朱涛, 王洪亮, 徐学义, 赵燕, 李智佩, 朱小辉. 甘肃多坝沟地区黑云斜长片麻岩锆石U-Pb年龄和Hf同位素特征[J]. 地质通报, 2018, 37(4): 682-692.
    引用本文: 朱涛, 王洪亮, 徐学义, 赵燕, 李智佩, 朱小辉. 甘肃多坝沟地区黑云斜长片麻岩锆石U-Pb年龄和Hf同位素特征[J]. 地质通报, 2018, 37(4): 682-692.
    ZHU Tao, WANG Hongliang, XU Xueyi, ZHAO Yan, LI Zhipei, ZHU Xiaohui. Zircon U-Pb age and Hf isotopes of the biotite plagioclase genesis in Duobagou area, Gansu Province[J]. Geological Bulletin of China, 2018, 37(4): 682-692.
    Citation: ZHU Tao, WANG Hongliang, XU Xueyi, ZHAO Yan, LI Zhipei, ZHU Xiaohui. Zircon U-Pb age and Hf isotopes of the biotite plagioclase genesis in Duobagou area, Gansu Province[J]. Geological Bulletin of China, 2018, 37(4): 682-692.

    甘肃多坝沟地区黑云斜长片麻岩锆石U-Pb年龄和Hf同位素特征

    Zircon U-Pb age and Hf isotopes of the biotite plagioclase genesis in Duobagou area, Gansu Province

    • 摘要: 通过对多坝沟地区敦煌杂岩中黑云斜长片麻岩LA-ICP-MS锆石U-Pb年龄和Lu-Hf同位素的研究,对敦煌杂岩的形成时代和敦煌地块的前寒武纪地壳生长演化进行探讨。锆石U-Pb年代学研究表明,710Ma代表了敦煌杂岩的最大沉积时代,黑云斜长片麻岩发育422Ma的早古生代变质事件,表明敦煌地块卷入了早古生代古亚洲洋俯冲-碰撞的演化过程。锆石Hf同位素研究结果表明,敦煌地块具有幕式生长特征,经历了约2.7Ga、2.5Ga、2.3Ga、2.0Ga和1.8Ga多个地壳生长时期。黑云斜长片麻岩发育的约0.9Ga和约0.8Ga的峰值年龄表明,敦煌地块新元古代构造热事件可与塔里木克拉通对比。

       

      Abstract: The LA-ICP-MS zircon U-Pb age and zircon Lu-Hf isotope were analyzed for biotite-plagioclase gneiss from Duoba-gou area, Dunhuang terrain, with the purpose of determining the formation age of the Dunhuang complex and discussing the crustal growth and evolution history of the Dunhuang terrain during Precambrian. Zircon U-Pb dating results indicate that the maximum depositional age of supracrustal rocks from the Dunhuang complex is ca. 710Ma. Additionally, the studied biotite-plagioclase gneiss indicates a metamorphic event at 422Ma, suggesting that the Precambrian Dunhuang terrain might have been involved in the subduc-tion-collision process of the Paleo-Asian Ocean during Early Paleozoic. Zircon Hf isotopes show that the Dunhuang terrain experi-enced episodic crustal growth events at ca. 2.7Ga, ca.2.5Ga, ca. 2.3Ga, ca. 2.0Ga and ca. 1.8Ga, suggesting episodic crustal growth. It is considered that the tectonic attribute could be compared with that of the Tarim craton during Neoproterozoic, as shown by the peak age at ca. 0.9Ga and ca. 0.8Ga.

       

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