Physico-Chemical Characteristics of Waterlogged Archaeological Wood

Waterlogged wood samples 300 to 100.000 years old of Picea abies, Pinus sylvestris and Quercus sp. from northern Europe (Norway, Sweden) that had been preserved in a glacier, burial grounds, house settlements, harbour installations and sunken ships in the sea were examined for changes in physico-chemical characteristics as compared to recent wood. The results showed that in waterlogged wood of all species the solubility in 1% NaOH (8.39-22.85%) was found to be higher than that of recent wood (3.84-5.57%). Ash content varied between 1.37-7.12% in old wood and was much higher than in fresh wood (0.31-0.65%). Klason ligin in old wood (25.71-72.40%) was higher than in fresh wood (20.31-30.95%) while crystallinity index (12.79-33.69%) was found to be lower than in fresh wood (34.56-40.20%). Increasing lignin content in old wood resulted in reducing the crystallinity index up to 3.1 times.