24. LITHOSTRATIGRAPHY AND CLAY MINERALOGY OF THE WESTERN MARGIN OF THE ROCKALL PLATEAU AND THE HATTON SEDIMENT DRIFT1

• Main Authors: Herman B. Zimmerman, Union College
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Greenland; Norwegian Sea; Rockall Plateau; Greenland-Scotland Ridge; North Atlantic; Northeast Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.503.769; http://www.deepseadrilling.org/81/volume/dsdp81_24.pdf

Learning more about the history of oceanic sedimentation and its relationship to the development of abyssal circula-tion in the northeastern Atlantic was a major objective of Leg 81 drilling. Accordingly, sites were situated on an East-West traverse across the southwestern margin of Rockall Plateau and the Hatton Drift. All sites had a similar strati-graphic sequence of late Paleocene-early Eocene volcanogenic/shallow-water sediments lying below a major late Eo-cene-Miocene unconformity. Overlying this hiatus was a sediment-drift sequence of Mio-Pliocene pelagic ooze capped by a Plio-Pleistocene rhythmic sequence of ooze and marl deposited during glacial conditions. The clay-mineral compo-nents of these sediments reflect the developing exchange of water between the northeastern Atlantic and the Norwegian Sea as the Greenland-Scotland Ridge subsided during the Cenozoic. Evidence presented here suggests an early Eocene initiation of the Northeast Atlantic Passage. Major flow through this passage in the late Eocene/Oligocene stimulated changes in abyssal circulation throughout the North Atlantic, the regional mid-Tertiary unconformity being the most dramatic result.