Late Quaternary evolution of the central Texas shelf: Sequence stratigraphic implications
Eckles, Brenda Jean
Anderson, John B.
Master of Arts
This study documents the evolution of the interdeltaic central Texas continental shelf over the last 350,000 years. The dataset consists of high-resolution seismic data, platform boring descriptions, oxygen isotope analyses, and radiocarbon dates. A strong correlation exists between seismic facies and lithofacies enabling seven stages of evolution to be mapped. The distribution of these facies is primarily controlled by fourth-order glacio-eustatic cycles. Seismic stratigraphy, oxygen isotope analyses, and radiocarbon dating were integrated to develop an independent sea-level curve for the area. Longshore and surface currents transport large volumes of sand into the area which is deposited as widespread, thick $(>$10 meters) barrier-bar highstand sand bodies on the inner shelf. Sediments are deposited and preserved in a repetitive manner during each glacio-eustatic cycle. This implies a predictable pattern of deposition, therefore, allowing for the development of depositional models that can be applied to ancient deposits in the exploration for hydrocarbons.