The Rock Cycle

1. The Rock Cycle The process that creates and changes rocks

2. The Rock Cycle • Earths rocks are constantly changing • Forces deep inside the Earth and at the surface produce a slow cycle that builds reforms and changes the rock in the Earth’s crust • Defined as: a series of processes on Earth’s surface and in the crust and mantle that slowly change rocks from one kind to another.

3. The Rock Cycle – many pathways

4. The Rock Cycle – an example • Igneous granite formed beneath the surface. • Tectonic forcespush the granite to the surface. • Weathering and erosion over millions of years – layers of sediment. • Sediment compacts and cements forming the sedimentary rock sandstone.

6. The Rock Cycle – an example 5) The sandstone becomes deeply buried over time. 6) Heat and pressure change the sandstone into a metamorphic rock – quartzite 7) Quartzite becomes magma – igneous rocks form again. The cycle continues: The Law of Conservation of Matter: a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system

8. The Rock Cycle & Plate Tectonics • Processes closely related • Plate movements help form magma, the source of igneous rocks • Plate movements cause faults, folding and other motions of the crust that help form sedimentary and metamorphic rocks.

9. Igneous Rock • Oceanic plates move apart – sea floor spreading. New igneous rock is formed. • Subduction zones – volcanoes formed made of igneous rock, rocks may get pushed deeper, melting occurs, eventual cooling to igneous rock.

10. Sedimentary rock and Metamorphic rock • Continental collisions cause faults, folds and crust uplifts. • Erosion begins • Sedimentary rocks are formed • Collisions can also push rocks down deep into the mantle. • Heat and pressure change the rocks into metamorphic rocks.