Cenozoic erosion of the Transantarctic Mountains: A source-to-sink thermochronological study

- New apatite fission-track data from Transantarctic Mountains are provided.
- An Oligocene tectonic exhumation phase has been detected.
- Up to 5 km of erosion have been derived from the modeling of AFT data.
- A source for sediments drilled in the Victoria Land Basin has been identified.

The formation of the Transantarctic Mountains (TAM) is strictly related to the evolution of the West Antarctic Rift system, but the timing of their exhumation is still not fully assessed. In this work, we provide new apatite fission-track data collected on the region between the Royal Society Range and the Britannia Range. Cooling ages are late Eocene-Oligocene in the center of the region but they get older both northwards and southwards. We infer that exhumation was strictly controlled by TAM-parallel fault strands that were active after the Oligocene. The Royal Society Range and the Britannia Range represent transition zones corresponding to transverse structures, probably inherited from early basement crustal discontinuities and reactivated as transfer regions during rift propagation. The exhumation of the investigated region has been then modeled and predicted thermochronological ages have been compared with detrital data from the Miocene sedimentary succession drilled in the Victoria Land Basin. Results indicate that this sector of the TAM is the most probable candidate for the source of sediments and that during the Neogene 3 km (but up to 5 km) of rocks was exhumed.