Salt tectonics in the Sureste Basin, SE Mexico: some implications for hydrocarbon exploration

The Sureste Basin salt became diapiric soon after deposition in the Bajocian (169 Ma). Salt ridges and diapirs grew throughout the Jurassic–Cretaceous. The Mexican Fold and Thrust Belt propagated into the Sureste Basin at 70–60 Ma, causing squeezing/extrusion of allochthonous salt sheets. The more intense Mid-Miocene (c. 13–11 Ma) compression (‘Chiapaneco Event’) produced folding and thrusting over a north–south distance of 600 km. The Mid-Miocene–Recent bulk horizontal flow is indicated by anticline and thrust traces mapped from seismic data and bathymetry. In the SE sector of the salt basin, flow is towards N60°E, where thrusting is intense and the salt is thin. The flow swings to a northerly direction in the basin centre, where folding is important. A parabolic fold arc was produced due to drag on the edges of the salt basin. This indicates that both salt and overburden behaved in a ductile manner at a large scale. Mesozoic carbonate slabs were overthrusted up to 20 km during the Mid-Miocene. Intense fracturing and karstification produced potential reservoir rocks with many untested structures that are leaking hydrocarbons. Pre-Mid-Miocene clastic reservoirs may be trapped in folds below the allochthonous salt, which also have not been drilled.