Located in northern Vietnam, the Fansipan mountain range is the highest topography in the Indochina area. Until recently, there has been limited research regarding the tectonic deformation of the Fansipan mountain range and whether there are notable surface ruptures or active faults in the area. This study provides the first insight into the deformation patterns and potential active movements of the Fansipan mountain range, and may improve our understanding of the overall tectonic activities in northern Vietnam. Our observations from ASTER 30-m DEM show a symmetrical mountain form in the north and an asymmetrical form in the south. The analysis of river profiles indicates similar patterns on both sides in the north and different patterns in the south with short and steep rivers on the SW side and long and gentle rivers on the NE side. The results of the normalized steepness index (k_sn) also show higher values on the SW side of the south part than the values from the other sides. These results suggest a spatial variation in rock uplift patterns of the Fansipan mountain range. Notably, the mountain front of the SW side of the southern Fansipan mountain range is associated with the Phong Tho-Nam Pia normal fault, suggesting that the normal faulting activity likely played an important role in tectonic uplift of this high mountain range. Our investigation of the stress field using fault kinematics indicates that the Fansipan mountain range and its surrounding areas are undergoing an inhomogeneous mixture of strike-slip and normal faulting. It is proposed that the strike-slip and normal motions alternated because of a permutation of σ₁/σ₂ under the same extensional stress regime of approximately NE–SW σ₃. This kinematic pattern may effectively control the recent tectonic movements in northern Vietnam.

范西潘山脉位于越南北部，是印度支那地区最高的地形。直到最近，关于范西潘山脉的构造变形以及该地区是否存在明显的地表破裂或活动断裂的研究还很少。这项研究首次发现了范西潘山脉的变形模式和潜在的活跃运动，可能会增进我们对越南北部整体构造活动的了解。我们对ASTER 30米DEM的观测显示，北部呈对称的山形，南部呈非对称的山形。河流剖面分析表明，北部两侧相似，南部南部则不同，西南侧为短而陡的河流，东北侧为长而缓和的河流。k _sn）在南部的西南侧也显示出比其他侧更高的值。这些结果表明，范思潘山脉的岩石隆升模式存在空间差异。值得注意的是，南部范西潘山脉西南侧的山前与Phong Tho-Nam Pia正断层有关，这表明正断层活动可能在这一高山山脉的构造隆升中起了重要作用。我们使用断层运动学对应力场的研究表明，范思潘山脉及其周围地区正经历走滑和正断层的不均匀混合。所以建议走滑和正常的运动，因为一个排列的交替σ ₁ / σ₂约NE-SW的相同拉伸应力状态下σ ₃。这种运动学模式可以有效地控制越南北部最近的构造运动。