Wikipedia contributors. (2023, August 28). Intrusive rock. In Wikipedia, The Free Encyclopedia. Retrieved October 29, 2023, from https://en.wikipedia.org/w/index.php?title=Intrusive_rock&oldid=1172656316
Intrusive rock (Wikipedia) 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.