J Archaeol Sci 30 (4)

To date, direct measurements of bone porosity have been used primarily to quantify the degree of diagenetic alteration. Qualitative zooarchaeological observations over many years have suggested that, for equivalent burial conditions, the bones of different taxa degrade at different rates, and that, even within a single skeleton, systematic variation often occurs. Given that freedom of access of water to the internal bone surface is likely to be an important factor in controlling the rate of chemical alteration, it is postulated that the initial porosity of a bone may be an important factor in predicting the rate of degradation. To test this, nitrogen porosimetry was used as a technique for comparing the total pore volume and size distribution of pores between a selection of anatomical elements taken from a range of modern animals commonly represented on European archaeological sites. It is illustrated that the bones of modern domestic pig are, on average, more porous than those of other ungulates, and should therefore be likely to degrade faster after burial. Systematic differences in porosity are also shown between different anatomical elements from a single individual and between adult and juvenile bone. However, that porosity measurements are affected by sample storage and preparation methodology, particularly freezing, is also seen. Variations in bone porosity between different skeletal elements and taxa necessitate careful sample selection and matching in order to minimize variation. It is concluded that, despite these restrictions, direct measurement of variations in bone porosity shows good potential for contributing to a predictive model for bone diagenesis.

This paper deals with the quantification of use-wear polish, using image analysis as a means to increase the objectivity of use-wear analysis. The three elements which characterize polish (texture, pattern and degree of development) are measured. First results are promising, showing that, if the degree of development of the polish is isolated, the characteristics of pattern and texture enable consistent grouping of polishes from different worked materials (wood, bone, hide, etc.). Image analysis can be used to improve the use-wear methodology.