WSU SWB-10

sketchfab

This sample was collected from a basatic cinder cone west of the Island Park Caldera in SE Idaho. The basalt consists of oxidized vesicular groundmass with large subhedral crystals of bytonite An70-90 plagioclase. The remainder of the sample comprises a partially melted xenolith of apparent crustal origin that appears to be derived from metaplutonic igneous rocks at depth. Most of the black glassy material is exactly that: glassy remains of partial melting of the xenolith. Note that melting is most prevalent between individual grains.