HR: 1340h
AN: OS43A-0983    [Abstracts]
TI: Manganese Cycles as a Stratigraphic Tool in the Arctic Ocean: Reevaluation of Core AO96/12- 1PC Using the new Itrax XRF Core Scanner at Stockholm University
AU: * Lowemark, L A
EM: loewemark@gmail.com
AF: Department of Geology and Geochemistry, Stockholm University, Svante Arrhenius väg 8C, Stockholm, 106 91, Sweden
AU: Jakobsson, M
EM: martin.jakobsson@geo.su.se
AF: Department of Geology and Geochemistry, Stockholm University, Svante Arrhenius väg 8C, Stockholm, 106 91, Sweden
AB: Cyclical variation in the manganese content in key core 96/12-1PC taken during the Arctic Ocean-96 cruise on the Lomonosov Ridge have been interpreted to represent climatically controlled changes in the input of manganese from the Siberian hinterland and/or variations in the intermediate and deep water ventilation of the Arctic basins. It was therefore suggested that these manganese cycles represent warm phases that correlate to marine oxygen isotope stages and, thus, could be used for chronostratigraphic correlation between cores from the central Arctic Ocean where traditional isotope stratigraphy is difficult or impossible to establish due to the lack of calcareous microfossils. Analysis performed on 96/12-1PC using the new Itrax XRF core scanner at Stockholm University confirms these manganese cycles, and first measurements on neighboring cores suggest that these cycles may be correlated over large distances. Moreover, the XRF results confirm the previously suggested strong correlation between sediment color and manganese content. These manganese cycles therefore likely can be used for a first order chronostratigraphic correlation on at least a regional scale in the central Arctic Ocean. However, our XRF results does not rule out that local variations in cycle thicknesses or occurrences well may occur. The hypothesis of that brown manganese rich sediment cycles represent warm phases that can be correlated to marine oxygen stages will be tested further on material to be obtained on the southernmost part of the Lomonosov Ridge during the LOMROG expedition in August-September 2007.
DE: 1065 Major and trace element geochemistry
DE: 1105 Quaternary geochronology
DE: 3022 Marine sediments: processes and transport
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting