3D model of magma plumes

Magma is a mixture of molten rock and gases below the surface of the Earth that may erupt from a volcano as lava. It may also cool and solidify below the surface.

The rocks that form from magma are crystalline and fit into a general category called igneous rocks. Examples of common types of igneous rock include granite and basalt.

One way to learn how different types of igneous rock form is to compare the relative sizes of their mineral crystals. Igneous rocks with larger mineral crystals (for example, granite) cool slowly below the surface. Basalt, with its fine mineral structure, cools relatively quickly after it erupts as lava from a volcano.

Image: 3D model of hot magma plumes (light orange) rising from the Earth's core (dark orange, centre), cooling, and sinking back down (credit: Shuxia Zhang/Shuo Wang/SPL)


3D model of magma plumes Magma

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Magma (from Ancient Greek μάγμα (mágma) meaning "thick unguent") is a mixture of molten or semi-molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals, dissolved gas and sometimes gas bubbles. Magma often collects in magma chambers that may feed a volcano or solidify underground to form an intrusion. Magma is capable of intruding into adjacent rocks (forming igneous dikes and sills), extrusion onto the surface as lava, and explosive ejection as tephra to form pyroclastic rock.

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