Metal sulphides encountered in Hole KSZDD001
Kavango Resources plc (LSE:KAV), the exploration company targeting the discovery of world-class mineral deposits in Botswana, is pleased to announce completion of Hole KSZDD001 in the Company’s Kalahari Suture Zone (“KSZ”) Project. Copper sulphide mineralisation and locally abundant fine grained, interstitial magnetite were encountered from first contact with the Proterozoic gabbro, at 951m to the end of hole at 1,000m (“EOH”). This was consistent with the Company’s geophysical modelling of the Proterozoic gabbros, which are believed to be the source of the “Great Red Spot” magnetic anomaly (the “GRS”).
Hole KSZDD001 is the deepest borehole ever drilled into the GRS and is the first to recover physical evidence of sulphide mineralisation in this system.
Kavango has confirmed the presence of fine-grained, interstitial disseminated chalcopyrite (copper sulphide) and abundant magnetite through sections of the 49m of recovered Proterozoic core. This includes occasional 1cm elongated blebs of chalcopyrite (copper sulphide) with minor nickel.
The magnetic susceptibility readings for the intersected Proterozoic rocks are in the range of 140 to 280 milli SI units, with an average of 230 milli SI. In the absence of any observations of pyrrhotite, these magnetic susceptibility values are well above the typical values for gabbros, which are typically in the range of 10 to 80 milli SI.
Preliminary field analysis and visual inspection of core samples taken from Hole KSZDD001 suggest the Proterozoic gabbros in the GRS in Target Area B exhibit differences to those encountered in Hole TA2DD002 in Target Area A (announced 14 September 2021), notably around alteration events. The Company’s preliminary view of this observation is that Target Areas A and B have experienced differing intrusive and/or metamorphosing events, these including potential mineralising phases within separate, but likely linked systems.
Kavango will test these theories and the provenance of the chalcopyrite through petrographic and geochemical analysis of core samples taken from both holes. This detailed petrographic work will be coupled with various assay techniques with all samples sent to internationally accredited laboratories in South Africa.
Drilling conditions in Hole KSZDD001 were challenging, with poor and fractured ground conditions encountered in several sections. As such, Kavango has elected not to attempt a downhole electromagnetic (“DHEM”) survey of Hole KSZDD001, as the risk of losing the DHEM probe in the uncased sections of the hole were considered too high.
Kavango congratulates Mindea Exploration and Drilling Services (Pty) (“Mindea”) & Equity Drilling on successfully drilling Hole KSZDD001 in difficult ground conditions to target depth and recovering all cores. A number of historic exploration holes, including GRS-1 drilled in 2002, were abandoned due to technical difficulties.
Lessons learned from the drilling of Hole KSZDD001 will be applied to KSZDD002, which will target the 8,200 Siemens conductor (announced 02 July 2021). The rig has mobilised to the drill collar location and drilling operations are expected to begin by the middle of this week.
Kavango will publish photos of core recovered from the Proterozoic in Hole KSZDD001 on its website (www.kavangoresources.com) and Twitter feed (through the handle @KavangoRes).
Ben Turney, Chief Executive Officer of Kavango Resources, commented:
“Once again we’ve broken new ground in the 50-year effort to unlock the Kalahari Suture Zone’s potential to host nickel/copper ore bodies.
We are the first company to confirm the presence of interstitial chalcopyrite (copper sulphide) in the Great Red Spot and the first successfully to drill to 1,000m in this area. For this we have to thank Mindea/Equity Drilling for stepping up to the complex engineering challenge.
We now await the results of petrology and geochemical analyses of our core samples to confirm the chalcopyrite’s origin and to tell us more about the extent to which the Great Red Spot is a favourable environment for massive sulphides.
We are particularly interested in the strength of the magnetic readings from where we made contact with the Proterozoic. They were 3 to 23 times higher than what one would expect in common gabbros. The magnetic pencil our field geologist used stuck to the core. We expect to complete follow-up analyses of various geophysical survey data we have available to us, to model what might be the deeper source of the underlying vast anomaly.
The decision to drill the deep geological hole into the Great Red Spot, before drilling the 8,200 Siemens B1 Conductor, has been fully vindicated. A downhole electromagnetic survey of Hole KSZDD001 would have been optimal, but we now have a much clearer idea of what is in front of us for Hole KSZDD002.
At this point, we believe we have done everything we can to maximise our chances of operational success in the next drill. What we encounter will then be up to the geology.”