What would you call an aphanitic, vesicular, black rock having small pale green phenocrysts of olivine and small white lath shaped phenocrysts of plagioclase?
A)andesite
B)basalt
C)obsidian
D)rhyolite

Question

Quizplus · Accepted Answer

The characteristics described in the question (aphanitic texture, vesicularity, black color, and olivine and plagioclase phenocrysts) all point towards a type of basalt. Andesite and rhyolite typically have different colors, textures, and mineral compositions, while obsidian does not have the same type of phenocrysts.

What Would You Call an Aphanitic, Vesicular, Black Rock Having