Growth rate of the preserved Antarctic continent reveals the anatomy of a late developer

Abstract Ice covers 99.5% of Antarctica. Consequently, its interior geology can only be inferred through subglacial topography and remotely sensed geophysical signatures. We present U-Pb dates, trace elements, and O-Hf isotope data from detrital zircons recovered from scientific ocean drilling sites and derived by glacial erosion of 90% of Antarctica. Areal-restricted outcrops, particularly in Eastern Antarctica, reveal the presence of Archean terranes, but our results show these terranes cannot be extensive beneath the ice. Less than 3% of zircons recovered from offshore cores yield Archean ages. The majority are much younger, with a predominant age population at 650–450 Ma, produced during the orogenic events associated with the amalgamation of Gondwana. Detritus shed from the Antarctic mountains dominated sedimentation, generating giant turbidite fans that extended across Antarctica to southeastern Australia. Our findings characterize Antarctica as a “late developer,” with its primary continental growth occurring a billion years later than other well-studied continents.