华永成, 张素梅, 张韶斐, 肖震霞, 张树岐. 黑龙江宝清地区早古生代花岗岩锆石U-Pb年龄及岩石地球化学特征[J]. 地质通报, 2019, 38(7): 1228-1239.
    引用本文: 华永成, 张素梅, 张韶斐, 肖震霞, 张树岐. 黑龙江宝清地区早古生代花岗岩锆石U-Pb年龄及岩石地球化学特征[J]. 地质通报, 2019, 38(7): 1228-1239.
    HUA Yongcheng, ZHANG Sumei, ZHANG Shaofei, XIAO Zhenxia, ZHANG Shuqi. U-Pb zircon age and geochemical characteristics of Early Paleozoic granites in the Baoqing area, Heilongjiang Province[J]. Geological Bulletin of China, 2019, 38(7): 1228-1239.
    Citation: HUA Yongcheng, ZHANG Sumei, ZHANG Shaofei, XIAO Zhenxia, ZHANG Shuqi. U-Pb zircon age and geochemical characteristics of Early Paleozoic granites in the Baoqing area, Heilongjiang Province[J]. Geological Bulletin of China, 2019, 38(7): 1228-1239.

    黑龙江宝清地区早古生代花岗岩锆石U-Pb年龄及岩石地球化学特征

    U-Pb zircon age and geochemical characteristics of Early Paleozoic granites in the Baoqing area, Heilongjiang Province

    • 摘要: 对黑龙江宝清地区七一林场正长花岗岩岩体、干涸沟口二长花岗岩进行了详细的地球化学分析和U-Pb锆石测年,结果表明,正长花岗岩与二长花岗岩的形成年龄分别为523.3±2.4Ma和523.3±2.3Ma,属于早寒武世。地球化学的研究显示,岩石具有准铝质-过铝质钙碱性碱性和高分异I型花岗岩的特点,高硅、高铝、富碱。属于轻稀土元素富集、重稀土元素亏损型;δEu=0.38~1.73,平均值为1.05,根据Eu的正负异常,将宝清地区的花岗岩分为2类,正Eu异常型花岗岩和负Eu异常型花岗岩。富集大离子亲石元素(LILE)Rb、K,亏损高场强元素(HFSE)Nb、Ta、P、Ti。结合区域构造背景与年代学特征,在早古代以前佳木斯-兴凯地块可能属于同一个大陆——冈瓦纳大陆,在泛非运动主峰期之后,由于陆块的碰撞,形成大量的早古生代花岗质岩石。

       

      Abstract: Detailed geochemical analysis and U-Pb zircon dating were carried out for Qiyilinchang syenogranite and Ganhegoukou monzonitic granite in Baoqing area, Heilongjiang Province. The results show that the ages of the syenogranite and monzonitic granite are 523.3±2.4Ma and 523.3±2.3Ma respectively, implying early Cambrian. Petrogeochemical studies show that they have the features of quasi aluminous peraluminous calc alkaline and high differentiation Ⅰ-type granite with high silicon, high aluminum and rich alkali. They belong to the type of LREE enrichment and HREE depletion. δEu=0.38~1.73, averaging 1.05. According to positive and negative Eu anomalies, the granites in Baoqing area are divided into positive Eu anomaly granite and negative anomaly granite. They are enriched in large ion rock elements (LILE) Rb and K, and depleted in high field strength elements (HFSE) Nb, Ta, P and Ti. Combined with regional tectonic background and chronology, the authors hold that, before early Proterozoic, Jiamusi-Xingkai massif might have belonged to the same continent of Gondwana and then, after the peak period of the Pan African movement, due to the collision of continental blocks, large quantities of Early Paleozoic granitic rocks were formed.

       

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