Geochemical fingerprinting of specular hematite from prehistoric mines and archaeological sites in southern Africa

Abstract

Specularite ore was collected from five prehistoric mining regions in Botswana and the Northern Cape Province of South Africa and 172 samples were analyzed by instrumental neutron activation analysis. A fingerprinting methodology was developed using the geochemical signatures of specularite sources represented by first-row transition metals. A validation set of 15 samples was chosen and underwent the fingerprinting process to test the validity of the method. A deductive elemental limit series analysis reduced the number of possible sources for each validation sample. Discriminant function analysis then correctly classified 14 of 15 validation samples and 6 of 7 specularite artifacts from archaeological sites in Botswana.