What drives mountain building and basin evolution during changes in subduction? Insights from new geo- & thermochronological datasets and numerical modeling in the southern central Andes

The Andes are defined by exceptionally high hinterland topography and thick, rapidly accumulated foreland basin successions above the modern Argentina-Chile flat-slab subduction segment (28–33ºS). Did flat-slab subduction drive these patterns of extreme uplift and subsidence? We integrate new geo- & thermochronological data with balanced cross sections and numerical modeling techniques to interrogate potential uplift and subsidence mechanisms, including (1) shortening-induced uplift and flexural subsidence linked to emergent or subsurface faults, or (2) dynamic uplift associated with slab flattening and inboard migration of the subduction hinge. Our findings highlight the influence of enhanced retroarc shortening and tectonic loading on patterns of uplift, exhumation, and subsidence during aseismic ridge collision and the transition to flat-slab conditions, with no signals of significant dynamic controls. This research demonstrates the utility of integrated field, analytical, and modeling techniques in evaluating the drivers of mountain building and basin evolution under changing geodynamic conditions.