Expanded Silver & Copper-Gold Potential at Paris-Nankivel
- Paris Silver Project:
o Further drilling proposed on Paris extensions
-- Opportunity to add resources to Paris
o Additional geometallurgical study completed
-- Advanced metallurgical study has commenced with improved information
o Prefeasibility study extended to mid-2018
-- Aiming for a stronger PFS with a larger resource and robust metallurgical model
o IP geophysical surveying planned for satellite silver targets.
- Nankivel Copper-Gold Prospect:
o New mapping and geological interpretations enhance and add porphyry targets
o Heritage survey scheduled for drill access to initial Trojan IP porphyry target
o Extended IP surveying proposed
o Joint Venture partner being sought.
Investigator Resources Managing Director John Anderson said "The opportunity to grow the Paris resource with more drilling is the best avenue to add value to the Paris silver project. This has arisen from an improved geological model and reassessment of the target potential around Paris.
Investigator considers Paris to be the best undeveloped silver deposit in Australia due to its high grade. It has potential to elevate Investigator to a producer while we seek partners to test our concepts for larger copper-gold targets such as Nankivel and Maslins."
A) PARIS SILVER PROJECT
Resource extension drilling on improved targeting
As previously announced (Investigator ASX Release: 31 July 2017), discrete geochemical signatures for three sets of intrusive dykes at Paris were identified during geometallurgical studies. The mineralising dykes have distinct values recently recognised by researchers as globally indicative of ore forming systems. This new "dyke" model has improved our targeting for the Paris deposit and wider Paris-Nankivel mineral system (see Figure 2 in the link below).
The extensions to the Paris deposit were accordingly reviewed. This identified under-drilled northern extensions near a northerly dyke and undrilled IP anomalies on the eastern side near north-easterly dykes (see Figure 3 in the link below).
Drilling is proposed to follow-up on those targets as an opportunity to directly add to the Paris silver Mineral Resource. Fifty reverse circulation percussion ("RCP") holes, both inclined or vertical and totalling 5,000m, are allocated.
The first 25 holes will drill the Paris extensions and a further 25 holes are provided to follow up the initial Paris holes and test new targets at the satellite silver prospects arising from the IP surveying described in the link below.
Pre-feasibility study to capture new metallurgy and potential resource extensions
The geometallurgical study is completed with domains selected and samples composited for the advanced metallurgical testing that has commenced.
Utilising the multi-element geochemical dataset generated at Paris, CSA Global Consultants derived a model of geometallurgical domains suitable for selecting composite samples for metallurgical test work. The classifications considered oxidation state, sulphide content and gangue mineralogy.
The improved samples selection will maximise the metallurgical processing outcomes and options for the Paris project.
The Company has appointed CORE Resources, who conducted the initial metallurgical study (Investigator ASX Release: 21 October 2013), to undertake the pre-feasibility study metallurgical test-work. CORE will complete silver and lead flotation test-work, as well as lead gravity test-work and silver cyanide leach work to ascertain the optimum process flowsheet. They will complete high-level process engineering work to allow completion of PFS level design activities on the selected process flowsheet. This study is expected to take around twelve weeks with reporting in Q1 2018. Initial hydrological and open-pit optimisation studies are also underway and are near completion.
The pre-feasibility study is now extended to mid-2018 to accommodate firstly the additional work of the geometallurgical study to better classify the metallurgical samples and secondly the opportunity to drill test upgraded extensions to the Paris deposit.
Satellite silver targets
Exploration of the other silver prospects around the Paris Silver Project, such as Alexander West and Argos (see Figure 2 in the link below) were initially targeted with silver soil geochemistry used to make the Paris discovery. Despite some strong soil anomalies, there was little additional success and this was attributed to variable cover and drainage dispersal. The new dyke model enables renewed focus along the dykes for more subtle geochemical and geophysical signatures through the cover, indicative of the primary sources to the initial soil anomalies and hence targets.
As an initial action, the soil geochemistry coverage was extended along dyke trends west of Alexander West with progressive sampling and assaying during April to September 2017. A total of 377 soil samples were submitted with a density of 100m x 100m for this program (previous 500m x 500m reconnaissance coverage). The analyses delineated weak silver and lead anomalies that may be subdued by the cover and need further geophysical support.
Induced Polarisation ("IP") surveying is proposed for the Alexander, Argos, Ares and Helen-Diomedes target areas (see Figure 4 in the link below). The IP surveying will be extended from the initial 2013 survey at central Paris and will include the potential for deeper northern extensions across the northerly dyke currently defining the north end of the Paris Mineral Resource (see Figure 3 in the link below). The IP surveying will start in the priority areas circled in brown on Figure 2 (see the link below) with provision to expand the coverage according to results to 85 line kilometres of surveying. The aim is to conduct the IP surveys before Christmas 2017.
B) Nankivel porphyry copper-gold targets
The revised dyke model also encouraged extended mapping of the Nankivel target area in subtle topographic rises to the south and west of the area that was surveyed with IP geophysics in 2016. The mapping located surface indications of new targets surrounding the initial Nankivel IP target, now renamed the Trojan porphyry target to discriminate multiple targets within the Nankivel Hill area.
Quartz veins of both straight and wavy styles were found over a large area at Nankivel South along with crackle breccias and polymict breccias within pyritic altered volcanic outcrops (Photographs A - D).
The polymict volcanic breccia is a positive association with the setting at Paris supported by the silver anomalism in the Trojan and Nankivel South areas. As for the Trojan area, the Nankivel South area also has positive indications of multiple subvolcanic dykes as expected for a prospective porphyry system.
The veins and breccias add further ingredients to the strong evidence of mineral alteration and geochemical zoning for the Nankivel porphyry system including the advanced argillic alteration on Nankivel Hill and geochemical/mineralogical zoning in the adjacent drilling. As previously reported, these indicators and vectors are consistent with the Industry's porphyry target models.
A heritage survey is scheduled for October 2017 to establish access for the drill-ready Trojan IP target.
Extended IP surveying is also proposed for the Nankivel and Helen areas to complete coverage of the prospective intrusive complex for copper-gold targets (see Figure 4 in the link below).
A joint venture partner will be sought to explore the exciting breakthrough opportunity for Olympic Dam aged porphyry copper-gold systems.
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About Investigator Resources Ltd
The Company's priority is progressing the development pathway for the Paris silver project with the preparation of a pre-feasibility study. The Paris Mineral Resource Estimate is 9.3Mt @ 139g/t silver and 0.6% lead, comprising 42Moz of contained silver and 55kt of contained lead, at a 50g/t silver cut-off. The resource has been categorised with an Indicated Resource estimate of 4.3Mt @ 163g/t silver and 0.6% lead for 23Moz contained silver and 26kt contained lead, and an Inferred Resource: 5.0Mt @ 119g/t silver and 0.6% lead for 19Moz contained silver and 29kt contained lead.
The Company has applied an innovative strategy that has developed multiple ideas and targets giving Investigator first-mover status. These include: the Paris silver discovery; recognition of other epithermal fields and the associated potential for porphyry copper-gold of Olympic Dam age; extending the ideas developed at Paris-Nankivel and using breakthrough government Magneto-Telluric surveying to rejuvenate targeting with the Maslins IOCG target as the next priority drill target.
Investigator Resources Ltd