When clay minerals in a shale are subjected to elevated temperature and pressure, they may change in the solid state (that is, without melting) to form platy minerals like ___ that are at equilibrium with the new temperature/pressure conditions.
A) feldspar
B) amphibole
C) mica
D) carbonate
E) pyroxene

Question

Quizplus · Accepted Answer

Clay minerals often transform into mica minerals under elevated temperature and pressure. Mica minerals have a platy, layered structure that is more stable under these conditions.

When Clay Minerals in a Shale Are Subjected to Elevated