Late Quaternary evolution of sediment provenances in the Central Arctic Ocean : mineral assemblage, trace element composition and Nd and Pb isotope fingerprints of detrital fraction from the Northern Mendeleev Ridge

Mineral assemblage, trace element content and Nd and Pb isotope signatures were analysed on the fine fraction (<20 μm) of sedimentary records from the Northern Mendeleev Ridge in the Central Arctic Ocean. Our aim was to identify the detrital particle provenance and to interpret the changes over the past ∼250 ka in the relative contribution of the different source-areas in relation to paleoenvironmental conditions. The clay mineral assemblage and the Nd and Pb isotope signatures depict systematic changes over the Late Quaternary. The bulk mineralogy exhibits increases in the relative contribution of carbonate minerals vs. silicates in interglacial/deglacial intervals. In glacial intervals, the mineral assemblage of the <20 μm fraction is characterised by an enrichment in kaolinite, counterbalanced by a decrease in illite. The Nd and Pb isotope signatures of