COMPARING THE SMOOTH, PARABOLIC SHAPES OF INTERFLUVES IN CONTINENTAL SLOPES TO PREDICTIONS OF DIFFUSION TRANSPORT MODELS

Abstract

Computer models of stratigraphic development at continental margins often include elements in which sediment topography evolves according to a diffusion equation, representing effects of down-slope sediment transport. However, there has been little effort to verify the model, for example by showing whether deposit geometries are as expected from it or by considering whether transport is consistent with the model's assumptions. The issue is important for understanding transport, erosion and deposition in continental slopes more generally and the extent to which such processes are recorded in seabed morphology. Examples of slope topography illustrating diffusive-like characteristics are examined here. In the uppermost slope of the USA central Atlantic margin, sandy areas between canyon heads are smoothly convex-upwards and almost parabolic, a morphology similar to subaerial soil-mantled hillslopes known to evolve according to a diffusion equation. Other data of interfluves in muddy sediment from both Atlantic and Pacific USA margins also show this smooth convex-upwards form.