Understanding Prehistoric Lithic Raw Material Selection: Application of a Gravity Model

Provenance studies can tell us which sources of lithic raw material were used in the past, but can they tell us why? After all, many factors can have entered into a person’s choice to use one source rather than another. Those factors can be grouped into two categories, the geologic/geographic characteristics of the source itself (quality, abundance, size of pieces, etc.), and the human factors (direction of travel, time available, social restrictions, etc.). This paper demonstrates how the geologic/geographic characteristics can be quantified and calculated together to give one value, the attractiveness of the source, which can then be used in a gravity model approach to predict which sources ‘should’ have been used more than others. Deviations from the predicted pattern point to situations where the human factors were of greater or lesser importance. The values are also used to delineate geographical areas within which particular sources would be likely to be used (‘areas of influence’), which gives us a useful new way of understanding the landscape within which the prehistoric group lived.