Bushmanland
The Bushmanland project is located on two farms about 150km south-southeast of the town of Springbok. The farms cover part of an area that contains swarms of kimberlite-related pipe-like intrusives.
The Bushmanland project is based on the theory that some of the pipes in the project area are lamproitic in composition (similar to Argyle and other Western Australian diamondiferous pipes), that they are diamond bearing and that they are the source of some of the alluvial diamond occurrences in the region. To date very few lamproites have been discovered in South Africa. This is in stark contrast to the Australian experience, where lamproites outnumber kimberlites. Two of the three hard rock Australian mines are lamproites (Argyle and Ellendale 9). So far, no lamproite pipes have been discovered in the Bushmanland project area.
Northville Minerals, a company in which Gemstar has an effective 49% interest has applied for a prospecting licence in respect to the Bushmanland project. Subject to this application, the evaluation programme on the two farms will initially focus on the known pipes that are visible on aerial photographs. The task will be to determine the petrology and geochemistry of these bodies in order to accurately classify them. If any lamproites are identified their microdiamond content will be established, followed by bulk sampling for grade determination. A large diameter drill will be used for the excavation of the rock to a depth of up to 50 metres. Treatment of resulting material would be done with a dense media separation plant and a Flowsort x-ray separator.
Attention will also be given to the region covered by the Kalahari sand-veld which encroaches on parts of the Bushmanland pipe swarm. This would require a regional aeromagnetic or EM surveys to detect the buried pipes. In the Independent Geologist’s Report, Snowden state that “discovery of a lamproite (sensu stricto) pipe by Gemstar would be an important achievement. If lamproite (sensu stricto) is discovered this would cause a re-evaluation of the importance of the Bushmanland pipe swarm as a source of diamonds.”
