大地构造学和地球动力学现代问题——从板块构造学到全球动力学
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摘要
６０年代板块构造概念的出现标志着地球科学革命性的进步。３０年来，我们获得的经验表明，现代板块构造在岩石圈和软流圈物性、三种板块运动形式、扩张和俯冲的均衡以及板块运动原因等都与经典板块构造有很大不同。同时，它仍有一些问题和缺陷。世纪交替之时，随着象地震层析成像等新技术的发展，有可能建立新的全球理论来取代板块构造。新理论应该包括整个固体地球，岩石圈是分层的，而且地球内部的对流准自动地进行。同时，地球层圈之间具有相互作用。还应该承认，构造圈（岩石圈＋软流圈，深至４００ｋｍ）中以板块构造为主，而在软流圈之下地幔柱构造起控制作用。在所有的上部层圈能够探测到抬升或下降过程中热—物质流之间的补偿。整个地球历史中，地球和其层圈的内生过程，包括板块构造和地幔柱构造相互作用的变化，具有旋回性和方向性。由此，地球体积呈脉动性变化是必然的。此外，还必须考虑宇宙因素对地球动力学的影响
The appearance of the conception of plate tectonics in 1960s marked a revolutionary era of earth sciences. Since then the experience we have obtained suggests that the modern plate tectonics have become quite different from the classical one with respects to properties of lithosphere and asthenosphere, three plate motion types, balance between spreading and subduction, and causes of plate motion. However, related to this theory some problems and shortcomings have also emerged. At the eve of the 21th century, with the development of new techniques like seismic tomography, it is possible to find out a new global theory to replace the theory of plate tectonics. The new expected theory should deal with whole solid earth. The lithosphere should be multiple layered. And convections within the earth interior occur quasi-autonomically. Meanwhile, the geospheres of the earth interact with each other. It should be admitted that plate tectonics is dominate in tectonosphere (lithosphere plus asthenosphere, upto 400 km deep), while beneath asthenosphere plume tectonics is more important. The compensation between heat mass flows during uplifting or subsiding processes should be proved in all upper geospheres. During the earth history, the endogentic processes, including changes of mutual interactions between plate tectonics and plume tectonics, are of cyclicity and tendency in whole earth or its geospheres. By all above, it should be certain to admit the pulsation changes of the earth volume. Finally, the influence of the cosmic factors on geodynamics should be also taken into account.
The appearance of the conception of plate tectonics in 1960s marked a revolutionary era of earth sciences. Since then the experience we have obtained suggests that the modern plate tectonics have become quite different from the classical one with respects to properties of lithosphere and asthenosphere, three plate motion types, balance between spreading and subduction, and causes of plate motion. However, related to this theory some problems and shortcomings have also emerged. At the eve of the 21th century, with the development of new techniques like seismic tomography, it is possible to find out a new global theory to replace the theory of plate tectonics. The new expected theory should deal with whole solid earth. The lithosphere should be multiple layered. And convections within the earth interior occur quasi-autonomically. Meanwhile, the geospheres of the earth interact with each other. It should be admitted that plate tectonics is dominate in tectonosphere (lithosphere plus asthenosphere, upto 400 km deep), while beneath asthenosphere plume tectonics is more important. The compensation between heat mass flows during uplifting or subsiding processes should be proved in all upper geospheres. During the earth history, the endogentic processes, including changes of mutual interactions between plate tectonics and plume tectonics, are of cyclicity and tendency in whole earth or its geospheres. By all above, it should be certain to admit the pulsation changes of the earth volume. Finally, the influence of the cosmic factors on geodynamics should be also taken into account.
引文
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