SEQUENCE STRATIGRAPHY AND DEPOSITIONAL HISTORY OF THE EASTERN MISSISSIPPI FAN (PLEISTOCENE), NORTHEASTERN DEEP GULF-OF-MEXICO

The eastern Mississippi Fan is a moderate-size, mud-dominated, Pleisto cene submarine fan in the northeastern deep Gulf of Mexico. Analysis o f 6900 km of multifold seismic data identified eight discrete depositi onal sequences interpreted to be coeval to the younger sequences in th e western Mississippi Fan. All sequences consist of channel-levee depo sits and slides, Channel-fill deposits are characterized by high-ampli tude subparallel reflections, and levee-overbank deposits are characte rized by interbedded subparallel to hummocky and mounded reflections. All sequences are affected by a series of volumetrically and areally l arge submarine slides, that are characterized by hummocky to chaotic r eflections. Individual slides are up to 5000 km(2) in area. The channe l-levee systems within six of the sequences are derived from sediment sources located northwest in the Mississippi Canyon lease area. The ch annel-levee systems within the remaining two sequences are downfan con tinuations of systems in the western Mississippi Fan.These changing po sitions of the channels presumably reflect changes in the position of the shallow-marine depocenter that fed the fan throughout the Pleistoc ene. The eastern Mississippi Fan can serve as an exploration analog fo r mud-dominated turbidite systems with similar seismic facies and geom etries. The fan has four potential reservoir facies: channel-fill sedi ments with sinuous to linear trends, thin-bedded sands in levee-overba nk sediments, sheet sands deposited at the terminus of channels, and o ne possible basin-floor fan. Channel valley width/thickness ratio valu es range from 2.9 to 13/1 upfan to 2.9 to 8.8/1 downfan.