Orapa drilling yields new ultramafic rock find – Botswana Diamonds

7th October 2015 By: Megan van Wyngaardt - Creamer Media Contributing Editor Online

JOHANNESBURG (miningweekly.com) – Aim-listed Botswana Diamonds has completed a three-hole drilling programme at its joint venure (JV) PL 210 licence area, in the Orapa region of Botswana.

The programme targeted an anomaly discovered by JV partner Alrosa, using its transient electromagnetic method (TEM), reinforced by soil sampling, which had earlier discovered significant kimberlite indicator minerals (KIMs).

Two of the three holes intersected the anomaly, as well as intensively altered ultramafic rock. While kimberlite was an ultramafic rock, initial field analysis suggested this rock was older than the kimberlites found in the Orapa area.

Chrome spinellids and olivines, which were significant KIMs, were in the core.

The company noted that detailed petrographic analysis of the drill core would now take place in St Petersburg, Russia, to identify what was in the rock.

The exploration team would continue work on site, conducting further sampling and ground geophysics.

"The good news is that the techniques used by our partners Alrosa have worked, in this instance, by delineating ultramafic rock, of which kimberlite is one type buried under 90 m of sand. The rock discovered is not Orapa kimberlite, but appears to be another older ultramafic rock.

“The core is now being processed to identify what it contains. Exploration on this block continues to identify the source of the two small diamonds we discovered in earlier work,” Botswana Diamonds chairperson John Teeling commented.