Using Induced Polarisation as a Follow up to Magnetic Method in Prospecting for Gold at Lady A Claims

Bernard Siachingoma, Renisia Tipedze

Abstract: Lady A Claims lie about 9km NNW of Concession, some 75km to the NNW of Harare. The survey area lies in the mineral rich greenstone belt. The rocks in the study area include mafic to felsic volcanics with occasional sediments and ironstone intercalations. The gold mineralization is associated with quartz reefs hosted within meta-basalts. Based on the promising results from the magnetic surveys, induced polarization (IP) surveys were completed across all the six Lady A Claims in Concession. Gradient Array results show south-east north-west trending zones of high chargeability accompanied by low resistivity. There is a zone towards the eastern end of the blocks, which show high resistivity and high chargeability. High chargeability zones can be thought to correspond to zones associated with quartz veins. Real Section Induced Polarization (RSIP) was done over ten lines to determine the apparent behaviour of the anomalies with depth. The results from this survey showed the complicated nature of the ore-body with depth and along strike. Possible drilling targets were delineated along each of these lines.

Keywords: greenstone belt, induced polarization, chargeability, anomalies, ore-body