Pleistocene seismic stratigraphy of the Galveston South addition, offshore Texas
Lewis, Dana Lynn
Clark, Howard C.
Master of Arts
Seven seismic sequences were identified on the outer shelf and upper slope of the northwestern Gulf of Mexico from a grid of high resolution seismic sections. The sequences were deposited during eustatic fluctuations of sea level during Wisconsin glacial and interglacial stages. The sequences include deposits of an early Wisconsin low stand, middle Wisconsin high stand, and late Wisconsin low stand of sea level. Growth faults trending parallel to the shelf break expanded the secton from 6% to 6%. The faults resulted from salt flowage at depth in response to loading by thick deltaic deposits, which prograded to the shelf edge during low stands of sea level. Smaller, local fault systems are associated with diapiric intrusions. Diapirs exerted little control over Wisconsin sedimentation in the study area. Diapirs on the inner shelf are stock-like in appearance while those on the outer shelf and upper slope are broad swells and ridges.