These grabens, like the hinge of the box fold, are curvilinear in map view. The forelimb of the box fold steepens, slumps, and sheds pale-brown sediments onto a fan at its base. The rear diapir continues to rise reactively. The reactive diapir underlying the foregraben pierces actively and emerges along zones of greatest extension at the two seaward salients of the foregraben, and at the lateral edges of the model owing to edge effects. In map view, as the extrusive salt spreads radially, we infer that the synclines propagate, northward and southward, away from each salt breakout site.
Extrusive salt spreads radially as lobes in the abyssal plain like piedmont glaciers.
The lobate front of this canopy resembles that of the Sigsbee Scarp in the abyssal Gulf of Mexico. They extend and segment into rafts that migrate seaward as overthrusts . The overthrusted rafts above the isoclinal syncline create a triple stratigraphic repetition of the prekinematic layer, a repetition visible only in cross section. Rafts may later ground and collide as described in Stage 9. The new salt flow covers early detached rafts, which become entirely engulfed by salt.