简论中生代大陆活化与多元动力学体系──以湖南地区研究为例

中生代大陆活化是一个典型的陆内变形与运动演化问题，所产生的构造变形、大范围岩浆活动和成矿作用等一系列问题是目前俯冲碰撞观点难以圆满解释的。湖南地区对冲构造带和背冲构造带相间排列，反映中生代至少发育两套相反的道冲剪切推覆构造系统，它们是壳块不同演化时期多向运动变形的产物。由此提出多元动力体系组成、增减、转换和叠加影响综合模式。其中会聚式地＠蠕动和扩散式地撞蠕动所产生的岩石囵增厚和减薄是引起中生代构造变形和活化的根本原因，西太平洋壳体的西向俯冲、特提斯东向俯冲及周缘造山带的侧向挤出效应等则是不可忽略的外部因素。

ON THE MESOZOIC CONTINENTAL ACTIVATION AND ITS MULTIPLE DYNAMICS SYSTEM--TAKING HUNAN PROVINCE AS AN EXAMPLE

Mesozoic continental activation is an important typical problem in understanding the intracontinental deformation and tectonic evolution.A series of problems including Mesozoic tectonic deformation,large-area magmatism and metallogeny etc. could not be well explained by the previous hypothesis of single subduction and collision.An interwoven array of back-thrust and opposite-thrust structural belts were distributed over the Hunan region.It is indicated that at least two sets of tectonic systems of inverse thrust,shear and nappe structures in opposite direction developed.They would be the result of multiple movement deformation during different evolution periods of crustoblocks.So we proposed a synthetic model affected by composition,accretion-collision,transformation and superimposition of the multiple dynamics system,of which thinning-thickening process of lithosphere brought into by setting convergence-type mantle creep-flow is the crucial reason of Mesozoic continental activation.However,the long-distance effect of the tectonic setting of the circum-Pacific,the Tethys setting and the margin orogenic belt are the external factors inducing crust movement and deformation.