File:Basalt 36mw1041.jpg - Wikimedia Commons
English: Bedrock sample from a UGSG drill core at Western Cape Cod, Massachusetts. An olivine-plagioclase phyric basalt, sample 36MW1041 contains plagioclase (60%), clinopyroxene (25%), chlorite (8%), and oxides (7%). Tabular plagioclase phenocrysts reach 2.5 mm. All olivine has been replaced by chlorite. The matrix, composed of plagioclase, clinopyroxene, chloritized olivine, and oxides exhibits a felty texture. Olivine also occurred as phenocrysts up to 0.6 mm long. Oxides show anhedral growth rims, suggesting a second growth episode, possibly during alteration of other minerals.