Late Neogene Louisiana Continental Margin Construction Timed by Sea-Level Fluctuations: Chapter 18: Sea-Level and Seismic Stratigraphic Studies

Deltaic complexes, shelf, slope, and Mississippi fan in the northern Gulf of Mexico show differences in lithologies, depositional environment, and stratigraphy. Each province reveals vertical sequences that can relate to fluctuations in relative sea level, especially for the late Neogene. Shelf and upper slope deposition during periods of relatively high sea level is characterized by thin, laterally continuous, condensed clay-rich sections, with thin calcareous layers, showing well-defined, strong, and laterally continuous seismic reflections. During periods of relatively low sea level sediments reveal expanded sections with variable thicknesses and lithologies, with well-defined depositional trends, displaying a wide range of acoustical responses. The Mississippi fan consists of successive channel-levee-overbank complexes, while the intraslope basins reveal a cyclicity in seismic and lithological characteristics.