Heinemeier, Jan

Jungner, Högne

Lindroos, Alf

Ringbom, Åsa

Rud, Niels

Sveinbjörnsdóttir, Árný

von Konow, Thorborg

English

Journal.fi

AMS 14C DATING OF LIME MORTAR Jan Heinemeier1, Högne Jungner2, Alf Lindroos 3, Åsa Ringbom4, Thorborg von Konow5, Niels Rud 1 and Arny Sveinbjörnsd6ttir6 1 AMS 14C Dating Laboratory, Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark. 2 Dating Laboratory, University of Helsinki, P.O. Box 11, FIN-00014 Helsinki, Finland. 3 Department of Geology and Mineralogy, Åbo Academy University, FIN-20500 Turku, Finland. 4 Department of Art History, Åbo Academy University, FIN-20500 Turku, Finland. 5 Department of Jnorganic Chemistry, Åbo Academy University, FIN-20500 Turku, Finland. 6 Science Institute, Dunhaga 3, IS-107 Reykjavik, lceland. There has long since been great interest in possibity of radiocarbon analysis directly on mortar to date the construction time of buildings where no other type of materia! is available for dating or can be safely associated with the time of construction. Mortar has great potential as dating materia! not only because of its ample availability and clear association with the construction to be dated but also because the carbonate formed from the burnt limestone (CaO) in the hardening process represents a sam-pling of the contemporaneous atmospheric CO2 content. However, mortar is a very complex materia! consisting of not only mortar carbon-ate but also unburnt fossil limestone inclusions and other carbon bearing minerals and organic components. Attempts to apply conventional 14C dating has thus proven very difficult. Likewise, the seemingly obvious solution of utilizing AMS to selectively date the organic fraction has often led to exceedingly high ages (Tubbs & Kinder 1990). Van Strydonck et al. (1992) used both carbonate and organic fractions and found very scattered results. The method of mortar dating and the possible sources of error have been discussed extensively in the literature (see Delibrias et al. 1964, Delibrias and Labeyrie 1964, 1965, Stuiver and Smith 1965, Baxter and Walton 1970a, 1970b, Folk and Valastro 1976, 1979, Malone et al. 1980, van Strydonk et al. 1983, 1986, 1989, Willaime et al. 1983, Sonninen et al. 1985, 1989, Gustavsson et al. 1990, Ringbom et al. 1996). Because of the urgent need for reliable mortar dating, we have continued work to develop a technique to isolate the pure mortar carbonate fraction from the rest of the crude mortar components as reported elsewhere in these proceedings (Lindroos and von Konow 1997). So far, a large series (>100) of mortar samples on different chemi-cal fractions from a number of different (medieval) buildings have been measured at the AMS 14C dating facility at Aarhus. The results have shown promising internal con-sistency. A detailed report of results on medieval churches from Åland, Finland (Ring-bom and Remmer 1995) and the Newport Tower, Rhode Island, USA has been given in Heinemeier et al. 1997. References Baxter, M.S. and A. Walton, 1970a. Glasgow University Radiocarbon Measurements III. Radiocar-bon, v 12, p 496- 502. Baxter, M.S. and A. Walton, 1970b. Radiocarbon Dating of Mortars. Nature, v 225, p 937-938. 214 Delibrias, G. and J. Labeyrie, 1964. Dating of Old Mortars by the Carbon-14 Method. Nature, V 201, p 742-743. Delibrias, G., M.T. Guillier and J. Labeyrie, 1964. Saclay Natural Radiocarbon Measurements I. Ra-diocarbon, v 6, p 233-250. Delibrias, G. and J. Labeyrie, 1965. The Dating of Mortars by the Carbon-14 Method. Proc. sixth Intern. Conf. on Radiocarbon and Tritium Dating (Pullman, Washington) p 344-347. Folk, R.L. and S. Valastro Jr., 1976. Successful Technique for Dating of Lime Mortar by Carbon-14. Journal of Field Archaeology, v 3, p 203-208. Folk, R.L. and S. Valastro Jr., 1979. Dating of Lime Mortar by 14C. Radiocarbon Dating. Proceed-ings of the ninth International Conference, ed. R. Berger and H.E. Suess (University of Cali-fornia Press, Berkley, California), p 721-732. Gustavsson, K., P. Erämetsä, E. Sonninen and H. Jungner, 1990. Radiocarbon Dating of Mortar and Thermoluminescence Dating of Bricks from Åland. PACT Journal, v 29 III.2, p 203-212. Heinemeier, J ., H. Jungner, A. Lindroos, Å. Ringbom, T. von Konow and N . Rud, 1997. AMS 14C dating of !ime mortar, Proceedings of the 7th International Conference on Accelerator Mass Spectrometry, Tucson, Arizona, May 1996. Nuclear Instruments and Methods in Physics Re-search, B 123, 487-493. Lindroos, A. and T. von Konow, 1997. 14C dating of lime mortar - preparation of the sample, a chal-lenge for the geologist and the mineral chemist. These proceedings . Malone, G., S. Valastro Jr. and A.G. Vazela, 1980. Carbon-14 Chronology of Mortar from Excava-tion in the Medieval Church of Saint-Benigne, Dijon, France. Journal of Field Archaeology, V 7 , p 329-343. Ringbom, Å., Christina Remmer, 1995. Ålands Kyrkor, Voi. 1, Hammarland och Eckerö. (Ålands Landskapsstyrelsens Museibyrå, Mariehamn, Åland, Finland) 300 pp (in Swedish with English summary). Ringbom, Å., G. Hakkarainen, T. Bartholin and H. Jungner, 1996. Åland Churches and their scien-tific dating. Proceedings of the sixth Nordic conference on the application of scientific methods in archaeology, Esbjerg September 1993, p 267-278. Sonninen, E., H. Jungner and P. Erämetsä, 1985 . Dating of Mortar and Bricks from the Castle of Kastelholm. Third Nordic Conference on the Application of Scientific Methods in Archaeolo-gy, Mariehamn 1984, Finska Fornminnesföreningen , ISKOS v 5, p 384-389. Sonninen , E., P. Erämetsä and H. Jungner, 1989. Dating of mortar and bricks : an example from Fin-land. Archaeometry, Proceedings of the 25th International Symposium, ed. Y. Maniatis (Am-sterdam- Oxford- New York- Tokyo) p 99- 107. Stuiver, M. and C.S. Smith, 1965. Radiocarbon Dating of Ancient Mortar and Plaster. Proc. sixth lntern. Conf. on Radiocarbon and Tritium Dating (Pullman, Washington) p 338-341. Tubbs, L.E. and T.N. Kinder, 1990. The use of AMS for the dating of lime mortars. Nuclear Instru-ments and Methods in Physics Research, v B52, p 438-441. Van Strydonck, M, M. Dupas and M. Dauchot-Dehon, 1983. Radiocarbon Dating of Old Mortars. PACT Journal , v 8, p 337-343 . Van Strydonck, M., M. Dupas, M . Dauchot-Dehon, C. Pachiaaudi and J. Marechal , 1986. The Influ-ence of Contaminating (Fossil) Carbonate and the Variations of Ö13C in Mortar Dating. Radio-carbon, v 28-2A, p 702-710. Van Strydonck, M., M. Dupas and E. Keppens, 1989. Isotopic Fractionation of oxygen and carbon in lime mortar under natural environmental conditions. Radiocarbon , v 31(3), p 610-618. Van Strydonck, M.J.Y, K. van der Borg, A.F.M. de Jong and E. Keppens, 1992. Radiocarbon dating of lime fractions and organic materia! from buildings. Radiocarbon, v 34- 3, p 873-879. Willaime, B., R . Coppens and R. Jaegy, 1983. Datation des mortiers du chateau de Chatel-sur-Moselle par le carbone 14. PACT Journal, v 8, p 345-349. 215 

AMS 14C dating of lime mortar

https://journal.fi/iskos/article/download/110468/64950

AMS 14C dating of lime mortar

Abstract

Similar works

Full text

Available Versions

Journal.fi