试论峨眉山玄武岩的地球动力学含义  

Discussion on geodynamic significance of the Emeishan basalts

作　　者：刘成英[1] 朱日祥[1] 

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化重点实验室,北京100029

出　　处：《地学前缘》2009年第2期52-69,共18页Earth Science Frontiers

基　　金：国家自然科学基金优秀群体资助项目(40221402);国家自然科学基金重点项目(40523003)

摘　　要：峨眉山大陆溢流玄武岩是中国唯一被国际学术界认可的、地幔柱成因的大火成岩省。峨眉山玄武岩的主相喷发时间约为260Ma,与二叠纪晚瓜德鲁普期生物灭绝事件的时间相当。地球动力学模拟结果显示,地幔柱活动不仅与超静磁带的产生和结束有密切联系,而且地幔柱活动可能引发生物大灭绝。文中讨论了前人对峨眉山玄武岩的来源、成因以及喷发与持续时间等重要研究进展,并基于新的古地磁研究结果,探讨了峨眉山玄武岩与Kiaman负极性超静磁带(KRS)和二叠纪晚瓜德鲁普期生物灭绝事件的联系以及相应的地球动力学含义。It had been accepted that the Emeishan large igneous province was generated by the mantle plume, yet the plume formation is still hotly debated. Radiometrie datings showed that the main phase of the Emeishan basalts is -260 Ma, corresponding to the end-Guadalupian mass extinction. Recent numerical modeling suggested that the mantle plume activity was closely linked to both superchron and the mass extinction. Therefore, probing into the age and duration of Emeishan basahs is of significance to the understanding of the relationships among Emeishan mantle plume activity, the end-Guadalupian mass extinction and the genesis of the Kiaman reverse superchron （KRS）. Important progresses on these topics are reviewed in this paper. Besides, on the basis of new paleomagnetic work, the relationships between the Emeishan basalts and the end-Guaduluplan mass extinction were discussed, as well as their geodynamie significance.

关 键 词：峨眉山玄武岩 地幔柱 喷发与持续时间 生物灭绝 古地磁 

分 类 号：P588.145[天文地球—岩石学]