Neogene Salt Tectonics in the Salina Basin, Southern Mexico

Renaud Bouroullec¹, William A. Ambrose¹, Khaled Fouad¹, Rebecca Jones¹, Alejandro Alberto Sosa Patron², and Juan de Guadalupe Cardenas Lopez^3
1 The University of Texas at Austin, Austin, TX
² PEMEX Exploración y Producción, Villahermosa, Mexico
³ PEMEX Exploración y Producción, Coatzacoalcos, Mexico

The evolution of the Salina basin was affected by intense salt deformation. The Jurassic autochthonous salt was mobilized to accommodate successive compressional and extensional tectonic phases. The compression between the Chortis block and the southern part of Mexico during the Miocene caused thrusting to propagate northward through the onshore and shallow offshore parts of the basin. The thick autochthonous salt was used as detachment for the thin-skin compressional structures.

The main salt migration occurred in this compressional regime during early and middle Miocene time. Large volumes of salt were mobilized within the folds and thrusts and locally emplaced at the seafloor during middle Miocene time. Allochthonous salt stocks, sheets and canopies grew after the main compressional phase ceased. These salt systems were subsequently loaded by northward upper Miocene and Plio-Pleistocene shallow and deep water clastic sedimentation.

Suprasalt minibasins locally formed onto the Miocene allochthonous salt, which remobilized to accommodate these depocenters. The upper Miocene to Pleistocene interval is affected by extensional structures such as growth faults, grabens and crestal faults. Local strike slip structures are also observed throughout the study area. The main structural styles observed within this interval consist of expulsion rollovers and large EW-trending, counterregional salt systems, indicating a northward movement of the allochthonous salt forming EW-trending ridges between the suprasalt minibasins.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005