Provenance of mineral dust deposited on Antarctica over the last sixty years by strontium isotopic analysis of snow from Dome C

The strontium (Sr) concentration and 87 Sr/ 86 Sr isotope ratio have been determined in 132 snow pit samples collected at Dome C, on the East Antarctic Plateau, corresponding to the period 1958–2019, and in 12 surface snow samples collected at the same site in 2016–2017. The average Sr concentration was 8.1 ± 5.7 pg g −1 (mean ± SD) in snow pit samples and 10.1 ± 8.0 pg g −1 (mean ± SD) in surface snow, without any significant temporal trend. The 87 Sr/ 86 Sr isotope ratio showed small variations (<0.15%), with an average 87 Sr/ 86 Sr value of 0.7094 ± 0.0010 (mean ± SD) in snow pit and 0.7103 ± 0.0004 (mean ± SD) in surface snow samples. These results seem to suggest that no change in the source(s) of mineral dust has occurred throughout the period investigated. Comparison of the 87 Sr/ 86 Sr isotope ratio of the snow samples with those of potential source areas suggests that the mineral dust reaching the East Antarctic plateau over the last decades is of a mixed origin, with a contribution from Patagonia and one or more other source(s) having a more radiogenic Sr isotopic signature, with a major fraction coming from South Australia. • Sources of dust to the Antarctic plateau have not changed in the last sixty years. • Dust reaching inner Antarctica derives from Patagonia and (an) additional source(s). • South Australia likely contributes to mineral dust reaching inner Antarctica.