Jurassic and Cretaceous transgressive-regressive (T-R) cycles, Northern Gulf of Mexico, USA

Abstract

Establishment of a chronostratigraphic framework is fundamental to the correlation of strata and for the interpretation of the geohistory of a basin. For the onshore basins in the northern Gulf of Mexico, an integrated sequence stratigraphic and biostratigraphic approach has utility as amethod for establishing such a framework. Eleven transgressive-regressive (T-R) cycles and numerous biozones are recognized in Jurassic and Cretaceous non-marine, coastal and marine shelf strata of basins of the northern Gulf ofMexico. The cycles consist of a transgressive phase (aggrading and backstepping intervals) and a regressive phase (infilling interval). Cycle recognition is based on stratal geometries, the nature of the cycle boundaries, facies stacking patterns and large-scale shifts in major facies belts. Cycles are primarily controlled by the change in accommodation space resulting from stratigraphic base-level changes (eustatic and tectonic effects) and sediment supply. Utilizing this integrated approach, 12 regional unconformities and 11 surfaces of maximum transgression (regional marine flooding surfaces) were identified as major events in the Mesozoic geohistory of the northern Gulf of Mexico region. The surfaces of maximum transgression have potential as events for chronocorrelation.