Wagner (1914) described two main kimberlite varieties, as well as examples of late-stage internal dykes. Clement (1982) recognized three varieties of kimberlite in the main pipe, which he named KOF1-3. These comprised two diatreme-facies (KOF1 and 2) and a hypabyssalfacies kimberlite (KOF3). The KOF-1 variety was a TKB that occupied the main pipe, whereas KOF-2 was a TKB that occupied the “West Fissure”. The KOF-3 variety was the hypabyssal intrusion that occurred as the “East Fissure”. A further notable feature was the presence of a large floating reef comprising various Karoo lithologies in the main pipe. A satellite kimberlite pipe named Ebenhaezer, which also contained diatreme-facies kimberlite, is located close to the main pipe. Clement speculated that these two pipes once coalesced to form a single large crater.

Mapping of deeper levels by Naidoo et al. (2004) found evidence for at least two main volcaniclastic kimberlite varieties in the main pipe, and demonstrated that these were geochemically distinct based on their groundmass spinel compositions. They described the layered nature of the “floating reef” as well as intermixing between layered breccias and relatively lithic-poor volcaniclastic kimberlite. They also demonstrated that the kimberlite between the floating reef and the eastern contact at depth to be geochemically distinct from the main kimberlite variety that had been mined throughout the life of the mine. They called into question the appropria ........

Mining method: Underground sub level cave.

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