摘要
本文以岩石圈多层构造为基础 ,按照下地壳和岩石圈地幔塑性流动控制上地壳构造变形的思想 ,采用脆延性双层模型进行伸展构造模拟实验。模拟结果表明 ,延性层流动速度比脆性层运动速度大 ,对脆性层具有牵引作用 ;受挤压和边界流动控制 ,模型构造变形出现伸展区、过渡区和挤压区 ,其中以伸展区的“地堑 地垒”式伸展构造为主。模型表面标志点位移表明 ,模型脆性层变形量主要集中在断裂发育部位 ,而断裂之间块体变形量基本可以忽略不计。此外 ,实验中还观察到在脆性层断裂部位出现延性层被动上隆现象。
According to the theory that plastic flow of the lower layer (including lower crust and upper mantle lithosphere) controls upper layer (upper crust) deformation in the multi-layer lithosphere, the paper studies the physical experiments of extensional structures adopted ductile/brittle double-layers model. The experiment results show that the lower ductile layer whose flow speed is larger than that of upper brittle layer. Controlled by compressed and free flow, the areas of model deformation can be divided into three parts: extensional region, transition region and compressive region. Among all, the main part is extensional region where “graben-horst” is characterized by major extensional structures. The displacements of mark points on upper face of models show that the deformation quantities of upper brittle layer are focus on the parts of faults. In addition, the passive uplifting of lower ductile layer is found at faults region of upper brittle layer in our models.
出处
《地质力学学报》
CSCD
2002年第2期141-148,共8页
Journal of Geomechanics
基金
地震科学联合基金项目 (编号 :196 0 6 5 )
中国地震局地质研究所论著 :99B0 0 42
