UNITING PETROLOGICAL, MINERALOGICAL AND GEOCHEMICAL DATA FOR IMPROVED SEDIMENT SOURCE DESCRIPTION OF ARCTIC OCEAN CORES (Invited Presentation)

The PFS “Polarstern” core PS2185-6 KAL – collected in 1991 at the central Lomonosov Ridge – has been and still is intensively investigated for multiple paleoceanographic proxies. In terms of reconstruction of the detrital and terrigenous input a set of bulk, clay and heavy mineral assemblage data was produced (Vogt, 1997; Behrends, 1999; see Stein, 2008 for a compilation). Bulk inorganic geochemistry was investigated by Schoster (2005). Radionuclide data was compiled by Strobl (1998; see also Spielhagen et al., 1997, 2004) and Haley et al. (2008). Paleomagnetic data was detailed by Friedrichs (1995; see Spielhagen et al., 1997, 2004). Physical properties were initially determined by Bergmann (1996).

The Central Lomonosov Ridge is well positioned to provide reconstructions of the changing Arctic Ocean current systems being at the convergence of the Beaufort Sea Gyre above the Amerasian Basin and the Transpolar Drift which moves today sea ice and surface waters from the Eurasian Siberian Shelves to the Fram Strait and into the Norwegian Greenland Sea.

Therefore, the Lomonosov Ridge was also chosen to be drilled by IODP in 2004 by means of a massive three icebreaking ship fleet. ACEX cores have been correlated to PS2185 and other Lomonosov Ridge gravity cores and the age model of the ACEX cores was deduced in high precision for the upper approx. 10 m of the Quaternary (O´Reagan et al., 2010).

In this presentation we will exercise a detailed comparison of the datasets of PS2185-6 to better understand source region information in every grain size, petrological and/or geochemical sediment fraction. Finally, we might see a more detailed interpretation of bulk data which can easily and fast be acquired (e.g. X-ray core scanning).

O'Regan, M., John, K.S., Moran, K., Backman, J., King, J., Haley, B.A., Jakobsson, M., Frank, M., Röhl, U., 2010. Plio-Pleistocene trends in ice rafted debris on the Lomonosov Ridge. Quat. Int., 219: 168-176.

Stein, R., 2008. Arctic Ocean Sediments: Processes, Proxies, and Paleoenvironment. Dev. Mar. Geol., Vol. 2.: 592 pp. (incl. all other references).

Vogt, C., 1997. Regional and Temporal Variations of Mineral Assemblages in Arctic Ocean Sediments as Climatic Indicator During Glacial/ Interglacial Changes. Rep. on Pol. Res., 251: 309 pp., http://hdl.handle.net/10013/epic.10254.