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为了研究软弱地质体对挤压构造变形的影响,利用物理模拟方法,设置了6组实验模型,探讨软弱体不同面积、所处位置和挤压应力方向对构造变形的影响,最后基于模拟结果,讨论了软弱体对莺-琼两盆地凹陷中心挤压褶皱发育的影响.结果表明:在挤压作用下,软弱区先迅速隆起,随后隆起向无软弱体区延伸发育,软弱区隆起发育范围大于无软弱体区隆起范围,且其褶皱变形比无软弱体区变形更强烈;随着软弱体铺设面积不断增大,软弱区的变形范围越来越大,变形也越来越强烈,而无软弱体区变形范围基本保持不变;软弱区离所受挤压边界距离越近,挤压构造变形发育就越早,表现越强烈,反之,构造变形发育晚且表现弱;正向挤压比斜向挤压形成的构造变形更强烈.由分析可知,与莺-琼两盆地凹陷中心的挤压褶皱发育特征相关的因素主要是:软弱体和其与受斜向挤压作用带间有一定距离.笔者推测,斜压应力主要来源于印支地块的左旋挤出作用,其褶皱个体发育的区域大小与软弱体初始面积大小有关.
In order to study the effect of weak geologic bodies on the deformation of extrusion structure, six sets of experimental models were set up by physical simulation method to study the influence of different area, location and compressive stress direction of tectonic deformation on the tectonic deformation. Based on the simulation results, The effect of weak body on the extrusion fold in the center of the Ying-Qiong basin was studied. The results show that the weak zone first swelled rapidly under the action of pressure, then the extension of the weak zone extended to the non-weak zone, No soft body area uplift range, and the deformation of the fold is more intense than that of the no-weak body area. With the increasing of the laying area of the weak body, the deformation range of the weak area becomes larger and larger, and the deformation is more and more intense with no weakness The deformation range of the body area remains basically unchanged; the nearer the distance of the weak zone from the crushed boundary, the earlier the deformation and development of the compression structure develop, the stronger the deformation. On the contrary, The tectonic deformation formed by extrusion is more intense.According to the analysis, the main factors related to the development of crustal depressions in the center of the depression of Ying-Qiong basin are as follows: Certain distance. I guess, mainly from the left oblique stress Indochina block out effect, the folds of initial size of the area ontogeny area size related to the body and weakness.