活化构造的动力学机制研究进展

活化构造理论的核心是构造活化, 他强调的是陆内活化区造山。活化构造动力学机制是活化构造理论的研究重点。在活化构造理论提出的初期, 就提出了热能聚散交替, 地幔蠕动假说。随着大陆动力学研究的深入,活化构造动力学机制的研究也获得了较快的发展。运用“岩石探针”和数值模拟实验, 对中国东部典型构造活化区进行了探讨。华北陆块中新生代构造活化( /岩石圈减薄)的动力学过程, 是源自地幔的热流与伸展应力共同作用的结果,其构造活化( /减薄)过程可以描述为:早期以热侵蚀作用为主,晚期则以机械伸展占主导地位。华南陆块的活化构造动力学机制研究表明,华南陆块的形成与发展,与岩石圈下地幔热能聚集, 导致软流圈上涌的热侵蚀、置换动力机制密切有关。活化构造动力学机制的研究发展, 是对大陆动力学研究的促进。

ADVANCES IN STUDY ON DYNAMICS OF ACTIVATED STRUCTURE

The kernel ideal of the activated tectonic theory is the structure activization. It emphasizes the intracontinental activization-orogenesis developed in activated regions. The dynamics of the activated structure is the key problem of the activated tectonic theory. From this theory the hypothesis on mantle creep, convergence and divergence of heat energy was derived in the early period. Study on dynamics of activated structure is developing with the study on geodynamics. Research was carried out concerning the dynamics of the typical activated regions in East China with the lithoprobe and numerical modeling. It was found that the thermal perturbation seems to be the predominant mechanism responsible for the significant dynamics of the activated structure (lithosphere thinning) in North China block. The effects of mechanical tectonic extension may become more profound on the dynamics of the activated structure (lithosphere thinning) at a later stage when the lithosphere had already been heterogeneously thinned. The studies on the dynamics of the activated structure in Southern China indicate that the formation and development of South China block were related to the convergence of heat energy in the lithospheric mantel that led to the thermal erosion and the replacement dynamic mechanism. The development in the study on the dynamics of activated structure can promote the study on continental geodynamics.