Heritage Cases

The Gauteng province is renowned for its cave sites including Sterkfontein, Swartkrans and Kromdraai, which preserve a fossil record of human evolution that spans the last ~3 million years (Pickering et al., 2019). These localities have also yielded an accompanying archaeological record, which documents technological adaptations throughout Earlier, Middle and Later Stone Age sequences (Kuman, 2007). The Earlier Stone Age (ESA) is particularly significant to this area as it provides evidence of complex behaviours amongst early hominin species, as well as insights into how they mitigated ecological challenges (Caruana, 2020). One of the most important evolutionary events to take place within the ESA period is the transition from Oldowan to Acheulian technology. The Acheulian Industry is characterized by hierarchical shaping routines, embodied in the production of Large Cutting Tools (LCTs), including handaxes and cleavers (Shipton, 2018; Semaw et al., 2009). While the development of shaped stone tools has important cognitive implications, land-use behaviours also become more complex during the Acheulian period, which is of similar evolutionary significance (Caruana et al., 2019; Gopher and Barkai, 2014; Potts et al., 1999). Examining how ancient populations sourced raw materials, and then produced and used tools at different localities provides critical insight into their mobility patterns and ranging behaviours (Caruana et al., 2019). This information can be used to reconstruct how such populations centralized certain activities relative to local resource availability, which reflects their ‘understanding’ of the landscape. However, cave sites in the Gauteng region are a primary source of Acheulian material, yet they often present difficulties in reconstructing land-use patterns of ancient toolmakers (Caruana et al. 2019). To date, definitive Acheulian assemblages from the ‘Cradle of Humankind’ cave sites have been found in Sterkfontein Member 5 West, Swartkrans Members 2 and 3, and Gladysvale (Hall et al., 2006; Kuman and Clarke, 2000). However, these collections are relatively small, or their chronologies remain either preliminary, contentious or absent. Patterns of raw material procurement are typically focused on local drainage systems within 1 km of these sites, and examining how tools were produced rarely offers any perspective on how they were actually used. Larger, open-air assemblages also occur within the surrounding region most notably at Maropeng and Elandsdrift, but these also present significant chronological and spatial challenges (Pollaolo et al., 2010; Caruana et al., 2019). Thus, it is important to extend our analytical focus beyond cave sites to gain better insight into the mobility patterns of Acheulian hominins in the Gauteng region (Caruana et al., 2019; Caruana and Stratford, 2019). The site of Wonderboom, originally discovered in the 1950s, offers potential for increasing resolution on land-use and mobility patterns, but also provides rare insight into site function. For this reason, the site is now part of a new research project that is being coordinated by members of the Palaeo-Research Institute (P-RI), at the University of Johannesburg. Originally, Mason (1962, 1958, 1957) suspected that the position of the site and its tool composition indicated a workshop area related to animal carcass butchery. Wonderboom is located within the Magaliesberg Mountain range, next to a natural poort (Fig. 1). Mason (1958, 1957) suggested that this pass potentially acted as a hunting blind for Acheulian hominins as migrating animals were bottlenecked between this section of the mountain range. He proposed that the tools were made on site for the purpose of butchering killed animals (Mason, 1962). This suggests that Wonderboom acted as an area where Acheulian hominins potentially planned to ambush animal herds, which infers complex levels of planning. The Magaliesberg range is comprised of quartzitic sandstone outcrops in the area surrounding Wonderboom, which Acheulian toolmakers were well adept to knapping (Sharon, 2008). Thus, Wonderboom may provide perspective on the planning and organization of Acheulian hominins who strategically used geological features to their advantage in attaining meat and raw materials. There are few Acheulian sites in South that reflect such behavioural complexity in their geographic positioning alone, so this site provides us with a unique landscape-archaeology research opportunity. Before the significance of Wonderboom can be fully appreciated, understanding its chronology is imperative. Mason (1958, 1957) preliminarily assigned the site to the Late Acheulian. This period is characterized by increasing technological complexity, including levallois core preparation (Tryon et al., 2006). Moreover, the reduction sequences of LCTs become increasingly complex, with more of a focus on thinning procedures (Shipton et al., 2013). While these technological perspectives provide insights into the technical abilities of Acheulian hominins, a better perspective on land-use behaviours is needed to understand how such tools were used in the past. The goal of this project is to attain dates for the Wonderboom Acheulian site using optically-stimulated luminescence (OSL) techniques. Given the shallow nature of the deposit and its lack of fossil materials (see below), it is likely that OSL will be the only radiometric dating technique that can be applied to the site. Attaining dates will increase the significance of Wonderboom and potentially provide some perspective on the age of the archaeological occurrence. This is the first vital step in re-investigating the Wonderboom stone tool collection and understanding their place within the Acheulian techno-complex of southern Africa.