Hostname: page-component-848d4c4894-2xdlg Total loading time: 0 Render date: 2024-06-19T08:40:42.506Z Has data issue: false hasContentIssue false

On the Eve of Urbanization: Bayesian Model Dating for Medieval Turku

Published online by Cambridge University Press:  09 February 2016

M Oinonen*
Finnish Museum of Natural History - LUOMUS, University of Helsinki, Finland Docent, University of Turku, Finland
E Hilasvuori
Finnish Museum of Natural History - LUOMUS, University of Helsinki, Finland Finnish Environmental Institute, Helsinki, Finland
H Mehtonen
Finnish Museum of Natural History - LUOMUS, University of Helsinki, Finland
K Uotila
Muuritutkimus ky, Kaarina, Finland Laboratory of Dendrochronology, University of Eastern Finland, Finland
P Zetterberg
Laboratory of Dendrochronology, University of Eastern Finland, Finland
2Corresponding author. Email:


The era of early urbanization in Finland coincides with large variations in the atmospheric radiocarbon concentration around the 13th–14th centuries AD. Therefore, the uncertainties of an individual 14C date are too large to support studies of this time period effectively. In this work, we have employ tree-ring wiggle-matching methodology and used Bayesian modeling of dates to account for stratigraphical a priori information within Aboa Vetus Museum, Turku, Finland. The wiggle-match method helps significantly to overcome the calibration-curve-induced challenges within 14C dating. The results of the dating model agree with the typological dates of the archaeological finds and illustrate a gradual evolution of urbanization in one of the oldest cities in Finland.

Archaeology of Eurasia and Africa
Copyright © 2013 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Bronk Ramsey, C. 1995. Radiocarbon calibration and analysis of stratigraphy: the OxCal program. Radiocarbon 37(2):425–30.CrossRefGoogle Scholar
Bronk Ramsey, C. 2009a. Bayesian analysis of radiocarbon dates. Radiocarbon 51(1):337–60.CrossRefGoogle Scholar
Bronk Ramsey, C. 2009b. Dealing with outliers and offsets in radiocarbon dating. Radiocarbon 51(3):1023–45.CrossRefGoogle Scholar
Bronk Ramsey, C, van der Plicht, J, Weninger, B. 2001. ‘Wiggle matching’ radiocarbon dates. Radiocarbon 43(2A):381–9.Google Scholar
Christen, JA, Litton, CD. 1995. A Bayesian approach to wiggle-matching. Journal of Archaeological Science 22(6):719–25.Google Scholar
Haggren, G. 2012. Lasipikareita ja ikkunansirpaleita – Aboa Vetuksen alueen uudet löydöt ja Turun varhais-vaiheet. SKAS 4:50–6.Google Scholar
Heinemeier, J, Ringbom, Å, Lindroos, A, Sveinbjörnsdóttir, ÁE. 2010. Successful AMS 14C dating of non-hydraulic lime mortars from the Medieval churches of the Åland Islands, Finland. Radiocarbon 52(1):171204.CrossRefGoogle Scholar
Hiekkanen, M. 2002. Die Gründung der Stadt Turku. Civitas et castrum ad Mare Balticum, Baltijas arheoloijas un vstures problmas dzelzs laikmet un viduslaikos. Rakstu krjums – veltjums LZA stenajam loceklim prof. Dr. habil. hist. Andrim Caunem 65 gadu dzves jubilej. Latvijas vstures institta apgds. Riga. p 156–77.Google Scholar
Lindroos, A, Regev, L, Oinonen, M, Ringbom, Å, Heinemeier, J. 2012. 14C dating of fire-damaged mortars from Medieval Finland. Radiocarbon 54(3–4):915–31.Google Scholar
Longin, R. 1971. New method of collagen extraction for radiocarbon dating. Nature 230(5291):241–2.Google Scholar
Oinonen, M, Hilasvuori, E, Nordqvist, H, Uotila, K, Zetterberg, P. 2012a. Context dating of medieval Turku - wiggle matching technique scrutinized at Aboa Vetus. Castella Maris Baltici X (2009). In: Uotila, K, Mikkola, T, Vilkuna, A-M, editors. Archaeologica Medii Aevi Finlandiae XVIII. Saarijärvi. p 191–6.Google Scholar
Oinonen, M, Hilasvuori, E, Nordqvist, H, Uotila, K, Zetterberg, P. 2012b. Turun kaupungistumisen alkuhetkien radiohiiliajoituksia bayesilaisella menetelmällä. SKAS 4:1526.Google Scholar
Pearson, GW. 1986. Precise calendrical dating of known growth-period samples using a “curve fitting” technique. Radiocarbon 28(2A):292–9.Google Scholar
Pihlman, A. 2010. Turun kaupungin muodostuminen ja kaupunkiasutuksen laajeneminen 1300-luvulla. In: Söderstöm, M, editor. Varhainen Turku. Turun museokeskuksen raportteja 22. p 7994.Google Scholar
Pihlman, A. 2012. Aboa Vetus & Ars Nova museon tontin vv. 2009–2010 laivausten saviastiat 1200-luvun jälkipuoliskolla ja 1300-luvun alkupuolella. SKAS 4:43–9.Google Scholar
Reimer, PJ, Baillie, MGL, Bard, E, Bayliss, A, Beck, JW, Blackwell, PG, Bronk Ramsey, C, Buck, CE, Burr, GS, Edwards, RL, Friedrich, M, Grootes, PM, Guilderson, TP, Hajdas, I, Heaton, T, Hogg, AG, Hughen, KA, Kaiser, KF, Kromer, B, McCormac, FG, Manning, SW, Reimer, RW, Richards, DA, Southon, JR, Talamo, S, Turney, CSM, van der Plicht, J, Weyhenmeyer, CE. 2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0–50,000 years cal BP. Radiocarbon 51(4): 1111–50.CrossRefGoogle Scholar
Sartes, M. 2003. Rettigin palatsin tontista tuli Aboa Vetus–museo. Kaupunkia pintaa syvemmältä. In: Seppänen, L, editor. Arkeologisia näkökulmia Turun historiaan. AMAF IX. p 7786.Google Scholar
Seppänen, L. 2011. Lost but found underground. Construction, development and maintenance of medieval streets and squares of Turku (Finland). In: Proceedings of the 16th International Conference on Cultural Heritage and New Technologies. Vienna, Austria 2011. p 476–90.Google Scholar
Seppänen, L. 2012. Rakentaminen ja kaupunkitilan käyttö keskiajan Turussa – Eritystarkastelussa Åbo Akademin päärakennuksen tontin arkeologinen aineisto [PhD thesis]. University of Turku.Google Scholar
Slota, PJ Jr, Jull, AJT, Linick, TW, Toolin, LJ. 1986. Preparation of small samples for 14C accelerator targets by catalytic reduction of CO. Radiocarbon 29(2):303–6.Google Scholar
Taavitsainen, J-P, Uotila, K. 2009. Recent urban archaeological work in Finland with particular reference to the towns of Turku/Åbo and Naantali/Nådendal in Finland Proper. The Hansa town Riga as mediator between East and West. Andris Caune and Ieva Ose. Riga. p 5867.Google Scholar
Uotila, K. 2009. Aboa Vetus. In: Muhonen, T, Lehto-Vahtera, J, editors. Rauniokohde ja sen tutkimus. Ikuinen raunio. p 4263.Google Scholar
Zetterberg, P. 2008. Turun Aboa Vetus & Ars Nova -museon vuoden 2008 arkeologisen kaivauksen puunäytteen dendrokronologinen ajoitus, näyte F1T4806. Joensuun yliopisto, Biotieteiden tiedekunta, Ekologian tutkimusinstituutti, Dendrokronologian laboratorio, ajoitusseloste 335. p 14.Google Scholar
Zetterberg, P. 2012. Dendrokronologisten näytteiden ristiinvertailulla uusia ajoitustuloksia Aboa Vetus-museon vanhoista näytteistä. SKAS 4:2731.Google Scholar