Mud-laden Gravity Flows – The fun of mixing clays…

Abstract:

Clay minerals are very prevalent in many depositional systems. Clay minerals are important as their surface properties makes them cohesive causing them to commonly exist as aggregate grains rather than dispersed suspension. Understanding this aggregation process and the subsequent effects of this process on the, transport, deposition and erosion of these materials is essential to effectively comprehend, model and predict modern and ancient sedimentary systems. Past work in the subject had revealed that during transport and prior to deposition these materials undergo a complex range of processes involving erosion, re-deposition, and transport that are much more complicated than those that occur in the sandy systems. This complexity is likely caused by substantial inter-particle interaction. Despite this work, most of it had been limited to relatively dilute turbulent flows where fine particles either aggregate into flocs or are involved in hindered settling without considering the effects of changes in rheology. In the light of this problem we present a set of rheological analysis of pure kaolinite, pure bentonite and mix kaolininite-bentonite slurries to understand i) the range of concentrations to which rheological changes occur, and ii) different transport mechanisms as a function of their concentration.