Turbidite

Definition

A turbidite is a sediment deposited from a turbidity current, which is a current of sediment-charged water that moves under the force of gravity; it is therefore the product of a mass flow type of sediment movement.

Sediment grains in turbidity currents are eroded and suspended (and thus transported) by turbulence, in contrast to debris flows or grain flows, the other common types of mass flow processes. Importantly, the sediment plays the essential role in turbidity currents because they impose a density to the flow which drives it downslope; the water only acts as dilutant, passive lubricant, and provides turbulence. During flow, the turbidity current “tunnels” through the bottom of a standing water column; it slows down (and thus gradually diminishes in turbulence and drops – as a consequence – sediment) when the gradient of the slope decreases. Because turbidity currents accelerate near the shelf margin, can reach large dimensions, and flow steadily over inclined...