If a rock containing kyanite and andalusite were to undergo a decrease in pressure, what must happen to temperature in order for that rock to continue to have stable kyanite and andalusite?
A) temperature must increase
B) temperature must decrease
C) temperature must stay the same
D) It is impossible for it to continue to have stable kyanite and andalusite.

Question

Quizplus · Accepted Answer

Kyanite and andalusite are metamorphic minerals that form under high pressure and low temperature conditions. If the pressure on the rock decreases, the rock will be out of its equilibrium conditions, and the kyanite and andalusite may transform into other minerals. However, if the temperature decreases at the same time, the rock may remain in its stable kyanite and andalusite phase. Therefore, in order to keep the stable kyanite and andalusite, the temperature must decrease.

If a Rock Containing Kyanite and Andalusite Were to Undergo