Tectonic and Stratigraphic Evolution of the Mississippi Fan Fold Belt, Atwater Valley Area, Northern Deep Gulf of Mexico

Peter L. Morris¹, Paul Weimer², Renaud Bouroullec², and R. Jay Austin^2
1 ChevronTexaco, Bakersfield, California
² University of Colorado, Boulder, Colorado

A series of palinspastic seafloor maps were created to provide a qualitative estimation of the temporal and spatial growth history of the Mississippi Fan fold belt in the Atwater Valley protraction area. These qualitative maps are based on isochron maps of growth intervals, onlap lines of growth sediments, truncation lines of different strata, and structural restorations. Maps were generated for four discrete growth intervals: 15.5, 12.5, 10.5, and 5.5 Ma.

The 21.5 to 15.5 Ma interval is interpreted to be the pre-growth in the study area. At 15.5 Ma, cross section restorations and isochron maps indicate that folding initiated at the eastern portion of the foldbelt. In the central and western part of the foldbelt, folding had initiated, however the restorations indicate that no faulting had developed.

At 12.5 Ma, the Mississippi Fan fold belt continued to grow and displays signs of linkage of individual folds, particularly in the eastern Mississippi Fan fold belt. At 10.5 Ma, extensive folding and faulting have occurred. Isochron maps suggest extensive linkage and fold growth. The 5.5 Ma palinspastic map reflects the timing of faulting and folding for the above descriptions. However, by 5.5 Ma the majority of the fold belt deformation associated with the Mississippi Fan has taken place. There is minor folding after this time interval as well as minor fault linkage.

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