magma: Quick Facts

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Last updated

Oct. 11, 2026

Photos and Videos

Diagram of the rock cycle showing sediments forming sedimentary rocks, which can become metamorphic rocks through heat and pressure, melt into magma, or uplift and form igneous rocks through cooling and solidification, with arrows illustrating the transitions and processes.

Diagram showing seafloor spreading at a midocean ridge, with arrows indicating tectonic plates moving apart. Magma rises to form new seafloor, and bands of normal and reversed magnetic polarity are labeled on either side of the ridge.

Cross-sectional diagram showing three tectonic plates at ocean ridges, transform faults, and a subduction zone. The image illustrates rising magma forming rift and subduction volcanoes, convection currents in the mantle, and features such as ocean trenches, extinct and hot-spot volcanoes, and the movement of plates above a molten core and low-velocity mantle layer.

Magma streaming down a volcano.

Magma reaches Earth's surface as lava and flows over Hawaiian vegetation and into the ocean

Why some volcanic eruptions are more explosive than others

How and where does magma form on Earth?

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Topics

magmatic segregation silicic magma andesitic magma basaltic magma granitic magma magma chamber resurgent boiling magmatic stoping in-place crystallization Geochemical cycle volcano volcanic eruption How was Devils Tower formed?

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Cross section of Earth showing the core, mantle, and crust

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