--> Abstract: Structural Restorations of Salt-Cored Anticlines, Mississippi Fan Foldbelt, Northern Deep Gulf of Mexico, by R. Kligfield, P. Weimer, and M. Torrente; #91012 (1992).

Datapages, Inc.Print this page

ABSTRACT: Structural Restorations of Salt-Cored Anticlines, Mississippi Fan Foldbelt, Northern Deep Gulf of Mexico

KLIGFIELD, ROY, PAUL WEIMER, and MAURIZIO TORRENTE, University of Colorado, Boulder, CO

The Mississippi Fan foldbelt is one of three Cenozoic-age deep-water foldbelts in the northern and western deep Gulf of Mexico. These foldbelts represent the downdip contractional features that developed within the overall extensional regime. The Mississippi Fan foldbelt is characterized by salt-cored anticlines that extend approximately 300 km eastward and is approximately 50 km wide. In the northern and eastern portion of the foldbelt, the entire Challenger sequence (Upper Jurassic through Lower Cretaceous) has been deformed with 2000 to 3000 m of structural relief. Major growth of the folds occurred at the 15.5, 12.5, 10.5, and 5.5 Ma sequence boundaries.

Using a 6 x 8 km grid of multifold seismic data in the eastern part of the foldbelt, we have interpreted the geometric relationships between sediments and underlying folds to characterize the pregrowth, syngrowth, and postgrowth strata. We have constructed structural restorations of several dip- and strike-oriented profiles by mapping the sequential, decompacted growth at the known sequence boundaries.

The amplification rates of limb rotation and uplift resulting from buckle folding are initially greater than the linear uplift produced by fault propagation folding. Using geometric results of the sequential restorations, we have determined the fold uplift rates from the interruption of sequence stratigraphic markers of correlated ages. The results suggest: (1) a buckle fold origin for these salt-cored folds, (2) that the salt swells controlled the original nucleation sites of these folds, and (3) that the folds formed in a two-stage process in which the initial folding was followed by out-of-the-core thrusting.

 

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)