A layer of well sorted angular pumice fall lapilli , clast supported with a bare intraclast space, up to three meters thick. It is remarkable to note the presence of white (70%) and gray-colored pumice, as well as obsidian fragments. Micro-phenocrysts observed are plagioclase, hornblende, clinopyroxene and magnetite.

There are sporadic occurrences of xenocrystals of muscovite and quartz.

Correlation of this sediment to an ash layer in deep sea sediment cores, yields an age of 31 Ka (Federman & Karey, 1980).

The deposit is covered by red paleosol, 30-70 cm thick.