• Login
    About WHOAS
    View Item 
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Academic Programs
    • WHOI Theses
    • View Item
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Academic Programs
    • WHOI Theses
    • 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 Paleogene (Eocene to Oligocene) paleoceanography of the northern North Atlantic

    Thumbnail
    View/Open
    Miller_thesis.pdf (30.25Mb)
    Date
    1982-10
    Author
    Miller, Kenneth George  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/2604
    Location
    Northern North Atlantic
    DOI
    10.1575/1912/2604
    Keyword
     Ocean bottom; Stratigraphic geology; Eocene; Oligocene 
    Abstract
    Seismic stratigraphic evidence from the western and northern North Atlantic indicates that a major change in abyssal circulation occurred in the latest Eocene to earliest Oligocene. In the northern North Atlantic, the widely-distributed reflector R4 correlates with an unconformity that can be traced to its correlative conformity near the top of the Eocene. This horizon reflects a change from weakly circulating (Eocene) to vigorously circulating bottom water (early Oligocene). Sediment distribution patterns provide evidence for strong contour-following bottom water flow beginning at reflector R4 time; this suggests a northern source for this bottom water, probably from the Arctic via the Norwegian-Greenland Sea and Faeroe-Shetland Channel. Erosion and current-controlled sedimentation continued through the Oligocene; however, above reflector R3 (middle to upper Oligocene), the intensity of abyssal currents decreased. Above reflector R2 (upper lower Miocene) current-controlled sedimentation became more coherent and a major phase of sedimentary drift development began. This resulted from further reduction in speeds and stabilization of abyssal currents. Paleontological and stable isotopic data support these interpretations. In the Bay of Biscay/Goban Spur regions, a major δ180 increase began at -38 Ma (late Eocene), culminating in a rapid (<0.5 my) increase in δ180 just above the Eocene/Oligocene boundary (-36.5 Ma). A rapid δ13C increase also occurs at -36.5 Ma in these sites. Major changes in benthic foraminiferal assemblages also occurred between the middle Eocene and the earliest Oligocene: 1) In the Labrador Sea, a predominantly agglutinated assemblage was replaced by a calcareous assemblage between the middle Eocene and early Oligocene; 2) In the abyssal (> 3km) Bay of Biscay, an indigenous Eocene calcareous fauna including Nuttallides truempyi, Clinapertina spp., Abyssammina spp., Aragonia spp., and Alabamina dissonata became extinct between the middle Eocene and earliest Oligocene; 3) In shallower sites (< 3km paleodepth) throughout the Atlantic, a Nuttallides truempyi-dominated assemblage was replaced by a Globocassidulina subglobosa--Gyroidinoides-Cibicidoides ungerianus-Oridorsalis assemblage in the early late Eocene (-40-38.5 Ma). These faunal and isotopic changes represent the transition from warm, old, corrosive Eocene bottom waters to colder, younger (lower C02 and higher pH, hence less corrosive) early Oligocene bottom waters.
    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 October 1982
    Collections
    • Geology and Geophysics (G&G)
    • WHOI Theses
    Suggested Citation
    Thesis: Miller, Kenneth George, "Late Paleogene (Eocene to Oligocene) paleoceanography of the northern North Atlantic", 1982-10, DOI:10.1575/1912/2604, https://hdl.handle.net/1912/2604
     

    Related items

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

    • Thumbnail

      The Late Eocene 187Os / 188Os excursion : chemostratigraphy, cosmic dust flux and the early Oligocene glaciation 

      Dalai, Tarun K.; Ravizza, Gregory E.; Peucker-Ehrenbrink, Bernhard (2005-09-12)
      High resolution records (ca. 100 kyr) of Os isotope composition (187Os/188Os) in bulk sediments from two tropical Pacific sites (ODP Sites 1218 and 1219) capture the complete Late Eocene 187Os/188Os excursion and confirm ...
    • Thumbnail

      A magmatic trigger for the Paleocene-Eocene Thermal Maximum? 

      Dubin, Andrea R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2015-06)
      Fifty-six million years ago Earth experienced rapid global warming (~6°C) that was caused by the release of large amounts of carbon into the ocean-atmosphere system. This Paleocene-Eocene Thermal Maximum (PETM) is often ...
    • Thumbnail

      Early Miocene Mollusca from McMurdo Sound, Antarctica (ANDRILL 2A drill core), with a review of Antarctic Oligocene and Neogene Pectinidae (Bivalvia) 

      Beu, Alan; Taviani, Marco (2013-06)
      Retrotapes andrillorum n. sp., Hiatella cf. arctica (Linnaeus, 1767), ?Yoldia sp. (internal mould), and six taxa of Pectinidae are reported from the Burdigalian section of the ANDRILL 2A core, drilled in McMurdo Sound, ...
    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