Modelling the Spatial Spread of Iron Technology in Sub-Saharan Africa Using Nigerian Radiocarbon Data

The origins and spread of iron technology across sub-Saharan Africa remain among the most actively debated questions in African archaeology, with the relative merits of single-origin diffusion models, multi-origin independent invention models, and intermediate network transmission models each commanding significant scholarly support. This dissertation makes an original methodological and empirical contribution to this debate by developing and applying a spatially explicit computational model of iron technology spread, calibrated using a comprehensive synthesis of Nigerian radiocarbon dates for iron smelting contexts and evaluated against the broader sub-Saharan African radiocarbon database. A database of one hundred and ninety-two radiocarbon dates for iron smelting or iron working contexts from Nigeria was compiled and critically evaluated for taphonomic and contextual reliability, retaining one hundred and forty-three dates meeting pre-specified quality criteria. These Nigerian dates were integrated with a curated database of sub-Saharan African iron dates compiled from published literature, creating a comparative dataset of over one thousand dates spanning from approximately 800 BCE to 500 CE. Computational modelling using a Bayesian wave-of-advance framework, implemented in a custom Python simulation environment, tests the compatibility of the observed spatial distribution of early iron dates with single-origin, two-origin, and distributed network transmission models. Results indicate that the Nigerian data, particularly the early dates from the Nok-Taruga zone, are statistically incompatible with any model requiring the derivation of West African iron technology from North Africa or the Nile Valley within the observed chronological range, providing the strongest quantitative support yet published for the independent development of iron technology in West Africa. Keywords: iron technology origins, radiocarbon modelling, sub-Saharan Africa, wave-of-advance model, Nigerian metallurgy.