The groundmass of this porphyritic basalt is predominantly glass with less abundant plagioclase microlites. The most readily-identifiable mineral of the phenocryst population is plagioclase. Of greater abundance are euhedral, opaque pseudomorphs. Rare inclusions of pyroxene are observed within these opaques. Pockets of chalcedony disrupt the otherwise uniform groundmass.
The author has given permission for this work to be deposited in the Digital Archive of Colorado College.
The author has given permission for this work to be deposited in the Digital Archive of Colorado College.
