Subduction-zone magmas are characterized by high fluid contents and Fe3+/ΣFe ratios, which are closely associated with slab-derived fluids during subduction. However, instead of a heavier iron isotope composition preferred ...
Earth Sciences
Jun 6, 2023
0
2
The Okinawa Trough is a newly formed back-arc basin located in the outer margin of the continental shelf of the East China Sea. The submarine hydrothermal activities are widely developed in the Okinawa Trough. A typical feature ...
Earth Sciences
May 5, 2023
0
2
Earth is a dynamic and constantly changing planet. From the formation of mountains and oceans to the eruption of volcanoes, the surface of our planet is in a constant state of flux. At the heart of these changes lies the ...
Earth Sciences
Apr 4, 2023
0
227
Our new study published in Nature Geoscience on an ancient chain of Australian volcanoes is helping to change our understanding of "hotspot" volcanism.
Earth Sciences
Mar 25, 2023
0
83
Volcanic relics scattered throughout the Australian landscape are a map of the northward movement of the continent over a "hotspot" inside the Earth, during the last 35 million years.
Earth Sciences
Mar 24, 2023
0
322
Early in the formation of Earth, an ocean of magma covered the planet's surface and stretched thousands of miles deep into its core. The rate at which that "magma ocean" cooled affected the formation of the distinct layering ...
Earth Sciences
Feb 27, 2023
0
311
Cornell researchers have unearthed precise, microscopic clues to where magma is stored, offering scientists—and government officials in populated areas—a way to better assess the risk of volcanic eruptions.
Earth Sciences
Feb 8, 2023
2
131
Yale researchers have a new theory to explain some of the geochemistry of "hotspots"—magma plumes from deep in the Earth that erupt at the surface.
Earth Sciences
Jan 16, 2023
6
306
The Kingdom of Tonga exploded into global news on January 15 last year with one of the most spectacular and violent volcanic eruptions ever seen.
Earth Sciences
Jan 13, 2023
0
818
Using a novel imaging technique for volcanoes that produces high-resolution pictures of seismic wave properties, a new study reveals a large, previously undetected body of mobile magma underneath Kolumbo, an active submarine ...
Earth Sciences
Jan 12, 2023
0
2342
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
