accretion

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Related to accretionary: accretionary growth, accretionary prism

accretion

1. Botany the growing together of normally separate plant or animal parts
2. Pathol
a. abnormal union or growing together of parts; adhesion
b. a mass of foreign matter collected in a cavity
3. Law an increase in the share of a beneficiary in an estate, as when a co-beneficiary fails to take his share
4. Astronomy the process in which matter under the influence of gravity is attracted to and increases the mass of a celestial body. The matter usually forms an accretion disc around the accreting object
5. Geology the process in which a continent is enlarged by the tectonic movement and deformation of the earth's crust

accretion

(aggregation) The increase in mass of a body by the addition of smaller bodies that collide and stick to it. The relative velocity of any two colliding bodies must be low enough for them to coalesce on impact rather than fly apart. Once a large enough body forms, its gravitational attraction accelerates the accretion process. Accreting objects in the Universe are numerous and diverse. They include protoplanets, protostars, black holes, and X-ray binaries. The accretion process is thought to occur generally in the form of a disk. Accretion is now assumed to have had an important role in the formation of the planets from swarms of dust grains. In the outer Solar System the grains were like dirty snowflakes and thus accretion was accelerated. See Solar System, origin.

accretion

[ə′krē·shən]
(astronomy)
A process in which a star gathers molecules of interstellar gas to itself by gravitational attraction.
(civil engineering)
Artificial buildup of land due to the construction of a groin, breakwater, dam, or beach fill.
(geology)
Gradual buildup of land on a shore due to wave action, tides, currents, airborne material, or alluvial deposits.
The process whereby stones or other inorganic masses add to their bulk by adding particles to their surfaces. Also known as aggradation.
(meteorology)
The growth of a precipitation particle by the collision of a frozen particle (ice crystal or snowflake) with a supercooled liquid droplet which freezes upon contact.
References in periodicals archive ?
This feature is the northernmost exposure of Oligocene and Miocene clastic sediments which originated as part of an accretionary prism (Fig.
The Pocologan Metamorphic Suite: High pressure metamorphism in a Silurian accretionary complex in the Avalon Zone of southern New Brunswick.
The accretionary prism model is the simplest, resulting in interpretation of the Northwest Borneo Trough as a fossil trench.
(2007) considered them as a basal accretionary complex, similar to the one exposed further south, between 34[degrees] 32' S and 40[degrees] 57' S, along the Chilean coast (Willner et al., 2004; Willner, 2005).
Detailed microscopic examination of the volcaniclastic (epiclastic) deposits was carried out, discriminating them into accretionary lapilli tuff and finer grained hyaloclastite tuffs.
In other words, while the animal survival success may partially depend upon the (presumably) functionally relevant set of shell-shape parameters [9-29], the animal control upon this category of shell-shape parameters is only indirect, readily operating only via the accretionary growth process of shell, which is best accounted for by the set of growth-based shape parameters (defined below).
This is because the shape of shell outline is not a geometrical figuration generated per se, defined at the outset, but it is the cumulative result of an accretionary growth process [4].
Palmer, P.M.: Provenance of Cretaceous accretionary wedge sediments: the Mangapokia Formation, Wairarapa, New Zealand.
In during of tectonic evolution of Lut block margin from Eocene until now a new accretionary prism as Nehcomplex has jointed to the other old terrene.
Tambien se observan bloques metricos de lava subredondeados, escoreaceos, semejantes a las denominadas "bolas de lava" (lava ballso accretionary lava balls sensu Macdonal, 1972), producto del rodamiento y friccion de bloques pastosos de lava, por lo que ocasionalmente pueden mostrar una estructura espiral y en capas (Fig.
Badarch et al., "Accretionary growth and crust formation in the Central Asian Orogenic Belt and comparison with the Arabian-Nubian shield," Memoir of the Geological Society of America, vol.