INFLATION OF PONDED, PARTICULATE LADEN DENSITY CURRENTS

Field-based, physical modeling and analytical research approaches currently suggest that topographically confined particle-laden density currents commonly inflate to produce suspension clouds that generate tabular and texturally homogeneous sedimentary deposits. Here, a novel three-dimensional theoretical model details a phase space of the criteria for inflation as a function of flow duration, basin size and geometry, total mass transport, sediment concentration, and particle grain size. It shows that under most circumstances cloud inflation is unlikely at real-world scales. Even where inflation is possible, inflation relative to initial flow height is small except for suspensions of silt or finer-grained sediment. Tabular deposits therefore either arise from processes other than flow ponding, or deposits in confined settings may be significantly more complex than are currently understood, due to processes of autogenic compensation and channelization, with associated implications for reservoir characterization in applied contexts. This study illustrates the potential of analytical flow modeling as a powerful complement to other research approaches.