Archaeological Investigation on Iron Metallurgy in Damba Iron Smelting of the Nok Culture Area, Central Nigeria

This research presents the findings of an archaeological investigation into iron metallurgy at the Damba iron smelting site, located in the Nok cultural area of central Nigeria. The study addresses significant gaps in our understanding of indigenous iron production technologies, specifically focusing on technological innovation and industrial organization within the Nok culture during the first millennium BCE. While previous archaeological investigations on African/Nigerian Iron Age were predominantly based on ethnographic studies and speculation due to limited scientific analysis of metallurgical remains, this research employs systematic archaeological methods combined with scientific analyses to examine iron smelting technology at Damba. The Damba iron smelting site, situated in a valley close to Janajala in Kagarko Local Government Area, Kaduna State, exhibits characteristics of a well-organized iron production workshop. The site's environmental setting, including proximity to River Damba (a perennial water source) and the presence of a mountain with documented rock hollows possibly used for ore processing, suggests strategic selection for smelting activities. Excavation of a 5m × 3.20m area revealed four furnaces labeled A, B, C, and D, with diameters ranging from 60-65 centimeters. The systematic excavation employed spits of 0-20 centimeters for the workshop area and 0-10 centimeters for individual furnaces, reaching sterile layers to ensure complete recovery of archaeological materials. The research methodology integrated comprehensive survey techniques including systematic field walking, GPS mapping, and detailed documentation of surface features. Ground reconnaissance identified the stream serving as water source at N09.550880 E007.674800 (614m NW), and a rock hollow with diameter 26cm and depth 9cm at N09.551700 E007.6741300 (625m). Excavation recovered significant cultural materials including iron slag, pot sherds, iron implements, stone implements (including a round stone hammer), charcoal samples, soil samples, and burnt clay. Notably, Furnace B yielded two large iron slags at 50cm depth, while Furnace D produced two large burnt clay pieces at the same depth, possibly indicating foundation preparations for fire management. Soil samples collected from the workshop floor and individual furnaces were subjected to laboratory analysis at the Soil Science Department, Nasarawa State University. Atomic Absorption Spectrophotometer analysis revealed iron content ranging from 9.458 mg/L to 9.759 mg/L across samples, providing preliminary evidence of the intensity and scale of smelting operations. The presence of a complete pottery vessel in Furnace D and significant pot sherds in other furnaces, except Furnace A, indicates the integration of ceramic production with metallurgical activities. The research aims to: (1) survey, excavate, and document the characteristics of Damba iron smelting site; (2) examine operational functions through comparative analysis of four excavated furnaces focusing on slag morphology and chemistry, soil micro-stratigraphy, ore characterization, and stone hammer analysis; (3) compare Damba evidence with data from Taruga and other Nok sites; (4) reconstruct the chaîne opératoire of iron smelting at Damba; and (5) study pottery decoration and form attributes as chronological indicators. This investigation addresses critical questions in Nok iron metallurgy, including whether furnace diameter correlates with chronological age and whether sites with limited slag deposition represent older traditions. The research contributes to broader understanding of technological choices, knowledge systems, and cultural traditions in early African iron production, providing crucial evidence for the organization and expertise of iron smelters in the Nok culture area.