The infralittoral prograding wedge: a new large-scale progradational sedimentary body in shallow marine environments

A progradational sedimentary body, the infralittoral prograding wedge (IPW) , has been developing from the mean fair-weather wave-base level to the sto rm wave-base level between the onshore (beach) and the offshore (inner cont inental shelf) depositional zones along the Spanish coast during the Late H olocene. The main sedimentary body is composed of large inclined master bed s which prograde seawards parallel to the shoreline, formed by sediments sw ept offshore by waves from shallow-water littoral environments. The incline d beds downlap onto finer-grained offshore sediments and, in turn, are over lain by shoreface deposits. The IPW is generated by downwelling storm curre nts and associated seaward transport of sediment. It represents a new depos itional model for elastic wave-dominated coasts, and its identification req uires a new subdivision of the nearshore environment.