Another method of change or metamorphism involves molten igneous rock
material. When hot magma moves up through rocks, it not only heats and
pushes them, but it also may soak them with liquids and gases, causing
the nearby rocks to change into new rocks, by a process called _contact
metamorphism_.
[Illustration: Some rocks are altered by heat and fluids when they are
invaded by hot magma in a process called contact metamorphism.]
UNALTERED ROCK
METAMORPHIC ROCK
MAGMA