Figure F4. Backscattered electron photomicrographs of grains mounted with epoxy resin. (A) Diamictite and (B) volcanic groundmass grain consisting of plagioclase laths and Fe-Ti oxides enclosed in glass (Sample 178-1103A-31R-2, 0-4 cm). (C) Volcanic groundmass grain consisting of plagioclase laths and Fe-Ti oxides enclosed in glass and (D) the same matrix but with a different proportion of plagioclase(Pl)-glass and minor clipyroxene (Cpx) (Sample 178-1103A-36R-3, 4-8 cm). (E, F) Grains consisting of plagioclase and irresolvable alteration products probably replacing interstitial glass (Sample 178-1097A-27R-1, 38-58 cm). Note that volcanic groundmass grains of the three samples show rounded shapes resulting from mechanical reworking.