Dents in our confidence: The interaction of damage and material properties in interpreting use-wear on copper-alloy weaponry Christian Horn a, * , Isabella C.C. von Holstein b a Institut für Ur- und Frühgeschichte, Christian-Albrechts-Universit€ at, Johanna-Mestorf-Straße 2-6, D-24098, Kiel, Germany b Department of Earth Sciences, Faculty of Earth & Life Sciences, VU University Amsterdam, De Boelelaan 1085,1081 HV, Amsterdam, The Netherlands article info Article history: Received 6 September 2016 Received in revised form 4 April 2017 Accepted 6 April 2017 Keywords: Copper Corrosion Patina Fracture Repair Damage formation Wear analysis Weaponry abstract The presence or absence of use-wear marks on copper (Cu)-alloy weaponry has been used since the late 1990s to investigate the balance between functional (combat) and symbolic (value, status, religious) use of these objects, and thus explore their social and economic context. In this paper, we suggest that this work has not taken sufficient account of the material properties of Cu-alloys. We discuss mechanisms of plastic deformation, incremental repairs and corrosion in detail to show how these can obscure use-wear traces. In a survey of Cu-alloy weaponry from the Nordic Bronze Age (1800/1700e550 BCE) from Denmark, Sweden and Germany, we show that corrosion of Cu-alloy objects is strongly linked to depositional context, being greater in burials (both inhumations and cremations) than hoards or as single objects. A relative paucity of use-wear marks on burial weapons should therefore not be used to argue that these were purely symbolic objects, e.g. in contrast to the better preserved hoard material. We propose that use-wear traces on Cu-alloy weaponry, particularly on blade edges, is significantly more elusive than previously realised, and that undamaged objects have been over-identified. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction The first use-wear studies on metal weaponry pre-date the surge in the study of warfare of the past 20 years (Carman, 1997; Carman and Harding, 1999; Keeley, 1996; Molloy, 2007a; Otto et al., 2006; Uckelmann and M€ odlinger, 2011). Two studies stand out as the earliest that reconstruct fighting styles and social orga- nization by means of analysing the use-wear on copper (Cu)-alloy weaponry in particular. Schauer (1979) reconstructed a fencing fighting style for Late Bronze Age spears based on the notches on the blade of a spear discovered in a grave in Gau Algesheim, Ger- many. In his seminal analysis of period II and III swords, Kristiansen (1979, 1984; see also Kristiansen, 2002) used the stages of reduc- tion of shape through use and repair to argue for a division of Nordic Bronze Age society into classes of fighters, who used swords as tools (objects often damaged and repaired), and an elite, who used swords as status signifiers (objects show no damage). How- ever interesting the interpretations, neither study considered the material properties of Cu or the working and effects of corrosion on the shape of the weapon when recovered. Even in recent publica- tions, such considerations are not factored into interpretations. For example, in an otherwise excellent study of the spearhead from Hochgosch, Austria, the corrosion of the entire blade edge is noted (M€ odlinger, 2011a: 13). Despite this, the spear is still interpreted as a throwing and thrusting implement, precisely because of the lack of damage to the edge (contra Anderson, 2011): “Wird der Speer als Wurfspeer oder Stoßwaffe eingesetzt, wird die Schneide kaum, die Spitze dagegen umso mehr besch€ adigt. Tats€ a- chlich weisen Speerspitzen h€ aufig Besch€ adigungen oder Abnut- zungsspuren an der Spitze e wie auch die vorliegende Speerspitze! e und nur selten an der Schneide auf” [If the spears were used as throwing or thrusting implements, then their edges will only rarely be damaged but their tips will be more frequently damaged. Spearheads do indeed frequently show damage or use-wear on their tips e as does the discussed spearhead! e and only rarely on their cutting edges] M€ odlinger, 2011a: 17). Such source-critical considerations are all the more important as use-wear studies attempt to join the ranks of the established archaeological sciences (Dolfini and Crellin, 2016). In order to delineate what can be said about the use of a given object or group * Corresponding author. E-mail address: chorn@gshdl.uni-kiel.de (C. Horn). Contents lists available at ScienceDirect Journal of Archaeological Science journal homepage: http://www.elsevier.com/locate/jas http://dx.doi.org/10.1016/j.jas.2017.04.002 0305-4403/© 2017 Elsevier Ltd. All rights reserved. Journal of Archaeological Science 81 (2017) 90e100