Rock Types

Sedimentary

Igneous

Metamorphic

Rocks Igneous Sedimentary Metamorphic

Igneous Rocks Igneous rocks are rocks formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from partial melts of pre-existing rocks in either the Earth's mantle or crust.

Sedimentary Rocks Rock formed from sediments covers 75-80% of the Earth's land area, and includes common types such as chalk, limestone, dolomite, sandstone, conglomerate and shale.The sediments are compacted and converted to rock by the process of lithification.

Metamorphic Rocks Metamorphic rock is the result of the transformation of a pre-existing rock type in a process called metamorphism, which means "change in form ". The source rock is subjected to heat and pressure causing profound physical and/or chemical change. The source rock may be sedimentary rock, igneous rock or another older metamorphic rock.