Other projects in PNG | Exploration map
Crater Mountain
The Crater Mountain exploration license (EL1115) is situated in the Eastern Highlands Province of Papua New Guinea. This tenement covers 44 sq km. The joint venture has recently been granted EL1353 covering 751 sq km surrounding and contiguous with EL1115.
Crater Mountain is one of several Pliocene to Quaternary aged volcanic complexes located along the tectonically active New Guinea Mobile Belt at the margin of the Australian Continental Plate. The Mobile Belt hosts world-class gold and copper-gold deposits of the same young geological age such as Porgera and Ok Tedi in PNG and Grasberg further west in Irian Jaya. Previous exploration has indicated that Crater Mountain has potential for developing a large epithermal gold deposit.
The Crater Mountain complex is a partly dissected strata-volcano and has geological similarities to the Porgera gold deposit (over 6 million ounces). Although masked by younger volcanic ash cover over much of the area, five prospects have so far been identified along a north-northeast trending structural corridor or transfer structure that traverses the project area. A 12 sq. km area of alteration including vughy silica, epithermal textured quartz, active hot springs and zones of hydrothermal breccia has been recognised within this corridor. Four of the five prospects occur in the Nevera alteration area, a 5km long by over 2km wide argillic altered area that contains several extensive gold and base metal soil geochemical anomalies. Only one of these prospects, the Nevera Prospect, has been tested by limited hand trenching and drilling. Petrographic studies have suggested that the Nevera Prospect represents the top of a telescoped porphyry Cu/Au system.
Exploration work by TPJ has focused on the Nevera area and included detailed mapping and rock chip sampling to understand the controls on gold mineralisation. A drill rig was rapidly mobilized early this year to follow up excellent results from previous drilling by both Macmin and BHP. Nev-09 intersected a mineralised width of 158 metres averaging 1.4 g/t gold from 220 metres to 378 metres hole depth, with hydrothermal brecciation, disseminated, fracture-filled and vein sulphide mineralization encountered throughout the hole length of 450 metres. The results confirm a drill hole interval of 115 metres of 1.8 g/t gold reported by then BHP in the same area in 1997, and appear to significantly increase the intersected width of mineralization.
A further 3 holes have been drilled into Nevera and continue to demonstrate significant widths of low grade mineralisation. Gold mineralisation occurs in pyrite fracture networks, basemetal carbonate veining and quartz-chalcopyrite veins. The latter style of mineralisation can be very high grade up to 46.6 g/t Au. Basemetal carbonate veining occurs from surface but gives way at depth to more chalcopyrite dominant veins and breccias. This zonation indicates increasing temperatures of formation and a possible vector to porphyry mineralisation at depth.
A soil orientation sampling is currently progressing at the Nevera Prospect between drill holes Nev10 and Nev11. Due to the extensive volcanic ash cover masking reliable geochemical signatures, MMI and the partial leach techniques are being tested in orientation programs as well as standard auger sampling and assaying methods. The method giving the optimum results will be applied on a larger sampling grid being planned.
Prospect mapping and sampling in the Nevera prospect is ongoing and has been extended to the south and southwest. Concurrent with this program will be a push out to the south west to follow up coincident aeromagnetic, rock chip and stream sediment anomalies at Nimi.
