The workshop "The Big Puzzle 30 years after: a multidisciplinary, shared, Palaeolithic perspective" was kindly supported by the Wenner-Gren Foundation Ref: Gr CONF-737. We are also thankful to the volunteers of the UCL-Lithics Lab that helped in processing the experiments. T. Proffitt's contribution was funded by a British Academy Fellowship (#542133). Raw material collection at Olduvai Gorge was funded by the European Research Council (Starting Grants 283366).

Freehand and bipolar experimental knapping of quartzite from Olduvai Gorge in Tanzania is used to conduct spatial analysis of artefact distributions using GIS techniques, and to investigate the orientation of refit lines using circular histograms. The aim of our study is to discern patterns that can be applied to the archaeological record in two domains, namely the identification of knapping episodes and the utility of refitting line orientations in addressing post-depositional disturbance. Our spatial analysis shows that distinctive clustering patterns can be discerned according to knapping stance, handedness and flaking technique. The circular dispersion of refit lines in the horizontal distribution of bipolar assemblages is strongly patterned, indicating that anisotropy of conjoining sets is inherent to pristine hammer-and-anvil knapping episodes.