Sediment containing significant proportion of clays, the electromagnetic properties of which cause the sediment to bind together .
- CIRIA (1996). Beach management manual. CIRIA Report 153.
A definition of mud given in Definitions of coastal terms:
Fine cohesive sediment deposit containing a high fraction (≥20%) of clay minerals. Fine sedimentary particles, consisting of clay minerals, but also other particles (silt, fine sand, organic matter), can be glued together by large organic molecules (extracellular polymeric substances, EPS) into large mud flocs. These flocs, with a diameter of 0.1-1 mm, settle much faster than the individual particles and can form a colloidal suspension on the seabed. This so-called fluid mud layer can move along the seabed (driven by pressure gradients at the interface, by flow entrainment or by bed slope effect) and be a major cause of harbor siltation. After consolidation, which is often a lengthy process, a mud bed can become highly resistant to erosion by currents.