3D numerical modeling of the collision at Taiwan

The Taiwan orogeny is well-regarded as a key location for studying the initial stages of collision and the interactions between tectonics and surface processes. Another significant yet relatively less explored aspect of this orogeny is its obliquity. In this region, two distinct types of obliquity can be identified: (1) the oblique convergence between the Eurasian plate and the Philippine Sea plate, which creates a transpressional regime leading to strain partitioning, and (2)  the orientation of the inherited margin structure from the South China Sea relative to the direction of convergence.

How do the obliquity of inherited structures and convergence affect the thermal structure and strain localization within the orogen?

To address this question, we develop a 3D thermo-mechanical model of oblique subduction-collision using pTatin3D. This model accounts for erosion-sedimentation processes using diffusion, thermo-dynamically consistent densities, and new Navier-slip type boundary conditions specifically designed for oblique setting. We aim to conduct two parametric studies: one focusing on the obliquity of the convergence, while the other focuses on the obliquity imposed by the structural inheritance.  By comparing simulations results with thermo-chronological models and structural observations, we target the development of a framework to help interpreting geological observations and records in the highly 3D Taiwann region.