How is a Spit, a Stack and a stump formed (Geography)?
A stack is an isolated pillar of rock that has become separated from a headland by coastal erosion. It is usually formed by the collapse of an arch. Further erosion will reduce it to a stump, which is exposed only at low tide. A stump is low outcrop of rock formed by the erosion of a coastal stack. Unlike a stack, which is exposed at all times, a stump is exposed only at low tide. Eventually it is worn away completely. A spit is a 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.
