柴达木盆地北缘构造格局及在中、新生代的演化

柴达木盆地北缘地区，由北向南可划分为祁连山断褶山系、柴北缘逆冲推覆构造带、前陆滑脱拆商带及前陆盆地低应变区等四个构造带，且断褶构造的形成时间有自北向南逐渐变新的趋势。综合研究表明，印支旋回和三叠纪末的印支运动，是柴北缘前陆盆地北部边界——南祁连断褶山系的强化、定型时期，奠定了山前前陆盆地发育的基本格局：燕山旋回及白垩纪末的燕山运动对柴北缘逆冲推覆构造带的影响最为强烈，并使下第三系沉降-沉积中心向盆内迁移，且在这一带有构造圈闭雏型形成；喜马拉雅旋回在柴达木盆地有两次规模较大的构造运动，渐新世末的构造运动对柴北缘前陆滑脱拆商带影响最强，并使上第三系沉降-沉积中心进一步向盆内推移，且在这一带形成有关的构造圈闭；上新世末的构造运动是一次最强烈的构造运动，使柴北缘地区各断褶构造带基本定型。

Tectonic Framework and Structure Evolution of Mecozoic and Cenzoic in Northern Margin of Qaidam Basin

The northern margin area of Qaidam basin is divided into four structural zones, from north toward south,the Qilianshan fault-folding mountain system, the thrust-overthrust structural zone, the foreland decollement-detachment zone and low strain zone in the foreland basin. For all the fault-folding structural zones, their forming time shows a tendency becoming younger and younger southward. The overall configuration shows the north boundary of foreland basin is at Qaidarn basin＇s northern margin and southern Qilian fault-folding mountain system are enhanced and fixed during the Indo-China cycle and Indo-China movement by the end of Triassic, so determining the basic development configuration of foreland basin in the foremont area. The Yanshan cycle and Yanshan movement by the end of Cretaceous, exerted very intensive influence on the thrust-overthrust structural zone. It makes the center of subsidence and deposition shifted into the basin and formed some structural trapment preliminarily. During the Himalayan cycle period two tectonic movements occurred in Qaidam basin both of bigger scale. The movement that occurred by the end of Oligocene shows strongest influence on Qaidam northern marginal foreland decollement-detachment zone, not only pushing the center of subsidence-deposition further into the basin but also forming structural trap related in this zone. All the fault-folding tectonic zones at the basins northern margin area are basically fixed by one most intensive structural movement at the end of Pliocene.