• Login
    About WHOAS
    View Item 
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • WHOI Technical Reports
    • View Item
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • WHOI Technical Reports
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of WHOASCommunities & CollectionsBy Issue DateAuthorsTitlesKeywordsThis CollectionBy Issue DateAuthorsTitlesKeywords

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Late quaternary sedimentation in the Eastern Angola Basin

    Thumbnail
    View/Open
    WHOI-73-80.pdf (15.86Mb)
    Date
    1973-11
    Author
    Bornhold, Brian D.  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/1228
    Location
    East Angola Basin
    DOI
    10.1575/1912/1228
    Keyword
     Quaternary sedimentation; Oceanographic variations; Jean Charcot (Ship) Cruise; Atlantis II (Ship : 1963-) Cruise AII67 
    Abstract
    Recent sedimentation in the eastern Angola Basin includes calcareous oozes in the north and south (Guinea Rise and Walvis Ridge) and hemipelagic lutites and terrigenous turbidites on the Congo Cone and on the Angola rise and abyssal plain. Slumped and ponded sediments are dominant within the Angola diapir field. Illite and montmorillonite are abundant in the southern part of the basin, reflecting the source in soils of South West Africa and northward transport in the Benguela Current system. Kaolinite dominates the clay-mineral assemblage in the north-central part of the basin, reflecting a source in the tropical-humid Congo Basin and transport to the deep-sea through the Congo River and canyon systems. Piston cores from the continental rise revealed major fluctuations in the surface oceanographic conditions, primary productivity, and near-bottom depositional environment during the late Quaternary. Sediments deposited during glacial intervals contain markedly lower carbonate, higher levels of organic carbon, and more abundant siliceous biogenic components, fecal pellets, and pyrite. Sedimentation rates during the past 200-300 x 103 years remained relatively constant on the rise, averaging 3-5 cm/103 years. Oceanographic changes from interglacial to glacial periods, based on sediment composition and geochemistry, include: (1) northward extension and intensification of the Benguela Current and associated high primary productivity off southern Angola; (2) onset of upwelling and high surface productivity off northern Angola, Congo, and Gabon; and (3) major influx of bottom water into the Angola and Guinea Basins. These conditions resulted in higher benthic productivity, a shallower lysocline, and a more reducing near-bottom environment, as bottom water in the Angola Basin, produced during glacial maxima, became isolated. This "climax" bottom water was eventually mixed with the overlying water by geothermal heating.
    Description
    Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August, 1973
    Collections
    • Geology and Geophysics (G&G)
    • WHOI Theses
    • WHOI Technical Reports
    Suggested Citation
    Technical ReportThesis: Bornhold, Brian D., "Late quaternary sedimentation in the Eastern Angola Basin", 1973-11, DOI:10.1575/1912/1228, https://hdl.handle.net/1912/1228
     

    Related items

    Showing items related by title, author, creator and subject.

    • Thumbnail

      High-resolution and high-precision correlation of dark and light layers in the Quaternary hemipelagic sediments of the Japan Sea recovered during IODP Expedition 346 

      Tada, Ryuji; Irino, Tomohisa; Ikehara, Ken; Karasuda, Akinori; Sugisaki, Saiko; Xuan, Chuang; Sagawa, Takuya; Itaki, Takuya; Kubota, Yoshimi; Lu, Song; Seki, Arisa; Murray, Richard W.; Alvarez-Zarikian, Carlos A.; Anderson, William T.; Bassetti, Maria-Angela; Brace, Bobbi J.; Clemens, Steven C.; da Costa Gurgel, Marcio H.; Dickens, Gerald R.; Dunlea, Ann G.; Gallagher, Stephen J.; Giosan, Liviu; Henderson, Andrew C. G.; Holbourn, Ann E.; Kinsley, Christopher W.; Lee, Gwang Soo; Lee, Kyung Eun; Lofi, Johanna; Lopes, Christina I. C. D.; Saavedra-Pellitero, Mariem; Peterson, Larry C.; Singh, Raj K.; Toucanne, Samuel; Wan, Shiming; Zheng, Hongbo; Ziegler, Martin (Springer, 2018-03-26)
      The Quaternary hemipelagic sediments of the Japan Sea are characterized by centimeter- to decimeter-scale alternation of dark and light clay to silty clay, which are bio-siliceous and/or bio-calcareous to a various degree. ...
    • Thumbnail

      Organic matter in river-influenced continental margin sediments : the land-ocean and climate linkage at the Late Quaternary Congo fan (ODP Site 1075) 

      Holtvoeth, Jens; Wagner, Thomas; Schubert, Carsten J. (American Geophysical Union, 2003-12-31)
      Late Quaternary sections (1.2 Ma) of ODP-Site 1075 from the Congo deep-sea fan are investigated to reconstruct variations of terrigenous organic matter supply to the eastern equatorial Atlantic. To characterize the organic ...
    • Thumbnail

      Comment on “Geochemistry of buried river sediments from Ghaggar Plains, NW India: Multi - proxy records of variations in provenance, paleoclimate, and paleovegetation patterns in the late quaternary” by Ajit Singh, Debajyoti Paul, Rajiv Sinha, Kristina J. Thomsen, Sanjeev Gupta 

      Clift, Peter D.; Giosan, Liviu; East, Amy E. (2016-03)
      Singh et al. (2016) published a geochemical record of sediment compositions from the flood plain of the Ghaggar River in western India and use the changing provenance, particularly as traced by Nd isotope composition, ...
    All Items in WHOAS are protected by original copyright, with all rights reserved, unless otherwise indicated. WHOAS also supports the use of the Creative Commons licenses for original content.
    A service of the MBLWHOI Library | About WHOAS
    Contact Us | Send Feedback | Privacy Policy
    Core Trust Logo