Chenier development begins with progradation by rapid deposition. This is followed by a period of reworking, shore retreat, and formation of a ridge along the landward side of a beach. Sand is concentrated on the upper beach and on top of the adjacent marsh. The contact of the chenier with underlying marsh and mudflat deposits is disconformable in areas of shore retreat, but the chenier may intertongue with finer sediments laterally along the shore. Barriers originate from a topographic ridge along the landward side of a beach which subsequently is partly submerged. Lagoonal-marsh sediments are deposited behind the barrier; however, continued submergence accompanied by transgression may result in intertonguing of barrier and lagoonal-marsh sediments. Generally, barriers predate the lagoonal-marsh sediments.