Biostratigraphy of Paleogene Diatom Assemblages in the Southern Ocean

• Main Author: Kaup, Angela
• Format: Text
• Language: unknown
• Published: DigitalCommons@University of Nebraska - Lincoln 2021
• Subjects: Paleogene; diatom; silicoflagellate; Eocene; Oligocene; South Atlantic; marine; biostratigraphy; Falkland; Earth Sciences; Oceanography and Atmospheric Sciences and Meteorology; Antarctic; Southern Ocean; Maurice; Ewing; Orcadas; Falkland Plateau; Harwood; Maurice Ewing Bank; Antarc*; South Atlantic Ocean
• Online Access: https://digitalcommons.unl.edu/geoscidiss/137; https://digitalcommons.unl.edu/context/geoscidiss/article/1140/viewcontent/Thesis.FinalDraft.pdf

The record of siliceous microfossil sedimentation in the high latitude South Atlantic Ocean has great potential for dating seismic and stratigraphic units. Over the last several decades, scientists have documented diatom biostratigraphic record from sediment cores and drill cores in the Falkland Plateau and Maurice Ewing Bank region, as well as other areas of the Southern Ocean, and a robust chronostratigraphic framework is available for Neogene sequences. Given the complicated nature of ocean bathymetry, tectonic plate motion (vertical and lateral), and ocean current flow, the sedimentological evolution of this oceanic region is not well understood. Sampling sediment cores at high resolution intervals has the potential to offer additional understanding of sedimentation, erosion, and diatom occurrences in this region. This thesis adds new information from diatom records in the South Atlantic Ocean, specifically around the Falkland Plateau and Maurice Ewing Bank. Chapter 1 identifies the structure of this thesis and presents an overview of the project, including a summary of the present state of diatom biostratigraphy in the Southern Ocean. Chapter 2 presents new information on the diatom-based age of sediment cores recovered during a site survey cruise by The Royal Research Ship (RRS) Discovery during Cruise DY087, as well as existing cores from the same region. The goal of dating these cores is to assess the age of seismic units in this region in order to identify future drilling targets. Chapter 3 presents details of the age and diatom assemblages of two Paleogene piston cores the cores from ARA Islas Orcadas Cruise 1678. These cores are correlated to existing Antarctic and Southern Ocean drill core records. Advisor: David Harwood