Lagoon

Depth of water

High tide -

Circumstances

The sea separated from the ocean by barrier islands, sand spits / longshore bars, and organic reef. Seawater is supplied through tidal channels during high tide, whereas lagoons become brackish during the low tide as relatively more terrestrial water is supplied. Waves are weak, and it is subjected to the strong influence of tide currents. In full activity of living things. Inner back-reef lagoon and Outer back-reef lagoon are variations.

Sedimentary facies (Sediments)

Terrestrial sands and mud.

Sedimentary facies (Structures)

No graded bedding by the strong bio-turbation. Herringbone cross-stratifications

Facies fossils

Shellfishes such as oysters.