A general term for carbonate sediment composed of particles up to 62 μ‎m in size. Lime muds are found in a wide range of depositional settings, ranging from pelagic to intertidal. The mud comes from various sources; it may be derived from microfauna, calcareous algae, and from the mechanical or biological breakdown of coarser particles or, more problematically, it may be formed by chemical/biochemical precipitation (this is as yet unobserved in modern marine settings).