Delta geomorphology: is it in equilibrium with present day dynamic conditions?

PERILLO, G.M.E.; PICCOLO, M.C.; SYVISTKI, J.M.P.

Mendoza

Congreso; 18th International Sedimentological Congress; 2010

Asociación Argentina de Sedimentología - International Association of Sedimentology

        Deltas are common features at river mouths where continental sediment input outbalances sediment redistribution by waves and tides. Most delta classifications are based on the relationship among these variables. However, we propose the hypothesis that even the most active deltas have general shapes that are not in equilibrium with present dynamic conditions but represent the conditions when they were formed in the past. A comparison of the typical triangular morphologic classifications with present day data shows that the location of the deltas in the triangles does not match the qualitative classifications that are commonly used. Therefore, we propose that present day deltas conserve the general characteristics of the original dynamic conditions, for instance, when mean sea level was below present, or fluvial sediment input was much higher than present.