Kimberlite blow discovered at Botswana Diamonds’ Thorny River prospect

2nd December 2020 By: Donna Slater - Features Deputy Editor and Chief Photographer

A recent drilling programme, targeting an area of 0.4 ha, at Botswana Diamonds’ Thorny River project in Limpopo, in South Africa, has led to the discovery of a new kimberlite blow (a small volcanic pipe).

Botswana Diamonds chairperson John Teeling says the discovery is “very significant” as the nearby Marsfontein (0.4 ha) and Sugarbird (0.5 ha) blows were “extremely profitable” diamond-producing operations.

“We are moving forward with a programme to define the extent of this new resource, particularly as the diamond grades are known to be consistent across the whole area.”

A total of six holes were drilled in the Thorny River area. A combined 39.5 m intersected kimberlite, while an additional 55 m intersected a weathered kimberlite breccia.

The best hole contained a down-the-hole (at 45o dip) intersection of kimberlite and kimberlite breccia of 19 m. Both kimberlite and kimberlite breccia are being analysed for diamonds and indicators.

Following the blow discovery, Botswana Diamonds has enough data to build a preliminary three-dimensional model of the resource, as well as to estimate kimberlite volumes. Going forward, the company will perform core drilling to confirm the precise geology and kimberlite profile.
 
Drilling on the Marsfontein targets discovered no additional extensions to the M8 kimberlite.

The focus on this property will be on the diamondiferous alluvial deposits confirmed by Botswana Diamonds’ recent geophysics programme and by Professor Tania Marshall – SamCode Standards Committee chairperson and a recognised expert in the geology and assessment of diamondiferous alluvial deposits.

A further five targets will be drilled in the Thorny River area in the near future.