How the present-day northern Tibetan Plateau was involved in the plateau formation process in context of the Cenozoic India – Eurasia collision has been disputed for decades. As the largest sedimentary basin within the Tibetan Plateau and enclosed by high mountains such as the Qiman Tagh – East Kunlun Shan and the Qilian Shan in the Cenozoic, the Qaidam Basin preserves a continuous and complete record that is key to addressing this issue. Herein, we review the sedimentary and structural features of the Qaidam Basin in the Cenozoic, as well as their relationship with surrounding orogenic belts. The review suggests that the subsidence and in-filling of the Qaidam Basin are closely linked to the uplifting and exhumation of the bordering orogenic belts during the Cenozoic. Therefore, the tectonic subsidence pattern of the Qaidam Basin could be applied to investigate the deformation mechanism of the northern Tibetan Plateau. Guided by this, we implement two-dimensional (2-D) subsidence analysis and related numerical modeling to investigate the subsidence and deformation mechanisms of the Cenozoic Qaidam Basin. The tectonic-driven subsidence across the Qaidam Basin has occurred since the deposition of the Lulehe Formation, the lowermost Cenozoic stratum in the basin, and is largest (several kilometers) near the center but decreases gradually toward the margins. This subsidence pattern is best explained by lithospheric buckling with a wavelength of ∼200 km, which is likely controlled by the strength of entire lithosphere. Structural observations further reveal that parallel folds with a peak wavelength of ∼20 km prevail in the basin interior, and are likely caused by upper-crustal buckling controlled by the strength of upper crust. These observations suggest that the northern Tibetan Plateau initially responded to the India – Eurasia collision by long-wavelength lithospheric buckling in Eocene to Oligocene. As a result, the Qaidam Basin tectonically subsided as a synclinal depression. Destruction of the lithospheric buckling folds occurred under continued horizontal force, and may generate major bounding reverse faults of the Qaidam Basin, leading to strain localization and thus rapid crustal thickening in the surrounding mountains since the middle Miocene. At the same time, shorter-wavelength upper-crustal buckling folds developed in the interior of the Qaidam Basin. Our findings portray a multiscale buckling mechanism, which is controlled by a strong upper crust and uppermost mantle with a weaker lower crust beneath the Qaidam Basin, and suggest that horizontal contraction plays a dominant role in driving the tectonic evolution of the entire northern Tibetan Plateau.

在新生代印度-欧亚大陆碰撞的背景下，今天的青藏高原北部是如何参与高原形成过程的，几十年来一直存在争议。柴达木盆地作为青藏高原最大的沉积盆地，被新生代奇曼塔格—东昆仑山、祁连山等高山围合，保存了一个连续完整的记录，是解决这一问题的关键。在此，我们回顾了柴达木盆地新生代的沉积和构造特征，以及它们与周边造山带的关系。审查表明，沉降柴达木盆地的充填和充填与新生代周边造山带的抬升和折返密切相关。因此，柴达木盆地的构造沉降模式可用于研究变形机制。位于青藏高原北部。在此指导下，我们实施了二维（2-D）沉降分析和相关的数值模拟，以研究柴达木盆地新生代的沉降和变形机制。整个柴达木盆地的构造沉降发生在盆地最下部新生代地层鲁乐河组沉积后，在中心附近最大（数公里），向边缘逐渐减小。这种沉降模式最好用波长约为 200 km 的岩石圈屈曲来解释，这可能是由整个岩石圈的强度控制的。构造观测进一步表明，盆地内部普遍存在峰值波长约为20 km的平行褶皱，可能是由上地壳强度控制的上地壳屈曲造成的。始新世至渐新世。结果，柴达木盆地构造沉降为向斜凹陷。岩石圈屈曲褶皱的破坏发生在持续的水平力作用下，可能会产生柴达木盆地的主要边界反向断层，导致中中新世以来周边山脉的应变局部化和地壳快速增厚。同时，柴达木盆地内部发育较短波长的上地壳屈曲褶皱。我们的研究结果描绘了一种多尺度屈曲机制，该机制由强大的上地壳和最上层的地幔和较弱的下地壳控制在柴达木盆地下方，表明水平收缩在驱动整个青藏高原北部的构造演化中起主导作用。