| 与云南个旧超大型锡矿床有关的花岗岩锆石U-Pb定年及意义 |
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| 引用本文：CHENG YanBo,MAO JingWen,XIE GuiQing，CHEN MaoHong, YANG ZongXi.2009.Zircon U-Pb dating of granites in Gejiu superlarge tin polymetallic orefield and its significance[J].Mineral Deposits,28(3):297~312 |
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| 基金项目:国家重点基础研究发展计划(973计划)(2007CB411405、2007CB411407)”、中国地质调查局大调查项目“我国主要金属矿床模型研究(1212010634001)”及“斯伦贝谢科技研究计划(SLBX0804) |
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| 中文摘要:云南个旧地区发育大量与成矿时空密切相关的火成岩，包括玄武岩、辉长岩、花岗岩和正长岩，花岗岩被认为是个旧地区与成矿关系最密切的侵入岩。文章首次采用LA_ICP_MS和SHRIMP U_Pb方法对研究区内的花岗岩进行了精确定年，数据表明，不同类型的花岗岩同时或近于同时形成。龙岔河似斑状花岗岩主要形成于（82.0±0.3)～（83.2±1.4） Ma，马拉格_松树脚似斑状花岗岩形成于（82.8±1.7） Ma，老厂似斑状花岗岩形成于（83.3±1.6） Ma，白沙冲等粒花岗岩形成于（77.4±2.5） Ma，均集中形成于晚白垩世。结合前人的研究成果和本次新获得的数据，矿区内岩浆作用发生的时限基本可以限定在76～85 Ma之间，与整个华南西部地区成岩成矿时代吻合。年代学研究表明，个旧地区燕山晚期的构造背景与滇东南_桂西地区相同，而与红河断裂以西的藏南_三江锡矿带具有较明显的不同。 |
| 中文关键词:地球化学 花岗岩 锆石U_Pb年龄 动力学背景 云南个旧 |
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| Zircon U-Pb dating of granites in Gejiu superlarge tin polymetallic orefield and its significance |
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| Abstract:Lots of igneous rocks are distributed in the Gejiu tin polymetallic orefield of Yunnan Province, and granites here are considered to have some original connection with the ore deposits. SHRIMP and LA-ICP-MS zircon U_Pb dating yielded some age data: the Longchahe porphyritic granite is (81.2±1.4)～(83.2±1.4) Ma, the porphyritic granite in Malage_Songshujia area is (82.8±1.7) Ma, the porphyritic granite in Laochang area is (83.3±1.6) Ma and the Baishachong equigranular granite is (77.4±2.5) Ma. Based on these data together with some new data obtained in this study, the authors hold that southeast Yunnan and west Guangxi belonged to the same geotectonic setting in Late Yanshanian period, but were obviously different from the south Tibet-Three River tin belt. |
| keywords:geochemistry, granite, zircon U_Pb dating, geodynamic setting, Gejiu in Yunnan |
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