印度-澳大利亚板块应力场数值模拟及其动力学分析

印度-澳大利亚板块的边界类型和性质十分复杂。本文采用伪三维有限元方法,利用WSM2000观测应力场数据的应力取向和应力状态作为主要约束,建立了印度-澳大利亚板块岩石层三维模型,对印度-澳大利亚板块构造应力场进行了数值模拟,进而探讨印度-澳大利亚板块所受边界力对板块内部应力场的影响。结果显示,印度-澳大利亚板块的构造应力场主要受到两个因素的控制:①软流层静压推力;②来自碰撞带的阻力,包括喜马拉雅、巴布亚新几内亚、新西兰和印度-澳大利亚板块与欧亚板块的西北边界。而来自俯冲消减带的拉张作用力对板内应力场的作用相对较小。 

NUMERICAL SIMULATION AND DYNAMIC ANALYSIS OF THE STRESS FIELD OF THE INDO-AUSTRALIAN PLATE

The types and nature of the Indo-Australian plate are very complex.A 3D lithosphere model of the Indo-Australian plate is constructed and numerical simulation of the tectonic stress field of the Indo-Australian plate is performed by using the pseudo-3D finite element method and adopting the WSM2000 observed stress data and stress state as constraints,and then the influence of the boundary forces applied at the Indo-Australian plate on the intraplate stress field is discussed.The results show that the intraplate tectonic stress field of the IndoAustralian plate is mainly controlled by two factors:(1) the asthenospheric static push;and(2) the resistance coming from collision zones,including Himalaya,Papua New Guinea,New Zealand and the northwestern boundary between the Indo-Australian plate and Eurasian plate.However,the effect of the extensional forces from the subduction zone on the intraplate stress field is relatively small.