Quantifying Southern Hemisphere dust sources during the Last Glacial-Interglacial Transition using rare earth elements in the EPICA Dome C ice core

Abstract. Dust deposits in ice cores provides a valuable archive of past atmospheric circulation, offering insights into climate dynamics during key climate transitions such as the last glacial termination. Here, we present a novel continuous, high-resolution reconstruction of dust provenance in the EPICA Dome C (EDC) ice core from 33.7 to 2.9 kyr BP, based on Rare Earth Element (REE) patterns. Using a statistical unmixing algorithm on 241 samples, we quantify for the first-time contributions from key Southern Hemisphere dust sources. During the Marine isotope 3 (MIS3), the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS1), dust at EDC was dominated by Patagonia sources (~65–75 %), with secondary inputs from Australia, Southern Africa, New Zealand, and Puna-Altiplano. After ~14.5 kyr BP, the dust assemblage shifted toward greater inputs from low-latitude sources – Australia, Southern Africa, and the Puna-Altiplano – culminating during the Holocene with more variable compositions and reduced Patagonian input (~49 % on average). This transition is supported by Sr-Nd isotopic calculations and aligns with changes observed in other East Antarctic ice cores. Comparison with the EDML ice core reveals overall agreement in major sources and timing of the shifts but also highlights regional variations in the secondary contributions, with EDC showing more consistent inputs from Australia and EDML from Southern Africa. We attribute the shift in provenance to long-lasting hydrological changes in Patagonian river systems and a rapid submersion of the Patagonian shelf around 14.5 kyr BP, linking dust composition to eustatic sea-level rise.