearing rich magnesium and high content of Cr and Ni. They belong to the calc-alkaline series，intensely enriched in LILE (Rb, Ba, Th, U, and K) and depleted in HFSE with strong negative anomalies of Nb, Ta, and P. The Ti. The REE element distribution pattern displays a flat type with LREE slightly enriched. They can be ascribed to high-Mg andesites, comparable with other high-Mg andesites in the world. Combined with previous research results, we speculate the andesite and quartz diorite porphyrite in the Langlike cooper deposit are products of magma events in an island-arc tectonic environment triggered by slab subduction, and generated by the reaction between the fused mass from dehydration melting of subducted oceanic crust and a mantle wedge. |
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