KeywordsBioorganic Chemistry Land Area Accretionary Disk Plate Tectonic Oceanic Plate
In planetary sciences, accretion is the complex process of formation of a planet, either rocky or gaseous, from the disk of dust and gas around a protostar. In geology, accretion is a process by which rocks and sediments are added to a tectonic plate (plate accretion) or a landmass (landmass accretion). When subduction of an oceanic plate under a continental plate occurs, plate accretion is the process of scraping oceanic floor sediments against the continental plate which form a prism of material called accretionary wedge. Landmass accretion is the process of adding sediments (alluvium) to a coastline or a riverbank, increasing land area surface.