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.