Deposition in many Ocean Margin settings involves settling of non-cohesive grains ('sand') through a non-Newtonian suspension of colloidal ('mud') particles. Although sand or mud-only settling is well constrained, combined sand-mud settling is poorly understood. Complex particle interactions ensure sand-mud settling is not simply the addition of individual sand and mud settling behaviour. Novel experiments will develop a better understanding of sand-mud settling dynamics in the context of submarine turbidity currents, in order to predict lateral variations in mud-content and reservoir quality of their deposits (turbidites). Many of the World's largest petroleum reservoirs occur within turbidites. Results will also aid prediction of pollutant flux to the sea-floor in diverse marine settings, as pollutants are preferentially incorporated onto mud particles.