Methodology and history of discovery of uranium mineralization in North-Western Province of Zambia

Substantially negative results were obtained by an airborne spectrometer survey over an area of approximately 60 000 km2 where geological mapping had revealed the presence of probable Roan age metasediments, the host rock of the famous Shinkolobwe uranium deposit. In spite of the negative results Agip SpA decided to continue exploration on a purely theoretical geological basis. The geological history of the Katanga Basin was reviewed, correlations established and evidence of a sedimentary origin of the known uranium occurrences, previously believed to be magmatic, collected. The Lower Roan Formation, which is the lowest part of the Katanga Sequence, was identified as the host rock of original mineralization. Photogeological interpretation revealed a band of Lower Roan some hundred metres thick dipping at approximately 300 and encompassing four large windows of basement. A long and hard campaign of detailed prospection over the formation on a 100-m grid revealed fifteen uranium occurrences and several tens of anomalous areas. The subsequent drilling campaign intersected scattered mineralization, locally thick and of good grade, in vein-like type deposits. A uranium province has been brought to light but its economic significance is still to be established. A drilling campaign to evaluate the uranium reserves is planned. (author)