spit

Longshore drift carries sand and shingle up coastlines. Deposited material gradually builds up over time at headlands forming a new stretch of land called a spit. A spit that extends across a bay is known as a bar.

Ridge of sand or shingle projecting from the land into a body of water. It is formed by a combination of longshore drift, tides, river currents, and/or a bend in the coastline. The decrease in wave energy causes more material to be deposited than is transported down the coast, building up a finger of sand that points in the direction of the longshore drift. Deposition in the brackish water behind a spit may result in the formation of a salt marsh.