Hostname: page-component-7479d7b7d-8zxtt Total loading time: 0 Render date: 2024-07-15T23:05:37.877Z Has data issue: false hasContentIssue false

Successful AMS 14C Dating of Non-Hydraulic Lime Mortars from the Medieval Churches of the Åland Islands, Finland

Published online by Cambridge University Press:  18 July 2016

Jan Heinemeier*
Affiliation:
AMS 14C Dating Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
Åsa Ringbom
Affiliation:
Art History, Åbo Akademi University, Turku, Finland
Alf Lindroos
Affiliation:
Geology and Mineralogy, Åbo Akademi University, Turku, Finland
Árný E Sveinbjörnsdóttir
Affiliation:
Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland
*
Corresponding author. [email protected].
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.

Fifteen years of research on accelerator mass spectrometry (AMS) radiocarbon dating of non-hydraulic mortar has now led to the establishment of a chronology for the medieval stone churches of the Åland Islands (Finland), where no contemporary written records could shed light on the first building phases. In contrast to other material for dating, well-preserved mortar is abundantly available from every building stage.

We have gathered experience from AMS dating of 150 Åland mortar samples. Approximately half of them have age control from dendrochronology or from 14C analysis of wooden fragments in direct contact with the mortar. Of the samples with age control, 95% of the results agree with the age of the wood. The age control from dendrochronology, petrologic microscopy, chemical testing of the mortars, and mathematical modeling of their behavior during dissolution in acid have helped us to define criteria of reliability to interpret the 14C results when mortar dating is the only possibility to constrain the buildings in time. With these criteria, 80% of all samples reached conclusive results, and we have thus far been able to establish the chronology of 12 out of the 14 churches and chapels, while 2 still require complementary analyses.

Type
Methods, Applications, and Developments
Copyright
Copyright © 2010 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Ambers, J. 1987. Stable carbon isotope ratios and their relevance to the determination of accurate radiocarbon dates for lime mortars. Journal of Archaeological Science 14(6):569–76.CrossRefGoogle Scholar
Andersen, GJ, Heinemeier, J, Nielsen, HL, Rud, N, Thomsen, MS, Johnsen, S, Sveinbjörnsdóttir, Á, Hjartarson, Á. 1989. AMS 14C dating on the Fossvogur sediments, Iceland. Radiocarbon 31(3):592600.CrossRefGoogle Scholar
Baxter, MS, Walton, A. 1970. Radiocarbon dating of mortars. Nature 225(5236):937–8.Google Scholar
Borrelli, E. 1999. Binders. In: ARC Laboratory Handbook, ICCROM, Conservation of Architectural Heritage, Historic Structures and Materials. Available at http://www.iccrom.org/pdf/ICCROM_14_ARCLabHandbook02_en.pdf. p 19.Google Scholar
Bronk Ramsey, C. 1995. Radiocarbon calibration and analysis of stratigraphy: the OxCal program. Radiocarbon 37(2):425–30.Google Scholar
Bronk Ramsey, C. 2001. Development of the radiocarbon calibration program. Radiocarbon 43(2A):355–63.CrossRefGoogle Scholar
Dreijer, M. 1983. Det åländska folkets historia. In: 1 Från stenåldem till Gustav Vasa. Mariehamn.Google Scholar
Folk, RL, Valastro, S Jr. 1976. Successful technique for dating of lime mortar by carbon-14. Journal of Field Archaeology 3:203–8.Google Scholar
Hale, J, Heinemeier, J, Lancaster, L, Lindroos, A, Ringbom, Å. 2003. Dating ancient mortar. American Scientist 91(2):130–7.Google Scholar
Heinemeier, J, Jungner, H, Lindroos, A, Ringbom, Å, von Konow, T, Rud, N. 1997. AMS 14C dating of lime mortar. Nuclear Instruments and Methods in Physics Research B 123(1–4):487–95.Google Scholar
Hiekkanen, M. 1994. The stone churches of the medieval diocese of Turku. A systematic classification and chronology. Suomen muinaismuistoyhdistyksen Aikakauskirja, Finska Fornminnesföreningens Tidskrift 101. Google Scholar
Hiekkanen, M. 1998. Finland's medieval stone churches and their dating – a topical problem. Suomen Museo 1997. Google Scholar
Hiekkanen, M. 2004. Kalkkilaastin ajoitusmenetelmä – arvio epäuskottavuudesta vahvistuu. Tieteessä tapahtuu 6/2004. Google Scholar
Hiekkanen, M. 2007. Suomen keskiajan kivikirkot. Suomalaisen Kirjallisuuden Seuran Toimituksia 1117. Helsinki.Google Scholar
Hiekkanen, M. 2008. Kalkkilaastin 14C-ajoituksen ongelmat – onko niistä ulospääsyä? SKAS 2/2008:318.Google Scholar
Hiekkanen, M. 2009. Kalkkilaastiajoitus – ei rauhoittavia tietoja vaan päinvastoin. SKAS 1/2009:34–8.Google Scholar
Hodgins, G, Lindroos, A, Ringbom, Å, Heinemeier, J, Brock, F. 2010. 14C dating of Roman mortars – preliminary tests using diluted hydrochloric acid injected in batches. In: Ringbom, Å, Hohlfelder, R, editors. Proceedings from Building Roma Aeterna Conference. 27–29 March 2008, Rome. In press.Google Scholar
Labeyrie, J, Delibrias, G. 1964. Dating of old mortars by carbon-14 method. Nature 201(4920):742.Google Scholar
Langley, MM, Maloney, SJ, Ringbom, Å, Heinemeier, J, Lindroos, A. 2010. A comparison of dating techniques at Torre de Palma, Portugal: mortars and ceramics. In: Ringbom, Å, Hohlfelder, R, editors. Proceedings from Building Roma Aeterna Conference. 27–29 March 2008, Rome. In press.Google Scholar
Létolle, R, Gégout, P, Moranville-Regourd, M, Gaveau, B. 1990. Carbon-13 and oxygen-18 mass spectrometry as a potential tool for the study of carbonate phases in concretes. Journal of the American Ceramic Society 73(12):3617–25.Google Scholar
Lindroos, A. 2005. Carbonate phases in historical building mortars and pozzolana concrete. Implications for AMS 14C dating [PhD thesis]. Turku: Åbo Akademi University. 92 p.Google Scholar
Lindroos, A, Heinemeier, J, Ringbom, Å, Braskén, M, Sveinbjörnsdóttir, Á. 2007. Mortar dating using AMS 14C and sequential dissolution: examples from medieval, non-hydraulic lime mortars from the Åland Islands, SW Finland. Radiocarbon 49(1):4767.CrossRefGoogle Scholar
Lindroos, A, Heinemeier, J, Ringbom, Å, Brock, F, Sonck-Koota, P, Pehkonen, M, Suksi, J. 2010. Problems in radiocarbon dating of Roman pozzolana mortars. In: Ringbom, Å, Hohlfelder, R, editors. Proceedings from Building Roma Aeterna Conference. 27–29 March 2008, Rome. In press.Google Scholar
Pachiaudi, C, Marechal, J, Van Strydonck, M, Dupas, M, Dauchot-Dehon, M. 1986. Isotopic fractionation of carbon during CO2 absorption by mortar. Radiocarbon 28(2A):691–7.Google Scholar
Ringbom, Å, Remmer, C. 1995. Ålands Kyrkor, Volume 1, Hammarland och Eckerö. Mariehamn: Ålands landskapsstyrelse/Museibyrån. 300 p. In Swedish with English summary.Google Scholar
Ringbom, Å, Remmer, C. 2000. Ålands Kyrkor, Volume 2 Saltvik. Mariehamn: Ålands landskapsstyrelse/Museibyrån. 280 p. In Swedish with English summary.Google Scholar
Ringbom, Å, Remmer, C. 2005. Ålands Kyrkor, Volume 3, Sund og Vårdö. Mariehamn: Ålands landskapsstyrelse/Museibyrån. 336 p. In Swedish with English summary.Google Scholar
Ringbom, Å, Hakkarainen, G, Bartholin, T, Jungner, H. 1996. Åland churches and their scientific dating. Proceedings of the Sixth Nordic Conference on the Application of Scientific Methods in Archaeology, Esbjerg 1993, Arkæologiske rapporter 1:291302.Google Scholar
Ringbom, Å, Hale, J, Heinemeier, J, Lindroos, A, Brock, F. 2006. Mortar dating in Medieval and Classical archaeology. Constructional History Society Newsletter 73 (ISSN 0951 9203). p 11–8.Google Scholar
Ringbom, Å, Heinemeier, J, Lindroos, A, Sveinbjörnsdóttir, Á. 2009. Projektet Ålands kyrkor och murbruksdatering - rapport från en metodutveckling. 9, Kirkearkeologi i Norden. Kalundborg, Danmark 2007. hikuin, 36. Forlaget Hikuin. p 129–58.Google Scholar
Ringbom, Å, Heinemeier, J, Lindroos, A, Brock, F. 2010. Mortar dating and roman pozzolana, results and interpretations. In: Ringbom, Å, Hohlfelder, R, editors. Proceedings from Building Roma Aeterna Conference. 27–29 March 2008, Rome. In press.Google Scholar
Sárkány, T. 1973. Ålands medeltida kyrkor. Acta Universitatis Stockholmiensis, Stockholm Studies in History of Art 25. Lund. p 115–34.Google Scholar
Sonninen, E, Jungner, H. 2001. An improvement in preparation of mortar for radiocarbon dating. Radiocarbon 43(2A):271–3.Google Scholar
Stuiver, M, Polach, HA. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355–63.Google Scholar
Stuiver, M, Smith, CS. 1965. Radiocarbon dating of ancient mortar and plaster. In: Chatters, RM, Olson, EA, editors. Proceedings of the 6th International Conference on Radiocarbon and Tritium Dating. Washington, DC: US Department of Commerce. p 338–41.Google Scholar
Tubbs, LE, Kinder, TN. 1990. The use of AMS for the dating of lime mortars. Nuclear Instruments and Methods in Physics Research B 52(3–4):438–41.CrossRefGoogle Scholar
Van Strydonck, M, Dupas, M. 1991. The classification and dating of lime mortars by chemical analysis and radiocarbon dating: a review. In: Waldren, WH, Ensenyat, JA, Kennard, RC, editors. Second Deya International Conference of Prehistory. Volume II. BAR International Series 574. Oxford: Archaeopress. p 543.Google Scholar
Van Strydonck, M, Dupas, M, Dauchot-Dehon, M. 1983. Radiocarbon dating of old mortars. PACT 8:337–43.Google Scholar
Van Strydonck, M, Dupas, M, Dauchot-Dehon, M, Pachiaudi, C, Marechal, J. 1986. The influence of contaminating (fossil) carbonate and the variations of δ13C in mortar dating. Radiocarbon 28(2A):702–10.Google Scholar
Van Strydonck, M, Dupas, M, Keppens, E. 1989. Isotopic fractionation of oxygen and carbon in lime mortar under natural environmental conditions. Radiocarbon 31(3):610–8.Google Scholar
Veizer, J, Ala, D, Azmy, K, Bruckschen, P, Buhl, D, Bruhn, F, Carden, GAP, Diener, A, Ebneth, S, Godderis, Y, Jasper, T, Korte, C, Pawellek, F, Podlaha, OG, Strauss, H. 1999. 87Sr/86Sr, δ13C and δ18O evolution of Phanerozoic seawater. Chemical Geology 161(1–3):5988.CrossRefGoogle Scholar
Vogel, JS, Southon, JR, Nelson, DE, Brown, TA. 1984. Performance of catalytically condensed carbon for use in accelerator mass spectrometry. Nuclear Instruments and Methods in Physics Research B 5(2):289–93.Google Scholar
Willaime, B, Coppens, R, Jaegy, R. 1983. Datation des mortiers du chateau de Chatel-sur-Moselle par le carbone 14. PACT 8:345–9.Google Scholar
Winterhalter, B, Flodén, T, Ignatius, H, Axberg, S, Niemistä, L. 1981. Geology of the Baltic Sea. Amsterdam: Elsevier Oceanographic Series 30. 418 p.Google Scholar