Mantle convection modeling of the supercontinent cycle: Introversion,extroversion, or a combination?  

作　　者：Masaki Yoshida M.Santosh 

机构地区：[1]Institute for Research on Earth Evolution (IFREE), Japan Agency for MarineeEarth Science and Technology (JAMSTEC), 2-15 Natsushima-cho,Yokosuka,Kanagawa 237-0061, Japan [2]Division of Interdisciplinary Science, Faculty of Science, Kochi University,Akebono-cho 2-5-1,Kochi 780-8520, Japan [3]School of Earth Sciences and Resources, China University of Geosciences (Beijing)

出　　处：《Geoscience Frontiers》2014年第1期77-81,共5页地学前缘（英文版）

基　　金：supported partly by a Grant-in-Aid for Scientifc Research (B) (No. 23340132) from the Ministry of Education, Culture, Sports, Science and Technology, Japan

摘　　要：The periodic assembly and dispersal of continental fragments, referred to as the supercontinent cycle, bear close relation to the evolution of mantle convection and plate tectonics. Supercontinent formation involves complex processes of ＂introversion＂ （closure of interior oceans）, ＂extroversion＂ （closure of exterior oceans）, or a combination of these processes in uniting dispersed continental fragments, Recent developments in numerical modeling and advancements in computation techniques enable us to simulate Earth＇s mantle convection with drifting continents under realistic convection vigor and rheology in Earth-like geometry （i.e., 3D spherical-shell）. We report a numerical simulation of 3D mantle convection, incorporating drifting deformable continents, to evaluate supercontinent processes in a realistic mantle convection regime. Our results show that supercontinents are assembled by a combi- nation of introversion and extroversion processes. Small-scale thermal heterogeneity dominates deep mantle convection during the supercontinent cycle, although large-scale upwelling plumes intermit- tently originate under the drifting continents and/or the supercontinent.The periodic assembly and dispersal of continental fragments, referred to as the supercontinent cycle, bear close relation to the evolution of mantle convection and plate tectonics. Supercontinent formation involves complex processes of ＂introversion＂ （closure of interior oceans）, ＂extroversion＂ （closure of exterior oceans）, or a combination of these processes in uniting dispersed continental fragments, Recent developments in numerical modeling and advancements in computation techniques enable us to simulate Earth＇s mantle convection with drifting continents under realistic convection vigor and rheology in Earth-like geometry （i.e., 3D spherical-shell）. We report a numerical simulation of 3D mantle convection, incorporating drifting deformable continents, to evaluate supercontinent processes in a realistic mantle convection regime. Our results show that supercontinents are assembled by a combi- nation of introversion and extroversion processes. Small-scale thermal heterogeneity dominates deep mantle convection during the supercontinent cycle, although large-scale upwelling plumes intermit- tently originate under the drifting continents and/or the supercontinent.

关 键 词：Mantle convection Numerical simulation Tectonics Supercontinent cycle Introversion Extroversion 

分 类 号：P542[天文地球—构造地质学]