下扬子区前陆盆地逆冲推覆构造的研究

下扬子地区广泛发育哟逆冲推覆构造的形成与该区不同深度层次的多套滑动系统是密切相关的。推覆构造的分布在地球物理场上有明显的反映,外来系统与原地系统间节理裂隙的发育有明显差异。逆冲断裂带由浅到深其变形特征为由脆性—脆轫性—轫性变形。推覆构造的成因类型主要有挤压推覆型、重力滑动型和复合迭覆型。该区推覆构造的形成和演化是与中国东部不同时期板块运动密切相关的。逆冲推覆构造改遗了该区中、古生界沉积盆地的形态,因此,对推覆构造的研究是在该区进行中,古生界油气藏评价的关键。

A STUDY ON THE THRUST-NAPPE STRCTURE OF FORELAND BASIN IN LOWER YANGZI AREA

The thrust-nappes exist widely in Lower Yangzi area. The developmets of thrust-nappes are related with glidingg systems at different depths. It makes obviors reflections in geophysical field. And there are distinct differences in the development of joints and fractures between the allochthonous and auchthonous systems. There are both ductile and brittle deformations in the thrust zones. The thrust-nappes can be divided into three types(pressure type, gravity gliding type and compound superimposition type). The forming and developing of thrust-nappes are related with the plate movement in different geological period in East China. Thrust-nappes trasformed the forms of sedimentary basin of Mesozoic-Palaeozoic Era. It is the key for us to evaluate the oil and gas of Mesozoic-Palaeozoic Era basin that study at length thrustnappes in this area.