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

[1] The contemporary presence of the Puli Topographic Embayment within the Taiwanese thrust belt provides insight into processes that initiate and maintain a subcritical state in a thin-skinned compressive wedge. Orogen-scale analyses of Taiwan have succeeded in describing the processes and interactions that affect overall development of the thrust belt; however, relatively little is known about which processes or boundary conditions control first-order organization of strain at intermediate scales within the orogenic wedge. We investigate spatial and temporal scales of variation in the overall topographic and structural architecture of a critical wedge and explore the boundary conditions that affect very rapid shortening and erosion at intermediate scales on the order of 10¹ kilometers and 10⁴–10⁵ 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.