Plagioclase is always present as phenocrysts, microphenocrysts and microlites, in all the samples analyzed. A normal zoning pattern occurs in most phenocryst plagioclase. Some of them have brown glass inclusions. Clinopyroxene occurs as microphenocrysts and microlites in most samples, and is very rarely observed as phenocryst. Olivine occurs as phenocrysts and microphenocrysts, but not presents as microlites.
Magnetite occurs as microlites, and microphenocryst magnetite is exceptional and destabilized.
Typical mineral assemblage of volcanic products of the August 18 eruption. Long dimension approximately 2mm. Mineral compositions of volcanic products from June 27 submarine eruption are also plotted.