Atmospheric dust accession in South-Eastern Australia.

Abstract

Reddish dust, transported by strong winds from the dry central regions of Australia, is periodically deposited in the humid eastern part of the continent. Dust sampled in snow on the Australian alps during 1968 is comparable in amount with accession reported earlier in the 1900's in New Zealand and Melbourne. The dust reported here has a median diameter of 4 pm, relatively high organic content, and mineralogy in the less than 2 pm fraction dominated by illite and kaolin. The rate of dust accession during the past was probably sufficient to have modified alpine soils. In particular, snow patch soils have a particle size and mineralogy consistent with dust enrichment. A much lower rate of dust accession seems to occur at present in Canberra on the Southern Tablelands.