The backshore area of a beach extends from the limit of high water
foam lines 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, flat ...
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 solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...
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
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Coastal geography