Sediment gravity flow

Sediment gravity flow is one of several types of sediment transport and most geologists recognise four principal types, differentiated by their dominant supporting mechanisms for the sediment.^[1] These can be difficult to distinguish as flows can be in transition from one type to the next.^[2]

• Grain flow – The sediment is supported by the grain-to-grain interactions, with the fluid acting only as a lubricant. (e.g. sand avalanches)
• Liquified/fluidized flow – Formed in cohesionless granular substances. The grains are kept in suspension by pore fluid pressure and begin to flow when pressure is applied to the fluid. This pressure can often be applied by a seismic shock which can turn firm sand into the highly viscous flow as in quicksand.
• Debris flow or mudflow – The sediment is supported by the strength and buoyancy of the matrix.
• Turbidity current – The sediment is supported by the upward turbulence of the supporting fluid.

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