Geological dating wiki
The upper shoreface is constantly effected by wave action.
This results in development of herringbone sedimentary structures because of the constant differing flow of waves. The foreshore is the area on land between high and low tide.
The grain size of the material comprising a bar is related to the size of the waves or the strength of the currents moving the material, but the availability of material to be worked by waves and currents is also important.
The term bar can apply to landform features spanning a considerable range in size, from a length of a few meters in a small stream to marine depositions stretching for hundreds of kilometres along a coastline, often called barrier islands.
Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! Shoals can appear in the sea, in a lake, or in a river.
Other longshore bars may lie further offshore, representing the break point of even larger waves, or the break point at low tide.Where beaches are suitably mobile, or the river’s suspended and/or bed loads are large enough, wave action can build up a bar to completely block a river mouth, damming the river, preventing access for boats or shipping, and causing flooding in the lower reaches of the river.This situation will persist until the bar is eroded by the sea, or the dammed river develops sufficient head to break through the bar.Characteristics common to the lower shoreface are fine sands with muds and possibly silt.Further out into the ocean the sediment becomes finer.