Turbidites are the deposits of turbidity currents, which are gravity-driven turbid suspensions of fluid (usually water) and sediment. They form a class of subaqueous sediment gravity flow (see Gravity-Driven Mass Flows) in which the suspended sediment is supported during transport largely or wholly by fluid turbulence. Turbidites range in grain-size from mud to gravel, and may be of any composition-siliciclastic, carbonate, or even sulfide near deep-sea hydrothermal vents. Turbidite beds range in thickness from millimeters to tens of meters, and individual events can, in extreme cases, involve the resedimentation of hundreds of cubic kilometers of sediment. They are amongst the commonest of sedimentary deposits, and turbidite depositional systems such as submarine fans and basin plains form the largest individual sedimentary accumulations on the Earth. Thick sequences of synorogenic turbidites (flysch) are common in the ancient record.
Turbidity currents were first so named