Abstract Combination traps. Salt domes: occurrence – Gulf Coast salt plugs – cap rock – associated traps – origin. SOME TRAPS combine structural, stratigraphic, and fluid barriers in varying proportions. The reader might, in fact, classify as combination traps some of the traps that have been described earlier as either structural or stratigraphic traps, for the contribution of each element to the trap is sometimes a matter of personal judgment.

Abstract In the sub-Alpine chains of Haut Provence, SE France, a very well-exposed Mesozoic sequence showing rapid thickness and facies changes associated with Jurassic and Cretaceous extension on the margin of the Ligurian Tethys has been deformed by ‘Alpine’ compression which occurred from the Late Cretaceous to the Pliocene. Although the geology has been very well known for decades, aspects of the structure remain enigmatic and cannot be explained by either Mesozoic extension or Alpine shortening alone. We infer that some deformation resulted from salt tectonics. A completely overturned, highly condensed Jurassic section near Barles village resembles the elevated roof of a Triassic salt body in a deep-marine basin. This carapace became overturned as a flap in the Middle Jurassic when salt broke out at the seafloor and overran the inverted flap as an allochthonous extrusion, comparable to those in the deepwater Gulf of Mexico or Angola. Later, Alpine compression exploited the weakness of the salt sheet as the Digne Thrust moved over the inverted flap. Although the flap is in the footwall of the thrust, evidence of soft-sediment deformation and other anomalous structures within the flap suggest that it did not originate as an overturned footwall syncline.