王嘉星, 肖亮, 姜魁, 黄新华, 张顺新, 宁勇云, 谢彪武, 刘伟, 唐志祥. 内蒙古东部央格力雅山中酸性岩地球化学特征、锆石U-Pb年龄及地质意义[J]. 地质通报, 2019, 38(9): 1455-1468.
    引用本文: 王嘉星, 肖亮, 姜魁, 黄新华, 张顺新, 宁勇云, 谢彪武, 刘伟, 唐志祥. 内蒙古东部央格力雅山中酸性岩地球化学特征、锆石U-Pb年龄及地质意义[J]. 地质通报, 2019, 38(9): 1455-1468.
    WANG Jiaxing, XIAO Liang, JIANG Kui, HUANG Huaxin, ZHANG Shunxin, NING Yongyun, XIE Biaowu, LIU Wei, TANG Zhixiang. Geochemical characteristics, zircon U-Pb ages and geological implications of the eastern Innermongolia in Yanggeliya Mountain intermediate-acid rock[J]. Geological Bulletin of China, 2019, 38(9): 1455-1468.
    Citation: WANG Jiaxing, XIAO Liang, JIANG Kui, HUANG Huaxin, ZHANG Shunxin, NING Yongyun, XIE Biaowu, LIU Wei, TANG Zhixiang. Geochemical characteristics, zircon U-Pb ages and geological implications of the eastern Innermongolia in Yanggeliya Mountain intermediate-acid rock[J]. Geological Bulletin of China, 2019, 38(9): 1455-1468.

    内蒙古东部央格力雅山中酸性岩地球化学特征、锆石U-Pb年龄及地质意义

    Geochemical characteristics, zircon U-Pb ages and geological implications of the eastern Innermongolia in Yanggeliya Mountain intermediate-acid rock

    • 摘要: 内蒙古东部央格力雅山岩体岩性为正长花岗岩、二长花岗岩和英云闪长岩。正长花岗岩U-Pb年龄为130.4±1.1Ma,英云闪长岩U-Pb年龄为126.6±3.0Ma、二长花岗岩锆石U-Pb年龄分别为131.6±1.1Ma和130.7±1.5Ma,显示岩体侵位时间为早白垩世。地球化学研究表明,该花岗岩体具有富硅、富碱、贫钙的特征,属准铝质-过铝质高钾钙碱性系列岩石;稀土元素总量较低、轻重稀土元素分馏明显,(La/Nb)N值在9.14~24.86之间、正Eu异常显著(δEu值为1.03~1.53);微量元素K、La、Sr、Gd等明显富集,Nb、Pr、P、Ti等亏损;大离子亲石元素相对高场强元素富集。岩石分异指数平均为80.63,岩石成因类型属高分异I型花岗岩,岩浆来源于下地壳岩石的部分熔融,形成于伸展环境,与古太平洋板块俯冲作用密切相关。

       

      Abstract: The Yanggeliya Mountain is located in the Oroqen Autonomous Banner, Hulunbuir City, eastern Inner Mongolia. Syenogranite, monzoniticgranite and tonalite are the main rocks, and the LA-ICP-MS zircon U-Pb age indicates that the emplacement time is Early Cretaceous (130.4 ±1.1Ma) for syenogranite, 126.6 ±3.0Ma for monzoniticgranite, 131.6 ±1.1Ma and 130.7±1.5Ma for tonalite. The study of rock geochemistry shows that the granite body is characterized by rich silicon and alkali, and depletion of calcium, belonging to the quasi-aluminum-peraluminous, high-potassic, calcium-alkali series of rocks. The total amount of rare earths is relatively low, the fractionation between LREE and HREE is obvious, and the (La/Nb)N values are between 9.14 and 24.86. The Eu has obvious positive anomalies (the δEu values are in the range of 1.03~1.53). As for trace elements, the values of K, La, Sr and Gd are obviously enriched, whereas Nb, Pr, P and Ti are depleted. Large ionic lithophile elements are enriched with relatively high field strength elements. The rock differentiation index DI averages 80.63. The above characteristics are similar to those of highly differentiated I-type granites. The source of magma was the crust-derived magma series, which was the product of the partial melting of continental crust rock, and the tectonic setting was a stretching environment which was closely related to subduction of ancient Pacific plate.

       

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