Abstract

Turbidity currents are a form of generally discrete, relatively dilute, submarine, particulate gravity current. They are the principal means whereby coarse clastic material is transported into the deep oceans, constitute a significant hazard to submarine infrastructure and form deposits (turbidites) of economic interest due to their potential role as hydrocarbon reservoirs. Turbidites and related deposits commonly show spatial trends in their characteristics (both vertically and laterally) that can be related to the spatio-temporal evolution of the structure of the depositing flow. Experimental and field data indicate that flow fractionation is implicated in the development of such heterogeneity in flow structure, and can induce changes in both flow rheology and depositional regime. As well as being expressed in the deposits of individual events, these forms of self organisation at the flow scale also find expression at larger scale, and may indirectly indicate the dynamic evolution of the depositional systems (submarine fans) that such flows build.