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Chromitite and anorthosite layered igneous rocks in Critical Zone UG1 of the Bushveld Igneous Complex at the Mononono River outcrop, near Steelpoort, South Africa. A layered intrusion is a large sill-like body of igneous rock which exhibits vertical layering or differences in composition and texture.
Sabancaya volcano erupting, Peru in 2017 A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
Submarine volcanoes are underwater vents or fissures in the Earth's surface from which magma can erupt. Many submarine volcanoes are located near areas of tectonic plate formation, known as mid-ocean ridges. The volcanoes at mid-ocean ridges alone are estimated to account for 75% of the magma output on Earth. [1]
The process powering Plinian eruptions starts in the magma chamber, where dissolved volatile gases are stored in the magma. The gases vesiculate and accumulate as they rise through the magma conduit. These bubbles agglutinate and once they reach a certain size (about 75% of the total volume of the magma conduit) they explode.
Subglacial eruption: 1 water vapor cloud, 2 lake, 3 ice, 4 layers of lava and ash, 5 strata, 6 pillow lava, 7 magma conduit, 8 magma chamber, 9 dike Lava domes at Mount St. Helens and a "runaway glacier" Explosive subglacial eruption of Mount Redoubt, Alaska Subglacial lava dome extrusion at Mount Redoubt, Alaska
The feature is much less active than in its first recorded description, although the area is quite dynamic. Yellowstone is an active geothermal area with a magma chamber near the surface, and active gases are chiefly steam, carbon dioxide, and hydrogen sulfide. However, there are mud volcanoes and mud geysers elsewhere in Yellowstone. [49]
The most energetic Strombolian eruptions are sometimes termed "Violent Strombolian" by volcanologists. [2] Such eruptions are associated with higher magma gas content, leading to a turbulent churn flow regime in the conduit, producing stronger and much more frequent explosions.
It takes place around intrusions of a rare type of magma called a carbonatite that is highly enriched in carbonates and low in silica. Cooling bodies of carbonatite magma give off highly alkaline fluids rich in sodium as they solidify, and the hot, reactive fluid replaces much of the mineral content in the aureole with sodium-rich minerals. [59]