Late Mesozoic gravity sliding and Oxfordian hydrocarbon reservoir potential of the northern Yucatan margin

Abstract

Abstract The stratigraphy and structural evolution of the western Florida margin is much better understood than its northern Yucatan conjugate because previous hydrocarbon exploration has been more extensive on the Florida margin. In the deep-water northeastern GOM, the post-salt section records late Jurassic-Cretaceous gravity sliding of rafted blocks along a basinward-dipping layer of Callovian salt. This study uses approximately 31,000 line-km of 2D seismic data to describe a coeval area of widespread, gravity sliding along the less-studied, northern Yucatan margin. We define three structural domains based on their distinctive salt structures and associated deformation: 1) a region in the northeastern study area consists of relatively undeformed, late Jurassic-Cretaceous section underlain by 0–300\u202fm-thick salt; 2) areas in the central and southwestern study area contain late Mesozoic gravity slides defined by 300–600\u202fm-thick salt rollers and normal faults rooted onto a 1–4° basinward-dipping salt detachment; and 3) the distal margin of the western and central study area exhibits large salt diapirs up to 6\u202fkm tall that deform Quaternary stratigraphic units. In the central Yucatan study area containing late Mesozoic gravity slides, a stratigraphic unit equivalent to the productive Oxfordian Norphlet sandstone of the deep-water northeastern GOM is identified based on its similar seismic character. Reconstructing the extent of this Norphlet-equivalent unit along the Yucatan margin to its location during Oxfordian deposition places it adjacent to an extensive area of Norphlet sandstone mapped in the deep-water northeastern GOM by previous authors. Our reconstruction suggests a 48,000\u202fkm2 fairway of potential aeolian, late Jurassic reservoirs on the Yucatan and Campeche margins that includes productive reservoirs in the southeastern Bay of Campeche, which previous authors correlated with the Norphlet Formation.