lagoondelta

Lagoondelta is a term used to describe a specific type of geological formation where a lagoon, a shallow body of brackish water separated from the sea by a barrier, transitions into a delta, a landform created by deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water. This formation is characterized by the interplay of marine and fluvial processes.

The formation begins with a river carrying sediment that empties into a coastal area. If this coastal area contains a lagoon, the river's sediment can be deposited within and around the lagoon's margins. Over time, the continuous deposition of silt, sand, and clay can gradually fill in the lagoon. This process can lead to the development of distinct environments within the lagoondelta.

These environments may include areas of freshwater influence from the river, brackish zones where freshwater mixes with seawater, and more saline areas closer to the open sea. The landforms created can be complex, featuring intertidal flats, salt marshes, mangrove forests in tropical regions, and channels that adapt to the changing sediment load and water levels. Lagoondeltas are often rich in biodiversity due to the variety of habitats they support. They can be important for coastal protection, as the deposited sediments can help to stabilize shorelines.