An iron formation of late Proterozoic age is developed as a narrow band in a succession of metasediments and metavolcanic rocks in the Southern Margin Zone of the Damara Orogen south of Windhoek. The succession has undergone low- to medium-grade metamorphism. Two primary metamorphic assemblages are distinguished containing a) magnetite, hematite, quartz, apatite with no or minor ilmenite, minnesotaite, stilpnomelane, chlorite, amphiboles and carbonate, and b) magnetite, quartz, plagioclase, amphiboles, chlorite, minnesotaite, stilpnomelane, biotite, carbonate and apatite. Bulk compositions in the two rock types are highly variable with respect to their concentrations in Ti, AI, Mg, Na, Zr, and Nb. A volcanogenic exhalative origin is indicated by its high apatite content, the formation of plagioclase and actinolite in layers within the iron formation, from possible metamorphosed volcanogenic detritus, and its close association with mafic metavolcanic rocks.