_________are dissolved in melts at depth but they have a tendency to evolve and vaporize at lower (atmospheric) pressure and drive volcanic processes.
A) Crystals of quartz and feldspar
B) Volatiles
C) Silica, sodium, and potassium
D) Volcanic lavas

Question

Quizplus · Accepted Answer

Volatiles are substances that can vaporize at relatively low temperatures and are often dissolved in magma. As the magma rises and pressure decreases, these volatiles can exsolve to form a gas phase, which can significantly drive volcanic eruptions by providing additional pressure.

_________Are Dissolved in Melts at Depth but They Have a Tendency