Depositional Units and Growth Pattern of the Mississippi Fan

Abstract

Basin-wide unconformities within the Plio-Pleistocene section of the Mississippi Fan define eight major sequences. Isopach maps of the sequences reveal that the fan depocenter has migrated both eastward and seaward through its development. Definition and interpretation of seismic facies suggest mass transport, with channelized/unchannelized turbidite deposition were the important depositional mechanisms during fan growth. Although each sequence has a unique history, certain characteristics, particularly the vertical and lateral succession of seismic facies, are common to the majority of sequences. This succession suggests a dominant controlling mechanism on fan development, possibly sea-level fluctuations, with secondary influences of salt tectonics and sediment supply.