Mineralogy of insoluble particles in the Vostok Antarctic ice core over the last climatic cycle (150 kyr)

Abstract

Mineralogical characterisation of insoluble microparticles entrapped in ice layers successively deposited on the Antarctic continent is a useful tool for paleoclimate reconstruction. Indeed, it is likely to provide information on the distribution of potential source areas and of climatic conditions prevailing over different time periods. A first study, covering the last 30 kyr and including the end of the last glacial age, has shown that, over central East Antarctica, continental input was soil derived and originated probably from South America. In this work, the time period covered is l60 kyrs which includes a complete climate cycle. Clay species and particle size considerations suggest that local sources and Australia have been of minor importance for the studied area over the last 160 kyr. They support the hypothesis of colder and drier conditions prevailing over the source areas during glacial extrema. Lastly the predominance of illite, feldspar and quartz in association with presumably weathered volcanic products is consistent with a continental input originating from South America for the East Antarctic area, but is not in complete agreement with the results of general circulation models.