Drilling on KSZ identifies magma plumbing system
2 December 2019
KAVANGO RESOURCES PLC
("Kavango" or "the Company")
DRILLING ON THE KSZ IDENTIFIES MAGMA PLUMBING SYSTEM
Kavango Resources plc (LSE: KAV), the exploration group listed on the Standard List segment of the main market of the London Stock Exchange and targeting the discovery of world-class copper-nickel-PGE deposits in SW Botswana, is pleased to announce that the current drilling programme on the Kalahari Suture Zone Drilling Project (KSZ) appears to have identified multiple magma conduits, which would have supplied molten lava to the surface.
· Drilling on the final target of Kavango's current drilling programme has intersected a 16m gabbroic sill at 120m from surface on hole RIT08DH2.
· The gabbro sill contains disseminated sulphides as in the other intrusives intersected in this drilling programme. What is significant, however, is that the sediments above and below the sill show intensive alteration by heat. This alteration extends several meters either side of the sill.
· The extent of the heat alteration in the sediments is unusual for a relatively thin gabbro and suggests that the sill represents a formerly active conduit that would have allowed a constant flow of magma over an extended period to the surface.
DISCUSSION and SIGNIFICANCE
· Kavango's geological team believe that they have intersected a small part of a very extensive magma plumbing system that lay beneath multiple volcanic vents and fissures which extruded large quantities of basaltic lava onto the surface about 180 million years ago.
· This is the type of plumbing system that hosts massive sulphide orebodies at Voisey Bay in Canada, one of the world's largest Ni/Cu/Co deposits.
· Typically these complex plumbing systems are composed of stacked (horizontal) sills connected to each other via (vertical) dykes.
· If the magma contained "free" sulphur (due partly to contamination of the magma by the incorporation of coal), a continuous flow of magma along the conduit over extended periods may have allowed for the accumulation of metal suphides in certain localities within the sill.
· The application of downhole geophysical techniques should locate accumulations of metal sulphides within the gabbro. This will be undertaken as soon as the equipment becomes available.
Michael Foster, Chief Executive Officer of Kavango Resources, commented:
"It is most encouraging that the current drilling programme may have identified a magma plumbing system typical of those that host some of the world's largest metal sulphide deposits. If it can be established that the disseminated metal sulphides seen in the gabbroic sills are a primary feature, then there is an excellent possibility that economically viable metal sulphide deposits exist within the KSZ. The Company will continue to keep the market informed of all developments on the KSZ in the coming days."
For further information please contact:
Kavango Resources plc +44 20 3651 5705
SI Capital Limited (Joint Broker) +44 1483 413500
Turner Pope Investments (Joint Broker) +44 20 3657 0050
Andy Thacker and Zoe Alexander
Note to Editors:
Kavango's 100% subsidiary in Botswana, Kavango Minerals (Pty) Ltd, is the holder of 15 prospecting licences covering 9,231 km2 of ground, including 13 licences over most of the 450km long KSZ magnetic anomaly in the southwest of the country along which Kavango is exploring for Cu-Ni-PGE rich sulphide ore bodies. This large area, which is entirely covered by Cretaceous and post-Cretaceous Kalahari sediments, has not previously been explored using modern techniques.
The area covered by Kavango's KSZ licences displays a geological setting with distinct similarities to that hosting World Class magmatic sulphide deposits such as those at Norilsk (Siberia) and Voisey's Bay (Canada).
· When a deposit consists almost entirely of sulphides it is termed "massive". When it consists of grains or crystals of sulphide in a matrix of silicate minerals, it is termed "disseminated".
· Gabbro/gabbroic: A coarse grained, medium to dark coloured rock, formed from the intrusion of mantle derived molten magma into the earth's crust.
· Gabbroic sills: Relatively thin, planar bodies of solidified gabbroic magma that intruded into layers of sedimentary rock whilst still molten.
· High level sills: Are sills that are emplaced in the upper levels of the earth's crust, close to the surface.
· Sulphide mineralisation: If there is sufficient sulphur in the molten magma, it will tend to combine with metals (Cu, Zn, Ni, Co, Pb, PGEs etc.) to form metal sulphide complexes, which may coalesce to form massive sulphide deposits. If the melt is sulphide poor, the metals will be taken up into the silicate minerals that form as the magma cools and will not usually form economic deposits.
· Primary sulphides: Are sulphide complexes (or crystals) that form as the magma cools and are composed of elements that are present at the time of initial crystallization. Secondary sulphides may form after the magma has solidified either by the introduction of new elements into the rock or by re-mobilising elements already present through changes in pressure, heat etc.
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