accretionary wedge


Also found in: Wikipedia.

accretionary wedge

or

accretionary prism

n
(Geological Science) geology a body of deformed sediments, wedge-shaped in two dimensions or prism-shaped in three dimensions, that has been scraped off the surface of the oceanic lithosphere as it moves downwards beneath a continent or island arc. The sediments are added to the continental edge
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
The Neogene subduction of Arabian Plate set up complex structural geometries like arc trench features, rotation of central Iran Block (Lutvs Afghan) and the development of an accretionary wedge. From the Paleogene to Recent, the Chaman Transform Fault and its splays have deformed the sediments of Kharan Fore-Arc into positive flower features in the area of study.
East-directed crustal thrusts developed, producing the exhumation of both the basal accretionary wedge and a part of the oceanic crust, as well as the thrusting of the ChMC units over the no- or low grade metamorphic Arrayan and Huentelauquen formations (Fig.
The deposition continued once the accretionary wedge was already developed and formed an outer ridge that separated a retrowedge basin (Arrayan basin) from the open sea.
This phenomenon can be explained by a presence of intrabed slips and in general, by total strip thrust in the vicinity of the apical part of the Variscan accretionary wedge by its overthrusting the brunovistulicum (e.g.
From the information recorded in the cores, the research team can draw conclusions on the mechanics of the accretionary wedge.
As the leeward accretionary wedge developed, the subsequent surface was only drowned at exceptional high tides and became converted to sabkha as the accretion proceeded.
Keywords: Lithofacies; Detrital modes; Provenance; Makran accretionary wedge; Submarine fan complex.
The succession is part of the emergent Makran Accretionary Wedge, which formed in response to the northward subduction of the oceanic crust of the Gulf of Oman under the southern margin of the Afghan Block of the Eurasian Plate (White and Clittgord, 1976; Farhaudi and Karig, 1977; Jacob and Quittmeyer,1979; White, 1979; Platt et al., 1985; Platt andLeggett, 1986; McCall, 2003).
(2) the subduction complex, or accretionary wedge, where deformed rocks adhere as a result of subduction;
The models of the central and eastern SR/PP show that the accretionary wedge develops a prominent culmination structure with fault-bend fold geometry over the frontal ramp.
The Tuva-Mongol and South Gobi units possess Precambrian basements, whereas the Ozernaya, South Mongolian, Khangai-Khentei and composite Kharkhirin-West Sayan units comprise accretionary wedges and, commonly superimposed upon them, magmatic arcs no older than Vendian.
The closing of ocean basins through subduction means that the ultimate fate of these turbidite sequences is to be highly fragmented and deformed in subduction zone accretionary wedges and eventually to form part of collisional orogenic belts, and become welded into the crystalline metamorphic fabric of continental crust.