Several leveed channels can be observed on bathymetric charts from the middle and outer fan of the Mississippi delta apron. Shallow seismic surveys indicate a complexity of shallow channels and associated low levees, although cores show only minor differences between subenvironments. The levees normally contain a higher plant debris content and finer material than the channels. The irregular surface smooths southeastward, and small ripples are present locally on its surface. These deposits are interpreted as contourites; fine sands and silts that are redeposited by deep-water bottom currents.

Off the Mississippi delta apron toward the west, the flat abyssal plain is present. The subbottom reflectors are dense and parallel with the surface, the cores indicate a general increase in sand-clay ratio followed by a decrease farther west. The deposits can be interpreted as distal turbidites.

Although the variation in aspect and the density of each sedimentary property differs little among the 3 depositional areas, the combination of lithologic alternations, sedimentary structures, high-resolution subbottom profiling, and bottom photography provide information for the development of interpretive models of recent and ancient sediments.

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