SPL 1271, VIT 1, VIT 2,
Emperor Gold Mining Co. Ltd; Western Mining Corporation (Fiji) Ltd; Paterson, Grant and Watson Ltd; Geoterrex Pty Ltd; Tesla-10 Pty Ltd,
geochemical exploration, epithermal gold, magnetic survey - airborne, radiometric survey - airborne, geological mapping, soil sampling, magnetic susceptibility, magnetic remanence, Euler deconvolution,
vertically integrated total magnetic field,
geochemical analysis, Au, Hg, Cu, Pb, Zn,
Viti Levu, Tavua Volcano, Tavua, Korovou Hill Prospect, Balata, Nasivi River,
SPL 1271 was granted on 24/6/86 and initially covered an area of 3500 hectares but, effective from March 1993, was reduced to an area of 1761 hectares. This summary covers the relinquished portion of SPL 1271, i.e., the northern part and consisting predominantly of the Nasivi Delta and the outer flank of the Tavua Volcano. Work was done initially by Western Mining Corporation (as managers of the Tavua Basin Joint Venture) and then after 1991, by Emperor Gold Mining Co. Ltd.
Work on the relinquished portion of SPL 1271 failed to locate any widespread surface alteration. Areas of SPL 1271 suitable for soil-grid geochemistry were sampled, but only about half of the samples were analysed - for Au, Hg and magnetic susceptibility. Anomalous areas from initial soil-grid sampling were followed up, including by geological mapping of anomalous areas. Several of the anomalies were considered spurious and probably derived from using gravel from the Nasivi River as road aggregate. One area of anomalous gold and mercury, associated with a magnetic-susceptibility low in soil samples, was found on the outskirts of Tavua. Two airborne magnetic surveys (and one radiometric survey) were carried out and the data sets linked together, continued to a common height of 125 m and reduced to the pole. In addition, another set of maps was produced using the analytical signal of the vertically integrated total magnetic intensity followed by an Euler deconvolution in pseudo sections to define depths to basement and define contacts or faults. No anomalies from the airborne survey were correlatable with soil geochemical anomalies. The potassium count data lack contrast and were apparently not useful in defining areas of alteration.
The airborne survey indicates three areas of residual interest:
- the NNW-trending Balata structure (which offsets the caldera contact in SPL 1201);
- magnetic lows along the Nasivi trend; and
- NE-trending lows in the northeast of SPL 1271, but with a possible topographic origin.
No prospects or targets were drilled in the relinquished portion of SPL 1271, and no work was done on alluvials of the Nasivi Delta.
SPL 1296, VIT 10,
geochemical exploration, epithermal gold, panned-concentrate sampling, rock-chip sampling, rock-float sampling, pyrite, fire assay, cyanide leach,
geochemical analysis, Au, Ag,
Nadi Sedimentary Group,
Viti Levu, Nadi River, Toko, Namulomulo, Namosi Creek,
Fieldwork was conducted in late 1990 and consisted of reconnaissance stream-sediment and rock-float geochemistry with panned concentrates. A total of 127 samples were analysed for gold + silver. Most of this relinquished portion of SPL 1296 consists of the Nadi Sedimentary Group - sedimentary breccias and finer-grained interbeds which are, in part, tuffaceous. Clasts within the breccia (? debris flows) range up to 20 m across.
The highest gold value in rock float was 0.878 ppm while in panned concentrates the maximum gold value was 0.027 ppm. Maximum silver content was 3 ppm. Mineralisation was apparently related to quartz veining and alteration as well as float of massive pyrite, rocks veined with quartz + pyrite and porphyries containing minor pyrite and rare base-metal sulphides. The source of mineralised float was, in most cases, traced back to clasts within breccias of the Nadi Sedimentary Group. In other cases, contamination was suspected from widespread use of gravels from the Sabeto River as road rubble.
The retained portion of SPL 1296 (and SPL 1283) contains the Tuvatu Prospect, which is the current focus of attention for Geopacific Ltd and the joint venture of Geopacific/Emperor.
SPL 1344, VIT 5, VIT 6,
Emperor Gold Mining Co Ltd; Geoterrex Pty Ltd; Western Mining Corporation (Fiji) Ltd; World Geoscience Corporation; Paterson, Grant and Watson Ltd,
geochemical exploration, geological mapping, magnetic survey - airborne, soil sampling, stream-sediment sampling, reverse-circulation drilling, RC drilling,
geochemical analysis, Au, Cu, As, Hg,
Viti Levu, South Ridge Road Prospect, Tavua Volcano, Vatia Volcano,
SPL 1344 was granted to Koula Mining Co. Ltd. and Emperor Gold Mining Co. Ltd on 14 May 1991, for an area of 17 811 hectares. The tenement was originally won on tender, following the non renewal of SPL 1208 (Pacific Energy and Minerals/AMAX joint venture). Western Mining Corporation were managers until 1991, after which Emperor assumed full control. From 1 April 1994, SPL 1344 was renewed but for a reduced area. This report only covers the relinquished portion, which contains only one prospect - South Ridge.
Work consisted of stream-sediment and soil sampling, geological mapping on 1:10 000 base maps and an airborne magnetic survey by Geoterrex in 1991, with RC drilling at the South Ridge Road Prospect - the only geochemical anomaly within the relinquished portion of SPL 1344. A total of 639 samples over 10 km of soil grid lines (sampled on 25-m spacings) were collected at South Ridge Road Prospect, with anomalous Hg and Au results. Seven RC holes were drilled, but without intersecting significant mineralisation. Re-assays of original drill-hole chips at external laboratories indicated contamination, source unknown, in the original samples. Better (uncontaminated) results were typically in the range of 0.10 to 0.15 g/t Au over several metres. The maximum 1-m interval was 0.19 g/t Au from 24 m in hole FERSR04.
Problems were encountered by World Geoscience Corporation in interpreting the original airborne magnetic data of Geoterrex as there was inadequate recording of heights above the ground, and hence steep valleys could appear as magnetic lows whereas ridges would appear as magnetic highs. This was partly rectified by the further processing by Paterson, Grant and Watson Ltd of Canada, but there appear to be no areas of alteration close to the surface in the relinquished portion of SPL 1344.