The Yucatan Platform bisects the NW-SE Sierra de Chiapas fold belt of SE Mexico at a right angle. The outcropping Sierra de Chiapas consists of Mesozoic platform carbonates, but their northwestern subsurface equivalents are mostly Mesozoic basinal and slope facies sediments in the Villahermosa folds and their offshore continuation, the Sonda de Campeche folds.

The main decollement level for the folds is a middle Jurassic evaporite sequence. The pre-salt "basement" of the area is poorly defined but is estimated to dip from a depth of about 6 km in the north (Campeche offshore) to 13 km in the south (Sierra de Chiapas). The foldbelt was formed during upper Miocene time and is characterized by divergent SW-SE striking folds. The amount of shortening is estimated to be in the order of 45 to 65 km.

In the onshore and offshore subsurface, the folded belt is orthogonally superimposed by a late Neogene growth fault system that soles out near the base of the Neogene. This growth fault system developed on the continental slope and intercepted salt diapirs that probably emanated from the core of deep-seated folds. Much of the salt accumulated farther north in the large allochthonous mass of the Campeche salt domes.

The Neogene Sierra de Chiapas folded belt appears as a compressional transfer zone between a sinistral transtensional system underlying the Trans-Mexican volcanic belt and the sinistral Polochic-Motagua strike system.

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