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 arise from the transformation of existing rock types, in a process called metamorphism, which means change in form. The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 Â°C) and pressure (1500 bars), causing profound physical and/or chemical change.The protolith may be a sedimentary rock, an igneous rock or another older metamorphic rock.etasomatism is the drastic change in the bulk chemical composition of a rock that often occurs during the processes of metamorphism. It is due to the introduction of chemicals from other surrounding rocks. Water may transport these chemicals rapidly over great distances.