李振焕, 刘学龙, 朱月琴, 张旗, 罗应, 张昌振, 陈建航, 王帅帅, 杨富成. 科马提岩与苦橄岩的区别及对若干晚古生代“科马提岩”的质疑[J]. 地质通报, 2019, 38(12): 1971-1980.
    引用本文: 李振焕, 刘学龙, 朱月琴, 张旗, 罗应, 张昌振, 陈建航, 王帅帅, 杨富成. 科马提岩与苦橄岩的区别及对若干晚古生代“科马提岩”的质疑[J]. 地质通报, 2019, 38(12): 1971-1980.
    LI Zhenhuan, LIU Xuelong, ZHU Yueqin, ZHANG Qi, LUO Ying, ZHANG Changzhen, CHEN Jianhang, WANG Shuaishuai, YANG Fucheng. Difference between komatiites and picrites and a discussion on some Late Paleozoic "komatiites"[J]. Geological Bulletin of China, 2019, 38(12): 1971-1980.
    Citation: LI Zhenhuan, LIU Xuelong, ZHU Yueqin, ZHANG Qi, LUO Ying, ZHANG Changzhen, CHEN Jianhang, WANG Shuaishuai, YANG Fucheng. Difference between komatiites and picrites and a discussion on some Late Paleozoic "komatiites"[J]. Geological Bulletin of China, 2019, 38(12): 1971-1980.

    科马提岩与苦橄岩的区别及对若干晚古生代“科马提岩”的质疑

    Difference between komatiites and picrites and a discussion on some Late Paleozoic "komatiites"

    • 摘要: 以往学术界更多的关注科马提岩和苦橄岩的相似性,忽略其差异。通过全数据模式,采集数据库内全球的太古宙科马提岩、后太古宙低/高钛苦橄岩数据,对比三者之间的差异发现,科马提岩更富MgO、Cr、Ni、Cs、Pb、Co和Zn,其次为低钛苦橄岩(除Co和Zn),其余主量、微量元素的含量由高至低依次为高钛苦橄岩、低钛苦橄岩、科马提岩。依据元素间的差异(如Cr/Ga、MgO/Ga、MnO/Zr、Cr/Zr等),采用密度分布函数(Density Distribution)在Matlab软件中绘制出可有效区分3类岩石的等密度判别图,并用该图对若干晚古生代"科马提岩"的岩性重新厘定。结合岩相学和地球化学特征研究表明,晚古生代"科马提岩"中,印度东部为高钛苦橄岩,越南为化学成分与科马提岩类似的低钛苦橄岩,印度拉达克地区为低钛苦橄岩。

       

      Abstract: In the past, academia paid much attention to the similarity between komatiites and picrites, but ignored their differences. In this paper, the global data of Archaean komatiites and Post-Archaean low/high titanium picrites in the database were collected by full data model. Based on comparing the differences between them, the authors found that komatiites are richer in MgO, Cr, Ni, Cs, Pb, Co and Zn, followed by low-titanium picrites (except for Co and Zn). As for the other main and trace elements, high-titanium picrites has the highest content, followed by low-titanium picrites and then by komatiites. Based on the differences between elements such as Cr/Ga, MgO/Ga, MnO/Zr and Cr/Zr, the authors used density distribution to draw an isodensity discriminant map which can effectively distinguish the three types of rocks, and redefined the lithology of some Late Paleozoic "komatiites" with this diagram. The results of lithofacies and geochemical characteristics show that, in the Late Paleozoic "komatiites", the rocks in the eastern part of India are high-titanium picrites, those in Vietnam are low-titanium picrites with similar chemical composition to komatiites, and those in Ladak area of India are low-titanium picrites.

       

    /

    返回文章
    返回