This article analyzes the stress fields in the Qaidam Basin since the entire Cenozoic using finite element numerical simulations. The stress fields are investigated by analyzing tectonic joints and the GPS velocity field in the basin. The relationship between the stress field patterns and the tectonic activity of the basin was discussed. Based on previous research on the uplift of the Tibetan Plateau, five stages of the tectonic evolution of the Qaidam Basin are modeled. The simulation results show that the stress trajectories in the Oligocence and the Pliocene–Quaternary were similar. In the Oligocence, the stress trajectories in the basin changed significantly and were mainly controlled by the compressional stress on the southern boundary in the initial stage. As the compressional stress on the northern boundary of the basin gradually increased, the compressional stress on the southern and northern boundaries had equal effects in the intermediate stage, and the compressional stress on the northern boundary mainly controlled the stress trajectories in the late stage. During the uplift of the Tibetan Plateau, the stress trajectories in the Qaidam Basin experienced an apparent reversal. The stress trajectories of the internal basin rotated clockwise from NE–SW to NW–SE in the Oligocence and which gradually changed to counterclockwise from NW–SE to NE–SW in the Miocene and recovered to clockwise from NE–SW to NW–SE in the Pliocene–Quaternary.

中文翻译：

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藏北柴达木盆地新生代构造演化古应力场

本文采用有限元数值模拟方法分析了柴达木盆地整个新生代以来的应力场。通过分析盆地中的构造节理和 GPS 速度场来研究应力场。讨论了应力场模式与盆地构造活动之间的关系。在以往青藏高原隆升研究的基础上，对柴达木盆地构造演化的五个阶段进行建模。模拟结果表明渐新世和上新世-第四纪的应力轨迹相似。渐新世盆地内应力轨迹变化明显，初期主要受南部边界压应力控制。随着盆地北边界压应力逐渐增大，南、北边界压应力在中期作用相同，而北边界压应力在后期主要控制应力轨迹。在青藏高原隆升过程中，柴达木盆地应力轨迹发生明显逆转。盆地内部应力轨迹在渐新世由NE-SW向NW-SE顺时针旋转，在中新世由NW-SE向NE-SW逐渐变为逆时针方向，在中新世由NE-SW向NW-SE顺时针方向恢复上新世-第四纪。在青藏高原隆升过程中，柴达木盆地应力轨迹发生明显逆转。盆地内部应力轨迹在渐新世由NE-SW向NW-SE顺时针旋转，在中新世由NW-SE向NE-SW逐渐变为逆时针方向，在中新世由NE-SW向NW-SE顺时针方向恢复上新世-第四纪。在青藏高原隆升过程中，柴达木盆地应力轨迹发生明显逆转。盆地内部应力轨迹在渐新世由NE-SW向NW-SE顺时针旋转，在中新世由NW-SE向NE-SW逐渐变为逆时针方向，在中新世由NE-SW向NW-SE顺时针方向恢复上新世-第四纪。