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Cyclical variations in colour and Mn content in sediment cores from the central Arctic Ocean are believed to represent climatically controlled changes in the input of Mn that correspond to interglacial phases, and therefore 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. Here we present a correlation between cores primarily from the Lomonosov Ridge based on Mn cycles and distinct excursions in other elements. The measurements were performed on material from the Arctic Ocean 96 and LOMROG'07 expeditions using the new Itrax X-ray fluorescence scanner at Stockholm University. The Itrax scanner rapidly measures a wide range of elements directly from split sediment cores. Elements from aluminum to uranium can be measured with an unprecedented spatial resolution of 0.2 mm, at detection limits in the ppm to permil-range for many elements. This possibility of making fast, non-destructive, high-resolution measurements of geochemical variations in the sediment opens up the possibility to characterize and map individual layers over large geographical distances. Measurements that would have taken months with traditional techniques can be performed in days with the Itrax scanner.
Generally, Mn-cycles are distinct and easily correlated between the cores in the upper part of the cores, approximately corresponding to the last glacial cycle. Below this interval hiatuses and variations in sedimentation rates make unambiguous correlation considerably more difficult although the general pattern shows large similarities between the cores. Using distinct event markers such as apparently basin wide abrupt fluctuations in e.g. Fe and Ti, several fix points can be made to facilitate the correlation of the deeper intervals, thus over bridging the difficulties caused by disturbances in the background sedimentation.
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