Stones In Motion: Cost Units To Understand Flint Procurement Strategies During The Upper Palaeolithic In The South-Western Pyrenees Using Gis

Studies on lithic resource management -mainly flint- by prehistoric groups south of the western Pyrenees have significantly increased during the past decades. These studies usually focus on identifying outcrops and characterising the different varieties found at archaeological sites. However, the understanding of mobility and territorial management patterns based on raw materials is still very limited and has only been tackled in terms of lineal distance.This paper proposes a methodological approach for the territorial analysis of flint distribution with the three following aims: 1) to determine the expansion ranges of each variety of flint from its outcrop; 2) to spatially relate these outcrops with archaeological sites; and 3) to improve our knowledge on the catchment strategies of Upper Palaeolithic groups.The methodological tool chosen to fulfil these objectives is the Geographic Information System (GIS), because it allows to relate spatially the flint outcrops and flint varieties identified at archaeological sites based on: 1) isocost maps showing the cost of expansion for each variety of flint across the territory built on topography; 2) the quantification of the cost of expansion using Cost Units (CU); and 3) the relationship between the percentage of each variety of flint at each archaeological site and the cost of accessing its outcrop. In order to demonstrate that cost is a powerful way to relate spatially raw material distribution and archaeological sites with outcrops, we contrasted its results with the ones obtained by more classic means (Euclidean distance and distance across the most optimal route). It was therefore shown that cost is better at explaining the spatial relationship between flint outcrops and archaeological sites, which, in turn, provides new data on catchment strategies, mobility patterns and territorial management of Upper Palaeolithic groups.