Abstract
M.Sc.
This dissertation describes the N1 manganese ore bed at Gloria Mine in the Kalahari Manganese
Field, Northern Cape Province. It also compares the ore bed at Gloria Mine with the correlative
bed further to the south at Mamatwan Mine. The ore bed at Gloria Mine can be subdivided into
ten texturally distinct zones that are laterally consistent throughout the mine lease area. The
mineralogy and geochemistry of the various lithostratigraphic zones are described from two drill
cores (GL28 and GL24), situated away from any known structural features or unconformities that
could have affected the properties of the Ore. The ore in drill core GL28 has a mineralogical
composition similar to that of typical Mamatwan-type ore described at Mamatwan Mine with
braunite and kutnahorite as the main minerals. However, in drill core GL24 the ore has a very
different mineralogical composition although it is texturally and geochemically rather similar to
Mamatwan-type ore. The ore is composed of hausmannite, calcite and jacobsite and is
apparently related to a post-depositional alteration event that did not effect Mamatwan-type ore
in the Mamatwan Mine area. This altered ore is similar in composition to low-grade leastaltered
manganese ores in the cores of fault blocks at Wessels and N’Chwaning Mines i.e. the
area known for its hydrothermally altered high-grade manganese ores in the northern part of the
Kalahari Manganese Field. In addition to the above, the N1 manganese ore bed at Gloria Mine
also underwent ferruginisation close to certain joints and normal faults. No obvious alteration
could be detected where the ore bed is unconformably overlain by Dwyka diamictite, nor
associated with a thrust fault displacing the ore.