PRESENT ANTARCTIC AEROSOL COMPOSITION - A MEMORY OF ICE-AGE ATMOSPHERIC DUST

The data obtained from the chemical analysis (Na, Al, and Ca concentrations) of deep Antarctic ice cores has been reexamined. The correlations found between the concentrations of these elements suggest that the Patagonian continental shelf was the dominant aerosol source during the last ice age, the dust being an intimate mixture of marine clay and carbonates. In addition, it is proposed that sea salt deposited on the continental shelf sediments during drop in sea level was emitted and transported jointly with this dust. The present Antarctic aerosol composition is very similar to the one deduced from ice core studies for glacial climatic conditions. It is concluded that present Antarctic aerosol originates mainly from ice age aeolian deposits in South American cold deserts.