Where do igneous rocks originate?
Igneous rocks form when magma solidifies. The origin of the molten material may be from plutons rising from the asthenosphere due to subduction of plates or from hot spots in the mantle or from the infill of divergent plate boundaries with basaltic magma. Molten material that cools and solidifies underground, like granite, is called intrusive igneous rock. Molten material that solidifies on the surface, like pumice, is called extrusive igneous rock.
