Abstract

Many studies have demonstrated that low-temperature thermochronology is a powerful tool for constraining and interpreting the thermal histories of rocks. When combined with tectonic and geomorphological analysis, it allows researchers to reconstruct how Earth’s crust has evolved over time as it was shaped by tectonic, geodynamic, and surface processes. Thermochronological studies typically rely on our understanding of radioactive decay and the temperature sensitivity of diffusion to estimate how long since a rock was at a certain temperature, enabling researchers to calculate an exhumation rate assuming a geothermal gradient. Using this traditional “date to exhumation rate” approach, we combine zircon U-Pb geochronology, apatite and zircon (U-Th)/He thermochronology, structural geology, and geomorphology in the Dominican Republic to link exhumation patterns with the tectonic evolution of the boundary between the North American and Caribbean Plates. We then shift focus to West Antarctica, presenting findings on how low-temperature thermochronology, combined with paleotopographic reconstructions and numerical modeling, can help constrain the geophysical properties of the crust beneath the Thwaites glacier. This approach inverts the “date to exhumation rate” method, using independent constraints on sediment flux and glacial incision to infer variability in geothermal heat flux across the Thwaites glacial catchment. Our results refine current heat flux models by better accounting for the effects of exhumation and topography on the thermal structure of the subsurface, leading to a deeper understanding of the processes influencing geothermal variability and more accurate models of the past and future behavior of the West Antarctic ice sheet, as part of the international SWAIS2C project (Sensitivity of the West Antarctic Ice Sheet to 2ºC warming). Additionally, despite their contrasting climates, both presented study areas are characterized by oblique tectonic regimes. Oblique tectonic settings exhibit complex and poorly understood patterns of relief development and concentrated exhumation, which these studies help to uncover.