METAMORPHIC ROCKS

RESULT FROM ALTERATION OF PRE-EXISTING ROCKS BY

HEAT, PRESSURE, AND CHEMICAL REACTIONS

CAN INVOLVE CHANGES IN MINERALOGY, TEXTURE, AND CHEMICAL COMPOSITION

ALTHOUGH SHALLOW BURIAL CAN PRODUCE LITHIFICATION AND DIAGENESIS OF SEDIMENT INTO SEDIMENTARY ROCK, ONLY PLATE TECTONIC PROCESSES CAN CAUSE PRESSURES AND TEMPERATURES HIGH ENOUGH TO PRODUCE METAMORPHIC ROCKS

METAMORPHIC ROCKS TELL US ABOUT THE TEMPERATURE AND PRESSURE CONDITIONS UNDER WHICH THEY FORMED