       Gold-silver mineralisation occurs at the two deposits of Lerokis and Kali Kuning which are 3.5 km apart on the north coast of the island of Wetar, Maluku Province. The reported Kali Kuning ore reserves at the commencement of mining were 1.9 Mt at 4.6 g/t gold, 151 g/t silver and 60% barite. The stated ore reserves at Lerokis at the commencement of mining were 2.2 Mt at 4.0 g/t gold, 146 g/t silver and 40% barite (Scotney et al, 2005).
The geology of Wetar Island is composed entirely of Neogene volcanic rocks and minor oceanic sediments (Sewell and Wheatley, 1994). Submarine, basaltic–andesites, with local pillows, form the volcanic basement to the island. The basaltic–andesites are intruded by rhyo-dacite domes and overlain by dacitic lavas, tuffs and breccias, debris flows, globerigina limestones and lahar deposits. Reef limestones are evident around the perimeter of the island at varying heights. Kali Kuning and Lerokis host a similar package of rocks. The precious metal mineralisation is hosted by stratiform barite sand, clay or silt which are interpreted to have arisen from submarine exhalative processes. Underlying this are Cu-rich massive pyrite bodies hosted by volcanic breccias and pillow basalts
The Kali Kuning copper deposit consists of a single pyritic massive sulphide lens with sharp upper and lower boundaries. The upper boundary now follows the base of the former gold mining pit, and has been covered with up to 15m of fill as part of PLM reclamation activities. The lower boundary ranges from sharp to a zone of mixed sulphide and tuff fragment breccia, with the massive sulphide overlying bleached, clay altered andesitic to basaltic tuffs, with disseminated and veinlet pyrite and minor chalcocite mineralization. Within the massive sulphide unit, there is virtually no oxidation or development of limonite. Three main textural types are recognized
Background gold values in the range 0.3-0.5 g/t Au occur throughout all three textural types, reflecting an early phase of gold-pyrite deposition. Zones of high chalcopyrite intergrown with the early stage pyrite appear to represent proximity to feeder zones, and occur mainly associated with high copper grades in breccia mineralization. The pyrite breccia unit forms a coherent cap at upper levels of the central part of the Kali Kuning massive sulphide. Copper grades in this unit are generally low (<0.3%Cu) with consistent gold grades in the 0.3-0.6 g/t range. This unit is interpreted to result of in-situ leaching of copper by ground waters. The unconsolidated nature of the matrix makes the pyrite breccia very difficult to drill, with significant matrix core losses common, particularly in early Finders’ drill holes. The pyrite breccia overlies and has a gradational contact with the underlying breccia and stockwork types. This zone appears to be subject to significant preferential losses of copper during the drilling process. Lerokis mineralization is similar in style to Kali Kuning, with a single pyritic massive sulphide lens containing breccia and stockwork phases of copper mineralization, but with a higher ratio of chalcopyrite to covellite/ chalcocite, and a significantly higher zinc content as sphalerite. There does not appear to be an equivalent of the pyrite breccia unit at Lerokis. A satellite deposit is known to occur at Meron, approximately 2 km east of Kali Kuning. The deposit is unmined and is reported by PLM (1987) to be insufficiently drilled to define its global limits. PLM reported an Inferred Resource for Meron copper body of 0.6 Mt @ 2.3% Cu, 0.6 g/t Au using a 1% Cu cut-off and an assumed density of 4.0. The resource was estimated using a manual cross-sectional area technique which is appropriate given its Inferred classification. The Meron data has not been assessed or modelled by H&S. The estimate was for the internal purposes of PLM and, as such, was not reported to JORC standards. It is provided here for historical purposes only.
A number of anomalies derived from a 1996 airborne EM program occur within the Tenement area. These were partially explored by PLM with a view to extending the life of the gold operations. Finders’ have begun a field programme to assess their copper potential. The most striking similarities to the mineralisation have come from recent discoveries on the sea floor such as in the Woodlark Basin, Okinawa Trough and Juan de Fuca Ridge. There are similarities with kuroko deposits albeit at shallower depths and temperatures. H&S has completed a new resource estimate for the Lerokis and Kali Kuning deposits. Plans showing resource extents and location of drill holes are provided in Figures 5 and Figure 6. Domains outlining mineralisation were received from Finders in the form of DXF files. For modelling purposes at Kali Kuning, three zones have been modelled- comprising pyrite breccia, stockwork and breccia massive sulphide combined together, and footwall tuff mineralization. Topographic data detailing the final extent of previous gold mining activity was used for the upper surface. 17 density determinations, averaging 3.8, of mineralisation are available for Kali Kuning mineralisation and 11, averaging 4.1, are available for Lerokis mineralisation. This compares to a density of 4.39 that was used by PT Prima Lirang Mining (1997) for their evaluation of these deposits. Densities were modelled, along with grades, to convert volumes to tonnages. A density of 3.7 was allocated to unestimated, but mineralised, blocks in the Kali Kuning deposit. Methods Ordinary kriging within mineralised domains was used to estimate Cu, Au, Ag, As, Ba, Pb, Sb and Zn grades. Data were composited into three metre intervals. Four searches were used to generate four categories of confidence. These are for Kali Kuning: category 1 = 30 x 30 x 8 metres; category 2 = 45 x 45 x 12 metres; category 3 = 60 x 60 x 16 metres and category 4 = 100 x 100 x 25 metres with a minimum number of data of 10, 8, 8, & 4, respectively. Search directions are based on the local grids and correspond to east, north and elevation, respectively. A 20 degree dip to the west accounted for the geometry of the mineralisation. For Lerokis, the searches were 24 x 24 x 18 metres; 30 x 30 x 22 metres; 48 x 48 x 36 metres and 100 x 100 x 75 metres with no dip. These searches were constrained by domains defined on geological and grade criteria. Results BMI’s QA/QC protocol (Coates, 1989) consisted of the insertion of field duplicates (5% of samples), standards (2 to 3 per batch) and blanks (2 to 3 per batch). Spot checks by H&S of laboratory assay sheets have confirmed the consistent use of standards, blanks and duplicates for QA/QC. Checks of printed laboratory results against results stored in the digital database have not found errors relevant to the copper resource. A consistent understatement of lead values was discovered whereby results at percent levels have been incorrectly stored as one tenth of the correct values. H&S has reviewed QA/QC results from Finders drilling at Kali Kuning. Inserted blanks show no evidence of cross contamination or background effects. Inserted standards report closely to recommended values. These results indicate that no QA/QC issues have been identified. H&S has reviewed core, and core photographs from Finders’ drilling program and notes that core loss appears to be associated with loss of copper. For example, this has particularly affected a strongly pyritic bouldery section in hole 05KKG006 where a 25 metre interval is characterised by unexpectedly low copper grades. H&S concurs with Finders that selective loss of copper minerals has occurred. This issue is commonly encountered with the drilling of friable mineralisation and will lead to an understatement of copper grades. A program of sludge sampling has been initiated by Finders to attempt to quantify these losses. Preliminary observations from the sludge samples from 11 holes indicates that in most cases there is higher copper reporting to the sludge than the corresponding drilled intervals. To further test this conclusion, Finders has completed three pairs of twinned holes, using more sophisticated mud programs in an attempt to minimize selective washing of fines from the core. The results are shown in the Table below.
The results support the interpretation that the average copper grade at Kali Kuning may be understated due to uneven levels of copper losses in earlier drilling, as demonstrated by the above data. Hole KKG050 also recorded an additional 15m @ 5.8% Cu beneath the corresponding interval in KKG011. Hole KKG011 failed to reach the base of the massive sulphide unit.
Sections & Plans
Drill Plan
Drilled Section at Kali Kuning
Drilled Section at Lerokis
Kali Kuning Drill Summary Plan
Kali Kuning 4175 N Section
Lerokis 4350 N Section
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