Uranium Potential of the Bushveld Complex, South Africa. Atomic Energy Corporation of South Africa Limited and University of Pretoria Working Group for Uranium in the Bushveld Complex: Progress Report No. 2

摘要

This paper presents a summary on much of the existing geochemical data on the siliceous components of the Bushveld Complex (i.e., the felsites, granophyres and granites) with a view to establishing the U potential of the district. Although very few U analyses are actually available, sophisticated normalised data plots are utilized to estimate the probable U contents of the rock types. The members of the siliceous suite exhibit a gradual chemical evolution through time and illustrates that the most evolved members of the suite probably contained the highest primary U contents. It is emphasized that most known Bushveld Sn and F occurrences, with which U is likely to be associated, and most of the recognized radiometric anomalies in the complex, are concentrated along major lineaments. In this respect the Murchison and Franspoort directions are considered to be particularly important. In conclusion the argument follows that the potential for undiscovered hydrothermal U ores in the Bushveld Complex is high, and that five factors will probably control the location of such deposits. These factors include: 1. Sn, F and LIL-enriched source granite; 2. High post-emplacement heat production to promote the development of post-emplacement mineralizing systems; 3. A tectonically unstable source region with major fracture zones; 4. Suitable trap environments in the granites and their country rocks; 5. A source of fluids from aquifers in the granite aureole. (ERA citation 12:032505)