Late Quaternary evolution of sediment provenances in the Central

• Published in: Quaternary Science Reviews
• Main Authors: Fagel, Nathalie, Not, Christelle, Gueibe, Jonathan, Mattielli, Nadine
• Other Authors: MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
• Format: Article in Journal/Newspaper
• Language: English
• Published: Pergamon Press - An Imprint of Elsevier Science 2014
• Subjects: Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; Arctic; Arctic Ocean; Mackenzie River; Canada; Central Arctic; Chukotka; lena river; Mackenzie river; Siberia
• Online Access: https://orbi.uliege.be/handle/2268/163582; https://doi.org/10.1016/j.quascirev.2013.12.011

peer reviewed Mineral assemblage, trace element content and Nd and Pb isotope signatures were analysed on the fine fraction (<20 mm) of sedimentary records from the Northern Mendeleev Ridge in the Central Arctic Ocean. Our aimwas to identify the detrital particle provenance and to interpret the changes over the past w250 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 mm fraction is characterised by an enrichment in kaolinite, counterbalanced by a decrease in illite. The Nd and Pb isotope signatures of <20 mm fraction are interpreted using a three end-member mixing model, involving crustal supplies from North America and Canada, from the Siberian margin and some from volcanic material. A compilation of geochemical signatures of geological terraines surrounding the Arctic Ocean allowed each end-member to be assigned a representative signature, averaging the signal of the eroded terraines. The Suspended Particulate Matter (SPM) of the MacKenzie River represents an average signature of the sedimentary supplies delivered from the North American platform and Canadian margin. The SPM of the Lena River reflects the mean sedimentary signature of the Siberian platform. The Okhotsh-Chukotka province from the Eastern border of Siberia is identified as the most probable volcanic source. Late Quaternary evolution of the estimated relative contribution of the three end-members confirms that the sediment provenances in the Central Arctic Ocean remain close to the current conditions during past interglacials/deglacials MIS1e3, MIS5/TII and MIS7/TIII. In contrast, glacial conditions (MIS4 and MIS6) record minimum supplies from the American margin, ...