Xenolith and host in lava flow (longest flow). Plagioclase, hypersthene, augite, olivine, and Fe-Ti oxide phenocrysts in a vesicular groundmass of plagioclase microlites, Fe-Ti oxides, pyroxenes, and brown interstitial glass. Olivine is subhedral to skeletal in form and is surrounded by a faint dusty zone of alteration. Xenolith: Plagioclase, hypersthene, augite, and Fe-Ti oxide phenocrysts in a holohyaline groundmass of interstitial brown glass. Both host and xenolith are very vesicular. The boundary between xenolith and host is transitional with pieces of the xenolith being incorporated into the host.
Petrology, geochemistry, and the evolution of magmas from Augustine Volcano, Alaska