Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-26T05:31:51.664Z Has data issue: false hasContentIssue false
  • English
  • Français

Correlation of Marine 14C Ages from the Nordic Seas with the GISP2 Isotope Record: Implications for 14C Calibration Beyond 25 ka BP

Published online by Cambridge University Press:  18 July 2016

Antje H. L. Voelker ,
Michael Sarnthein ,
Pieter M. Grootes ,
Helmut Erlenkeuser ,
Carlo Laj ,
Alain Mazaud ,
Marie-Josée Nadeau  and
Markus Schleicher
Antje H. L. Voelker
Affiliation:
Geologisch-Paläontologisches Institut, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Michael Sarnthein
Affiliation:
Geologisch-Paläontologisches Institut, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Pieter M. Grootes
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Helmut Erlenkeuser
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Carlo Laj
Affiliation:
Centre des Faibles Radioactivités, Laboratoire mixte CEA-CNRS, Avenue de la Terrasse, F-91198 Gif-sur-Yvette, France
Alain Mazaud
Affiliation:
Centre des Faibles Radioactivités, Laboratoire mixte CEA-CNRS, Avenue de la Terrasse, F-91198 Gif-sur-Yvette, France
Marie-Josée Nadeau
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Markus Schleicher
Affiliation:
Leibniz Labor für Altersbestimmung und Isotopenforschung, Universität Kiel, Olshausenstrasse 40, D-24118 Kiel, Germany
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present two new high-resolution sediment records from the southwestern Iceland and Norwegian Seas that were dated by numerous 14C ages up to 54 14C ka bp. Based on various lines of evidence, the local 14C reservoir effect was restricted to 400–1600 yr. The planktic stable isotope records reveal several meltwater spikes that were sampled with an average time resolution of 50 yr in PS2644 and 130 yr in core 23071 during isotope stage 3. Most of the δ18O spikes correlate peak-by-peak to the stadials and cold rebounds of the Dansgaard-Oeschger cycles in the annual-layer counted GISP2 ice core, with the major spikes reflecting the Heinrich events 1–6. This correlation indicates large fluctuations in the calibration of 14C ages between 20 and 54 14C ka bp. Generally the results confirm the 14C age shifts as predicted by the geomagnetic model of Laj, Mazaud and Duplessy (1996). However, the amplitude and speed of the abrupt decrease and subsequent major increase of our 14C shifts after 45 14C ka bp clearly exceed the geomagnetic prediction near 40–43 and 32–34 calendar (cal) ka bp. At these times, the geomagnetic field intensity minima linked to the Laschamp and the Mono Lake excursions and confirmed by a local geomagnetic record, probably led to a sudden increase in cosmogenic 14C and 10Be production, giving rise to excess 14C in the atmosphere of up to 1200%.

Type
Part 1: Methods
Information
Radiocarbon , Volume 40 , Issue 1: 16th International Radiocarbon Conference 16-20,1997 Groningen , 1997 , pp. 517 - 534
Copyright
Copyright © The American Journal of Science 

References

Andree, M., Oeschger, H., Broecker, W. S., Beavan, N., Klas, M., Mix, A., Bonani, G., Hofmann., H. J., Suter, M., Woelfli, W. and Peng, T.-H. 1986 Limits on the ventilation rate for the deep ocean over the last 12,000 years. Climate Dynamics 1: 53–62.CrossRefGoogle Scholar
Andrews, J. T., Jennings, A. E., Cooper, T., Williams, K. M. and Mienert, J. 1996 Late Quaternary sedimentation along a fjord to shelf (trough) transect, East Greenland (c. 68°N). In Andrews, J. T., Austin, W. E. N., Bergsten, H. and Jennings, A. E., eds., Late Quaternary Palaeoceanography of the North Atlantic Margins. Geological Society Special Publication no. 111, London: 153–166.Google Scholar
Arnold, M., Bard, E., Maurice, P., Valladas, H. and Duplessy, J.-C. 1989 14C Dating with the Gif-sur-Yvette Tandetron accelerator: Status report and study of isotopic fractionation in the sputter ion source. In Long, A., Kra, R. S. and Srdoč, D., eds., Proceedings of the 13th International 14C Conference. Radiocarbon 31(3): 284–291.Google Scholar
Bard, E., Arnold, M., Fairbanks, R. G. and Hamelin, B. 1993 230Th-234U and 14C ages obtained by mass spectrometry on corals. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 191–199.CrossRefGoogle Scholar
Bard, E., Arnold, M., Hamelin, B. and Tisnerat-Iaborde, N. 1998 Radiocarbon calibration by means of mass spectrometric 230Th/234U and 14C ages of corals: An updated data base including samples from Barbados, Mururoa and Tahiti. In Stuiver, M., ed. Calibration 1998. Radiocarbon, in press.Google Scholar
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 Letters 126: 275–287.Google Scholar
Bard, E., Hamelin, B., Fairbanks, R. G. and Zindler, A. 1990 Calibration of the 14C timescale over the past 30,000 years using mass spectrometric U-Th ages from Barbados Corals. Nature 345: 405–410.CrossRefGoogle Scholar
Bauch, D., Carstens, J. and Wefer, G. 1997 Oxygen isotope composition of living Neogloboquadrina pachyderma (sin.) in the Arctic Ocean. Earth and Planetary Science Letters 146: 47–58.CrossRefGoogle Scholar
Beer, J., Johnsen, S. J., Bonani, G., Finkel, R. C., Lang-way, C. C., Oeschger, H., Stauffer, B., Suter, M. and Woelfli, W. 1992 10Be peaks as time markers in polar ice cores. In Bard, E. and Broecker, W. S., eds., The Last Deglaciation: Absolute and Radiocarbon Chronologies. NATO ASI Series I2. Berlin, Springer Verlag: 141–153.CrossRefGoogle Scholar
Berkman, P. A. and Forman, S. L. 1996 Pre-bomb radiocarbon and reservoir correction for calcareous marine species in the Southern Ocean. Geophysical Research Letters 23(4): 363–366.Google Scholar
Bond, G., Broecker, W. S., Johnsen, S. J., McManus, J., Labeyrie, L., Jouzel, J. and Bonani, G. 1993 Correlations between climate records from North Atlantic sediments and Greenland ice. Nature 365: 143–147.Google Scholar
Bond, G. C. and Lotti, R. 1995 Iceberg discharges into the North Atlantic on millennial time scales during the last Glaciation. Science 267: 1005–1010.CrossRefGoogle ScholarPubMed
Bonhommet, N. and Babkine, J. 1967 Sur la presence d'aimantations inversées dans la chaine des Puys. Comptes Rendues de l'Académie des Sciences 264B: 92–94.Google Scholar
Broecker, W. S., Andree, M., Bonani, G., Woelfli, W., Oeschger, H., Klas, M., Mix, A. and Curry, W. 1988 Preliminary estimates for the radiocarbon age of deep water in the glacial ocean. Paleoceanography 3(6): 659–669.Google Scholar
Castagnoli, G. C., Albrecht, A., Beer, J., Bonino, G., Shen, Ch., Callegari, E., Taricco, C., Dittrich-Hannen, B., Kubik, P., Suter, M. and Zhu, G. M. 1995 Evidence for enhanced 10Be deposition in Mediterranean sediments 35 kyr BP. Geophysical Research Letters 22(6): 707–710.CrossRefGoogle Scholar
Channell, J. E. T., Hodell, D. A. and Lehman, B. 1997 Relative geomagnetic paleointensity and δ18O at ODP Site 983 (Gardar Drift, North Atlantic) since 350 ka. Earth and Planetary Science Letters 153: 103–118.Google Scholar
Chappell, J. and Veeh, H. H. 1978 230Th/234U age support of an interstadial sea level of −40m at 30,000 yr BP. Nature 276: 602–604.Google Scholar
Cortijo, E. (ms) 1995 La variabilité climatique rapide dans l'Atlantique Nord depuis 128 000 ans: Relations entre les calottes de glace et l'océan de surface. PhD dissertation, Université de Paris-Sud U.F.R. Scientifique D'Orsay, Paris: 235 p.Google Scholar
Cortijo, E., Labeyrie, L., Vidal, L., Vautravers, M., Chapman, M., Duplessy, J.-C., Elliot, M., Arnold, M., Turon, J.-L. and Auffret, G. 1997 Changes in sea surface hydrology associated with Heinrich event 4 in the North Atlantic Ocean between 40° and 60°N. Earth and Planetary Science Letters 146: 29–45.Google Scholar
Denham, C. R. and Cox, A. 1971 Evidence that the Laschamp event did not occur 13,300–30,400 years ago. Earth and Planetary Science Letters 13: 181–190.Google Scholar
Domack, E. W., Jull, A. J. T., Anderson, J. B., Linick, T. W. and Williams, C. R. 1989 Application of tandem accelerator mass-spectrometer dating to late Pleistocene-Holocene sediments of the East Antarctic continental shelf. Quaternary Research 31: 277–287.CrossRefGoogle Scholar
Edwards, R. L., Beck, J. W., Burr, G. S., Donahue, D. J., Chapell, J. M. A., Bloom, A. L., Druffel, E. R. M. and Taylor, F. W. 1993 A large drop in atmospheric 14C/12C and reduced melting in the Younger Dryas, documented with 230Th ages of corals. Science 260: 962–968.Google Scholar
Frank, M., Schwarz, B., Baumann, S., Kubik, P. W., Suter, M. and Mangini, A. 1997 A 200 kyr record of cosmogenic radionuclide production rate and geomagnetic field intensity from 10Be in globally stacked deep-sea sediments. Earth and Planetary Science Letters 149: 121–129.Google Scholar
Fronval, T., Jansen, E., Bloemendal, J. and Johnsen, S. 1995 Oceanic evidence for coherent fluctuations in Fennoscandian and Laurentide ice sheets on millennium timescales. Nature 374: 443–446.Google Scholar
Geyh, M. A. and Schlüchter, C. 1998 Calibration of the 14C time scale beyond 22,000 BP. Radiocarbon, this issue.CrossRefGoogle Scholar
Gordon, J. E. and Harkness, D. D. 1992 Magnitude and geographic variation of the radiocarbon content in Antarctic marine life: Implications for reservoir corrections in radiocarbon dating. Quaternary Science Reviews 11: 697–708.Google Scholar
Goslar, T., Arnold, M., Bard, E., Kuc, T., Pazdur, M. F., Ralska-Jasiewiczowa, M., Rózanski, K., Tisnerat, N., Walanus, A., Wicik, B. and Wieckowski, K. 1995 High concentration of atmospheric 14C during the Younger Dryas cold episode. Nature 377: 414–417.CrossRefGoogle Scholar
Grönvold, K., Oskarsson, N., Johnsen, S. J., Clausen, H. B., Hammer, C. U., Bond, G. and Bard, E. 1995 Ash layers from Iceland in the Greenland GRIP ice core correlated with oceanic and land sediments. Earth and Planetary Science Letters 135: 149–155.Google Scholar
Grootes, P. M. and Stuiver, M. 1997 18O/16O variability in Greenland snow and ice with 10-3 to 105 year time resolution. Journal of Geophysical Research: 102 (C12): 26,455–26,470.CrossRefGoogle Scholar
Haflidason, H., Seirup, H. P. and Kristensen, D. K. 1996 Quantification of the 14C difference between terrestrial and marine environments during the Younger Dryas and the Holocene period in the North Atlantic region. Eos Transactions AGU 77(46), Fall Meeting Supplement: F303.Google Scholar
Hopkins, T. S. 1991 The GIN Seas–A synthesis of its physical oceanography and literature review 1972–1985. Earth-Science Reviews 30: 175–318.Google Scholar
Johnsen, S. J., Clausen, H. B., Dansgaard, W., Fuhrer, K., Gundestrup, N., Hammer, C. U., Iversen, P., Jouzel, J., Stauffer, B. and Steffensen, J. P. 1992 Irregular glacial interstadials recorded in a new Greenland ice core. Nature 359: 311–313.Google Scholar
Kitagawa, H. and van der Plicht, J. 1997 A 40,000-year varve chronology from Lake Suigetsu, Japan: Extension of the 14C Calibration Curve. Radiocarbon, this issue.CrossRefGoogle Scholar
Kromer, B. and Becker, B. 1993 German oak and pine 14C calibration, 7200–9439 BC. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 125–135.Google Scholar
Laj, C., Mazaud, A. and Duplessy, J.-C. 1996 Geomagnetic intensity and 14C abundance in the atmosphere and ocean during the past 50 kyr. Geophysical Research Letters 23(16): 2045–2048.CrossRefGoogle Scholar
Larsen, B. 1983 Geology of the Greenland-Iceland ridge in the Denmark Strait. In Bott, M. H., Saxov, S., Talwani, M. and Thiede, J., eds., Structure and Development of the Greenland-Scotland Ridge: New Methods and Concepts. New York, Plenum Press: 425–444.Google Scholar
Lehman, B., Laj, C., Kissel, C., Mazaud, A., Paterne, M. and Labeyrie, L. 1996 Relative changes of the geomagnetic field intensity during the last 280 kyr from piston cores in the Azores area. Physics of the Earth and Planetary Interiors 93: 269–284.Google Scholar
Liddicoat, J. C. 1992 Mono Lake excursion in Mono Basin, California, and at Carson Sink and Pyramid Lake, Nevada. Geophysical Journal International 108: 442–452.Google Scholar
Mackensen, A., Sejrup, H. P. and Jansen, E. 1985 The distribution of living benthic foraminifera on the continental slope and rise off southwest Norway. Marine Micropaleontology 9: 275–306.CrossRefGoogle Scholar
Malmberg, S. A. 1984 Hydrographic conditions in the East Icelandic Current and sea ice in North Icelandic waters, 1970–1980. In Meincke, J., Otto, L., Lee, A. J. and Dickson, R. R., eds., Hydrobiological Variability in the North Atlantic and Adjacent Seas. Rapports et procès-verbaux des Réunions 185. Copenhagen, Conseil international pour l'exploration de la mer: 170–178.Google Scholar
Malmberg, S. A. and Kristmannsson, S. S. 1992 Hydrographic conditions in Icelandic waters, 1980–1989. In Dickson, R. R., Mälkki, P., Radach, G., Saetre, R. and Sissenwine, M. P., eds., Hydrobiological variability in the ICES Area, 1980–1989. ICES Marine Science Symposia 195: 76–92.Google Scholar
Malmberg, S. A. and Stefansson, U. 1972 Recent changes in the water masses of the East Icelandic Current. In Lee, A. J. and Charnock, H., eds., Physical Variability in the North Atlantic. Rapports et procès-verbaux des Réunions 162. Copenhagen, Conseil international pour l'exploration de la mer:: 195–200.Google Scholar
McHargue, L. R., Damon, P. E. and Donahue, D. J. 1995 Enhanced cosmic-ray production of 10Be coincident with the Mono Lake and Laschamp geomagnetic excursions. Geophysical Research Letters 22(5): 659–662.CrossRefGoogle Scholar
McIntyre, A. and Molfino, B. 1996 Forcing of Atlantic Equatorial and subpolar millennial cycles by precession. Science 214: 1867–1870.CrossRefGoogle Scholar
Meese, D. A., Alley, R. B., Gow, A. J., Grootes, P. M., Mayewski, P. A., Ram, M., Taylor, K. C., Waddington, E. D. and Zielinski, G. A. 1994 Preliminary depth-age scale of the GISP2 ice core. CRREL Special Report 94–1, Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire: 66 p.Google Scholar
Nadeau, M.-J., Schleicher, M., Grootes, P. M., Erlenkeuser, H., Gottdang, A., Mous, D. J. W., Sarnthein, J. M. and Willkomm, H. 1997 The Leibniz-Labor AMS facility at the Christian-Albrechts University, Kiel, Germany. Nuclear Instruments and Methods in Physics Research B123: 22–30.CrossRefGoogle Scholar
Niessen, F., Grobe, H., Kipfstuhl, J. and Voelker, A. H. L. 1996 High resolution records of sediment-physical properties from the Iceland Sea: Implications for rapid oceanic variability between 10 and 85 ka. Eos Transactions AGU 77(46), Fall Meeting Supplement: F24.Google Scholar
Olafsdóttir, Th. 1975 Jökulgardur a sjavarbotni ut af Breidafirdi (A moraine ridge on the Iceland shelf west of Breidafjördur) . Natturufraedingurinn 45: 31–36.Google Scholar
Plummer, M. A., Phillips, F. M., Fabryka-Martin, J., Turin, H. J., Wigand, P. E. and Sharma, P. 1997 Chlorine-36 in fossil rat urine: An archive of cosmogenic nuclide deposition during the past 40,000 years. Science 277: 538–541.Google Scholar
Raisbeck, G. M., Yiou, F., Bourles, D., Lorius, C., Jouzel, J. and Barkov, N. I. 1987 Evidence for two intervals of enhanced 10Be deposition in Antarctic ice during the last glacial period. Nature 326: 273–277.Google Scholar
Rasmussen, T. L., Thomsen, E., Labeyrie, L. and van Weering, T. C. E. 1996a Circulation changes in the Faeroe-Shetland Channel correlating with cold events during the last glacial period (58–10 ka). Geology 24(10): 937–940.Google Scholar
Rasmussen, T. L., Thomsen, E., van Weering, T. C. E. and Labeyrie, L. 1996b Rapid changes in surface and deep water conditions at the Faeroe margin during the last 58,000 years. Paleoceanography 11(6): 757–771.CrossRefGoogle Scholar
Robinson, C., Raisbeck, G. M., Yiou, F., Lehman, B. and Laj, C. 1995 The relationship between 10Be and geomagnetic field strength records in central North Atlantic sediments during the last 80 ka. Earth and Planetary Science Letters 136: 551–557.Google Scholar
Ruddiman, W. F. 1977 Late Quaternary deposition of ice-rafted sand in the subpolar North Atlantic (lat. 40° to 65°N). Geological Society of America Bulletin 88: 1813–1827.2.0.CO;2>CrossRefGoogle Scholar
Samtleben, C., Schäfer, P., Andruleit, H., Baumann, A., Baumann, K.-H., Kohly, A., Matthiessen, J., Schröder-Ritzrau, A. and Synpal Working Group 1995 Plankton in the Norwegian-Greenland Sea: From living communities to sediment assemblages - an actualistic approach. Geologische Rundschau 84: 108–136.Google Scholar
Sarnthein, M., Jansen, E., Weinelt, M., Arnold, M., Duplessy, J.-C., Erlenkeuser, H., Flatoy, A., Johannessen, G., Johannessen, T., Jung, S., Koc, N., Labeyrie, L., Maslin, M., Pflaumann, U. and Schulz, H. 1995 Variations in Atlantic surface ocean paleoceanography, 50–80°N: A time-slice record of the last 30,000 years. Paleoceanography 10(6): 1063–1094.Google Scholar
Schleicher, M., Grootes, P. M., Nadeau, M.-J. and Schoon, A. 1998 The carbonate 14C background and its components at the Leibniz AMS facility. Radiocarbon, this issue.Google Scholar
Schramm, A., Stein, M. and Goldstein, S. L. 1996 U-series and 14C dating of Lake Lisan (Paleo- Dead Sea) sediments: Implications for 14C time scale calibration and relation to global paleoclimate. Eos Transactions AGU 77(46), Fall Meeting Supplement: F303.Google Scholar
Schramm, A., Stein, M. and Goldstein, S. L. 1997 U-series and 14C dating of Lake Lisan (Paleo-Dead Sea) sediments and absolute calibration of the 14C time scale. Terra Nova 9, Abstract supplement no. 1: 629.Google Scholar
Seidov, D., Sarnthein, M., Stattegger, K., Prien, R. and Weinelt, M. 1996 North Atlantic ocean circulation during the last glacial maximum and subsequent meltwater event: A numerical model. Journal of Geophysical Research 101(C7): 16,305–16,332.Google Scholar
Simstich, J., Sarnthein, M., Erlenkeuser, H. and Schiebel., R. (ms) Differential calcification habitats of planktonic foraminifers in the Nordic Seas: δ18O records of the thermocline. In preparation.Google Scholar
Stefansson, U. 1962 North Icelandic Waters. Rit Fiskideildar 3: 269 p.Google Scholar
Stocker, T. F. and Wright, D. G. 1998 The Effect of a succession of ocean ventilation changes on 14C. Radiocarbon, this issue.CrossRefGoogle Scholar
Stuiver, M. and Braziunas, T. F. 1993 Modeling atmospheric 14C influences and 14C ages of marine samples to 10,000 BC. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 137–189.CrossRefGoogle Scholar
Stuiver, M. and Reimer, P. J. 1993 Extended 14C data base and revised CALIB 3.0 14C age calibration program. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 215–230.CrossRefGoogle Scholar
Swift, J. H. and Aagaard, K. 1981 Seasonal transitions and water mass formation in the Iceland and Greenland seas. Deep-Sea Research 28A(10): 1107–1129.Google Scholar
Trauth, M. H., Sarnthein, M. and Arnold, M. 1997 Bioturbational mixing depth and carbon flux at the seaf-loor. Paleoceanography 12(3): 517–526.Google Scholar
Vinje, T. E. 1977 Sea ice conditions in the European sector of the marginal seas of the Arctic, 1966–1975. Norsk Polarinstitutt Årbok: 163–174.Google Scholar
Vlag, P., Thouveny, N., Wiliamson, D., Rochette, P. and Ben-Atig, F. 1996 Evidence for a geomagnetic excursion recorded in the sediments of Lac St. Front, France: A link with the Laschamp excursion? Journal of Geophysical Research 101(B12): 28,211–28,230.Google Scholar
Voelker, A. H. L., Sarnthein, M. and Erlenkeuser, H. 1996 80 000 years of millennial climate oscillations off Northern Iceland and the history of water mass exchange across the Denmark Strait. Eos Transactions AGU 77(17), Spring Meeting Supplement: S165.Google Scholar
Voelker, A. H. L., Sarnthein, M., Erlenkeuser, H., Grootes, P. and Nadeau, M.-J. 1997 Meltwater spikes in the Nordic Seas: Are they triggering the Dansgaard-Oeschger climate oscillations? Terra Nova 9, Abstract supplement no. 1: 209.Google Scholar
Vogel, J. C. 1983 14C variations during the Upper Pleistocene. In Stuiver, M. and Kra, R., eds., Proceedings of the 11th International 14C Conference. Radiocarbon 25(2): 213–218.Google Scholar
Vogel, J. C. and Kronfeld, J. 1997 Calibration of radiocarbon dates for the late Pleistocene using U/Th dates on stalagmites. Radiocarbon 39(1): 27–32.Google Scholar
Vogt, P. R., Johnson, G. L. and Kristjansson, L. 1980 Morphology and magnetic anomalies north of Iceland. In Jacoby, W., Björnsson, A. and Möller, D., eds., Iceland: Evolution, active tectonics, and structure. Journal of Geophysics 47: 67–80.Google Scholar
Weeks, R., Laj, C., Endignoux, L., Fuller, M., Roberts, A., Manganne, R., Blanchard, E. and Goree, W. 1993 Improvements in long-core measurement techniques: Applications in palaeomagnetism and palaeoceanography. Geophysical Journal International 114: 651–662.Google Scholar
Weinelt, M., Sarnthein, M., Pflaumann, U., Schulz, H., Jung, S. and Erlenkeuser, H. 1996 Ice-free Nordic Seas during the last glacial maximum? Potential sites of deepwater formation. Palaeoclimates 1: 283–309.Google Scholar
Wilson, A. T. 1995 Application of AMS 14C dating to ice core research. In Cook, G. T., Harkness, D. D., Miller, B. F. and Scott, E. M., eds., Proceedings of the 15th International 14C Conference. Radiocarbon 37(2): 637–641.Google Scholar
Wu, G. and Hillaire-Marcel, C. 1994 Accelerator mass spectrometry radiocarbon stratigraphies in deep Labrador Sea cores: Paleoceanographic implications. Canadian Journal of Earth Sciences 31: 28–47.Google Scholar
Yiou, F., Raisbeck, G. M., Baumgartner, S., Beer, J., Hammer, C., Johnsen, S., Jouzel, J., Kubik, P. W., Lestringuez, J., Stievenard, M., Suter, M. and Yiou, P. 1997 Beryllium 10 in the Greenland Ice Core Project ice core at Summit, Greenland. Journal of Geophysical Research: 102 (C12): 26,783–26,794.Google Scholar
Zielinski, G. A., Mayewski, P. A., Meeker, L. D., Whitlow, S. and Twickler, M. S. 1996 A 110,000 year record of explosive volcanism from the GISP2 (Greenland) ice core. Quaternary Research 45: 109–118.Google Scholar