Accretionary prism. Artwork of a cross-section through the Earth's crust showing the formation of an accretionary prism at a subduction zone. A subduction zone occurs in the region where two convergent tectonic plates collide. Tectonic thrusting forces one plate beneath the other down into the mantle (orange) beneath the crust. This causes the formation of a trough or trench along the plate boundary. Sedimentary material is scraped off the subducted plate by the upper plate as they converge. This material accumulates in a prism or wedge shape (centre), filling the trough. The rock in the subducted plate melts as it is forced down and then rises again as magma. This is forced out of volcanoes (left).

Photo website with Rights Managed and Royalty Free stock photos, images, illustrations and footage available for download immediately for commercial and editorial uses. Aflo is a leading independent supplier and producer of stock pictures and visual content. Search and find high quality images and video for design, print, web-use and publishing. Buy photos from our extensive collection of model released and property released sports images. Search some of the most beautiful travel and landscape pictures from our own photographers and license from our large collection of content, modern and archive, focusing on Japan. We provide free research. Register for personal account management and for full use of our Stock Photography website and start to download images now.