Abstract
Peat cores collected from three sites in the Jura region of Switzerland, La Tourbière des Genevez, Etang de la Gruère and Praz Rodet, were analysed for the fallout radionuclides 210Pb, 137Cs, 134Cs and 241Am, and the minerogenic radionuclide 226Ra. Unsupported 210Pb inventories of the cores were all in the range 3900-4784 Bq m-2 and are consistent with their having largely retained the atmospheric flux (ca. 130 Bq m-2y-1). In contrast, comparisons with earlier (1986) cores from these sites suggest that there have been significant losses of fallout 137Cs. Samples from all three sites had low but significant levels of supported 210Pb (226Ra) activity, the origin of which is presumably wind blown soil dust. 210Pb dates calculated using the CRS model were independently validated by 241Am and pollen stratigraphy. The core from La Tourbière des Genevez had a fairly conventional 210Pb activity versus depth profile indicating more or less constant net accumulation during the past 100 years. At the other two sites however the 210Pb profiles contained significant deviations from simple exponential decline that may record episodes in the bog during which there were major variations in the net dry mass accumulation rate. These episodes are dated 1930-50 (Etang de la Gruère) and 1960-80 (Praz Rodet). Although the depths at which total 210Pb reaches equilibrium with the supporting 226Ra range widely, from ca.37 cm in Etang de la Gruére to ca.60 cm in Praz Rodet, mean net dry mass accumulation rates for the past 100 years are remarkably similar, the values for all three sites are in the range 0.023-0.027 g cm-2y-1.
Similar content being viewed by others
References
Appleby, P.G., Nolan, P.J., Gifford, D.W., Godfrey, M.J., Oldfield, F., Anderson, N.J. and Battarbee, R.W.; 1986, Hydrobiol. 143, 21–27.
Appleby, P.G. and Oldfield, F.; 1978, Catena 5, 1–8.
Appleby, P.G. and Oldfield, F.; 1992, in: Uranium series disequilibrium (eds. M. Ivanovich & R.S. Harmon), OUP, pp. 731–778.
Appleby, P.G., Richardson, N. and Nolan, P.J.; 1991, Hydrobiol. 214, 35–42.
Dominik, J., Burrus, D., Vernet, J.-P.; 1987, Earth Planet. Sci. Lett. 84 165–180.
Fankhauser, A.; 1995, Pollenanalytische Untersuchungen zur jungsten Vegetations-geschichte der Franche Montagnes (in German), Diploma thesis, University of Bern, 91pp. plus Figures.
Mitchell, A.D.E.; 1995, The postglacial developmental history of the Praz Rodet bog, Vallée de Joux, Swiss Jura, M.Sc. thesis, University of Neuchatel, 112pp plus appendices.
Norton, S.A. and Kahl, J.S.; 1987, in: New approaches to monitoring aquatic eco-systems (ed. T.P. Boyle), ASTM STP 940, 40–57.
Schell, W.R., Tobin, M.J. and Massey, C.D.; 1989, Sci. Tot. Envir. 87/88, 19–42.
Schuler, C., Wieland, E., Santschi, P.H., Sturm, M., Lucek, A., Bollhalder, S., Beer, J., Bonani, G., Hofman, H.J., Suter, M. and Wolfli, W.; 1991, J. Geophys. Res. 96, 17051–17065.
Shotyk, W. and Steinmann, P.; 1994, Chem. Geol. 116, 137–146.
Shotyk, W.; 1996a, Wat. Air Soil Pollut. 90, 375–405.
Shotyk, W.; 1996b, Envir. Revs. 4, 149–183
Shotyk, W., Cheburkin, A.K., Appleby, P.G., Fankhauser, A. and Kramers, J.D.; 1996, Earth Planet. Sci. Lett. 145, E1-E7.
Shotyk, W. and Steinmann, P.; 1994, Chem. Geol. 116, 137–146.
Urban, N., Eisenreich, S.I., Grigal, D.F. and Schur, K.T.: 1990, Geochim. Cosmochim. Acta 54, 3329–3346.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Appleby, P., Shotyk, W. & Fankhauser, A. Lead-210 Age Dating of Three Peat Cores in the Jura Mountains, Switzerland. Water, Air, & Soil Pollution 100, 223–231 (1997). https://doi.org/10.1023/A:1018380922280
Issue Date:
DOI: https://doi.org/10.1023/A:1018380922280