中国大陆地幔对流格局和岩石圈层构造运动

六十年代以来,由于卫星重力测量和计算技术的迅速发展,有些研究者,如Runcorn(1967)和Liu(1976-1980),根据卫星重力数据计算获得地幔对流及其应力场图象来研究全球板块构造和区域构造。愈来愈多的事实表明,构造运动不仅是地壳和岩石圈层物质运动的表现,而更重要的是地幔物质运动的反映。因此,本文应用作者计算获得的岩石圈层下面地幔流运动图象与大地构造及近代构造运动的资料相对比,探索我国岩石圈层下的地幔对流格局形成及其对构造运动的影响。

THE MANTLE CONVECTION PATTERN AND LITHOSPHERIC TECTONIC MOVEMENT OF CONTINENT IN CHINA

In this paper the 2-30 degree harmonic coefficients in the geopotantial and Runcorn’s stress equations of mantle convection are applied and the mantle convection pattern under continental lithosphere of China is obtained.(1) The boundaries of mantle convection pattern coincide with the boundaries of tectonic units of China. It has been shown that the moving of geological massif of tectonic units appears to be controlled by mantle convection currents.(2) The regional features of recent tectonic movement coincide mainly with the type of a regional mantle convection. Obviously, recent tectonic movement of continental lithosphere in China is also dominated by mantle flow moving.(3) The main part of mantle convection pattern in China was generated in Mesozoic era. The results are consistent with the periods of the northward drifting of Indian plate which was separated from Gondwanalan, the disappearing Kula plate and the westward subduction of the Pacific plate.