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A Comparison of Radiocarbon and U/Th Ages on Continental Carbonates

Published online by Cambridge University Press:  18 July 2016

J.-C. Fontes ,
J. N. Andrews ,
Christiane Causse  and
Elisabeth Gibert
J.-C. Fontes
Affiliation:
Laboratoire d'Hydrologie et de Géochimie Isotopique, Bâtiment 504, Université de Paris-Sud 91405 Orsay Cedex, France
J. N. Andrews
Affiliation:
Laboratoire d'Hydrologie et de Géochimie Isotopique, Bâtiment 504, Université de Paris-Sud 91405 Orsay Cedex, France
Christiane Causse
Affiliation:
Laboratoire d'Hydrologie et de Géochimie Isotopique, Bâtiment 504, Université de Paris-Sud 91405 Orsay Cedex, France
Elisabeth Gibert
Affiliation:
Laboratoire d'Hydrologie et de Géochimie Isotopique, Bâtiment 504, Université de Paris-Sud 91405 Orsay Cedex, France
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Abstract

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Authigenic micrite from a playa in the northern Sahara has been dated by both the U/Th and 14C methods. The U/Th ages can be a few thousand years greater or less than the 14C ages obtained on the smallest crystals of micrite. The latter are considered to form a reasonable chronology for the Holocene deposits. The deviations of the U/Th ages are explained by quantifiable losses and gains of uranium under changing redox conditions. Under conditions where U is conservative (reduced sediments with low permeability), the U/Th method can provide good chronologies for lacustrine deposits.

Type
II. Applied Isotope Geochemistry
Information
Radiocarbon , Volume 34 , Issue 3: Proceedings of the 14th International Radiocarbon Conference , 1992 , pp. 602 - 610
Copyright
Copyright © The American Journal of Science 

References

Bard, E., Hamelin, B., Fairbanks, R. G. and Zindler, A. 1990 Calibration of the 14C time scale over the past 30,000 years using mass spectrometric U/Th ages from Barbados corals. Nature 345: 405–410.Google Scholar
Bischoff, J. L. and Fitzpatrick, J. A. 1991 U-series dating of impure carbonates: An isochron technique using total-sample dissolution. Geochimica et Cosmochimica Acta 55: 543–554.CrossRefGoogle Scholar
Causse, C., Conrad, G., Fontes, J.-Ch., Gasse, F., Gibert, E. and Kassir, A. 1988 Le dernier “Humide” pléistocène du Sahara nord-occidental daterait de 80–100,000 ans. Comptes Rendus de l'Académie des Sciences 306, Série II: 1459–1464.Google Scholar
Causse, C., Coque, R., Fontes, J.-Ch., Gasse, F., Gibert, E., Ben Ouezdou, H. and Zouari, K. 1989 Two high levels of continental waters in the southern Tunisian chotts at about 90 and 150 ka. Geology 17: 922–925.Google Scholar
Deines, P. 1980 The isotopic composition of reduced organic carbon. In Fritz, P. and Fontes, J.-C., eds., Handbook of Environmental Geochemistry, Vol. 1 “The Terrestrial Environment” A: Elsevier: 329–406.Google Scholar
Fontes, J.-Ch. and Gasse, F. 1991 Palhydaf (Palaeohydrology in Africa) Program: Objectives, methods and major results. Palaeogeography, Palaeoclimatology, Palaeoecology 84: 191–215.Google Scholar
Gasse, F., Fontes, J.-Ch., Plaziat, J. C., Carbonel, P., Kaczmarska, I., de Deckker, P., Soulié–Märsche, I., Callot, Y. and Dupeuble, P. A. 1987 Biological remains, geochemistry and stable isotopes for the reconstruction of environmental and hydrological changes in the Holocene lakes from Northern Sahara. Palaeogeography, Palaeoclimatology, Palaeoecology 60: 1–46.Google Scholar
Gasse, F., Téhet, R., Durand, A., Gibert, E. and Fontes, J.-Ch. 1990 The arid-humid transition in the Sahara and the Sahel during the last deglaciation. Nature 346: 141–146.Google Scholar
Gaven, C., Hillaire-Marcel, C. and Petit-Maire, N. 1981 A Pleistocene lacustrine episode in southeastern Libya. Nature 290: 131–135.Google Scholar
Gibert, E., Arnold, M., Conrad, G., de Deckker, P., Fontes, J.-Ch., Gasse, F. and Kassir, A. 1990 Retour des conditions humides au Tardiglaciaire au Sahara septentrional (Sebkha Mellala, Algérie). Bulletin de la Société Géologique de France 8 (VI, 3): 497–504.Google Scholar
Gibert, E., Monrozier, L. and Fontes, J.-Ch. (ms.) Nitrogenous component and organic matter of paleosediments from Northern Sahara. Incidence on δ13C of associated carbonates. In preparation.Google Scholar
Hillaire-Marcel, C. and Casanova, J. 1987 Isotopic paleohydrology of the Magadi (Kenya) Natron (Tanzania) basin during the Late Quaternary. Palaeogeography, Palaeoclimatology, Palaeoecology 58: 155–181.Google Scholar
Kaufman, A. 1971 U-series dating of Dead Sea Basin carbonates. Geochimica et Cosmochimica Acta 35: 1269–1281.Google Scholar
Kaufman, A. and Broecker, W. 1965 Comparison of 230Th and 14C ages for carbonate materials from Lakes Lahontan and Bonneville. Journal of Geophysical Research 70: 4039–4054.Google Scholar
Ku, T. L. and Liang, Z. C. 1984 The dating of impure carbonates with decay-series isotopes. Nuclear Instruments and Methods 223: 563–571.Google Scholar
Luo, S. and Ku, T. L. 1991 U-series isochron dating: A generalized method employing total-sample dissolution. Geochimica et Cosmochimica Acta 55: 555–564.Google Scholar
Przybylowicz, W., Schwarcz, H. P. and Latham, A. G. 1991 Dirty calcites 2. Uranium series dating of artificial calcite-detritus mixtures. Chemical Geology (Isotope Science section) 86: 161–178.CrossRefGoogle Scholar
Rosholt, J. N. 1976 230Th/234U dating of travertine and caliche rinds. Geological Society of America, Abstracts with Programs 8: 1076.Google Scholar
Rozanski, K., Goslar, T., Dulinski, M., Kuc, T., Pazdur, M. F. and Walanus, A. 1992 The Late Glacial-Holocene transition in Central Europe derived from isotope studies of laminated sediments from the Lake Gosciaz (Central Poland). In Bard, E. and Broecker, W. S., eds., The Last Deglaciation: Absolute and Radiocarbon Chronology. NATO ASI Series I 2. Berlin/Heidelberg, Springer-Verlag: 69–80.Google Scholar
Schwarcz, H. P. and Latham, A. G. 1989 Dirty calcites. Uranium-series dating of contaminated calcite using leachates alone. Chemical Geology 80: 35–43.Google Scholar
Talbot, M. R. and Kelts, K. 1986 Primary and diagenetic carbonates in the anoxic sediments of Lake Bosumtwi, Ghana. Geology 14: 912–916.Google Scholar
Zouari, K. 1987 Géochimie et sédimentologie des depots continentaux d'origine aquatique du Quaternaire supérieur du Sud Tunisien: Interprétations paléohydrologiques et paléoclimatiques. , Université Paris XI: 216 p.Google Scholar