accretionary wedge


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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
References in periodicals archive ?
From the information recorded in the cores, the research team can draw conclusions on the mechanics of the accretionary wedge.
Due to the movement of the plates, these so-called accretionary wedges are exposed to enormous stress that form large faults.
2) the subduction complex, or accretionary wedge, where deformed rocks adhere as a result of subduction;
3) the forearc basin on the landward part of the accretionary wedge containing less-deformed sediments;
4) the frontal arc, a zone of uplift and deformation immediately between the accretionary wedge and the volcanic chain;
A low-stress subduction zone exhibits a small accretionary wedge, few large earthquakes, igneous rocks with a narrow basaltic compositional range, a steeply dipping down-going slab, and a well-developed backarc basin.
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.
The Barga Terrane is interpreted as having formed in ocean-margin environment with active island-and-Andean type magnetic arcs, rifted basis, accretionary wedges and continental margins.