Science / Geology / Magma: Molten rock material that forms igneous rocks upon cooling. Magma that reaches the surface is referred to as lava.

Magmatic Water

Science / Geology / Magmatic Water: Water that is dissolved in a magma or water that is released from a magma. Some magmas can contain up to several percent dissolved water by weight. MORE


Science / Geology / Phreatomagmatic: An explosive volcanic eruption initiated by the interaction of magma and water (usually either meteoric or groundwater). MORE

Magma Chamber

Science / Geology / Magma Chamber: A full or emptied magma reservoir in the shallow portion of the lithosphere. MORE


Science / Geology / Caldera: A large, bowl-shaped crater associated with a volcanic vent. A caldera can form from a volcanic blast or the collapse of a volcanic cone into an emptied magma chamber. MORE


Science / Geology / Xenolith: A preexisting rock that has been incorporated into magma without melting. When the magma crystallizes the preexisting rock fragment is known as a xenolith. MORE


Science / Geology / Pegmatite: A very coarse grained igneous rock, normally of granitic composition. Typically forms during the final states of magma chamber crystallization when the high water content solutions allow rapid crystal MORE