华南地区岩石圈三维结构类型与演化动力学

从地球层块结构研究思路出发,对华南及邻区天然地震面波层析成像进行系统地构造解析,发现岩石圈中下部存在形态各异,大小不等的高速块体,结合地质学、地球化学、其它地球物理学标志等多学科综合研究,将其称为幔块构造。研究显示高速块体或幔块构造是华南地区岩石圈构造格局和岩石圈表层构造变形最基本条件之一。首次建立起华南地区岩石圈三种三维几何结构样式:克拉通陆根状结构、造山带楔状结构和碎块状结构,以及岩石圈三类构造演化类型:克拉通型岩石圈、增厚型岩石圈和减薄型岩石圈(弱减薄型岩石圈及强减薄型岩石圈)。本文在论述华南岩石圈三维结构构造类型基本特征基础上,首次探讨了华南地区软流圈三维结构以及该区岩石圈演化动力学特征。

THREE-DIMENSIONAL TECTONIC TYPES AND EVOLUTIONAL DYNAMICS OF LITHOSPHERE OF SOUTH CHINA REGION

Based on the thinking of layered blocked structure of the Earth, a structural analysis has been made for the tomography of the natural seismic surface wave in South China region, and high speed blocks varying in shape and differing in size have been discovered in the lower lithosphere, which are termed mantle blocks, on the basis of the studies of the geological, geochemical and geophysical signs. It is showed that the tectonic pattern of the South China lithosphere and the superficial deformation are basically controlled by the high speed blocks or the mantle blocks. Based on the systematic 3D studies of the high speed blocks in the lithosphere, three 3D geometric tectonic styles (craton root shaped, orogen wedge shaped, and clastic massive) are formulated for the first time, and three tectonic evolution types of the lithospheres (cratonic, thickening and thinning) are divided. From the 3D geometric models of the lithosphere and asthenosphere in the south China region, the evolution pattern of the lithosphere is deduced.