Describe what longshore currents do in the formation of barrier islands. need help willing to give 40 points

Longshore currents are generated when a "train" of waves reach the coastline and release bursts of energy. ... Rather, they arrive at a slight angle, called the “angle of wave approach.” When a wave reaches a beach or coastline, it releases a burst of energy that generates a current, which runs parallel to the shoreline.

Longshore currents wash up sand and sediments, creating the base of a barrier island and eventually forming dunes.

Explanation:

Tidal action, stirring up sediment from the sea floor, was mainly responsible for the formation of barrier islands. De Beaumont's theory states that as waves push up to the shore, sand is carried along with them. The waves crash, expending their energy and depositing the sand into a growing sand bar. As the sand bar grows, it eventually rises above the surface and a barrier island is formed.