Modelling the fill of sedimentary basins

Abstract

Conventional sediment transport models are ideal, in theory, for modelling how sedimentary basins fill, but in practice there are rarely adequate data to constrain them. An alternative approach recognises that any basin is a spatially varying sedimentation system, evolving in time towards a steady state, and that its state at any time can be characterised by what can be termed the 'degradation potential' field. (The instantaneous degradation potential at any point is a reciprocal function of the expected survival time of any sediment then being deposited there.) The process of basin filling can be modelled as one of potential-driven flow: as the degradation potential field changes in time, so does the configuration of the depositional surface, and this can be calculated. This potential-driven flow model has been implemented using a finite-difference approximation over an irregular triangular mesh. It predicts realistic basin fill patterns, in three dimensions, and is computationally very economical.