A porphyritic igneous texture indicates that:
A) there was water in the magma
B) the rock cooled slowly and then quickly
C) the rock broke apart as it flowed
D) the rock cooled slowly
E) the ash and pumice were hot and became compacted

Question

Quizplus · Accepted Answer

A porphyritic texture in igneous rocks indicates a two-stage cooling process where the rock cooled slowly at first, allowing large crystals to form, and then cooled quickly, resulting in a finer-grained matrix.

A Porphyritic Igneous Texture Indicates That