image/svg+xml19XII/1/2021INTERDISCIPLINARIA ARCHAEOLOGICANATURAL SCIENCES IN ARCHAEOLOGYhomepage: http://www.iansa.euAnalysis of Middle Nubian Vessel-forming Technology Using Refectance Transformation Imaging (RTI)Aaron M. de Souza1*, Martina Trognitz21Austrian Archaeological Institute, Austrian Academy of Sciences, Franz Klein-Gasse 1, 1190 Vienna, Austria2Austrian Centre for Digital Humanities and Cultural Heritage, Austrian Academy of Sciences, Sonnenfelsgasse 19, 1010 Vienna, Austria1. IntroductionAccording to the existing framework, the Nile Valley of Lower and Upper Nubia (Figure 1) was populated by three so-called Middle Nubian Cultures – the C-Group, Kerma, and Pan-Grave cultures – during a period spanning c. 1850–1500 BCE (Figure 2). Each of the three groups was defned typologically, based on distinct material culture traditions and patterns of distribution following a now outdated culture-historical approach. The C-Group was thought to be confned primarily to Lower Nubia (Bietak, 1968; Säve-Söderbergh, 1989), the Kerma tradition to Upper Nubia (Edwards, 2004, pp.65–84), while the Pan-Grave tradition comprised mobile or partially mobile groups spread across a vast region from Middle Egypt up to the Fourth Nile Cataract and the surrounding desert regions (Bietak, 1966; Säve-Söderbergh, 1989, pp.15–19; de Souza, 2019, pp.140–143). For much of the 20thcentury, these three archaeological cultures were viewed as bounded and distinct entities, but recent research has demonstrated that these divisions can no longer be supported. It is now understood that the Nubian cultural landscape was highly complex and interconnected (Edwards, 2004, pp.10–23; Raue, 2019, pp.293–333), but the outdated divisions persist in scholarly discourse. In the absence of any alternative descriptive system, the labels C-Group, Pan-Grave, and Kerma will be used in this paper for reasons of clarity, albeit with the recognition that those labels need to be urgently revised.In order to investigate these interconnections, the current analysis uses the concept of chaîne opératoire (Gosselain, 2012, pp.244–246; Roux, 2016; D’Ercole et al., 2017, p.554; Gosselain, 2018) as a means for understanding the series of choices made by ancient Nubian potters when making these vessels. According to Gosselain (2012, p.246), the concept is also an analytical tool for documenting and interpreting those technological choices in a systematic way. This study applies Refectance Transformation Imaging (RTI) to Middle Nubian ceramics in order to identify and analyse physical traces of the vessel-forming process that might otherwise be invisible to the unaided eye or difcult to capture using Volume XII ● Issue 1/2021 ● Pages 19–35*Corresponding author. E-mail: aaron.desouza@oeaw.ac.atARTICLE INFOArticle history:Received: 9thSeptember 2020Accepted: 14thApril 2021DOI: http://dx.doi.org/10.24916/iansa.2021.1.2Key words:Refectance Transformation Imaging (RTI)documentationpottery technologysecond millennium BCEtechnological heritagematerial cultureKermaPan-GraveC-GroupABSTRACTRefectance Transformation Imaging (RTI) is a photographic technique used to generate digital surrogates of surfaces that can be viewed using virtual lighting coming from interactively set directions, enabling the close structural examination of objects under digital raking light.In this study, RTI was applied to Middle Nubian pottery from sites near the Second Nile Cataract that were excavated by the Scandinavian Joint Expedition to Sudanese Nubia in the early 1960s. The ceramic traditions under investigation are currently known as C-Group, Pan-Grave and Kerma. An overarching aim of the project is to assess the possibility of understanding the relationships between these groups through detailed analyses of their material traditions. Based on the hypothesis that technological traditions may be related to cultural heritage, RTI is applied in this study to observe morphological traces of ceramic vessel forming processes.Two technological groups were identifed, one consistent with paddle-forming, and another consistent with hand-building on a mat-lined surface. These technological groups correspond very closely to cemetery distributions, which suggests that the diferent techniques may be specifc to diferent pottery-making traditions. It is suggested that vessel forming-technology in the so-called C-Group tradition is distinct from that of the so-called Pan-Grave and Kerma traditions, and that the validity of the divisions between Nubian cultural groups should thus be further interrogated.
image/svg+xmlIANSA 2021 ● XII/1 ● 19–35Aaron M. de Souza, Martina Trognitz: Analysis of Middle Nubian Vessel-forming Technology Using Refectance Transformation Imaging (RTI)20standard photographic processes (see chapter 4). It will be shown that careful observation of the surface features revealed by the RTI process can assist in identifying similarities or diferences in pottery-making technologies that may in turn be linked to cultural heritage and traditions.2. Research objectiveThe goal of the analysis was to test hypotheses regarding ceramic vessel-forming technologies among the Middle Nubian cultures. It has previously been proposed that Nubian pottery was formed using either the coiling or slab-building method (Arnold, 1993, pp.33–36), or by using a percussive process such as paddle forming (Arnold, 1993, pp.17–20). Both of these methods have been cited as primary forming processes (i.e., the processes used to create the overall vessel shape), and it is likely that both slab building and paddle forming (see chapter 6.1) were employed for diferent types of vessels and perhaps even in combination (Nordström, 1972, pp.47–48; Williams, 1983, pp.29–36). RTI was employed on a group of Middle Nubian vessels selected from the