An archaeometallurgical investigation of iron smithing in Swahili contexts and its wider implications

This paper presents the most extensive archaeometallurgical study of iron-smithing debris excavated in East Africa. It presents an integrated methodology, including morphological, chemical, petrographic, and contextual analysis of iron slag excavated from secondary ironworking contexts. Iron slag from three Swahili sites was analysed—Unguja Ukuu located on the southwestern coast of Zanzibar, and Tumbe and Chwaka situated in the north-east of Pemba Island. The results suggest that Unguja Ukuu smithing is associated with oxidising hearth atmospheres and high amounts of CaO, while slag from Tumbe and Chwaka indicates reducing hearth atmospheres and high silica:alumina ratios, potentially pointing to the use of a flux. Distinct technical traditions can be seen at Unguja Ukuu when compared to Tumbe and Chwaka, suggesting a regional rather than chronological pattern. Temporal continuity is evident throughout the occupation of Unguja Ukuu and between sites of different periods in north-western Pemba. The spatial distribution of iron slag at these sites suggests that smithing was taking place across the extent of Unguja Ukuu, while slag scatters were more localised and disassociated from domestic contexts at Tumbe and Chwaka. The wealth of information on technological and organisational aspects of smithing obtained during this study indicates that an integrated methodology can yield valuable data for a variety of smithing sites, irrespective of excavation strategies

Developments in Rural Life on the Eastern African Coast, A.D. 700–1500

The eastern African coast is known for its Swahili “stonetowns.” Archaeological study of stonetowns has overshadowed that of Swahili rural life, and how it reformulated in the context of urban transformations after A.D. 1000. To help redress that imbalance, we focus here on village research carried out in a Swahili heartland—Pemba Island, Tanzania—in the context of two archaeological projects. We feature four settlements: later 1st millennium Kimimba village and its large, trading village neighbor, Tumbe; and 2nd millennium Kaliwa village, neighbor to Chwaka stonetown. Their archaeology, contextualized within a regional landscape, allows us to say new things about the changing nature of rural life on Pemba, and to make a case for the potential of village complexity elsewhere on the Swahili coast

Bead Grinders and Early Swahili Household Economy: Analysis of an Assemblage from Tumbe, Pemba Island, Tanzania, 7th-10th Centuries AD

This paper focuses on a specific class of locally made artifacts known in the archaeological literature of the eastern African coast as bead grinders. Bead grinders are discarded potsherds or stone cobbles distinguished by long grooves abraded into thei

An archaeometallurgical investigation of iron smithing in Swahili contexts and its wider implications

Acknowledgements: Archaeometallurgical work presented in this paper was conducted as part of the first author’s PhD and funded by the Danish National Research Foundation (DNRF119) as part of the Urbnet Centre of Excellence, Aarhus University. We thank Søren Sindbæk for his support and insightful comments that helped shape this research. We would also like to sincerely thank the Zanzibar Antiquities staff in Stone Town and Chake Chake, particularly Abdallah Khamis Ali, Head of Antiquities, for his support in all of the projects contributing to this study, and particularly for assistance in navigating the curated collections. Abdurrahman Juma’s excavations at Unguja Ukuu were supported by the Zanzibar Department of Antiquities and funded by the SIDA ‘Urban Origins in East Africa’ project based at Uppsala University, Sweden. Excavations at Tumbe and Chwaka were carried out as part of the Pemba Archaeological Project, co-directed by Adria LaViolette, Jeffrey Fleisher, and Bertram Mapunda and funded by the US National Science Foundation (BCS0138319) with additional support from the Universities of Virginia and Dar es Salaam. Stephanie Wynne-Jones' excavations at Unguja Ukuu were funded through grants from the Center for Urban Network Evolutions, Aarhus (DNRF119; 2017) and the Leverhulme Trust (RPG2018-414; 2019).Funder: SIDA ‘Urban Origins in East Africa’AbstractThis paper presents the most extensive archaeometallurgical study of iron-smithing debris excavated in East Africa. It presents an integrated methodology, including morphological, chemical, petrographic, and contextual analysis of iron slag excavated from secondary ironworking contexts. Iron slag from three Swahili sites was analysed—Unguja Ukuu located on the southwestern coast of Zanzibar, and Tumbe and Chwaka situated in the north-east of Pemba Island. The results suggest that Unguja Ukuu smithing is associated with oxidising hearth atmospheres and high amounts of CaO, while slag from Tumbe and Chwaka indicates reducing hearth atmospheres and high silica:alumina ratios, potentially pointing to the use of a flux. Distinct technical traditions can be seen at Unguja Ukuu when compared to Tumbe and Chwaka, suggesting a regional rather than chronological pattern. Temporal continuity is evident throughout the occupation of Unguja Ukuu and between sites of different periods in north-western Pemba. The spatial distribution of iron slag at these sites suggests that smithing was taking place across the extent of Unguja Ukuu, while slag scatters were more localised and disassociated from domestic contexts at Tumbe and Chwaka. The wealth of information on technological and organisational aspects of smithing obtained during this study indicates that an integrated methodology can yield valuable data for a variety of smithing sites, irrespective of excavation strategies.</jats:p