Archaeometric measurements of human bones from the cemetaries in Ribe, Denmark

The results of this Ph.D. thesis show that the bones of prehistoric populations can be distinguished
based on the area of excavation. The bones used in the thesis were excavated, in Denmark, at two
locations in Ribe, and one location near Horsens, called Tirup. By measuring Sr, Ba, Ca Pb, and
Hg in the bones of prehistoric people excavated at two sites; Ribe and Tirup, the two buried
populations could be distinguished in a PCA analysis. Sr, Ba, Ca, and Pb were measured in the
bones with ICP-MS, and Hg was measured by AAS. A difference was also observed in a PCA
based on time. Viking-, Medieval-, and Renaissance bones were excavated in Ribe, and they
separated into three groups, in a PCA. Some division was also observed in a PCA based on burial
location within at a site of a demolished Franciscan Friary. A PCA analysis was used to analyse the
results of Sr, Ba, Ca, Pb, and Hg measured in medieval bones, from one of the excavation site in
Ribe, and the wealthy separated from the less wealthy, in the PCA. When chemical analysis, like
the once presented in this thesis, is used to measure Sr, Ba, Ca, Pb, and Hg in bone, it is important
to use the same type of bone tissue because the concentration of these elements varies greatly in the
different types of bone tissue. A PCA analysis performed, in this project, shows that the elements
vary more in the trabecular bone, than in the compact bone tissue, and the chemical composition of
the tissues are different.
Two studies were carried out with the purpose of studying two of the many possible sources for the
elements in the bone material. A study, of residues from the insides of potsherds, revealed that the
residues contained biomarkers from plant material or animal fat. Furthermore, there was a residue
of pitch on one of the potsherds. The potsherds were analysed with GC-MS, in Italy. In another
study, XRF was used to study moulds from medieval Ribe. The moulds consisted of several parts
which were assembles with nails. Two of the nails were found to be of Pb, while a third was of Sn.
Diagenesis and contamination are major problems in chemical analysis of archaeological materials.
Analysis of bones and teeth revealed that the surfaces were contaminated with Al, Mn, and Fe from
the soil, and there were also some indications of diagenetic changes inside the bones and teeth. The
bones and teeth were measured with LA-ICP-MS. The concentrations of Sr, Ba, Ca, Mn, Fe, Al,
Hg, and Pb were measured in the burned pig bone after one year, and again after 21 years of
deposition, and the results showed that the Mn, Al, Fe, and Ba concentrations increased in the 20
years of deposition, while Ca, Sr, Hg, and Pb were unchanged.