HIGH NORTHERN PALEOLATITUDE JURASSIC-CRETACEOUS PALEOTEMPERATURE VARIATION - NEW DATA FROM KONG-KARLS-LAND, SVALBARD

The traditional view of warm equable global climates in the Mesozoic w ith weakly developed latitudinal temperature gradients has been challe nged by several recent studies. However. reliable high palaeolatitude palaeotemperature data Is still rare. In this study palaeotemperature data, based on oxygen stable isotope palaeothermometry of well preserv ed mid Jurassic to Lower Cretaceous belemnites from Kong Karls Land. S valbard. are presented. These data show cool high latitude marine isot opic palaeotemperatures for endemic species during the Lower to mid Va langinian (7.7 degrees C). which may he compatible with the formation of high latitude ice. Middle Bathonian to Kimmeridgian samples give wa rmer isotopic palaeotemperatures (9.4 degrees C). whilst samples from the Aalenian to Bajocian give isotopic palaeotemperatures which are wa rmer still (12.7 degrees C). Comparison of the Callovian temperatures with those from a mid-latitude location shows them to he warmer than w ould be expected if previous latitudinal temperature gradients are cor rect. This may be due to the ameliorating effect of oceanic heat trans port pole-wards from the Panthalassa Ocean via the South Anyui Ocean. (C) Elsevier Science B.V.