Late Holocene Sr-Nd isotope and REE data from the Siple Dome ice core, Antarctica

Compositions of mineral dust in ice cores serve as tracers of paleo-atmospheric circulation patterns, providing linkages between sources and sinks. To determine the source(s) of dust to Siple Dome, Antarctica, we measured Sr-Nd isotope ratios and REE concentrations on late Holocene samples (~1030-1800 C.E.) from the Siple Dome A deep ice core. We also measured Sr-Nd isotope ratios of dust from the Clark Glacier ice core, Dry Valleys, to compare dust compositions from the eastern and western shores of Ross Sea embayment. Siple Dome data are characterized by low Nd isotope ratios (as low as εNd = -16.3) along with low Sr isotope ratios (highest 87Sr/86Sr = 0.7102) compared with other Antarctic dust signatures. A well-defined inverse correlation between Sr-Nd isotope ratios indicates two primary mixing sources. Siple Dome dust compositions are distinct from dust deposited on Taylor and Clark Glaciers in the McMurdo Dry Valleys of the western Ross Sea, precluding the Dry Valleys as a late Holocene dust source to this region of the eastern Ross Sea.