An estimator for bidirectional (naviform) blade productivity in the Near Eastern Pre-Pottery Neolithic B

A method is presented for calculating the blade productivity of bidirectional (naviform) blade cores, a hallmark of Near Eastern Pre-Pottery Neolithic B (PPNB) chipped stone tool assemblages. This approach involves estimating the volume of the core that furnished serial blades, together with the mean volume of a typical targeted blade blank. Simple computation of the volume of a wedge in both instances provides an estimate of the number of targeted blades that were produced in an average single reduction sequence. The method is checked against two replicated bidirectional blade reduction sequences, and a refitted bidirectional blade core from the site of Kfar HaHoresh, Israel. Finally, a case study from Kfar HaHoresh is presented in order to illustrate the application of the method, which may have ramifications concerning the evaluation of incipient craft specialization in the region.