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.

Rock Cycle_ILL

In This Section

Exhibit Granite This igneous rock formed when molten material intruded into the shallow crust, where it cooled and crystallized. Exhibit Claystone Weathering and erosion of rocks like granites concentrate elements that are necessary to form clay minerals.  Exhibit Gneiss With burial and the increase in pressure, shales may be transformed by re-crystallization into metamorphic rock.