ABSTRACT

The Sabinas Basin is located in northeastern Mexico in the states of Coahuila and Nuevo Len. Basin fill is composed mainly of Mesozoic marine sediments deposited during long-term subsidence and folded during Late Cretaceous and Paleogene Laramide orogenesis. The origin of the basin is related to a rift associated with the opening of the Gulf of Mexico. More than 5000 m of sedimentary rocks was deposited in the Sabinas Basin. Three supersequences have been defined. The first represents synrift sediments and is composed of conglomerates and evaporites with associated basic igneous rocks. The following supersequence (144-96 m.y.) comprises several higher-frequency cycles represented by carbonate, evaporite, and coastal siliciclastic deposits of extensive platforms on a passive margin. The youngest supersequence (96-39.5 m.y.) consists mainly of regressive, terrigenous clastic facies deposited in a foreland setting. Subsidence was 40% to 70% greater during the initial rift stage than during subsequent depositional stages. Several lateral and vertical facies changes in the basin were controlled by the Coahuila and Tamaulipas basement blocks, as well as other, smaller blocks.