μXAFS and TEM studies of Fe(III) oxides precipitated on submarine basaltic glass from South Pacific Gyre

Abstract

In the present study, we investigated secondary products formed on the surface of altered basaltic glass from the sediment-basalt interface by multiple characterizations with EPMA, μXANES, μEXAFS, TEM, and EELS. μXANES and EPMA analyses showed that secondary products with high Fe abundance were precipitated on the surface of basalt glass and that the Fe species in the secondary product was dominantly composed of Fe(III) oxides, hematite, which was also agreeable with EELS result. Characterization by TEM and μEXAFS suggested that the hematite was nanoparticulate with particle size of 10–20 nm. This is the first study showing the occurrence of nanosized hematite as secondary products in altered basaltic glass, although there are many studies on the formation of Fe(III) (hydr)oxides in basalt alteration.