Misima Porphyry Prospect

The exploration licence was initially targeted by WCB due to the presence of a significant high order copper stream sediment anomaly (1,950ppm) in multiple drainages and the recorded occurrence of porphyry Cu style alteration and low level mineralisation in the headwaters. Previous history research has shown that this anomaly was evaluated in the late 1960's by Noranda. This work confirmed the existence of upper level porphyry copper style mineralisation as well as the identification of the gold silver mineralisation (Umuna Lode) on the western portion of this anomaly.

Following this initial early assessment of the copper potential of the island, subsequent exploration activities were focussed on the gold potential culminating in the discovery, definition and development of the Misima Gold Mine in the late 1980's to mid 2004. This early stage activity clearly defined a zone of porphyry style alteration and geochemistry with an adjacent spatially related zone of Au Ag and base metal mineralisation as shown in the map below.

Misima Porphyry Prospect image 1 

Gallipoli has been systematic in its exploration approach which has included extensive consultation and engagement with all stakeholders including the Landowners, the Local Level Government, the Provincial Government and the MRA. Exploration activities commenced in 2012 with work to date completed including:

Soil Sampling:- In excess of 4,000 samples were collected on a ridge and spur soil program. Results from this survey defined a significant 1,100m by 900m high order copper anomaly with coincident gold, silver and molybdenum. Numerous additional high order gold zinc, lead and silver anomalies were also defined in the region which will require follow up (see announcements 22 May 201214 June 2012, and 18 June 2012).

 Misima Porphyry Prospect soil sampling image

Rock Chip Sampling:- In conjunction with the soil sampling, rock chip sampling was also completed with highly encouraging results (see announcements 4 June 201216 October 2012).

Aeromagnetic Survey:- A 100m line spacing 40m flying height heliborne aeromagnetic survey was completed covering the entire EL1747. Resultant data has been processed and imaged outlining a well defined magnetic high associated with the copper anomalism in conjunction with other anomalies including large interpreted structures and intrusives (see announcement 7 August 2012).

Misima Porphyry Prospect aeromagnetic image 

Mapping and Channel Sampling:- Detailed mapping and associated channel sampling has been completed covering the copper anomaly in areas where there is exposure including tracks and benches. The data define broad zones of porphyry style mineralisation with the best result of 170.9m @ 0.36% Cu, 0.33 g/t Au and 10.10 g/t Ag (see announcement 9 July 2013).

Misima Porphyry Prospect mapping and channel sampling image 

Database:- Acquisition of the historic database (see announcement 22 November 2012) from Misima Mines Pty Ltd was completed. Following conversion and validation this provided access to important exploration and mine data. Data included

  • 25,980 Channel Samples

  • 2,941 Rock Samples

  • 11,846 Soil Samples

  • 1,446 Stream Samples

  • 4,853 Umuna Trench Samples

  • 2,640 Exploration Drill Holes

  • 280,000 Blast Holes

  • Environmental Data

  • Survey and Surface Data

Misima Porphyry Prospect database image 

 

Interpretation of Data

Compilation and interpretation of data including the geochemistry, alteration and mapping data suggest that the exposure level of the system is in the outer propylitic zone. This indicates that the system is preserved and deep drill testing will be required to vector into the central high grade zone of the porphyry. A schematic model of the system exposure level is shown below.

 Hydrothermal Alteration Zones image

Scout Drill Testing:- A scout diamond drill program in excess of 3000m (see announcement 11 September 2014) was aimed at testing the depth extensions of the large robust surface anomaly.

Locations of drill holes with respect to channel sample results and retained RTP magnetics are shown below.

 

 A review of the results and data from the 2014/2015 drill program outlined strong vectors including:

  • Increase in hydrothermal brecciation
  • Volume increase in intrusive
  • Strong increase in Cu-Au geochemistry
  • Decrease in Pb Zn association
  • Structural intersection

Which suggested that the porphyry Cu Au target is located at depth adjacent to the Umuna Fault Zone, as shown below.