The Southern Waterberg in Limpopo Province is archaeologically rich, especially when it comes to evidence of pre-colonial mining and metal working. Geologically, the area hosts important mineral resources such as copper, tin and iron which were smelted by agriculturalists in the precolonial period. In this region however, tin seems to be the major attraction given that Rooiberg is still the only source of cassiterite in southern Africa to have provided evidence of mining before European colonization. This paper reports the results of archaeological and archaeometallurgical work which was carried out in order to reconstruct the technology of metalworking as well as the cultural interaction in the study area and beyond. The ceramic evidence shows that from the Eiland Phase (1000–1300 AD) onwards there was cross borrowing of characteristic decorative traits amongst extant groups that later on culminated in the creation of a new ceramic group known as Rooiberg. In terms of mining and metal working, XRF and SEM analyses, when coupled with optical microscopy, indicate the use of indigenous bloomery techniques that are widespread in pre-colonial southern Africa. Tin and bronze production was also represented and their production remains also pin down this metallurgy to particular sites and excludes the possibility of importing of finished tin and bronze objects into this area.

In: Journal of African Archaeology

Abstract

Cross-cultural differences in argumentation may be explained by the use of different norms of reasoning. However, some norms derive from, presumably universal, mathematical laws. This inconsistency can be resolved, by considering that some norms of argumentation, like Bayes theorem, are mathematical functions. Systematic variation in the inputs may produce culture-dependent inductive biases although the function remains invariant. This hypothesis was tested by fitting a Bayesian model to data on informal argumentation from Turkish and English cultures, which linguistically mark evidence quality differently. The experiment varied evidential marking and informant reliability in argumentative dialogues and revealed cross-cultural differences for both independent variables. The Bayesian model fitted the data from both cultures well but there were differences in the parameters consistent with culture-specific inductive biases. These findings are related to current controversies over the universality of the norms of reasoning and the role of normative theories in the psychology of reasoning.

In: Journal of Cognition and Culture

The archaeological evidence for iron and especially copper production at Marothodi indicates that output far exceeded local requirements. Preliminary analyses of slag and metal provide insight into the technical processes of this production, while well-resolved spatial data comment upon the social and cultural organization of production. In this paper we attempt to integrate both technical and social aspects of production into the regional historic context with a view to developing ideas about the contextual specificity of surplus metal production from Marothodi early in the 19th century. Generally, Marothodi was occupied in a period of increasingly competitive economic and political relationships between lineages. The evidence from Marothodi indicates that although copper ore quality was poor, and had been largely mined out by previous producers, it was clearly worthwhile to produce a surplus because of regional demands. Importantly, the Tlokwa elites at Marothodi had the regional power to do so. Furthermore, although the location of Marothodi was a compromise between several factors, we suggest that proximity to the copper ore sources was important. Spatial data suggest that political authority did not physically centralize copper production, and that most home-steads were independent producers.

In: Journal of African Archaeology

Archaeological sites in the Shashe-Limpopo River Basin, southern Africa, reflect marked population growth and increased socio- political complexity between ca AD 880 and 1290, but the nature of agropastoral management that underpinned these extensive, more complex societies is not well understood. One key question concerns whether localized or more widespread regional strategies were employed to manage large herds of domestic animals. In order to identify potential herding areas we carried out strontium isotope analyses on tooth enamel from domestic fauna recovered at Shashe-Limpopo River Basin sites and compared them with those of modern wild and domestic fauna sampled from the greater region. Values were determined via low-resolution Inductively-Coupled Plasma Mass Spectrometry (ICP-MS) and Laser-ablation ICP-MS and high-resolution, standard Thermal Ionization Mass Spectrometry (TIMS). The low-resolution approaches gave values comparable to data produced by TIMS, within the level of precision required to distinguish geological areas contained in this exceptionally isotopically variable environment. The less invasive laser-ablation ICP-MS method provided a means to sample tooth enamel increments for indications of inter-seasonal movement of livestock. The archaeological data suggest that an inter-seasonal geographical expansion of herd management took place as socio-political complexity increased. A trans-humance or relocating herding strategy would have limited overgrazing of the local river basin landscape and results allow us to revisit hypotheses that overgrazing and environmental deterioration contributed to the subsequent political collapse and abandonment of the river basin at ca AD 1290.

In: Journal of African Archaeology