Mud Mound and Bank Depositional Environments

Mud banks form mounded-to-long, linear, low-energy deposits of bioturbated mud and shelly mud. Florida Bay has some of the worlds best developed and studied mud banks. The mud accumulates in the mounds by baffling of currents by organisms such as sea grass or algae.

Florida Bay behind the Florida Keys showing network of mud banks. Image by Scientific Visualization Studio, NASA Goddard Space Flight Center; data courtesy Landsat Project.

.Mud Bank Model

There is generally a windward and leeward side producing a gradation of energy across the bank. In Florida Bay, sea grass stabilizes the banks. Island development is common along the tops of the banks and tidal channels cut the banks. Enos (1983) presented a diagrammatic cross section of a Florida Bay mud bank. He showed that sea grass plays an important role in stabilizing the bank. In the ancient other organisms such as algae assumed this role of stabilization

Oblique aerial photograph of mud banks in Florida Bay. Spy Key is in the fore ground.

Island and tidal channel development along Twin Keys mud bank in Florida Bay.

Rock Types

In the ancient, these banks are represented by wackestone to packstone with some lenses of grainstone. Where not well outlined, as in photograph below, they would be difficult to distinguish from other muddy platform-interior sediments because they have similar fabrics and textures.

Mud mound of Pennsylvanian age in Central Texas. Photography courtesy of Ursula Hammes.

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