Drilling Results on the Lower Mississippi Fan

The sinuous migratory channel of the middle Mississippi Fan changes to a pattern of frequent lateral shifting and abandonment on the lower fan, with one channel being active at any given time. Borings in the upfan part of the lower fan recovered vertical successions of thin channel fill and overbank deposits. Near the distal end of the fan, the channels often bifurcate before merging with a low relief area of assumed laterally extensive “sheet sand” deposition. A significant amount of all the sand-sized sediment that came from the source area onto the Mississippi Fan during the Late Pleistocene was apparently transported to the lower fan.