From blunt to cutting: Distinguishing alternating method flakes in early stages on rounded blanks M. Guardiola a, b, c, * , J.I. Morales a, b , J.M. Verg  es a, b a IPHES: Institut Catal a de Paleoecologia Humana i Evoluci o Social, C/ Marcel·lí Domingo, s/n, 43007, Tarragona, Catalonia, Spain b  Area de Prehist oria Universitat Rovira i Virgili (URV), Av. Catalunya, 35, 43002, Tarragona, Catalonia, Spain c Laboratoy Arch eologie et Peuplement de l'Afrique, Department of Genetics and Evolution, Anthropology Unit, University of Geneva, Switzerland article info Article history: Available online xxx Keywords: Alternate Alternating Flaking sequence Cortical flakes Nodules/cobbles abstract Two main knapping strategies can be used to start bifacial reduction on a lithic cobble or nodule: the alternate strategy, in which first one face is knapped and then the other; and the alternating strategy, in which both faces are removed in the same sequence, interspersing core about-turns between strikes. Flaking reduction of spherical and elliptical blanks (cobbles or nodules) is a common knapping process documented in many archaeological records. Rounded and thick edges require different fracture parameters and give rise to constraints in terms of viable knapping methods. When analysing abandoned cores, it is only possible to see the last strikes, so it is important to know how they were shaped or exploited in the earlier knapping stages in order to understand the entire reduction process. As cortical flakes are the direct evidence of the first reduction phases, we undertook an experimental programme for the purpose of comparing the first flakes generated using the alternate and alternating knapping strategies. We have focused our efforts on identifying and diagnosing distinctive features produced by each strategy in the first or cortical flakes. Our study indicates that several platform attributes can be considered as diagnostic features to differentiate between the alternate and alter- nating knapping strategies, and that this kind of analysis can be translated to archaeological assemblages. © 2015 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction Understanding the way in which stone tools were produced in the past is important in order to infer the technological behaviours (Pelegrin, 1985, 1993; Delagnes and Roche, 2005; Braun et al., 2008; Stout et al., 2008, 2010) and capabilities of extinct hominin pop- ulations. Bifacial reduction strategies such as the alternate and alternating methods can be considered basic flaking methods that appeared early on in the technological record and were applied throughout hominin evolution (Pelegrin, 2005). Therefore, identi- fying the application of the alternate and alternating methods, as well as their origin and evolution, could be useful in constructing the referential framework for technological evolution as well as for all of the derived cognitive, motor skills, technological and cultural implications. Given the continuity and evolution of the reduction sequence (Braun et al., 2005), in a state of abandonment, many tools and cores do not exhibit the necessary attributes to identify how the knapping sequence was started, so primary reduction flakes may be a reliable indicator of the knapping sequences carried out. If it is possible to experimentally identify distinguishing at- tributes on flakes, then the recognition of different first stage reduction strategies could be translated to the archaeological record. Bifacial tools (e.g. handaxes) and cores (e.g. discoid) can be shaped and exploited using different types of blanks like large flakes, cobbles and nodules, or slab-like fragments as a matrix. From a technical point of view, cobbles and slabs tend to present thick rounded or squared edges that usually make beginning to perform bifacial reductions difficult (Callahan, 1979, pp. 64; Jones, 1994). The result of this starting phase determines the entire shaping process and is dependent on the structure (Roth and Dibble, 1998), shape (White, 1998; White and Ashton, 2003), and * Corresponding author. IPHES: Institut Catal a de Paleoecologia Humana i Evoluci o Social, C/ Marcel$lí Domingo, s/n, 43007, Tarragona, Catalonia, Spain. E-mail addresses: esclats@gmail.com (M. Guardiola), jignacio.morales@gmail. com (J.I. Morales), jmverges@iphes.cat (J.M. Verg es). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint http://dx.doi.org/10.1016/j.quaint.2015.08.039 1040-6182/© 2015 Elsevier Ltd and INQUA. All rights reserved. Quaternary International xxx (2015) 1e8 Please cite this article in press as: Guardiola, M., et al., From blunt to cutting: Distinguishing alternating method flakes in early stages on rounded blanks, Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.08.039