The backshore area of a beach extends from the limit of high water
foam line
Foam lines are accumulations of foam, with trapped insects, exuvia, etc. found on the surface of freshwater water courses or bodies. s to
dune
A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...
s or extreme inland limit of the beach. It is only affected by waves during exceptional high tides or severe storms.
[Whittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984, p. 47. .]
Sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...
s in this area are well-sorted and well-rounded. Its grain sizes are mainly coarse sand and medium sand, which are larger than that in littoral barrier dune. The sedimentary structures include parallel bedding and low-angle
cross-bedding
In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The origina ...
.
References
{{geology-stub
Coastal geography