Millennial scale deep circulation changes in the North Atlantic during the Plio-Pleistocene inferred from high resolution records of chemical- and physical sediment properties

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IODP Expeditions 303 (Fall 2004) and 306 (March-April, 2005; Participant Dr. Jens Grützner) focus on rapid changes in North Atlantic climate history during the late Neogene-Quaternary. Non-destructive X-ray fluorescence (XRF) core scanning is an advanced high-resolution method to help investigating several major research targets outlined in the drilling proposal. We here propose to perform XRF scans of element intensities (K, Ca, Fe, Ti, Al, Si, Ba) on selected 303/306 drilling locations to derive cm-resolution records of terrigenous and biogenic sediment composition. Combined with detailed age models these records will to characterize prominent millennial scale climate cycles of the last glacial period known as Dansgaard/Oeschger and Heinrich events and help to study their possible occurrence in time intervals prior to 100 ka BP. By using a depth transect approach we also intend to infer changes in the deep and intermediate water flow associated with these climate cycles. Furthermore elemental ratios (e.g. Al/Ti, Ba/Ti) will be used to explore millennial changes in terrigenous provenance and biogenic productivity. The research proposed here provides an ideal complement to our ongoing work on OOP Leg 172 Sites (subtropical North Atlantic) and by comparing results from both projects we intend to investigate latitudinal climate linkages in the North Atlantic.