Distribution patterns of stone-tool reduction: Establishing frames of reference to approximate occupational features and formation processes in Paleolithic societies Juan I. Morales ⇑ IPHES; Institut Català de Paleoecologia Humana i Evolució Social, C/ MarcelÁlí Domingo s/n, Campus Sescelades URV (Edifici W3), 43007 Tarragona, Spain Àrea de Prehistòria, Universitat Rovira i Virgili (URV), Avinguda de Catalunya, 35, 43002 Tarragona, Spain article info Article history: Received 4 May 2015 Revision received 14 January 2016 Keywords: Reduction analyses Lithic technology Weibull distribution Upper Paleolithic Iberian Peninsula abstract The main goal of this work is to illustrate the interpretative potential of regionally oriented tool-use-life approaches to infer patterns of mobility, occupational intensity, and assemblage formation processes. We apply a wide reduction analysis to 15 Late Upper Paleolithic lithic assemblages. We perform an explora- tory data analysis to observe reduction intensity tendencies among the different assemblages, and we characterize reduction distribution patterns using Weibull probability distribution functions. To avoid sampling effects, resampling and bootstrapping were performed. The Weibull profiles of the analyzed data show different degrees of occupational intensity and/or length that are not observable through the classical techno-typological approaches. A referential reduction space is also simulated to create a frame to interpret our results in a more absolute scale. Ó 2016 Elsevier Inc. All rights reserved. 1. Introduction Stone tools were used by prehistoric societies for a large variety of daily activities. Inherently, some of the features characterizing the archaeological stone tool associations recovered by archaeolo- gists should allow us to infer patterns of economic (Binford, 1977, 1979, 1980) and cultural organization of the prehistoric groups. The levels of inference performed through the study of lithic remains are closely related with the depth of the analysis and the outlined questions about the prehistoric dynamics. In some cases, the single appearance of a particular tool type or technology is enough to answer some of it, but this only covers classification, the lowest level of analysis that archaeologists can conduct. Notwithstanding, a classificatory approach is not enough to define structural social patterns or ranges of behavioral variability, especially between highly analogous assemblages of stone tools. The identification of regional settlement and mobility dynamics, the definition of site functions, or the establishment of land-use patterns represents the inferred results from approaches such as raw material procurement, knapping strategies or tool mainte- nance and discard (e:g:; Bamforth, 1990; Andrefsky, 1994; Bicho, 2002; Aubry et al., 2012). Ever since the empirical application of the ‘‘reduction thesis” precepts (Fig. 1)(Dibble, 1984, 1987a,b, 1995), reduction patterns, understood as the life history of every single tool (from the time that it is shaped or detached from a core until it is refused), have been largely explored and have been found to have a great poten- tial in the identification of past dynamics (see Andrefsky, 2009 and Andrefsky and Goodale, 2015 for detailed reviews). To illustrate this potential, the reader can picture two assem- blages with exactly the same composition, and assume the degree of reduction of each one must be correlated only with the amount and duration of the activities performed during the occupation of the sites. In a basic scenario, if one site is occupied continuously for several weeks, the observed reduction and discard patterns at the end of the occupation must be different to those displayed by a three-day bivouac campsite or even a site occupied during the same several weeks but only for the performance of particular activities in a daily mobility schedule. In every case, the resulting assemblage should be generally determined by the economic value of raw material in every systemic context. According to this, the characterization of the assemblage reduc- tion structure has evident implications in terms of occupation pat- terns, site function, mobility dynamics, regional networks, or in site formation processes (Schiffer, 1987). Thus, a standardized tool to analyze and compare reduction structures implies an important http://dx.doi.org/10.1016/j.jaa.2016.01.004 0278-4165/Ó 2016 Elsevier Inc. All rights reserved. ⇑ Address: IPHES; Institut Català de Paleoecologia Humana i Evolució Social, C/ MarcelÁlí Domingo s/n, Campus Sescelades URV (Edifici W3), 43007 Tarragona, Spain. E-mail address: jignacio.morales@gmail.com Journal of Anthropological Archaeology 41 (2016) 231–245 Contents lists available at ScienceDirect Journal of Anthropological Archaeology journal homepage: www.elsevier.com/locate/jaa