Which of the following igneous rocks has a texture consistent with a magma that cooled and solidified slowly at first, followed by more rapid cooling?
A) small felsic crystals enclosed in large mafic ones
B) small mafic crystals enclosed in large felsic ones
C) large crystals like those in pegmatite
D) large, early formed crystals surrounded by smaller, late formed crystals

Question

Quizplus · Accepted Answer

This describes a porphyritic texture, where large crystals (phenocrysts) form in a slow-cooling environment, followed by rapid cooling that forms smaller crystals around the larger ones.

Which of the Following Igneous Rocks Has a Texture Consistent