2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 15
Presentation Time: 11:30 AM

Quaternary Sedimentation and Subsidence History of the Lower Mississippi Delta Defined by An Industry-Grade 3D Seismic Survey

STRAUB, Kyle M., Saint Anthony Falls Laboratory, University of Minnesota, 2 3rd Avenue SE, Minneapolis, MN 55414, MOHRIG, David, Department of Geological Sciences, University of Texas, 1 University Station C1100, Austin, TX 78712-0254, PAOLA, Chris, Geology and Geophysics, Univ of Minnesota, St. Anthony Falls Laboratory, Mississippi River at 3rd Ave SE, Minneapolis, MN 55414 and GEORGE, Terra J., Jackson School of Geosciences, University of Texas at Austin, 1 University Station C1100, Austin, TX 78712, kmstraub@umn.edu

We present data from an industry-grade seismic volume located over 800 km2 of Breton Sound, LA that images the Quaternary stratigraphy of this section of the Mississippi Delta. Using the upper 1 km of this volume we mapped 9 regional seismic horizons which are used to constrain sedimentation patters over varying time intervals. We analyze spatial and temporal changes in sedimentation pattern to determine the influence of the regional subsidence pattern on the evolution of the Mississippi Delta. Specifically, this data is used to determine a stratigraphic integral scale – the thickness of strata required for individual depositional events to average to basin-scale stratal patterns. For this region of the delta we estimate a stratigraphic integral scale of 400 m, which is approximately equal to 200,000 years. Next, we quantify the tendency of deltas to aggrade via compensational stacking. Data from the Mississippi Delta is compared to a Gaussian random walk model with no compositional stacking and a Gaussian random walk model with complete compensation at every time step.