前陆盆地形成的力学机制

前陆盆地挠曲沉降的主要控制因素包括：逆冲带负荷，地壳内部水平挤压，盆地沉积负荷和地壳力学性质，描术前陆盆地挠曲过程的主要参数为：逆冲楔状体初始宽度，逆冲前缘推进速度，地表坡度，拆离面倾角，搬运系数，地壳的有效弹性厚度，地壳内部作用力，前陆盆地力学模型极两种：一种依据造山带深部岩石圈是破裂的，其力学模型为中间破裂的无限宽度线弹性薄板的水平挤压和垂向负荷作用下的挠曲，另一种假设造山带深部岩石圈是连续的

FORMATION MECHANISM OF FORELAND BASIN

The flexural process of foreland basins is controlled by thrust load,sediment load within the basins,the intracrustal horizontal compressive force and the mechanical property of crust, which can be described by 7 parameters:the initial width of the thrust wedge,the rate of thrust front advance, the surface slope of thrust wedge,the dip angle of detachment surface,the transport coefficient,the effective thickness of crust and the intracrustal compressive force.There are two kinds of mechanical models for foreland basins, the broken lithosphere modle and continous lithosphere model,simply defined as the deflections of the broden,elastic thin plate of the continuous,elastic thin plate respectively, both of which have an infinite length and are applied by the horizontal compressive force and the vertical load. The solutions to the deflections of the two models can be found. For example,from the southwestem Ordos foreland basin,the broken lithosphere model is selected for simulating and reproducing the subsiding and filling processes of the basin.