Light coloured aphanitic rocks________ .
A) consist predominantly of large ferromagnesian minerals
B) never form at the surface of the Earth
C) consist predominantly of small non- ferromagnesian minerals
D) always form deep in the crust

Question

Quizplus · Accepted Answer

Aphanitic rocks are characterized by a fine-grained texture, meaning their mineral crystals are too small to be seen with the naked eye. Light-coloured aphanitic rocks consist predominantly of small non-ferromagnesian minerals (such as feldspar and quartz), rather than large ferromagnesian minerals (such as olivine and pyroxene). This composition is not exclusive to any specific depth of formation and can occur at or near the surface, contrary to options B and D.

Light Coloured Aphanitic Rocks________