以地质-地球物理资料和柴达木盆地北缘构造几何学特征为基础,采用盆地反演模拟与宏观分析相结合的方法,系统解析了柴达木盆地北缘的构造运动学特征。研究表明,柴达木盆地北缘在中、新生代时期经历了水平伸展、水平挤压和垂直差异升降等几种运动型式。水平伸展运动主要集中在J1-J2,其NE—SW伸展强度西强东弱,最大伸展率和伸展速率分别达1.9%和19.48m/Ma·km。水平挤压运动可以划分为E3、N2和Q三个主要“挤压事件”并控制着新生代盆地形成和演化,盆地NE—SW的压缩强度具有由西向东递减的特点。垂直差异升降运动具有“幕式”渐进特点,J1、E3、N2和Q为主要沉降期,其中尤以N:的沉降速率最大(182m/Ma),E,的沉降速率次之(38m/Ma),J1一K和E,早期为抬升剥蚀期。柴达木盆地北缘的中、新生代沉降作用具有明显的自西向东迁移规律:J1期以西部坳陷沉降为主,E3期以中部坳陷沉降为主,N2期以东部坳陷沉降为主。
On the basis of geological - geophysical data and structural geometry of northern margin region in Qaidam Basin, kinematics characteristics of structural was systemically analyzed by adopting the associative method of basin inverse modeling and macroanalysis. The result shows that in Mesozoic and Cenozoic, northern margin region of Qaidam Basin had undergone several movements such as horizontal extension, horizontal compression, vertical differential elevation and sub- sidence. The horizontal extensional movements were mainly concentrated in Jx - J2, and the extensional intensity of EN - SW direction was stronger in the western area than in the east. The maximal extension ratio and rate are 1.9% and 19.48 m/Maokm,respectively. The horizontal compression movements can be divided into three main compression events: E3 , N2 and Q, which controlled the formation and evolution of Cenozoic basin, and the compression intensity of EN - SW di- rection gradually decreases from west to east. The vertical differential elevation and subsidence movements had episodic - progressive feature. Main subsidence stages were J1, E3 , N2 and Q, among them the subsidence velocity of N2 ( 182 m/Ma) is the biggest and one of E3 (38 m/Ma) comes second. The rising - denudation stages were J3 - K and EI. The settling of this basin during Mesozoic and Cenozoic had an obvious migration tendency from west to east:J1 subsidence was most distinct in the west depression, E3 was mainly in the central depression, and N2 was mainly in the west depression.