Palaeoceanography of the Early Cretaceous of the high latitudes (NE Greenland).

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The view of a generally warm-equable Early Cretaceous greenhouse world is questioned by a rather differentiated climatic scenario with cold snaps, possibly even causing polar ice caps. These contradictory interpretations are partly caused by a lack of data from the high latitudes which should be more sensitive to climatic changes. We therefore propose a multi-proxy approach based in the high latitudes (NE Greenland) to better understand the biotic, palaeoclimatic and palaeoceanographic evolution of the Early Cretaceous (Ryazanian – Barremian). Based on a biostratigraphic zonation (ammonites) we intend to a) establish a detailed multistratigraphic scheme for the Boreal-Arctic based on calcareous nannofossils, ammonites and strontium isotopy, which can be tied into the Tethyan succession, b) reconstruct changes of surface water conditions by evaluating calcareous nannofossil assemblages ecologically, c) use microfloras (calcareous nannofossils) and macrofaunas (ammonites, belemnites) to test the hypothesis of a proto-Golf stream, d) interpret the Ryazanian – Barremian interval of NE Greenland with respect to the enigma of high latitudinal carbonates.