| 华南大容山—十万大山花岗岩体LA-ICP-MS锆石U-Pb定年、地球化学特征及地质意义 |
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| 关键词:Triassic S-type granite Indosinian orogeny South China Shiwandashan |
| 基金项目:国家自然科学基金项目(编号: 41502197);中国地质科学院基本科研业务费项目(编号: DZLXJK201601);中国地质调查局项目(编号: 121201104000150009) |
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| Zircon LA-ICP-MS U-Pb Dating and Geochemical Analysis of the Darongshan–Shiwandashan Granitoids in Southwestern South China and Their Geological Implications |
| The authors conducted a combined study of petrologic, geochemical, geochronological, and Lu-Hf isotopic analysis of the plutons from the Darongshan–Shiwandashan granitoids. Igneous zircons from the Taima granite porphyry yielded a weighted 206Pb/238U age of (243±3) Ma, consistent with ages of other plutons of the granitoids. All these plutons are mainly composed of granite, granite porphyry and charnockite, and contain granulite enclaves. They are all strongly peraluminous, high-K calc-alkaline granites and show negative Eu anomalies with Eu/Eu* ratios being 0.30~0.54. They are enriched in Rb, Th and U, and depleted in Nb, Ta, P, Ti. They have high total REE content and display enrichment in LREE. These geochemical features are consistent well with the S-type characteristics of the granitoids. In situ zircon Hf analyses show negative εHf(t) values from –16 to –6, and have the depleted mantle two-stage Hf model ages (TDM2) of 1.6~2.3 Ga. The authors hold that the S-type granites were formed by melting of the Paleoproterozoic to Mesoproterozoic meta-sedimentary rocks in an extensional tectonic setting. Heat input associated with the asthenosphere mantle upwelling might have played an important role in crustal melting and crystallization of the granitoids. Geodynamically, the formation of the S-type granitoids was related to the subduction of the Paleo–Pacific plate. |
| WANG Wen-bao,LI Jian-hua,XIN Yu-jia,SUN Han-shen,YU Ying-qi.2018.Zircon LA-ICP-MS U-Pb Dating and Geochemical Analysis of the Darongshan–Shiwandashan Granitoids in Southwestern South China and Their Geological Implications[J].Acta Geoscientica Sinica,39(2):179-188. |
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