Origins of sulphate in Antarctic dry-valley soils as deduced from anomalous 17O compositions.

摘要: The dry valleys of Antarctica are some the oldest terrestrial surfaces on Earth. Despite much study soil weathering and development, ecosystem dynamics occurrence life in these extreme environments1,2,3, reasons behind exceptionally high salt content dry-valley soils4,5,6 have remained uncertain. In particular, origins sulphate still controversial; proposed sources include wind-blown sea salt5,7, chemical weathering8, marine incursion9, hydrothermal processes10 oxidation biogenic sulphur atmosphere1. Here we report measurements δ18O δ17O values sulphates from a range soils. These all large positive anomaly11 17O, up to 3.4‰. This suggests that Antarctic comes not just (which has no anomaly 17O) but also atmospheric reduced gaseous compounds, only known process can generate observed 17O anomaly. source is more prominent inland soils, suggesting distributions largely explained by differences particle size transport mode which exist between sea-salt aerosols formed emission.