Deterioration of archaeological bone - a statistical approach

The degradation of archaeological bone material in Sweden was studied (i) by examinating bone specimens, the surrounding soil and the local environment at excavations in progress, and (ii) by studying the reports of earlier excavations. Conventional and multivariate statistical methods applied to the data sets show that the degradation increases with time in the soil, and that the recent soil acidification is disastrous for the inorganic fraction of bone material. It is also observed that calcareous soil, the presence of organic matter in the soil, a deep grave, or a coffin of wood usually has a preserving effect. The empirical fact that bones of children deteriorate more than those of adults is confirmed, but no clear relation can be established between bone deterioration and soil type. The deterioration of the organic content and the histological microstructure is to a large degree dependent on microbial attack and unknown factors such as diseases, living conditions, or burial traditions.