Related topics: volcano

Formation of a huge underwater volcano offshore the Comoros

A new submarine volcano was formed off the island of Mayotte in the Indian Ocean in 2018. This was shown by an oceanographic campaign in May 2019. Now, an international team led by the scientist Simone Cesca from the German ...

Why some planets eat their own skies

For many years, for all we knew, our solar system was alone in the universe. Then better telescopes began to reveal a treasure trove of planets circling distant stars.

How and when was carbon distributed in the Earth?

It is generally accepted that planetary surfaces were covered with molten silicate, a "magma ocean," during the formation of terrestrial planets. In a deep magma ocean, iron would separate from silicate, sink, and eventually ...

Ancient volcanoes reveal Earth's recycled crust

Ancient volcanoes dating back billions of years could provide new insights into how the Earth's surface is recycled, according to scientists at the University of St Andrews.

page 1 from 21

Magma

Magma is molten rock that is found beneath the surface of the Earth, and may also exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma often collects in a magma chamber inside a volcano. Magma is capable of intrusion into adjacent rocks, extrusion onto the surface as lava, and explosive ejection as tephra to form pyroclastic rock.

Magma is a complex high-temperature fluid substance. Temperatures of most magmas are in the range 700°C to 1300°C (or 1292°F to 2372°F), but very rare carbonatite melts may be as cool as 600°C, and komatiite melts may have been as hot as 1600°C. Most are silicate solutions.

Environments of magma formation and compositions are commonly correlated. Environments include subduction zones, continental rift zones, mid-oceanic ridges, and hotspots, some of which are interpreted as mantle plumes. Despite being found in such widespread locales, the bulk of the Earth's crust and mantle is not molten. Rather, most of the Earth takes the form of a rheid, a form of solid that can move or deform under pressure. Magma, as liquid, preferentially forms in high temperature, low pressure environments within several kilometers of the Earth's surface.

Magma compositions may evolve after formation by fractional crystallization, contamination, and magma mixing. By definition, all igneous rock is formed from magma.

While the study of magma has historically relied on observing magma in the form of lava outflows, magma was discovered in situ for the first time in 2008.

This text uses material from Wikipedia, licensed under CC BY-SA