Antarctic erosion history reconstructed by Terre Adélie moraine geochronology
Résumé
We report apatitefission-track and10Be terrestrial cosmogenic nuclide (TCN) dating of14 moraine boulders originating from inland Terre Adélie, East Antarctica. These data show coolingof the Proterozoic Terre Adélie craton at <∼120°C between 350 and 300 Ma, suggesting > 4 kmtemperate glacial erosion during the Late Palaeozoic Ice Age, followed by nearly null Mesozoicerosion and low glacial erosion (< 2 km) in the Cenozoic. Based on glacialflux maps, the origin of theboulders may be located∼400 km upstream. Preliminary TCN (10Be) datings of moraine boulderscluster within the last 30 ka. Cosmogenic ages from the Lacroix Nunatak suggest a main deglaciationafter the Younger Dryas atc.10 ka, while those of Cap Prud'homme mostly cluster at 0.6 ka, inagreement with an exhumation of boulders during the Little Ice Age.