Combined noble gas and trace element measurements on individual stratospheric interplanetary dust particles

Abstract

The trace element compositions and noble gas contents of 32 individual interplanetary dust particles (IDPs) collected in the Earth's stratosphere were measured. Trace element compositions are generally similar to CI meteorites, with occasional depletions in Zn/Fe with respect to CI. Noble gases were detected in all but one of the IDPs. Noble gas elemental compositions are consistent with the presence of fractionated solar wind. A rough correlation between surface-normalized He abundances and Zn/Fe ratios is observed; Zn-poor particles generally have lower He contents than the other IDPs. This suggests that both elements were lost by frictional heating during atmospheric entry and confirms the view that Zn can serve as an entry-heating indicator in IDPs.