峨眉山地幔柱轴部位置的讨论  

The Location of the Tail of Emeishan Mantle Plume

作　　者：李宏博[1,2] 张招崇[1] 李永生[1] 汪云峰[1] 

机构地区：[1]地质过程与矿产资源国家重点实验室,中国地质大学(北京),北京100083 [2]中国地质博物馆,北京100034

出　　处：《地质论评》2013年第2期201-208,共8页Geological Review

基　　金：国家自然科学基金资助项目(编号40925006);科技部973项目(编号2009CB421002);教育部博士点基金(编号20090022110006);教育部111计划(编号B07011);地质过程与矿产资源国家重点实验室开放课题基金项目(编号GPMR2011)的成果

摘　　要：本文对峨眉山地幔柱的轴部位置进行了探讨,认为其应在米易—永仁一带。利用经典地幔柱模型,估算出峨眉山地幔柱到达上地幔时轴部直径大约为65～105km,高温苦橄岩的分布和差异剥蚀程度显示中心区的范围约为260～300km。深大断裂带、古地貌等因素控制了溢流玄武岩的喷发和展布,使得轴部岩浆的喷发偏于西部,形成了大理-丽江一带的苦橄岩分布较多的现象。This paper discusses the tail of Emeishan mantle plume and suggests that it locates in Miyi-- Yongren area, southern Sichuan--northern Yunnan. On the basis of the classic mantle plume theory, the estimated diameter of Emeishan plume tail was 65 - 105km when it reached the upper mantle. Picrite distributions and sedimentary responses showed that the center zone of the Emeishan plume was ca. 260 ~ 300km wide. Eruption and outcropping of flood basalts were constrained by deep-seated faults and paleogeomorphology, which resulted in the concentration of picrite in the west of the Emeishan large igneous province.

关 键 词：峨眉山大火成岩省 地幔柱 轴部位置 苦橄岩 深大断裂带 古地貌 

分 类 号：P542.5[天文地球—构造地质学]