孙崇波, 李忠权, 王道永, 陈晓东. 哀牢山构造带南段马玉花岗闪长岩地球化学特征及其锆石U-Pb年龄[J]. 地质通报, 2019, 38(2-3): 223-230.
    引用本文: 孙崇波, 李忠权, 王道永, 陈晓东. 哀牢山构造带南段马玉花岗闪长岩地球化学特征及其锆石U-Pb年龄[J]. 地质通报, 2019, 38(2-3): 223-230.
    SUN Chongbo, LI Zhongquan, WANG Daoyong, CHEN Xiaodong. Petrogeochemistry and zircon U-Pb age of the Mayu granodiorite in the southern section of Ailaoshan tectonic belt[J]. Geological Bulletin of China, 2019, 38(2-3): 223-230.
    Citation: SUN Chongbo, LI Zhongquan, WANG Daoyong, CHEN Xiaodong. Petrogeochemistry and zircon U-Pb age of the Mayu granodiorite in the southern section of Ailaoshan tectonic belt[J]. Geological Bulletin of China, 2019, 38(2-3): 223-230.

    哀牢山构造带南段马玉花岗闪长岩地球化学特征及其锆石U-Pb年龄

    Petrogeochemistry and zircon U-Pb age of the Mayu granodiorite in the southern section of Ailaoshan tectonic belt

    • 摘要: 对云南墨江县马玉花岗闪长岩进行了锆石U-Pb年龄和岩石地球化学分析。LA-ICP-MS锆石U-Pb测年显示,马玉花岗闪长岩年龄为263.6±2.4Ma,形成于晚二叠世。岩石地球化学显示,马玉花岗闪长岩SiO2含量为59.56%~70.50%,全碱(Na2O+K2O)含量为5.16%~7.92%,且Na2O>K2O;岩石富集轻稀土元素,负Eu异常明显(δEu=0.84~1.32),相对富集Sc、Hf,相对贫化Sr、Zr、Th、U。构造环境判别图解显示,马玉花岗闪长岩形成于碰撞期后板内构造环境,说明哀牢山构造带的古特提斯支洋或弧后盆地在晚二叠世(263.6±2.4Ma)已经闭合。

       

      Abstract: This study presents bulk petrogeochemistry and zircon U-Pb dating results for the Mayu granodiorite in Mojiang, Yunnan. LA-ICP-MS zircon U-Pb dating results show that the Mayu granodiorite was formed in the Late Permian period (263.6±2.4Ma). The Mayu granodiorite is characterized by SiO2 content of 59.56%~70.50%, alkali (Na2O+K2O)5.16%~7.92%, and Na2O higher than K2O. It is enriched in LREE and Sc, Hf, and depleted in Sr, Zr, Th, U, with negative Eu anomalies (δEu:0.84~1.32). According to the diagrams, the Mayu granodiorite was formed in a tectonic environment of island arc-continent or continental-arc collision, indicating that the branch of Paleo-Tethys Ocean or arc basin in Ailaoshan tectonic belt may have been closed in the Late Permian (263.6±2.4Ma).

       

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