The process that creates and changes rocks The Rock Cycle The process that creates and changes rocks
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.
The Rock Cycle – many pathways
The Rock Cycle – an example Igneous granite formed beneath the surface. Tectonic forces push the granite to the surface. Weathering and erosion over millions of years – layers of sediment. Sediment compacts and cements forming the sedimentary rock sandstone.
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
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.
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.
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.