http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Dallas County Community College District
Nearly all of the oceanic crust and large parts of the continental crust are comprised of igneous rock. Originating deep in Earth's underworld, magma is created from silicate minerals by tectonic forces. Some magma cools slowly beneath the surface, but some is forced to the surface as lava where it cools quickly. This video illustrates how process and materials affect the formation of igneous rock.
[produced by] Dallas County Community College District.
Title from resource description page (viewed March 02, 2018).