Reduction intensity of backed blades: Blank consumption, regularity and efficiency at the early Neolithic site of Boncuklu, Turkey

Estimating the extent of reduction intensity on lithic artefacts has become a key goal of lithic analyses in recent decades. An understanding of a core or tool's reduction intensity can lead to intra- and inter-site interpretations regarding patterns of human behaviour. Decades of research on this topic have led to a diverse suite of quantifiable measures of reduction encompassing almost all artefact types. We present and test the efficacy of a new method for measuring reduction intensity for backed blades, one of the few remaining artefact types lacking a reliable measure of reduction. As instances of successive retouching of backed blades are rarely documented, we use this reduction intensity metric to estimate original blank size, rather than model multiple stages of reduction. Allometric relationships of blade thickness to length and width were used to estimate original microlith blank size, thereby offering a quantification of reduction intensity. This method was then applied to the microliths, a specific type of small backed blade, from the early Neolithic site of Boncuklu, Turkey. Reconstructing the original mass and dimensions of microlith blanks allows inferences to be made regarding the regularity, efficiency and decision making involved in microlith production. These microliths were produced using similarly sized blanks that were selectively and nearly completely consumed in this reduction sequence. This aspect of lithic technology at Boncuklu involved little waste and therefore enabled the inhabitants to cope with the constraints of raw material access and negotiate the changes to subsistence and social organisation occurring at the beginning of the Neolithic. While we test the efficacy of this new method on the Neolithic of Turkey, it could equally be applied to any blade- or bladelet-based backed artefact industry. These industries existed at various times in Europe, the Near East, Africa, South Asia, and parts of Australia, together spanning the Middle Stone Age, Later Stone Age/Upper Palaeolithic, Epipalaeolithic, Mesolithic and Neolithic.