A seismic stratigraphic framework of the shelf in the northeastern Gulf of Mexico near Destin dome is established by correlating multifold seismic lines with deep wells that penetrate to the Middle Jurassic Louann Salt and with a previously published seismic stratigraphic study based on shallow core holes. Nine depositional sequences or seismic units are recognized and are designated A through I in the order of increasing age. During the Middle Jurassic to middle Cretaceous, shallow-water deposition prevailed in the area. This deposition was followed by a period of general transgression until middle Oligocene, during which deeper water deposition took place. After the middle Oligocene, a shallow-water regime returned to the area. Thinning of seismic units and onlap of reflectors of post-middle Cretaceous age on the Destin dome suggest that the dome was uplifted in Late Cretaceous and into the early Tertiary.
Six previously established seismic stratigraphic units from the deep Gulf of Mexico are traced into the lower slope near De Soto Canyon. Although several units thin and pinch out, two key boundaries can be traced onto the shelf. The important Challenger-Campeche boundary, which is recognized as a marker horizon and unconformity throughout the abyssal Gulf, is correlated to the F-E boundary, the middle Cretaceous (97 Ma) unconformity on the shelf. The base of the Sigsbee-Cinco de Mayo unit is correlated to an 8-Ma reflector on the shelf. These correlations confirm previous age estimates for the deep Gulf units.
Absence of coherent reflections in the Lower Cretaceous carbonate margin indicates possible reef growth. This margin is the southeastward subsurface extension of the Stuart City reef trend in Texas and Louisiana. This trend extends farther to the southeast where the carbonate margin crops out along the Florida Escarpment.