An explanation of the geological processes which lead to the formation of different types of rock.
- There are three types of rock: sedimentary, igneous and metamorphic.
- Sedimentary rock forms when deep layers of mineral and organic particles are compacted over millions of years, e.g sandstone.
- Igneous rocks form when magma cools to a solid, e.g basalt.
- Metamorphic rock is formed when rock is subject to heat and pressure, e.g. slate is produced from shale hardened as pressure and heat have rearranged the layers.