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Jan Mayen - Stratigraphic and paleoclimatic reconstructions for the last 1,000 ka BP

Abstract

Marjolaine Sabine¹, Guillaume Boisramé¹, Frédérique Eynaud¹, Sébastien Zaragosi¹, Jacques Giraudeau¹, Elodie Marches², Linda Rossignol¹, Thierry Garlan²

(1) EPOC (Environnements & Paléoenvironnements Océaniques et Continentaux) laboratory -UMR 5805, Bordeaux University, France.
(2) SHOM (Service Hydrographique et Océanographique de la Marine) Brest, France.

The deep-water formation occurs in the Nordic Seas, with a millenial variability. Deep water convection occurs in Jan Mayen island vicinity.

During warm periods, the convection occurs in the vicinity of Jan Mayen Island, and during cold periods, the convection area moves southward, near Iceland. This deep-water formation is essential for the North Atlantic Deep Water (NADW) formation and circulation. Here we present results obtained on a sediment core retrieved from Jan Mayen Island vicinity, which has been studied with a multiproxy approach to determine paleoceanographical and climatological changes over this area during the last 1.2 Ma BP. As shown by the data obtained on foraminifera assemblages, coccolithophorids, Ice-Rafted Detritus (IRD), oxygen isotope values (measured in Neogloboquadrina pachyderma s. and Cibicides wuellestorfi shells), and XRF elemental ratio (bulk sediment measurements), the recovered deposits span a time interval covering MIS 22 to MIS 1. Several muddy beds marked by the absence of microfossils and high IRD contents were observed recurrently in this core, implying a repeated occurrence of harsh conditions, that we attributed to icebergs calving in the southern part of the Nordic Seas. A tentative correlation, done on the basis of oxygen stable isotopic ratios with the reference core LR04 (e.g., Lisiecki & Remo, 2005), provides a preliminary stratigraphical frame detailing the last 1,000 ka BP.

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