Marine sediments of about 116 m drilled onshore at Skagen near the northernmost tip of Jutland, Denmark, provides a continuous and detailed palaeoceanographic and palaeoenvironmental record of the last 11 000 14C years in the Skagerrak-Kattegat. The whole Younger Dryas was characterized by an arctic-subarctic environment where the North Jutland Current flows today, instead of being succeeded by a minor climate warming at about 10 600 BP as recorded in the southern Kattegat and in the areas strongly influenced by the Baltic Current and currents along the Swedish west coast. The changes in components of diatom assemblages, combined with previously published benthic foraminiferal data from the present core, reflect a two-step climatic warming and consequently environmental change during the transition from the Younger Dryas to the Preboreal. An abrupt warming of the sea surface waters took place at about 10 100 BP, which resulted from the inflow of warm Atlantic surface water. Summer sea-surface temperature rose about 8°C. It had a great influence on the surface water of the Skagerrak-Kattegat and shallow areas, but had only little effect on the bottom water in the deep parts of the region. Warming of bottom water occurred a few hundred years after the first warming, and is most likely simultaneous with the end of the Preboreal oscillation. A warm period at 7700-5100 BP is registered by diatom assemblages that resulted from the opening of the English Channel because of eustatic sea-level rise, and by larger influence of the Norwegian Coastal Current and currents along the Swedish west coast. A climate cooling was documented at about 5100 BP by acceleration of the South Jutland Current.
Bard, E., Arnold, M., Mangerud, J., Paterne, M., Labeyrie, L.Duprat, J., Mélières, M.-A., Sønstegaard, E. and Duplessy, J.-C.1994: The North Atlantic atmosphere-sea surface 14C gradient during the Younger Dryas climatic event. Earth and Planetary Science Letters126, 275-87.
2.
Berglund, B.E. 1979: The deglaciation of southern Sweden 13,500-10,000 B.P. Boreas 8, 89-118.
3.
Berglund, B.E., Lemdahl, G., Liedberg-Jönsson, B. and Persson, T.1984: Biotic response to climatic changes during the time span 13,000-10,000 B.P. - a case study from SW Sweden. In Mörner, N.-A. and Karlén, W., editors, Climatic changes on a yearly to millennial basis, DordrechtReidel, 25-36.
4.
Bergsten, H.1994: A high-resolution record of Lateglacial and early Holocene marine sediments from southwestern Sweden; with special emphasis on environmental changes close to the Pleistocene-Holocene transition and the influence of fresh water from the Baltic basin. Journal of QuaternaryScience9, 1-12.
5.
Bergsten, H. and Nordberg, K.1992: Late Weichselian marine stratigraphy of the southern Kattegat, Scandinavia: evidence for drainage of the Baltic Ice Lake between 12,700 and 10,300 years BP. Boreas21, 223-52. Björck, S.1981: A stratigraphic study of Late Weichselian deglaciation shore displacement and vegetation history in south-eastern Sweden. Fossils and Strata, 14, 1-93.
6.
Björck, S. and Digerfeldt, G.1984: Climatic changes at Pleistocene/Holocene boundary in the Middle Swedish endmoraine zone, mainly inferred from stratigraphic indications . In Mörner, N.-A. and Karlén, W., editors, Climatic changes on a yearly to millennial basis, Dordrecht: Reidel, 37-56.
7.
Björck, S., Kromer, B., Johnsen, S., Bennike, O., Hammarlund, D., Lemdahl, G., Possnert, G., Rasmussen, T.L., Wohlfarth, B., Hammer, C.U. and Spurk, M.1996: Synchronized terrestrial-atmospheric deglacial records around the North Atlantic. Science274, 1155-60.
8.
Conradsen, K.1995: Late Younger Dryas to Holocene paleoenvironments of the southern Kattegat, Scandinavia. The Holocene5, 447-56.
9.
Conradsen, K. and Heier-Nielsen, S.1995: Holocene paleoceanography and paleoenvironments of the Skagerrak-Kattegat, Scandinavia. Paleoceanography10, 801-13.
10.
Fairbanks, R.G.1989: A 17,000-year glacio-eustatic sea level record: Influence of glacial melting on the Younger Dryas event and deep-ocean circulation . Nature342, 637-42.
11.
Fält, L.-M.1982: Late Quaternary sea-floor deposits off the Swedish west coast, PhD thesis A37, Department of Geology, University of Göteborg and Chalmers University of Technology, Sweden.
12.
Haflidason, H., Sejrup, H.P., Kristensen, D.K. and Johnsen, S.1995: Coupled response of the late glacial climatic shift of northwest Europe reflected in Greenland ice cores: Evidence from the northern North Sea. Geology23, 1059-62.
13.
Harrison, S.P. and Digerfeldt, G.1993: European lakes as palaeohydrological and palaeoclimatic indicators. Quaternary Science Reviews12, 233-48.
14.
Heier-Nielsen, S., Conradsen, K., Heinemeier, J., Knudsen, K.L., Nielsen, H.L., Rud, N. and Sveinbjörnsdottir, A.E.1995: Radiocarbon dating of shells and foraminifera from the Skagen core, Denmark: Evidence of reworking. Radiocarbon37, 119-30.
15.
Hendey, N.I.1964: An introductory account of the smaller algae of British coastal waters. Part V. Bacillariophyceae (diatoms). London : H.M.S.O.
16.
Horner, R.A.1984: Do ice algae produce the spring phytoplankton bloom in seasonally ice-covered water? In Mann, D.G. , editor, Proceeding of the Seventh International Diatom Symposium, Koenigstein: Otto Koeltz Science Publishers, 401-409.
17.
Håkansson, H.1984: The recent diatom succession of Lake Havgårdssjön, south Sweden. In Mann, D.G., editor, Proceeding of the Seventh International Diatom Symposium, Koenigstein: Otto Koeltz Science Publishers , 411-29.
18.
Jansen, J.H.F., van Weering, T.C.E. and Eisma, D.1979: Late Quaternary sedimentation in the North Sea . In Oele, E., Schüttenheim, R.T.E. and Wiggers, A.J. , editors, The Quaternary history of the North Sea, Acta Universitatis Upsaliensis Annum Quingentesimum Celebrantis, 2, Uppsala, Sweden, 175-87.
19.
Jiang, H.1992: Preliminary study on diatom distributions in the surface sediments of the Skagerrak and the Kattegat. In Dennegård, B. and Kuijpers, A., editors, Marine geological environmental investigations in the Skagerrak and northern Kattegat, Department of Marine Geology, University of Göteborg, Sweden.
20.
— 1996: Diatoms from the surface sediments of the Skagerrak and the Kattegat and their relationship to the spatial changes of environmental variables. Journal of Biogeography23, 129-37.
21.
Jiang, H. and Klingberg, F.1997: The transition from the Younger Dryas to the Preboreal: a case study from the Kattegat, Scandinavia. Boreas25, in press.
22.
Jiang, H. and Nordberg, K.1996: Late Weichselian environmental changes of the southern Kattegat, Scandinavia, inferred from diatom records. In Andrews, J.T., Austin, W.E.N. , Bergsten, H. and Jennings, A.E., editors, Late glacial palaeoceanography of north Atlantic margins, London: Geological Society Publishing House, 245-60.
23.
Juggins, S.1992: Diatoms in the Thames Estuary, England: ecology, palaeoecology, and salinity transfer function. Berlin: Gebrüder Borntraeger.
24.
Kang, S.-H. and Fryxell, G.A.1991: Most abundant diatom species in water column assemblages from five leg 119 drill sites in Prydz Bay, Antarctica: distributional Patterns . In Barron, J., Larsen, B. et al., editors, Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 119, 645-66.
25.
Knudsen, K.L., Conradsen, K., Heier-Nielsen, S. and Seidenkrantz, M.-S.1996: Palaeoenvironments in the Skagerrak-Kattegat basin in the eastern North Sea during the last deglaciation . Boreas25, 65-77.
26.
Koç Karpuz, N. and Jansen, E.1992: A high-resolution diatom record of the last deglaciation from the SE Norwegian Sea: documentation of rapid climatic changes. Paleoceanography7, 499-520.
27.
Koç Karpuz N. and Schrader, H.1990: Surface sediment diatom distribution and Holocene paleotemperature variations in the Greenland, Iceland and Norwegian Sea. Paleoceanography5, 557-80.
28.
Kromer, B. and Becker, B.1993: German oak and pine 14C calibration, 7,200-9,439 BC. Radiocarbon35, 125-35.
29.
Kutzbach, J.E. and Webb, T. III1993: Conceptual basis for understanding Late-Quaternary climates. In Wright, H.E. Jr., Kutzbach, J.E. Jr., Webb, T. III, Ruddiman, W.F., Street-Perrott, F.A. and Bartlein, P.J., editors, Global climates since the last glacial maximum, Minneapolis: University of Minnesota Press, 5-11.
30.
Lehman, S.J. and Keigwin, L.D.1992: Sudden changes in North Atlantic circulation during the last deglaciation. Nature356, 757-62.
31.
Lehman, S.J., Jones, G.A., Keigwin, L.D., Andersen, E.S., Butenko, G. and Østmo, S.-R.1991: Initiation of Fennoscandian ice-sheet retreat during the last glaciation. Nature349, 513-16.
32.
Miller, U.1982: Diatoms. In Olausson, E., editor, The Pleistocene/Holocene boundary in southwestern Sweden, Uppsala: Geological Survey of Sweden, 187-210.
33.
Nagy, J. and Qvale, G.1985: Benthic foraminiferas in Upper Quaternary Skagerrak deposits . Norsk Geologisk Tidsskrift65, 107-13.
34.
Nordberg, K.1991: Oceanography in the Kattegat and Skagerrak over the past 8000 years. Paleoceanography6, 461-85.
35.
Olausson, E.1982: The Pleistocene/Holocene boundary in southwestern Sweden . Sveriges Geologiska Undersökning, Series C794, 1-288.
36.
Rodhe, J.1992: Studies of currents and mixing in the Skagerrak . Thesis, Department of Oceanography, University of Göteborg, Sweden.
37.
Sarnthein, M., Win, K., Jung, S.J.A., Duplessy, J.-C., Labeyrie, L., Erlenkeuser, H. and Ganssen, G.1994: Changes in east Atlantic deep-water circulation over the last 30,000 years: eight time slice reconstructions. Paleoceanography9, 209-67.
38.
Stabell, B.1985: Diatoms in Upper Quaternary Skagerrak sediments . Norsk Geologisk Tidsskrift65, 91-95.
39.
Stigebrandt, A.1983: A model for exchange of water and salt between the Baltic and the Skagerrak. Journal ofPhysical Oceanography13, 411-27.
40.
Svansson, A.1975: Physical and chemical oceanography of the Skagerrak and the Kattegat, I, Open sea conditions. Institute of Marine Research Report No. 1, Fishery Board of Sweden, 1-88.
41.
van Weering, T.C.E.1981: Recent sediments and sediment transport in the northern North Sea: Surface sediments of the Skagerrak. Special Publications of the International Association of Sedimentologists 5, 335-59.
