(from Mineralogical
Society of America website)
The concept of the "Rock
Cycle" was created by James Hutton (1727–1797), the father of modern
geology.
Although he loved science and studied chemistry and medicine in college, he
became a farmer instead.
The
Rock Cycle is a group of changes. The
upper part of the earth (mantle, crust and surface) is like
a giant recycling machine. Rocks are not created or destroyed, but are only
broken or changed fom one
kind of rock to another. Igneous
rock can change into sedimentary rock or into metamorphic rock.
Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic
rock can change
into igneous or sedimentary rock. The
rock cycle never stops.
Mineralogical
Society of America: The Rock Cycle