【摘要】 结合地面地质调查和钻井资料,对柴达木盆地北缘4-5号构造三维地震资料进行了精细解释,厘定了构造要素,建立了构造模型。4-5号构造总体表现为近南北向被断层复杂化的背斜,但南北深浅层次构造又有所不同,4号构造是一被断裂复杂化了的箱状背斜,5号构造总体表现为斜歪背斜,但上下层变形样式不同,组合成复杂的构造叠置;4号、5号构造过渡区为断裂斜歪背斜。4-5号构造带复杂的构造样式受控于褶皱作用和剖面“X”型断裂作用的联合影响,断层的发育程度决定着构造样式。不整合和断层组合显示构造的形成主要在下油砂山组沉积后的喜马拉雅运动晚期,受南西-北东向挤压,且构造的形成与侏罗系的分布有关。更多还原

【Abstract】 The 3D seismic information from Structure 4 and Structure 5 in northern margin of Qaidam basin are fine interpreted, integrated with data of surface geological survey and drilling. By determining the structural elements, its tectonic model is developed. Structure 4 and Structure 5 occur as fault-complicated anticlines of S-N trend, with slight difference in structural depth to some extent. Structure 4 is a box-like anticline and Structure 5 an oblique one, but they have different deformation styles in overlying and underlying zones, which shape complex structural superimposition. The transition zone between Structure 4 and Structure 5 occur as faulted and oblique anticline. The study shows that the belt of Structure 4-5 is controlled by both folding and X-style faulting, and the structural style lies on the faulting development. Based on the unconformity and the fault assemblage, the period of forming these structures should be in late Himalayan movement when Lower Youshashan formation was deposited, with compression of SW-NE direction. The formation of these structures is also related with the Jurassic distribution in this area.更多还原