ROCKS WHICH ARE FORMED FROM EXISTING ROCK (SEDIMENTARY, IGNEOUS, METAMORPHIC) BY THE ACTION OF HEAT, PRESSURE, AND CHEMICALS PARENT ROCK - THE ROCK WHICH BECOMES METAMORPHOSED METAMORPHISM- THE PROCESS OF FORMING METAMORPHIC ROCKS WITHIN THE LITHOSPHERE, MAKING THE ROCKS MORE DENSE AND LESS POROUS CAUSED BY INTENSE HEAT AND PRESSURE ON THE ROCK MORE DENSE AND LESS POROUS THEN THE PARENT ROCK FROM WHICH IT FORMED RECRYSTALLIZATION- IS THE PROCESS OF INCREASING THE SIZE OF THE MINERAL CRYSTALS AND/OR CHANGING THE MINERAL COMPOSITION WITHOUT MELTING FOLIATION- PARALLEL LAYERS OF MINERALS CAUSED BY PRESSURES ON THE ROCK WHEN LARGE AREAS OF ROCK ARE UNDER INTENSE HEAT AND PRESSURE CAUSING THEM TO CHANGE FORM (RESULTS IN FOLIATION) EXAMPLE – THE BUILDING OF MOUNTAIN RANGES THE FOLIATION INCREASES AS HEAT AND PRESSURE ARE ADDED (LOW-GRADE - HIGH-GRADE) SLATE PHYLLITE SCHIST GNEISS OCCURS WHEN HOT MAGMA INTRUDES INTO OVERLYING ROCK AND BAKES THE ROCKS IN CONTACT WITH IT LESS ROCK IS AFFECTED THEN IN REGIONAL CHANGE IN THE ROCK IS LESS DRASTIC (NO FOLIATION) QUARTZITE MARBLE MAGMA HORNFELS