Abstract
Abstract
Alum-treatment was extensively applied to archaeological wood from the Oseberg collection in the early 1900s, and was a common conservation method at the time involving impregnating objects with hot concentrated solutions of potassium alum (KAl(SO4)2⋅12H2O). This now obsolete consolidation method has led to dramatic long-term consequences, heavily affecting the state of preservation of the historical wooden artefacts, and dedicated chemical characterisation campaigns have been undertaken to better understand the degradation processes and aid development of re-treatment strategies. Analyses with Fourier transform infrared spectroscopy (FTIR), elemental microanalysis, and ion chromatography (IC) was performed, suggesting the presence of ammonium alum (NH4Al(SO4)2·12H2O) in many alum-treated wood samples, though no record exists of use of ammonium compounds during treatment of the artefacts. C/N rations of 1.70–68.8 in wood samples, and ammonium alum contents between 8 and 84% of the alum component and 23–168 mmol/100 g of total sample suggested that objects were actually treated with various mixes of potassium and ammonium alum. The two alums have similar properties, and in model studies of their behaviour under the conditions of alum-treatment appeared to form similarly acidic solutions, thus the different alum mixtures probably did not significantly influence object treatment. Nor have we observed other indications of unusual degradation pathways related specifically to the presence of ammonium alum. Nonetheless, investigations into potential re-treatment of the archaeological objects must be adjusted accordingly.
Funder
Universitetet i Oslo
Norwegian Ministry of Education and Research
Publisher
Springer Science and Business Media LLC
Subject
Archaeology,Archaeology,Conservation
Reference27 articles.
1. Brorson Christensen B. The conservation of waterlogged wood in the National Museum of Denmark. Copenhagen: National Museum of Denmark; 1970.
2. Häggström C, Lindahl K, Sahlstedt M, Sandström T, Wikstad E. Alum-treated archaeological wood: characterization and re-conservation. Stockholm: Swedish National Heritage Board; 2013.
3. Eaton JW. The preservation of wood by the alum process. Florida Anthropol. 1962;15(4):115–7.
4. Brøgger AW, Shetelig H, Falk H. Osebergfundet. Oslo: Distribuert ved Universitetets Oldsaksamling; 1917.
5. Braovac S, Kutzke H. The presence of sulfuric acid in alum-conserved wood - Origin and consequences. J Cult Herit. 2012;13(3):S203–S208208.
Cited by
6 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献