This is an irregular verb and the conjugations need to be memorized. A short lesson explains how. Mentir - French Verb Conjugations Learn how to conjugate mentir, an irregular -ir French verb. This is not an easy verb to conjugate, so you will need a good lesson to show you how.
Metamorphism occurs because some minerals are stable only under certain conditions of pressure and temperature. When pressure and temperature change, chemical reactions occur to cause the minerals in the rock to change to an assemblage that is stable at the new pressure and temperature conditions.
Metamorphic rocks form when pre-existing or parent rocks (whether igneous, sedimentary, or even metamorphic) are altered by heat, pressure, and the chemical activity of fluids. When the dominant altering factor is heat, usually from direct contact , it may undergo fundamental change in texture and recrystallization is called contact metamorphism. While regional metamorphism, where rocks texture and minerals are changed by heat and pressure.