Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-24T15:33:32.675Z Has data issue: false hasContentIssue false

Temporal Changes of the 14C Reservoir Effect in Lakes

Published online by Cambridge University Press:  18 July 2016

Mebus A. Geyh
Affiliation:
State Geological Survey of Lower Saxony, P.O. Box 510153, D-30631 Hannover, Germany
U. Schotterer
Affiliation:
Physical Institute, University of Bern, Sidlerstrasse 5, CH-3013 Bern, Switzerland
M. Grosjean
Affiliation:
Geographical Institute, University of Bern, Hallerstrasse 12, CH-3013 Bern, Switzerland
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.

Conventional radiocarbon dates for sediment samples from aquatic systems and of coeval terrestrial samples deviate from each other due to the reservoir effect. The reservoir correction is usually assumed to be constant with time for a specific aquatic system. Our studies confirm that seasonal and secular changes are frequent and are governed by the limnological conditions. Lakes have two principal sources of 14C: atmospheric CO2 and the total dissolved inorganic carbon (TDIC) of the entering groundwater and runoff. The former has values of ca. 100 pMC; the latter usually has a 14C value well below 100 pMC. Atmospheric CO2 enters the lake by exchange via its surface. The proportions of these two kinds of input determine the magnitude of the reservoir correction in freshwater lakes. It is mainly a function of the volume/surface ratio of the lake and, consequently a function of the water depth. The surface of lakes with outflow does not change when sedimentation decreases the depth of the water. The depth of Schleinsee Lake in southern Germany has decreased from 30 to 15 m since ca. 9000 bp. As a result, the reservoir correction has decreased from ca. -1550 to -580 yr. In contrast, the depth of Lake Proscansko in Croatia increased with growth of the travertine dam and the reservoir correction changed from ca. -1790 to -2650 yr during the last 8800 yr. The largest fluctuations of lake levels occur in closed lakes in arid regions when the climate changes from humid to arid and vice versa. As a result, the reservoir correction of the 14C dates for the total organic fraction from Lejía Lake in the Atacama Desert of Chile varied between <-1800 yr and -4700 yr over a period of only 1800 yr between 11,500 and 9700 bp. The corresponding reservoir correction for the marl fraction is much higher. In summary, accurate and reliable 14C dating of lake sediments requires a study of the temporal changes of the reservoir effect by analysis of both the organic and marl fractions. The most reliable 14C dates are obtained from terrestrial plant remains.

Type
Part 2: Applications
Copyright
Copyright © The American Journal of Science 

References

Broecker, W. S. and Walton, A. 1959 The geochemistry of C14 in fresh-water systems. Geochimica et Cosmochimica Acta 16: 1538.Google Scholar
Deevey, E. S. Jr., Gross, M. S., Hutchinson, G. E. and Kraybill, H. L. 1954 The natural 14C contents of materials from hard-water lakes. Proceedings of the National Academy of Sciences of the USA, Washington. 40: 285288.Google Scholar
Geyh, M. A., Merkt, J. and Müller, H. 1971 Sediment-, Pollen- und Isotopenanalysen an jahreszeitlich geschichteten Ablagerungen im zentralen Teil des Schleinsees. Archiv für Hydrobiologie 69: 366399.Google Scholar
Grosjean, M. 1994 Paleohydrology of the Laguna Lejía (north Chilean Altiplano) and climatic implications for late-glacial times. Palaeography, Palaeoclimatology, Palaeoecology 109: 89100.CrossRefGoogle Scholar
Grosjean, M., Geyh, M. A., Messerli, B. and Schotterer, U. 1995 Late-glacial and early Holocene lake sediments, groundwater formation and climate in the Atacama Altiplano. Journal of Paleolimnology 14: 241252.CrossRefGoogle Scholar
Mook, W. G. 1970 Stable carbon and oxygen isotopes of natural waters in the Netherlands. In Isotope Hydrology 1970. Vienna, IAEA: 163190.Google Scholar
Olsson, I. U. 1979 Radiocarbon dating of material from different reservoirs. In Suess, H. E. and Berger, R., eds., Radiocarbon Dating: Proceedings of the Ninth International Conference, Los Angeles and La Jolla, 1976. Berkeley, University of California Press: 613618.CrossRefGoogle Scholar
Pazdur, A., Fontugne, M. R., Goslar, T. and Pazdur, M. F. 1995 Lateglacial and Holocene water-level changes of the Gościąż Lake, central Poland, derived from carbon isotope studies of laminated sediment. Quaternary Science Reviews 14: 125135.CrossRefGoogle Scholar
Robinson, S. W. 1981 Natural and man-made radiocarbon as a tracer for coastal upwelling process. Coastal and Estuarine Sciences 1: 298302.Google Scholar
Servant, M. and Fontes, J.-C. 1978 Les lacs quaternaires des hauts plateaux des Andes boliviennes. Premières interprétations paléoclimatiques. Cahiers ORSTOM Series Géologie 10(1): 923.Google Scholar
Srdoč, D., Obelić, B., Horvatinčić, N., Krajcar-Bronić, I., Marčenko, E., Merkt, J., Wong, H. K. and Sliepčević, A. 1985 Radiocarbon dating of lake sediment from two karst lakes in Yugoslavia. In Stuiver, M. and Kra, R., eds., Proceedings of the 12th International 14C Conference. Radiocarbon 28(2A): 495502.Google Scholar
Stuiver, M., Long, A. and Kra, R. S., eds. 1993 Calibration 1993. Radiocarbon 35(1): 1244.Google Scholar