Sediment gravity flow

A sediment gravity flow is one of several types of sediment transport mechanisms, of which most geologists recognize four principal processes. These flows are differentiated by their dominant sediment support mechanisms, which can be difficult to distinguish as flows can be in transition from one type to the next as they evolve downslope.
Sediment support mechanisms.
Sediment gravity flows are represented by four different mechanisms of keeping grains within the flow in suspension.
Resulting deposits.
Description.
Although the deposits of all four types of sediment support mechanisms are found in nature, pure grain flows are largely restricted to aeolian settings, whereas subaqueous environments are characterized by a spectrum of flow types with debris flows and mud flows on one end of the spectrum, and high-density and low-density turbidity currents on the other end. It is also useful in subaqueous environments to recognize transitional flows that are in between turbidity currents and mud flows. The deposits of these transitional flows are referred to by a variety of names, some of the more popular being "hybrid-event beds (HEB)", linked debrites" and "slurry beds". Powder snow avalanches and glowing avalanches (gas-charged flows of super heated volcanic ash) are examples of turbidity currents in non-marine settings.
Modern and ancient examples.
Modern and ancient (outcrop) examples of deposits resulting from different types of sediment gravity flows.
Significance.
Sediment gravity flows, primarily turbidity currents, but to a lesser extent debris flows and mud flows, are thought to be the primary processes responsible for depositing sand on the deep ocean floor. Because anoxic conditions at depth in the deep oceans are conducive to the preservation of organic matter, which with deep burial and subsequent maturation through the absorption of heat can generate oil and gas, the deposition of sand in deep ocean settings can ultimately juxtapose petroleum reservoirs and source rocks. In fact, a significant portion of the oil and gas produced in the world today is found in deposits (reservoirs) originating from sediment gravity flows.