Xenolith
Volcano Learning zone > Volcano Glossary
Xenolith means "foreign rock" in Greek. A xenolith is a rock fragment that has been enveloped by an igneous rock. This can happen as an intrusion pushes through country rock, or an eruption rips fragments of the vent wall or picked up by the base of a lava flow. Xenoliths can be igneous,metamorphic or sedimentary.