The rock cycle

Part of Hall of Planet Earth.

The Rock Cycle_HERO

The rock cycle takes eons. It strongly affects the carbon and other geochemical cycles by locking up critical elements for tens to hundreds of millions of years. Over the age of the Earth, some rocks have passed many times through the complete cycle. The igneous (granite), sedimentary (claystone), and meta-morphic (gneiss) rocks shown here represent stages in this cycle.