ABSTRACT

A detailed seismic stratigraphic analysis of the deep Gulf of Mexico basin has resulted in the definition of 18 post-mid-Cretaceous seismic sequences. A chronostratigraphic framework established in this study allows for the first time a detailed comparison of deep Gulf stratigraphy with that of the peripheral Gulf regions. This comparison reveals a genetic relationship in time and space between deep-water sedimentary rocks and Cenozoic shelf margins. It provides useful information to help infer approximate locations of large sediment fairways traversing the continental slope.

Upper Cretaceous to middle Eocene sequences reflect the influences of the Laramide orogeny and mountain building in the southern Cordilleran, which resulted in a tremendous sediment accumulation along the western margin of the deep basin. During the Oligocene and Miocene a progressive northward migration of depocenters occurred in the deep Gulf of Mexico, mainly in response to the major mid- Tertiary reorganization of source areas and the development of the Mississippi River drainage systems. A progressively westward migration of depocenters occurred during the Pliocene, which was followed by a subsequent eastward shift during the Pleistocene. These shifts are closely associated with the lateral migration of major deltaic shelf margins.

Deep-water sedimentary rocks are represented mainly by basinal turbidites deposited in lower fan settings. Each sequence contains several submarine fan lobes distributed along the deep basin margins, whereas the rest of the deep basin has been dominated by basinal mud-rich turbidites and sediment starvation.

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