Which of the following igneous rocks usually exhibit aphanitic texture?
A)granite, gabbro
B)andesite, rhyolite
C)andesite, diorite
D)rhyolite, gabbro

Question

Quizplus · Accepted Answer

Andesite and rhyolite are both extrusive igneous rocks that cool quickly on the Earth's surface, resulting in a fine-grained texture known as aphanitic. Granite and gabbro are both intrusive igneous rocks that cool slowly beneath the Earth's surface, resulting in a coarser-grained texture known as phaneritic. Diorite is also an intrusive igneous rock and can exhibit either texture depending on the cooling rate.

Which of the Following Igneous Rocks Usually Exhibit Aphanitic Texture