代雅然, 张嘉玮, 彭松柏, 叶太平, 王敏, 戴传固, 张慧, 陈建书. 贵州梵净山地区新元古代拉伸纪岩浆演化时序[J]. 地质通报, 2019, 38(2-3): 360-370.
    引用本文: 代雅然, 张嘉玮, 彭松柏, 叶太平, 王敏, 戴传固, 张慧, 陈建书. 贵州梵净山地区新元古代拉伸纪岩浆演化时序[J]. 地质通报, 2019, 38(2-3): 360-370.
    DAI Yaran, ZHANG Jiawei, PENG Songbai, YE Taiping, WANG Min, DAI Chuangu, ZHANG Hui, CHEN Jianshu. Geochronologic sequence of Neoproterozoic Tonian magmatism in Fanjingshan area, xiuning Country, Guizhou Province[J]. Geological Bulletin of China, 2019, 38(2-3): 360-370.
    Citation: DAI Yaran, ZHANG Jiawei, PENG Songbai, YE Taiping, WANG Min, DAI Chuangu, ZHANG Hui, CHEN Jianshu. Geochronologic sequence of Neoproterozoic Tonian magmatism in Fanjingshan area, xiuning Country, Guizhou Province[J]. Geological Bulletin of China, 2019, 38(2-3): 360-370.

    贵州梵净山地区新元古代拉伸纪岩浆演化时序

    Geochronologic sequence of Neoproterozoic Tonian magmatism in Fanjingshan area, xiuning Country, Guizhou Province

    • 摘要: 为获得江南造山带西段梵净山地区新元古代拉伸纪岩浆的演化时序,为区域综合对比提供可靠的典型地区岩浆岩年代学研究基础资料,以及为梵净山申报地质公园提供详实的科普素材,对研究区新发现的辉绿岩体进行了年代学研究,获得该岩体U-Pb年龄为805.3±4.5Ma。通过对已有年龄数据的系统梳理与总结,认为梵净山群回香坪组内玄武岩的喷发结束时间为840Ma,存在831Ma、814~805Ma两次基性-超基性岩浆活动和855Ma、834Ma两次酸性岩浆活动。梵净山地区的新元古代拉伸纪岩浆活动时序可与黔东南—桂北地区对比。结合岩石类型及其地球化学特征,认为江南造山带西段拉伸早期岩浆岩的成因可能与扬子和华夏板块的俯冲碰撞有关,拉伸晚期岩浆岩的形成可能与华南大陆伸展裂陷有关。

       

      Abstract: In order to obtain the geochronologic sequence of the Neoproterozoic magmatism in Fanjingshan area of the western Jiangnan Orogen and to provide a reliable foundation of chronological study in the typical area for comprehensive comparison and for geopark declaration and science popularization, the paper reports the zircon U-Pb dating of a newly discovered diabase in Fanjingshan area. The result shows that the diabase was formed at 805.3±4.5Ma. The authors also sorted and summarized the existing age reports in a comprehensive and systematic way, and hold that the end of the eruption of basalts was 840Ma. There were two periods of basic-ultrabasic magmatism (831Ma, 814~805Ma) and two periods of acid magmatism (855Ma, 834Ma) that occurred in Fanjingshan area during Neoproterozoic. The magmatic geochronology sequence of Fanjingshan area largely corresponds to that of southwest Guizhou-north Guangxi area. Combined with rock types and its geochemical features, it is implied that the Neoproterozoic Early Tonian magmatic rocks in western part of Jiangnan Orogen were formed by the subduction-collision process of Yangtze and Cathaysia blocks, and the Late Tonian magmatic rocks were formed by the rifting process of South China Craton.

       

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