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Radiocarbon calibration beyond 20,000 14C yr B.P. by means of planktonic foraminifera of the Iberian Margin

Published online by Cambridge University Press:  20 January 2017


We present a new set of 14C ages obtained by accelerator mass spectrometry (AMS) on planktonic foraminifera from a deep-sea core collected off the Iberian Margin (MD952042). This site, at 37°N, is distant from the high-latitude zones where 14C reservoir age is large and variable. Many independent proxies — alkenones, magnetic susceptibility, ice-rafted debris, foraminifera stable isotopes, abundances of foraminifera, pollen, and dinoflagellates — show abrupt changes correlative with Dansgaard-Oeschger and Heinrich events of the last glacial period. The good stratigraphic agreement of all proxies — from the fine to the coarse-size fractions — indicates that the foraminifera 14C ages are representative of the different sediment fractions. To obtain reliable 14C ages of foraminifera beyond 20,000 14C yr B.P. we leached the shells prior to carbonate hydrolysis and subsequent analysis. For a calendar age scale, we matched the Iberian Margin profile with that of Greenland Summit δ18O. Both are proxies for temperature, which in models varies synchronously in the two areas. The match creates no spurious jumps in sedimentation rate and requires only a limited number of tie points. Except for ages older than 40,000 14C yr B.P. Greenland's GISP2 and GRIP records yield similar calendars. The 14C and imported calendar ages of the Iberian Margin record are then compared to data — from lacustrine annual varves and from corals and speleothems dated by U–Th — previously used to extend the calibration beyond 20,000 14C yr B.P. The new record follows a smooth pattern between 23,000 and 50,000 cal yr B.P. We find good agreement with the previous data sets between 23,000 and 31,000 cal yr B.P. In the interval between 33,000 and 41,000 cal yr B.P. for which previous records disagree by up to 5000 cal yr, the Iberian Margin record closely follows the polynomial curve that was previously defined by an interpolation of the coral ages and runs between the Lake Suigetsu and the Bahamian speleothem data sets.

Research Article
University of Washington

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Austin, W.E.N., Bard, E., Hunt, J.B., Kroon, D., Peacock, J.D., (1995). The 14C age of the Icelandic Vedde Ash: implications for Younger Dryas marine reservoir age corrections. Radiocarbon. 37, 5362.CrossRefGoogle Scholar
Bard, E., (1988). Correction of accelerator mass spectrometry 14C ages measured in planktonic foraminifera: paleoceanographic implications. Paleoceanography. 3, 635645.CrossRefGoogle Scholar
Bard, E., (1997). Nuclide production by cosmic rays during the last ice age. Science. 277, 532533.CrossRefGoogle Scholar
Bard, E., (2001). Paleoceanographic implications of the difference in deep-sea sediment mixing between large and fine particles. Paleoceanography. 16, 235239.CrossRefGoogle Scholar
Bard, E., Arnold, M., Maurice, P., Duprat, J., Moyes, J., Duplessy, J.C., (1987a). Retreat velocity of the North Atlantic polar front during the last deglaciation determined by 14C accelerator mass spectrometry. Nature. 328, 791794.CrossRefGoogle Scholar
Bard, E., Arnold, M., Duprat, J., Moyes, J., Duplessy, J.C., (1987b). Reconstruction of the last deglaciation: deconvolved records of δ18O profiles, micropaleontological variations and accelerator mass spectrometric 14C dating. Climate Dynamics. 1, 101112.CrossRefGoogle Scholar
Bard, E., Hamelin, B., Fairbanks, R.G., Zindler, A., (1990a). Calibration of the 14C timescale over the past 30,000 years using mass spectrometric U–Th ages from Barbados corals. Nature. 345, 405410.CrossRefGoogle Scholar
Bard, E., Hamelin, B., Fairbanks, R.G., Zindler, A., Arnold, M., Mathieu, G., (1990b). U/Th and 14C ages of corals from Barbados and their use for calibrating the 14C timescale beyond 9000 years B.P. Nuclear Instruments and Methods B. 52, 461468.CrossRefGoogle Scholar
Bard, E., Arnold, M., Mangerud, M., Paterne, M., Labeyrie, L., Duprat, J., Mélières, M.A., Sonstegaard, E., Duplessy, J.C., (1994). The North Atlantic atmosphere-sea surface 14C gradient during the Younger Dryas climatic event. Earth and Planetary Science Letters. 126, 275287.CrossRefGoogle Scholar
Bard, E., Raisbeck, G., Yiou, F., Jouzel, J., (1997). Solar modulation of cosmogenic nuclide production over the last millennium: comparison between 14C and 10Be records. Earth and Planetary Science Letters. 150, 453462.CrossRefGoogle Scholar
Bard, E., Arnold, M., Hamelin, B., Tisnerat-Laborde, N., Cabioch, G., (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. Radiocarbon. 40, 10851092.CrossRefGoogle Scholar
Bard, E., Rostek, F., Turon, J.L., Gendreau, S., (2000). Hydrological impact of Heinrich events in the subtropical northeast Atlantic. Science. 289, 13211324.CrossRefGoogle Scholar
Baumgartner, S., Beer, J., Suter, M., Dittrich-Hannen, B., Synal, H.-A., Kubik, P.W., Hammer, C., Johnsen, S., (1997). Chlorine 36 fallout in the Summit Greenland Ice Core Project ice core. Journal of Geophysical Research. 102, C12 2665926662.CrossRefGoogle Scholar
Beck, J.W., Richards, D.A., Edwards, R.L., Silverman, B.W., Smart, P.L., Donahue, D.J., Hererra-Osterheld, S., Burr, G.S., Calsoyas, L., Jull, A.J.T., Biddulph, D., (2001). Extremely large variations of atmospheric C-14 concentration during the last glacial period. Science. 292, 24532458.CrossRefGoogle Scholar
Bond, G.C., Broecker, W., Johnsen, S., McManus, J., Labeyrie, L., Jouzel, J., Bonani, G., (1993). Correlations between climate records from North Atlantic sediments and Greenland ice. Nature. 365, 143147.CrossRefGoogle Scholar
Bond, G., Showers, W., Cheseby, M., Lotti, R., Almasi, P., deMenocal, P., Priore, P., Cullen, H., Hajdas, I., Bonani, G., (1997). A pervasive millennial-scale cycle in North Atlantic Holocene and glacial climates. Science. 278, 12571266.CrossRefGoogle Scholar
Bonhommet, N., Zähringer, J., (1969). Paleomagnetism and potassium argon determinations of the Laschamp geomagnetic polarity event. Earth and Planetary Science Letters. 6, 4346.CrossRefGoogle Scholar
Brassell, S.C., Eglinton, G., Marlowe, I.T., Pflaumann, U., Sarnthein, M., (1986). Molecular stratigraphy: a new tool for climatic assessment. Nature. 320, 129133.CrossRefGoogle Scholar
Broecker, W.S., Peng, T.H., (1982). Tracers in the Sea. Eldigio Press, Palisades NY.Google Scholar
Broecker, W.S., Mix, A., Andree, M., Oeschger, H., (1984). Radiocarbon measurements on coexisting benthic and planktic foraminifera shells: potential for reconstructing ocean ventilation times over the 20,000 years. Nuclear Instruments and Methods B. 5, 331339.CrossRefGoogle Scholar
Broecker, W.S., Peng, T.H., Trumbore, S., Bonani, G., Wölfli, W., (1990). The distribution of radiocarbon in the glacial ocean. Global Biogeochemical Cycles. 4, 103117.CrossRefGoogle Scholar
Brown, L., Cook, G.T., MacKenzie, A.B., Thomson, J., (2001). Radiocarbon age profiles and size dependency of mixing in Northeast Atlantic sediments. Radiocarbon. 43, 929937.CrossRefGoogle Scholar
Burr, G.S., Beck, J.W., Taylor, F.W., Recy, J., Edwards, R.L., Cabioch, G., Correge, T., Donahue, D.J., O'Malley, J.M., (1998). A high-resolution radiocarbon calibration between 11,700 and 12,400 calendar years B.P. derived from Th-230 ages of corals from Espiritu Santo Island, Vanuatu. Radiocarbon. 40, 10931105.CrossRefGoogle Scholar
Carcaillet, J., Bourlès, D.L., Thouveny, N., Arnold, M., (2004). An authigenic 10Be/9Be record of the geomagnetic moment variations and excursions over the last 300 kyr. Earth and Planetary Science Letters(in press).CrossRefGoogle Scholar
Cayre, O., Lancelot, Y., Vincent, E., Hall, M.A., (1999). Paleoceanographic reconstructions from planktonic foraminifera off the Iberian Margin: temperature, salinity, and Heinrich Events. Paleoceanography. 14, 384396.CrossRefGoogle Scholar
Cross, M., (compiler), (1997). Greenland summit ice cores. Boulder, CO: National Snow and Ice Data Center in association with the World Data Center for Paleoclimatology at NOAA-NGDC, and the Institute of Arctic and Alpine Research. CD-ROM.Google Scholar
Dansgaard, W., Johnsen, S.J., Clausen, H.B., Dahl-Jensen, D., Gundestrup, N.S., Hammer, C.U., Hvidberg, C.S., Steffensen, J.P., Sveinbjörnsdottir, A.E., Jouzel, J., Bond, G., (1993). Evidence for general instability of past climate from a 250-kyr ice-core record. Nature. 364, 218220.CrossRefGoogle Scholar
Duplessy, J.C., Bard, E., Labeyrie, L., Duprat, J., Moyes, J., (1993). Oxygen isotope records and salinity changes in the northeastern Atlantic during the last 18000 yrs. Paleoceanography. 8, 341350.CrossRefGoogle Scholar
Frank, M., (2000). Comparison of cosmogenic radionuclide production and geomagnetic field intensity over the last 200,000 years. Philosophical Transactions of the Royal Society of London Series A. 358, 10891107.CrossRefGoogle Scholar
Finkel, R.C., Nishiizumi, K., (1997). 10Be concentrations in the Greeland Ice Sheet Project 2 ice core from 3–40 ka. Journal of Geophysical Research. 102, C12 2669926706.CrossRefGoogle Scholar
Ganopolski, A., Rahmstorf, S., (2001). Rapid changes of glacial climate simulated in a coupled climate model. Nature. 409, 153158.CrossRefGoogle Scholar
Goslar, T., (2001). Absolute production of radiocarbon and the long-term trend of atmospheric radiocarbon. Radiocarbon. 43, 743749.CrossRefGoogle Scholar
Goslar, T., Arnold, M., Bard, E., Kuc, T., Pazdur, M.F., Ralska-Jasiewiczowa, M., Rozanski, K., Tisnerat, N., Walanus, A., Wicik, B., Wieckowski, K., (1995). High concentration of atmospheric 14C during the Younger Dryas cold Episode. Nature. 377, 414417.CrossRefGoogle Scholar
Hajdas, I., Ivy, S.D., Beer, J., Bonani, G., Imboden, D., Lotter, A.F., Sturm, M., Suter, M., (1993). AMS radiocarbon dating and varve chronology of Lake Soppensee — 6000 to 12000 C-14 Years B.P. Climate Dynamics. 9, 107116.CrossRefGoogle Scholar
Hajdas, I., Zolitschka, B., Ivy-Ochs, S.D., Beer, J., Bonani, G., Leroy, S.A.G., Negendank, J.W., Ramrath, M., Suter, M., (1995). AMS radiocarbon dating of annually laminated sediments from Lake Holzmaar, Germany. Quaternary Science Reviews. 14, 137143.CrossRefGoogle Scholar
Hamelin, B., Bard, E., Zindler, A., Fairbanks, R.G., (1991). 234U/238U mass spectrometry of corals: how accurate is the U–Th age of the last interglacial period. Earth and Planetary Science Letters. 106, 169180.CrossRefGoogle Scholar
Heier-Nielsen, S., Conradsen, K., Heinemeier, J., Knudsen, K.L., Nielsen, H.L., Rud, N., Sveinbjornsdottir, A.E., (1995). Radiocarbon dating of shells and foraminifera from the Skagen Core, Denmark: evidence of reworking. Radiocarbon. 37, 119130.CrossRefGoogle Scholar
Heinrich, H., (1988). Origin and consequences of cycling ice rafting in the Northeast Atlantic Ocean during the past 130,000 years. Quaternary Research. 29, 142152.CrossRefGoogle Scholar
Hughen, K.A., Overpeck, J.T., Lehman, S.J., Kashgarian, M., Peterson, L.C., Alley, R., Sigman, D., (1998). Deglacial changes in ocean circulation from an extended radiocarbon calibration. Nature. 391, 6568.CrossRefGoogle Scholar
Johnsen, S.J., Dahl-Jensen, D., Gundestrup, N., Steffensen, J.P., Clausen, H.B., Miller, H., Masson-Delmotte, V., Sveinbjornsdottir, A.E., White, J., (2001). Oxygen isotope and palaeotemperature records from six Greenland ice-core stations: Camp Century, Dye-3, GRIP, GISP2, Renland and NorthGRIP. Journal of Quaternary Science. 16, 299307.CrossRefGoogle Scholar
Keffer, T., Martinson, D.G., Corliss, B.H., (1988). The position of the Gulf-Stream during Quaternary glaciations. Science. 241, 440442.CrossRefGoogle ScholarPubMed
Kitagawa, H., van der Plicht, J., (1998). Atmospheric radiocarbon calibration to 45,000 yr B.P.: late glacial fluctuations and cosmogenic isotope production. Science. 279, 11871190.CrossRefGoogle ScholarPubMed
Kitagawa, H., van der Plicht, J., (2000). Atmospheric radiocarbon calibration beyond 11,900 cal B.P. from Lake Suigetsu laminated sediments. Radiocarbon. 42, 369380.CrossRefGoogle Scholar
Kitagawa, H., Fukuzawa, H., Nakamura, T., Okamura, M., Takemura, K., Hayashida, A., Yasuda, Y., (1995). AMS 14C dating of varved sediments from Lake Suigetsu, Central Japan and atmospheric 14C change during the Late Pleistocene. Radiocarbon. 37, 371378.CrossRefGoogle Scholar
Kromer, B., Spurk, M., (1998). Revision and tentative extension of the tree-ring based 14C calibration, 9200-11,855 Cal B.P. Radiocarbon. 40, 11171125.CrossRefGoogle Scholar
Libby, W.F., (1952). Radiocarbon Dating. University of Chicago Press, Chicago.Google ScholarPubMed
Manabe, S., Stouffer, R.J., (1995). Simulation of abrupt climate change induced by fresh-water input to the North-Atlantic Ocean. Nature. 378, 165167.CrossRefGoogle Scholar
Manabe, S., Stouffer, R.J., (1997). Coupled ocean-atmosphere model response to freshwater input: comparison to Younger Dryas event. Paleoceanography. 12, 321336.CrossRefGoogle Scholar
Mazaud, A., Laj, C., Bard, E., Arnold, M., Tric, E., (1991). Geomagnetic field control of 14C production over the last 80 ky: implications for the radiocarbon time-scale. Geophysical Research Letters. 18, 18851888.CrossRefGoogle Scholar
McNichol, A.P., Jull, A.J.T., Burr, G.S., (2001). Converting AMS data to radiocarbon values: considerations and conventions. Radiocarbon. 43, 313320.CrossRefGoogle Scholar
Mollenhauer, G., Eglinton, T.I., Ohkouchi, N., Schneider, R.R., Mueller, P.J., Grootes, P.M., Ruellkotter, J., (2003a). Asynchronous alkenone and foraminifera records from the Benguela Upwelling System. Geochimica et Cosmochimica Acta. 67, 21572171.CrossRefGoogle Scholar
Mollenhauer, G., Eglinton, T., Freudenthal, T., Lamy, F., (2003b). Alkenone radiocarbon stratigraphy at high resolution continental margin sites. Geophysical Research Abstracts. 5, 06130.Google Scholar
Nishiizumi, K, Finkel, RC., (2000). 10Be and 36Cl concentrations in the GISP2 and Siple Dome ice cores and atmospheric Δ14C. 17th International Radiocarbon Conference (Jerusalem), book of abstracts, 85.Google Scholar
Ohkouchi, N., Eglinton, T.I., Keigwin, L.D., Hayes, J.M., (2002). Spatial and temporal offsets between proxy records in a sediment drift. Science. 298, 12241227.CrossRefGoogle Scholar
Paillard, D., Labeyrie, L., Yiou, P., (1996). Macintosh program performs time-series analysis. Eos Transanctions AGU. 77, 379.CrossRefGoogle Scholar
Pailler, D., Bard, E., (2002). High frequency paleoceanographic changes during the past 140,000 years recorded by the organic matter in sediments off the Iberian Margin. Palaeogeography, Palaeoclimatology and Palaeoecology. 181, 431452.CrossRefGoogle Scholar
Paull, C.K., Hills, S.J., Thierstein, H.R., Bonani, G., Wolfli, W., (1991). 14C offsets and apparently non-synchronous δ18O stratigraphies between nannofossil and foraminiferal pelagic carbonates. Quaternary Research. 35, 274290.CrossRefGoogle Scholar
Reimer, P.J., Hughen, K.A., Guilderson, T.P., McCormac Baillie, M.G.L., Bard, E., Barratt, P., Beck, J.W., Buck, C.E., Damon, P.E., Friedrich, M., Kromer, B., Bronk-Ramsey, C., Reimer, R.W., Remmele, S., Southon, J.R., Stuiver, M., van der Plicht, J., (2002). Preliminary report of the first workshop of the IntCal04 radiocarbon calibration/comparison working group. Radiocarbon. 44, 653661.CrossRefGoogle Scholar
Sanchez-Goni, M.F., Turon, J.L., Eynaud, F., Gendreau, S., (2000). European climatic response to millennial-scale changes in the atmosphere-ocean system during the last glacial period. Quaternary Research. 54, 394403.CrossRefGoogle Scholar
Schmittner, A., Saenko, O.A., Weaver, A.J., (2003). Coupling of the hemispheres in observations and simulations of glacial climate change. Quaternary Science Reviews. 22, 659671.CrossRefGoogle Scholar
Schramm, A., Stein, M., Goldstein, S.L., (2000). Calibration of the C-14 time scale to >40 ka by U-234–Th-230 dating of Lake Lisan sediments (last glacial Dead Sea). Earth and Planetary Science Letters. 175, 2740.CrossRefGoogle Scholar
Schulte, S., Bard, E., (2003). Past changes of biologically mediated dissolution of calcite above the chemical lysocline documented in Indian Ocean sediments. Quaternary Science Reviews. 22, 17571770.CrossRefGoogle Scholar
Shackleton, N.J., Hall, M.A., Vincent, E., (2000). Phase relationships between millennial-scale events 64,000–24,000 years ago. Paleoceanography. 15, 565569.CrossRefGoogle Scholar
Siani, G., Paterne, M., Michel, E., Sulpizio, R., Sbrana, A., Arnold, M., Haddad, G., (2001). Mediterranean Sea surface radiocarbon reservoir age changes since the last glacial maximum. Science. 294, 19171920.CrossRefGoogle ScholarPubMed
Sikes, E.L., Samson, C.R., Guilderson, T.P., Howard, W.R., (2000). Old radiocarbon ages in the southwest Pacific Ocean during the last glacial period and deglaciation. Nature. 405, 555559.CrossRefGoogle ScholarPubMed
Stocker, T.F., (2000). Past and future reorganizations in the climate system. Quaternary Science Reviews. 19, 301319.CrossRefGoogle Scholar
Stuiver, M., Braziunas, T.F., Becker, B., Kromer, B., (1991). Climatic, solar, oceanic and geomagnetic influences on Late-Glacial and Holocene, atmospheric 14C/12C change. Quaternary Research. 35, 124.CrossRefGoogle Scholar
Stuiver, M., Grootes, P.M., (2000). GISP2 oxygen isotope ratios. Quaternary Research. 53, 277284.CrossRefGoogle Scholar
Stuiver, M., Reimer, P.J., Bard, E., Beck, W., Burr, G., Hughen, K., Kromer, B., McCormac, G., van der Plicht, J., Spurk, M., (1998). INTCAL98 radiocarbon age calibration, 24,000-0 cal B.P. Radiocarbon. 40, 10411083.CrossRefGoogle Scholar
Thouveny, N., Moreno, E., Delanghe, D., Candon, L., Lancelot, Y., Shackleton, N.J., (2000). Rock-magnetism of Pleistocene sediments of the Portuguese margin: detection of Heinrich events and implications for paleoenvironmental reconstructions. Earth and Planetary Science Letters. 180, 6175.CrossRefGoogle Scholar
Thouveny, N., Carcaillet, J., Moreno, E., Leduc, G., Nérini, D., (2004). Geomagnetic moment variation and paleomagnetic excursions during the past 400 kyr: a stacked record from sedimentary cores of the Portuguese margin. Earth and Planetary Science Letters(in press).CrossRefGoogle Scholar
Tziperman, E., (1997). Inherently unstable climate behaviour due to weak thermohaline ocean circulation. Nature. 386, 592595.CrossRefGoogle Scholar
Valladas, H., Clottes, J., Geneste, J.-M., Garcia, M.A., Arnold, M., Cachier, H., Tisnerat-Laborde, N., (2001). Evolution of prehistoric cave art. Nature. 413, 479.CrossRefGoogle ScholarPubMed
Vidal, L., Labeyrie, L., Cortijo, E., Arnold, M., Duplessy, J.C., Michel, E., Becque, S., van Weering, T.C.E., (1997). Evidence for changes in the North Atlantic Deep Water linked to meltwater surges during the Heinrich events. Earth and Planetary Science Letters. 146, 1–2 1327.CrossRefGoogle Scholar
Voelker, A.H.L., Sarnthein, M., Grootes, P.M., Erlenkeuser, H., Laj, C., Mazaud, A., Nadeau, M.J., Schleicher, M., (1998). Correlation of marine C-14 ages from the Nordic Seas with the GISP2 isotope record: implications for C-14 calibration beyond 25 ka B.P. Radiocarbon. 40, 517534.CrossRefGoogle Scholar
Waelbroeck, C., Duplessy, J.C., Michel, E., Labeyrie, L., Paillard, D., Duprat, J., (2001). The timing of the last deglaciation in North Atlantic climate records. Nature. 412, 724727.CrossRefGoogle ScholarPubMed
Wang, Z., Mysak, L.A., (2001). Ice sheet-thermohaline circulation interactions in a climate model of intermediate complexity. Journal of Oceanography. 57, 481494.CrossRefGoogle Scholar
Weaver, A.J., (1999). Millennial timescale variability in Ocean/climate models. Mechanisms of Global Climate Change at Millennial Time Scales. Geophysical Monograph. vol. 112, American Geophysical Union, Washington, D.C., 285300.Google Scholar
Wohlfarth, B., Possnert, G., (2000). AMS radiocarbon measurements from the Swedis varved clays. Radiocarbon. 42, 323333.CrossRefGoogle Scholar
Yiou, F., Raisbeck, G.M., Baumgartner, S., Beer, J., Hammer, C.U., Johnsen, S., Jouzel, J., Kubik, P.W., Lestringuez, J., Stievenard, M., Suter, M., Yiou, P., (1997). 10Be in the GRIP ice core at Summit, Greenland. Journal of Geophysical Research. 102, C12 2678326794.CrossRefGoogle Scholar
Yokoyama, Y., Esat, T.M., Lambeck, K., Fifield, L.K., (2000). Last ice age millennial scale climate changes recorded in Huon Peninsula corals. Radiocarbon. 42, 383401.CrossRefGoogle Scholar
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Radiocarbon calibration beyond 20,000 14C yr B.P. by means of planktonic foraminifera of the Iberian Margin
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Radiocarbon calibration beyond 20,000 14C yr B.P. by means of planktonic foraminifera of the Iberian Margin
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