Botswana Diamonds (BOD) has announced the completion of a three-hole drilling programme on licence PL 210 in the Orapa region of the southern Africa country.
According to the company, the joint venture (BOD 50%, Alrosa 50%) drilling programme targeted an anomaly discovered by Alrosa using its transient electromagnetic method (TEM) supported by soil sampling.
Heavy concentrate sampling on PL 206 is currently underway in the block's north-eastern area.
The sampling earlier discovered significant kimberlite indicator minerals (KIMs).
Two of the three holes intersected the anomaly and intensively altered ultramafic rock.
Based on initial field analysis, the kimberlite ultramafic rock is older compared with the other kimberlites found in the Orapa area. The core consists of chrome spinellids and olivines, which proves significant KIMs.
BOD plans to carry out detailed petrographic analysis of the drill core in St Petersburg Russia in order to identify what is present in the rock.
The company said that the exploration team is continuing work on-site and is in the process of conducting further sampling, as well as ground geophysics.
BOD chairman John Teeling said: "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 90m of sand.
"The rock discovered is not Orapa kimberlite, but appears to be another older ultramafic rock.
"Exploration on this block continues to identify the source of the two small diamonds we discovered in earlier work."
Drilling work on PL 210 commenced in September following which work on the new Gope prospecting licences will commence.