Geochemical methods for provenance studies of steatite
The aim of archaeology is the reconstruction of past cultures and the processes behind cultures. Conclusive evidence of cultural contacts between distinct groups of peoples is of great importance. It has long been realised that the study of the raw materials utilised for artifacts that were then moved far from their place of origin is vital in identifying these contacts and this study is concerned with the investigation of one such material - steatite. Steatite is a soft talcose rock that is easily carved even with stone, bone or metal tools. It also has a low coefficient of thermal expansion. These physical properties have resulted in steatite being used as a raw material for the production of many domestic and decorative items throughout the world from prehistoric times until the present. However, the geological formation process has only occurred in a limited number of locations, and hence steatite sources have a relatively restricted geographical distribution. Thus steatite can be seen to fulfil a number of the basic requirements for provenancing, namely limited geographical distribution and extensive utilisation in the past. As a lithic material the physical production techniques do not affect the physical and chemical nature of the material, which may be a considerable problem with characterisation of other archaeological material, eg. ceramics, metal and glass. Thus by characterisation of source material, steatite artifacts of unknown provenance may be compared and their ultimate origin established. However, the formation of steatite is a complex process that often results in a source body that is inhomogeneous, making simple characterisation techniques inadequate. This study seeks to establish differences between source regions and between individual quarries. If a unique pattern in measurable properties can be established, by comparing artifacts to sources, their origin may be established.