Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form intrusions, such as batholiths, dikes, sills, laccoliths, and volcanic necks.
Intrusive rocks are characterized by large crystal sizes, and as the individual crystals are visible, the rock is called phaneritic.
An intrusion is any body of intrusive igneous rock, formed from magma that cools and solidifies within the crust of the planet.
An intrusion is any body of intrusive igneous rock, formed from magma that cools and solidifies within the crust of the planet.