The rock cycle
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.
Topic: Earth Science
Subtopic: Earth Formation/Evolution
Keywords: Geochemical cycles, Geochemistry, Rocks
This igneous rock formed when molten material intruded into the shallow crust, where it cooled and crystallized.
Weathering and erosion of rocks like granites concentrate elements that are necessary to form clay minerals, which accumulate as sediments.
With burial and the associated increase in pressure and heating, shales may be transformed by re-crystallization in the deep crust into metamorphic rock, like this gneiss.