A Schematic Sketch of the Rock Cycle

In this sketch, boxes represent earth materials and arrows represent the processes that transform those materials. The processes are named in bold next to the arrows. The two major sources of energy for the rock cycle are also shown; the sun provides energy for surface processes such as weathering, erosion, and transport, and the earth's internal heat provides energy for processes like subduction, melting, and metamorphism. The complexity of the diagram reflects a real complexity in the rock cycle. Notice that there are many possibilities at any step along the way.