Sequence Stratigraphic Evolution of the Cenozoic Sediments of Eastern Viosca Knoll, Mississippi Canyon, and Atwater Valley Areas, Northern Gulf of Mexico

David R. Pyles, Paul Weimer, and Renaud Bouroullec
University of Colorado, Boulder, Colorado

Interpretation of the Cenozoic stratigraphic evolution of the eastern Viosca Knoll, Mississippi Canyon, Atwater Valley areas, northern deep Gulf of Mexico is based on 6760 kilometers of 2-dimension seismic data and on 18 well logs including paleontological reports. These strata are divided into three sequence sets that are distinguished on the basis of stacking patterns, centers of deposition, and percent of sand thickness versus the thickness (net:gross) of the each 3rd-order sequence.

Sequence set 1 comprises upper Oligocene through middle Miocene strata. The depocenter for this sequence set is located in the base-of-slope position. The net:gross for this interval is 0.25-0.33, the highest of the three sequence sets. The strata in this sequence set lap out onto the lower Tertiary section that blankets the Cretaceous carbonate slope in the landward direction and topographic highs related to an earlier extensional-contractional system in the basinward direction. Sequence set 2 comprises upper Miocene strata. The depocenter for this sequence set is located in the slope position. The net:gross is 0.09-0.22—the lowest of the three sequence sets. The strata in this sequence set form a basinward prograding succession that was deposited while the Mississippi Fan foldbelt was active in this area. Sequence set 3 comprises Pliocene and Pleistocene strata. The depocenter for this sequence set is located in the base of slope position. The net:gross is 0.18-0.23. This sequence set was deposited after the Mississippi Fan foldbelt was active in the area and coincides to the Plio-Pleistocene global increase in sedimentation.

AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004