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Melt production and accretion of melt onto continental crust in a subduction zone [1]. A subduction zone is a region of the Earth's crust where one tectonic plate moves under another tectonic plate; oceanic crust gets recycled back into the mantle and continental crust gets produced by the formation of arc magmas.
Subduction zones occur where an oceanic plate meets a continental plate and is pushed underneath it. Subduction zones are marked by oceanic trenches. The descending end of the oceanic plate melts and creates pressure in the mantle, causing volcanoes to form. Back-arc basins can form from extension in the overriding plate, in response to the ...
The eastern boundary of the Kermadec plate is also the site of the Kermadec Trench, which is the fifth deepest trench in the world at about 10,000 m. [2] The eastern boundary of the Tonga plate is one of the fastest subduction zones with a rate of up to 24 cm/year (9.4 in/year). [1]
The most massive subduction zone earthquakes, so-called "megaquakes", have been found to occur in flat-slab subduction zones. [40] Steep-angle subduction (subducting angle greater than 70°) occurs in subduction zones where Earth's oceanic crust and lithosphere are cold and thick and have, therefore, lost buoyancy. Recent studies have also ...
The increasingly felsic nature of preserved rocks between 3 and 2.5 billion years ago implies that subduction zones had emerged by this time, with preserved zircons suggesting that subduction may have begun as early as 3.8 billion years ago. Early subduction zones appear to have been temporary and localized, though to what degree is controversial.
Here, the Pacific Plate is being subducted underneath the North American Plate and the rate of subduction changes from west to east from 7.5 to 5.1 cm (3.0 to 2.0 in) per year. [2] The Aleutian subduction zone includes two prominent features, the Aleutian Arc and the Aleutian Trench. The Aleutian Arc was created via volcanic eruptions from ...
The figure is a schematic diagram depicting a subduction zone. The subduction slab on the right enters the mantle with a varying temperature gradient while importing water in a downward motion. A model of the subducting Farallon slab under North America. In geology, the slab is a significant constituent of subduction zones. [1]
The subduction of the African plate slab has led to the development of a volcanic arc, known as the South Aegean Volcanic Arc (SAVA). Magmatism began in the early Pliocene , with typical arc-related andesite – dacite volcanism, stretching from the Saronic Gulf in the west to Santorini in the east.