Labiilit ikäykset ja stabiilit isotoopit:lisää ¹⁴C-ajoituksia Keminmaan Valmarinniemeltä

• Main Author: Ikäheimo, J. (Janne)
• Format: Article in Journal/Newspaper
• Language: Finnish
• Published: Pohjois-Suomen historiallinen yhdistys 2018
• Subjects: Keminmaa; Valmarinniemi
• Online Access: http://urn.fi/urn:nbn:fi-fe2018061425873

Summary Labile datings and stable isotopes : more radiocarbon dates from the cemetery of Valmarinniemi This follow-up article to a contribution published in Faravid 43 (2017: 107–128) examines and discusses eleven new radiocarbon dates — nine bone collagen dates from inhumation burials and two charred bone dates from cremation burials — obtained from the early Medieval cemetery of the Kemi parish, located at Cape Valmarinniemi in Keminmaa. The results (Table 1) were somewhat surprising, as they seem to challenge the chronology of the site based on the rate of post-glacial land-uplift, historical sources and the datable finds made during the excavations of the cemetery in 1981. The area of Valmarinniemi is estimated to have emerged from the sea during the 11th century, while the use of the cemetery is dated to the 14th and 15th centuries. A partial explanation for "too old" dating results is the advanced decay of the unburned bone material recovered from the site. One of the samples (Beta-451048) sent to Beta Analytic Inc. for dating was contaminated with rootlets, while at least two bones from which samples were taken (Beta-451049 and Beta-451052) had been stabilized during conservation with Paraloid B-72 acrylic resin. While the radiocarbon service service provider treated both samples with a solvent to extract the resin, the anomalous dating result (Beta-451049) falling into the late first millennium AD indicates that the procedure had most likely been unsuccessful. Reservoir effect is another factor to be taken into account when reviewing the dating results of inhumation burials, as the δ13C-values are somewhat elevated (−17.9–−21.0 ‰) probably reflecting the importance of marine resources, especially salmon and other fish, in the diet. Reservoir corrections were calculated with Calib 7.1 -online software using 262+100 years as a full reservoir effect correction and δ13Cmin −20.9 ‰ (terrestrial) and δ13Cmax −14.8 ‰ (marine) as threshold values (Figure 2). However, as the calculation of marine corrections did ...