| Abstract | Confusion over the nomenclature and ages of the Woodbine-Eagle Ford transition in north Texas obscured its stratigraphic relationships and the nature of this transition. This study attempts to delineate the transition and its timing using lithostratigraphy, elemental handheld XRF data, and paleontologic data from two near-surface cores provided by the USGS and three outcrops representative of the transition within the DFW Metroplex and Fannin County. The study identified eight lithofacies; those found in the Tarrant (Woodbine) are associated with tidally-influenced environments, contained higher concentrations of aluminum and silicon, and are dominated by benthic foraminifera. The lithofacies in the Britton (Eagle Ford) are associated with distal dysoxic to anoxic environments, contained higher concentrations of calcium and redox proxies, and are dominated by planktic foraminifera. The transition in the sections examined is interpreted to represent a gradual transition from a tidally-influenced estuarine or shallow marine environment to a deeper water, anoxic shelf. |
