Final answer:
Longshore drift is the movement of sediment along the coastline caused by the longshore current. It shapes the coastline and creates geological features like cross-bedding, which can indicate the direction of sediment transport.
Step-by-step explanation:
Longshore drift refers to the transportation of sediment parallel to the shoreline. It's a phenomenon that occurs in the nearshore zone, where sediments such as sand and gravel are moved along the coast by the longshore current.
This current typically runs parallel to the shore and is influenced by wave action. Longshore drift is an important process that shapes coastlines and affects sedimentation patterns.
Related to longshore drift is the concept of cross-bedding, where groups of inclined layers known as cross strata form on sloping surfaces such as ripple marks and dunes.
This geological feature occurs when sediment is deposited on the steep side of these structures and can provide information about the direction of wind or water flow that created them.
Longshore drift should not be confused with other geological phenomena such as the formation of a ridge of sand connecting an island to the mainland (which would be a tombolo), the cause of star-shaped dunes, or the shallowest angle at which loose material is stable (the angle of repose).