What is the term for a ridge of sediment that forms across the mouth of a river at the coast?

A ridge of sediment that forms across the mouth of a river at the coast is called a bar. This geological feature occurs when sediment carried by river flow is deposited in the water as the river meets a larger body, like an ocean or sea. The resulting accumulation creates a barrier or ridge, which may alter the flows of water and sediment in the surrounding area.

This process often involves the action of waves and currents that can shape the sediment as it is deposited. A bar can function to influence the local aquatic environment, affecting ecosystems and navigation. It is distinct from other terms like delta, which refers to sediment build-up at the river mouth creating new land; spit, which refers to a narrow strip of land extending into water and formed by longshore drift; and inlet, which is an indentation in the coastline that provides access to a body of water. Each of these terms describes different coastal landforms with unique features and processes.