NOBLE-GASES IN SUBMARINE PILLOW BASALT GLASSES FROM LOIHI AND KILAUEA, HAWAII - A SOLAR COMPONENT IN THE EARTH

Noble gas elemental and isotopic abundances have been analysed in twenty-two samples of basaltic glass dredged from the submarine flanks of two currently active Hawaiian volcanoes, Loihi Seamount and Kilauea. Neon isotopic ratios are enriched in Ne-20 and Ne-21 by as much as 16% with respect to atmospheric ratios. All the Hawaiian basalt glass samples show relatively high He-3/He-4 ratios. The high Ne-20/Ne-22 values in some of the Hawaiian samples, together with correlations between neon and helium systematics, suggest the presence of a solar component in the source regions of the Hawaiian mantle plume. The solar hypothesis for the Earth's primordial noble gas composition can account for helium and neon isotopic ratios observed in basaltic glasses from both plume and spreading systems, in fluids in continental hydrothermal systems, in CO2 well gases, and in ancient diamonds. These results provide new insights into the origin and evolution of the Earth's atmosphere.