The horizontal propagation of slab detachment (slab tearing) is known to control lateral migration of the mountain uplift along the collisional belt. However, along-strike differential collision due to an oblique passive margin geometry can make the topography response more complex. In this study, we employ 3D thermomechanical modeling to distinguish between the lateral migration of the mountain topography driven by slab tearing and oblique continental collision itself. In our models, slab breakoff is triggered by the transition from oceanic to continental subduction, occurring earlier on one side of the passive margin than on the other due to the initial oblique configuration. However, once slab breakoff has begun, it spreads horizontally in the form of tearing at high velocity (∼38–118 cm yr⁻¹), and associated topographic uplift also propagates with the same velocity. In contrast, the along-strike migration of subsequent continental collision and related topographic uplift propagation is typically much slower (∼2–34 cm yr⁻¹). Similarly, the vertical magnitude of surface uplift caused by slab tearing is higher (up to 10 mm yr⁻¹) than the following collision phase (<4 mm yr⁻¹). The parametric analysis reveals that slab tearing velocity and the associated horizontal propagation of mountain uplift depends on obliquity angle and slab age, whereas the migration of collision-induced topographic growth is controlled by the convergence velocity and obliquity angle. Finally, we show that presence of microcontinental block detached from the passive margin leads to spatial and temporal transition from horizontal to vertical slab tearing and more intense syn-collisional mountain building.

中文翻译：

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地形对水平板撕裂和斜大陆碰撞的响应：来自 3D 热机械建模的见解


众所周知，板剥离（板撕裂）的水平传播控制了山体隆起沿碰撞带的横向迁移。然而，由于倾斜的被动边缘几何形状引起的沿走向差分碰撞会使地形响应更加复杂。在这项研究中，我们采用三维热机械建模来区分由板撕裂驱动的山地地形的横向迁移和倾斜大陆碰撞本身。在我们的模型中，板块断裂是由从海洋俯冲到大陆俯冲的转变触发的，由于初始斜向构型，被动边缘的一侧比另一侧更早发生。然而，一旦板块断裂开始，它就会以撕裂的形式以高速 （∼38–118 cm ^yr-1） 水平扩散，并且相关的地形隆起也以相同的速度传播。相比之下，随后的大陆碰撞和相关的地形隆起传播的沿走向迁移通常要慢得多（∼2-34 cm ^yr-1）。同样，板坯撕裂引起的表面隆起的垂直大小（高达 10 mm ^yr-1）高于下一个碰撞阶段 （<4 mm ^yr-1）。参数分析表明，板撕裂速度和相关的山体隆起水平传播取决于倾斜角和板龄，而碰撞诱导地形增长的迁移受收敛速度和倾斜角控制。最后，我们表明，从被动边缘分离的微大陆块的存在导致从水平到垂直板块撕裂的空间和时间转变和更强烈的协同碰撞山体建设。