Quantifying Tectonic and Glacial Controls on Topography in the Patagonian Andes (46.5°S) From Integrated Thermochronometry and Thermo?Kinematic Modeling

The Patagonian Andes have been used to illustrate the dependency of major topographic changes in response glacial erosion processes dominating over tectonic deformation and uplift. Here, we investigate contributors history evolution topography at 46.5°S. We present 33 new apatite zircon (U-Th)/He (AHe ZHe, respectively) fission track (AFT ZFT, ages integrated with 46 previously published bedrock thermochronometric a 3D thermo-kinematic model. Observed thermochronometer increase from eastern flank crest orogen toward retro-foreland basin (from AFT 4–10 Ma, ZHe 4–12 ZFT 6–14 Ma 28–32 68–117 Ma). Thermo-kinematic modeling indicates that spatial gradients can be explained by an up 100-km-wide, parabolic-shaped pattern exhumation rates maximum rate 0.5 mm/yr 15 until onset glaciation ?7 Ma. Furthermore, model results suggest youngest AHe require localized acceleration ?0.5 ?2.2 starting between ?5 ?3 coeval intensified subduction Chile Rise. Our long-wavelength (?100 km) patterns are likely controlled rock uplift above mid-crustal ramp(s) subsequent transpression along Liquiñe-Ofqui Fault. Superposed on these processes, Late Cenozoic resulted accelerated wavelengths <20 km.