London-listed Kavango Resources’ drilling programme on the Kalahari Suture Zone (KSZ) drilling project, in Botswana, has identified multiple magma conduits, which would have supplied molten lava to the surface.
Kavango says a drill hole on the final target of the drill programme intersected a 16 m gabbroic sill at 120 m from surface.
The gabbro sill contains disseminated sulphides as in the other intrusives intersected in the drill programme.
However, what is significant is that the sediments above and below the sill show intensive alteration by heat, which extends several metres on 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,” Kavango notes.
The company’s geological team believes they have intersected a small part of an extensive magma plumbing system that lies beneath multiple volcanic vents and fissures, which extruded large quantities of basaltic lava onto the surface about 180-million years ago.
This type of “plumbing system” typically hosts massive sulphide orebodies, such as Voisey’s Bay, in Canada, which is one of the world’s largest nickel/copper/cobalt deposits.
"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,” says CEO Michael Foster.