ABSTRACT

In the published case history, the apparent reflection structure on the base of the Louann salt "(Permian?)" displayed only "normal south dip" and was "conspicuous for its lack of structural manifestations". The geologic history inferred was that "the (Magnolia) structure is the result of salt movement which took place mainly during Jurassic time". However, at the top of the Smackover formation (the deepest level at which, currently, electric log control is available) the apparent reflection structure displayed appreciable negative spurious relief for which no provision was made for elimination from, or effect on, the apparent reflection structure shown for the Louann salt.

Extrapolation of the areal and local adjustments (required to effect coincidence of the apparent reflection and electric log structures at the top of the Smackover) introduced closure into the apparent reflection structure at the base of the Louann salt. Of the geologic histories inferred therefrom, the most probable appears to be that the folding at the Magnolia structure was post salt in age and, though possibly salt accentuated, was not salt generated.