地幔动力系统与演化最新进展评述

评述了９０年代以来地幔动力学研究的一些最新的观测和理论模拟的进展，探讨该领域的几个主要热点问题，包括地幔内部转换带和核幔边界的物理化学性质与演化，俯冲板片热结构及其与地幔的相互作用，热点物理化学性质与地幔柱动力学模拟，地幔对流系统及其对表层地质过程的影响等。这些结果是在多学科交叉研究的背景下取得的。地震层析的结果超越了８０年代取得的大尺度地幔结构，得到了越来越精细的结构，如俯冲板片的结构，６６０ｋｍ间断面的起伏，ＣＭＢ的超低速层和各向异性等。俯冲板片在某些区域平躺在上地幔底部，造成６６０ｋｍ间断面的凹陷。已有明显的迹象表明，俯冲板片至少在某些区域达到了地幔底部，说明下地幔是驱动地表板块运动的地幔对流不可分隔的一部分。全地幔对流模式对地幔中存在不同的地幔地球化学源区的看法提出重大挑战，计算机模拟三维球坐标地幔对流已经成为现实，新的研究正试图把地表板块加入到对流的模拟之中，并再造板块运动的动力学演化史。最后，对这些领域的最新进展提出自己的分析和看法，认为地球动力系统演化研究所面临的难题是地球内部动力状态演变的历史记录问题。而这样的记录，尤其是早期记录，只能从地球表面的造山带和盆地记录中去寻找。认为建立地质记录与?

A REVIEW ON THE MANTLE DYNAMIC SYSTEM AND ITS EVOLUTION

In the recently few years some new development of studies on the mantle dynamics and the latest observation and theoretical simulation have been obtained, this paper appreciated the progress on its theory and methods since 1990's and dealt with several main hot problems in this field, they include: physical and chemical structure and evolution in mantle interior transition zone and core mantle boundary; the thermal structure of the subducted slab and its interaction with mantle; hotspots morphology property and plume dynamical model; mantle convection system and its influence to the surface geological processes, etc. These results were obtained at the grounds of multi science interaction, the seismic topography result was better than the one obtained in 80's on large scale mantle texture, and showed more and more finer texture such as subducted slab, fluctuation at 660km discontinuity, the super lower velocity layer on the CMB and anisotropy. The depression at 660km discontinuity was explained by the fact that subducted slab overlay on the bottom of upper mantle, but there was also clear evidence to show that subducted slab cut into deep place of lower mantle in some regions, it indicates that lower mantle is an indispensable part of mantle convection which drives surface plate to move. Computer 3D spherical convection simulation has become a reality. New research has tried to make surface plate into simulation of mantle convection and rebuilt the evolution of plate to move. The establishment of connection between the earth's interior dynamic state and surface geological records is the puzzlement and key problem on studying earth dynamic system and evolution. This paper presented analysis and opinions on the new development in this field, and considered that the puzzle facing research in geological dynamic system evolution is the problem of historical records of the earth's interior dynamic evolution. And the records can only be obtained from the basin and mountain belt on the surface. It is further indicated that establishing the connection between the geological records and the earth's interior thermal state is the key step to solve the problem of the evolution on the earth's interior dynamic system. It is no doubt that reasons and mechanism of the rhythms of geological evolution are indispensable with the earth's interior dynamic processes. The main frame of the origin and early evolution process of the earth was accepted by most of scientists, but a great deal of details, particularly on dynamic system, was unknown to us. At present, exploring the early history of the earth only depends on super computer simulation, whether or not success of simulation is mainly determined by the boundary conditions, main parameters about dynamic model and a forceful arithmetic. Although the earth's dynamic simulation, especially on the simulation of plate movement, has been developed, but many problems have always perplexed us, such as the melting and differentiation of the early earth and its influence to the earth dynamic system; the redistribution of radioactive isotopes; the influence of the earth's interior substance phases to thermodynamics parameters; the mutual interaction between the earth's interior spheres and substance exchange; the dynamic processes of the origin and evolution in mantle plume, etc. Based on the systematic analysis, this paper presented some predictions on the development of the earth's interior dynamic system.