Yu-guo Chen

Linking Taiwan's subcritical Hsuehshan Range topography and foreland basin architecture

of 10 1 kilometers and 10 4 –10 5 years. Causal links between the structural and synorogenic stratigraphic architecture of the foreland basin and coincidence of the Puli Topographic Embayment provide a valuable case study of the effects of changing boundary conditions (e.g., variable erodibility or strength of rocks along strike) controlling the evolution of critically tapered thin‐skinned orogens. Deeper incision of river networks into a thicker sequence of unconsolidated synorogenic sediments in the central western foreland may affect the onset of a topographically subcritical state.

Structural inheritance and erosional controls on thrust kinematics in western Taiwan

Late Quaternary shortening along the length of the Western Foothills of Taiwan highlights the tectonic segmentation of the foreland and raises questions about the relationship between erosion and the thickness of synorogenic foreland basin fill, and their influence on thrust kinematics. We compare measurements of shortening with geodetic observations and numerical model results, and relate these to regional topography. Predictions of shortening from numerical modeling and observed strain gradients within central Taiwan are generally similar in terms of their scaling and kinematic behavior. Within this framework, the current deformation field is likely related to the inheritance of older passive-margin structures in the foreland, as well as to the easily erodible nature of the 5-km-thick sequence of synorogenic sediment accreted at the leading edge of the orogen in the last 1.1 m.y. Additionally, available constraints on the timing of recent activity of faults suggest that infilling of piggy-back or wedge-top basins there occurred rapidly, contemporaneously with the activation of the frontal thrust and a possible increase in the rate of shortening across the adjacent thrust sheet toward the center of the orogen.