EVOLUTION OF A BASIN MARGIN: PRELIMINARY RESULTS FROM FLUME TANK EXPERIMENTS

The stratigraphic architecture and evolution of basin margins and the controls of eustasy and sediment supply on these systems are often difficult to study in their natural settings due to their scale in size and time. Flume tanks allow to study such systems in which parameters such as sediment supply, flume tank water level, and topography/bathymetry can be adjusted to determine the varying effects they have on the fill of a basin margin. We constructed a flume tank that is 12 m long, 1 m wide, and 0.5 m high that allowed to modify sediment supply, water level, and slope morphology. Results indicate that changes in sediment supply and flume tank level significantly influence the stratigraphic architecture and stacking pattern of sedimentary systems. Patterns of progradation and aggradation were produced by varying sediment supply and keeping the flume tank water level constant. Patterns of progradation, aggradation, and retrogradation were observed by varying flume tank levels and keeping a constant sediment supply. When varying both parameters at the same time, progradation, aggradation, and retrogradation patterns were observed. However, it is hard to discriminate which variable is responsible for the resulting architecture and stacking pattern. The results indicate that sediment supply and flume tank level significantly control the resulting stratigraphic architecture of a basin margin. However, the results are non-unique, as any of the two parameters and a variation of both parameters at the same time produce similar results. This indicates that interpreting the stratigraphic architecture and stacking pattern of basin margins observed in seismic data only based on sea level is probably not possible.