London-listed Kavango Resources has completed a ground gravity survey over the Great Red Spot (GRS), in Target Area B of the company's Kalahari Suture Zone (KSZ) project, in Botswana, which has identified a strong gravity anomaly that is coincident with the roughly 2 250 nanoTesla positive magnetic anomaly of the GRS.
The GRS is a previously identified large-scale 11-km-diameter magnetic anomaly that has been subject to limited historic exploration.
The gravity anomaly has an amplitude of about 30 milliGal and is about 7 km in diameter at its widest along the north-south geophysical lines.
Gravity anomalies are the result of density contrasts in rock units relative to the background geology. In mineral exploration, a strong gravity anomaly can indicate the presence of an intrusion, alteration and mineralisation, the company explains.
Visual inspection of drill core from KSZDD001 and reinterpretation of existing magnetic data encouraged Kavango to perform the gravity survey.
The gravity survey was carried out over Target Area B in December, covering boreholes KSZDD001 and KSZDD002.
A Scintrex CG-5 Autograv gravimeter and Leica GPS1200 RTK differential GPS were used to perform the gravity survey.
Seven 13 km lines of gravity data were acquired.
A strong 30 milliGal Bouguer anomaly was detected.
Kavango is now preparing an audio-magnetotelluric survey over the GRS to further refine its understanding of this target.
"While it is too early to start drawing definitive conclusions, we are keen to pursue the possibility that the GRS could host stacked mineralised systems.
“Although this is a relatively new geological theory for Kavango, it is interesting that it builds on our existing work. The younger, shallower Karoo gabbros over the GRS remain our primary focus, but we are increasingly aware of the potential for the deeper, much older Proterozoic gabbros to host an entirely separate system,” says CEO Ben Turney.