Nadi Project
During 2007 five diamond drill holes (DDHNT001-5) were completed in Nadi South. These tested the northern portion of a strong chargeability anomaly (Togo Prospect) which was defined during late 2006 by a three dimensional Induced Polarisation (IP) survey using an offset pole-dipole (OPD) configuration.
The Togo Prospect is characterised by high chargeability values extending from near surface to over 500m depth and across a strike length of more than 2 kilometres. Alteration and low-grade mineralisation typical of porphyry copper-gold deposits was encountered in all of the Geopacific drill holes and Fiji Government drill hole DDH84/7.
NT001 was drilled at a high resistivity target on the NE edge of the chargeability anomaly defined by the IP survey. It was drilled towards grid west at 60 degrees dip and was completed at a depth of 447.5m. NT001 intersected varieties of equigranular to porphyritic diorite and tonalite with increasing content of gabbroic rocks close to the bottom of the hole. Fracturing, jointing and thin quartz–sulphide veins occur throughout the core and these have dominantly westerly dips. Assay data for sawn half and quarter core include anomalous assays in both gold and copper ranging up to 0.13g/t Au and 1,700ppm Cu.
NT002 was located 280m SW of NT001 and was also drilled towards grid west at a 60 degree dip. NT002 was completed at 200m and intersected similar intrusive rocks to NT001. Sulphide content, dominantly disseminated pyrite, is higher than for NT001 core and fracturing and veining is also conspicuous.
NT003 was collared 650m to grid west of NT001 and was drilled to 309m towards grid east at 60 degrees. Intrusive rocks in the upper part of NT003 have biotite alteration and higher sulphide content than NT001 and NT002. Assays of NT003 core include anomalous copper values between 79-219m (140m averaging 635ppm Cu) with individual samples of 2m lengths ranging up to 1,790ppm Cu.
NT004 was drilled to 355m towards grid east at 60 degrees. Assayed core includes anomalous copper values between 6-210m (204m averaging 693ppm Cu) and 292-310m (18m averaging 940ppm Cu) with individual samples of 2m lengths ranging up to 1,600ppm Cu and 0.53g/t Au.
NT005 was located at the same collar location as NT003 and drilled as a vertical hole to 441m to test high chargeability values at depth. Anomalous copper results occur throughout the core with highest assays close to the bottom of the hole (1,680ppm Cu for the interval between 412-414m).
Pyrite, minor chalcopyrite and rarer chalcocite is widespread in drill core from NT003, NT004 and NT005 and commonly occurs in fine grained fractures and veinlets as well as disseminations in intrusives within alteration zones containing sericite, biotite and magnetite.
The results of drilling NT001-5 are encouraging and show that the Togo Prospect has intrusive lithologies and alteration typical of large porphyry copper-gold systems.
Low-grade mineralisation in all of the drill holes completed during 2007 indicate that a zone of higher grade copper and gold mineralisation may be located in other parts of an apparently large and zoned deposit. Further step out drilling is planned to test other portions of the Togo Prospect.
The induced polarisation survey showed that strongly anomalous chargeability values extend to the south of the Togo Prospect into the Takara Prospect area (Figure 4) and reconnaissance surface mapping of this southern anomaly has confirmed extensive surface alteration and mineralisation. Gold values up to 36.4g/t have been reported from outcrops during previous company work and recent sampling by Geopacific has confirmed widespread gold mineralisation at Takara.
Geopacific plans to continue with mapping and undertake an IP survey of the Takara area prior to drill testing.