Impressions of Banana Pseudostem in Iron Slag from Eastern Africa

Abstract

The use of banana plants in the historical iron production industries of several pre-colonial kingdoms of southern and western Uganda has been documented by the presence of banana pseudostem impressions preserved in slag, a waste product of smelting. An investigation into the selection and use of plants within these technologies was undertaken in 2003 in southern Uganda, implementing a new methodology to record the archaeobotanical information contained within the slag. Non-destructive casts of plant impressions were made on-site using a polyvinylsiloxane dental gel. These were then taken to London for further examination, and the casts were identified to the level of plant family, enabling quantitative and qualitative analysis. More recently, archaeometallurgical research in western Uganda in 2007 also revealed the repeated presence of these banana pseudostem impressions in iron smelting slag, confirming that this was an unusual, yet intentional aspect of these localized iron production technologies.