The oceanic island arcs represent the sites of subduction of one oceanic lithospheric plate beneath another (Fig. 6.1). Their characteristic features are linear or arcuate chains of islands forming the volcanic front, often flanked by marginal basins formed by seafloor spreading type processes behind the arc (Ch. 8). Sediments forming the upper layer of the oceanic crust are frequently scraped off the subducting plate as it descends, and form an accretionary wedge in the forearc region.
KeywordsPartial Melting Oceanic Crust Mantle Wedge Primary Magma Overlie Mantle Wedge
Unable to display preview. Download preview PDF.