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Indeed, there is increasing evidence that most ophiolites are generated when subduction begins and thus represent fragments of fore-arc lithosphere. This led to introduction of the term "supra-subduction zone" (SSZ) ophiolite in the 1980s to acknowledge that some ophiolites are more closely related to island arcs than ocean ridges.
In the supra-subduction zone, spreading is not controlled like in mid-ocean ridge settings, as the extension is mainly facilitated by slab rollback that creates space independently of the availability of magma. Therefore, the fastest spreading rates are caused by the most rapid rollback and thus favours a magmatic spreading as in many cases the ...
Subduction zone physics: Sinking of the oceanic lithosphere (sediments, crust, mantle), by the contrast of density between the cold and old lithosphere and the hot asthenospheric mantle wedge, is the strongest force (but not the only one) needed to drive plate motion and is the dominant mode of mantle convection. [citation needed]
Diagram of a cross-section of the Patagonia slab window. The Nazca plate and Antarctic plate are colliding with the South American plate at the Chile Ridge. [1]In geology, a slab window is a gap that forms in a subducted oceanic plate when a mid-ocean ridge meets with a subduction zone and plate divergence at the ridge and convergence at the subduction zone continue, causing the ridge to be ...
Using the supra-subduction back-arc basin model of the Coast Range Ophiolite, geologists were able to reconstruct the deformation history of the western United States since the Jurassic time period between 160 and 170 million years ago.
Geochemical data of the peridotites at Dong Tso indicate that they have supra subduction zone characteristics. [12] The serpentinites have undergone silica-carbonate alteration predominately along major fault zones, but these alterations can be found in nearby areas as well. [12]
This assemblage is associated with subduction along the trench and low heat flow. Nearest the arc is a zone of high temperature-low pressure metamorphic conditions characterized by amphibolite to granulite facies mineral assemblages such as aluminosilicates, cordierite, and orthopyroxenes. This assemblage is associated with high heat flow ...
Pages in category "Subduction zones" The following 52 pages are in this category, out of 52 total. This list may not reflect recent changes. A. Aleutian subduction zone;