Question

What condition results in magma cooling and forming a “glassy” igneous rock?
a.
extremely slow cooling
b.
cooling in the presence of oxygen
c.
extremely rapid cooling
d.
partial melt cooling


Please select the best answer from the choices provided

A
B
C

Answer 1

C

Extremely rapid cooling prevents crystals from forming, producing a glassy igneous rock (e.g., obsidian).