Adelaide-based explorer Investigator Resources (ASX: IVR) has commenced follow-up drilling of targets proximal to its Paris silver project in South Australia with a view to extending the resource and enhancing the project’s economics.
The 6,750-metre program will comprise 51 holes across the Ares, Apollo, Helen East, Uno-Morgans, Diomedes and Ajax prospects to follow-up on previously delivered silver, lead and gold results.
The first four prospects were drilled during 2020 and 2021, while Diomedes and Ajax were last drilled in 2015.
Investigator plans to drill seven holes across these two prospects to follow-up new structural models and soil anomalism identified through the ultra-fine fraction+ (UFF+) method developed by Commonwealth Scientific and Industrial Research Organisation (CSIRO) researchers.
Investigator managing director Andrew McIlwain said the delineation of any mineralisation which complements the feed to a planned processing plant at Paris would have a significant effect on project economics.
Ares and Apollo
Drilling at the Ares prospect is aimed at extending coverage over an expanded area within the prospect’s footprint.
A total of 15 holes will be drilled to assess gravity, magnetic and induced polarisation (IP) features in areas where previous results included 1m at 96 grams per tonne silver and 1m at 0.13g/t gold from 66m; 4m at 0.17% lead from 90m; and 27m at 0.17% zinc from 86m.
At Apollo, 21 holes will aim to assess an identified demagnetised feature within the regional Gawler Range Volcanics (GRV), as well as the source of anomalous surface geochemistry at the base of the GRV.
Additional targeting of soil anomalism on the northern side of the east-west trending Uno Fault will test the model that mineralisation migrating along structures may be trapped beneath shallow GRV cover.
Previously known as Ares North, Apollo was subject to a soil sampling program in 2021 using the UFF+ method in conjunction with drilling to improve Investigator’s understanding of the orientation of mineralising structures.
A number of programs completed at the Helen prospect have provided an improved understanding of the structural complexity and geology of the area.
Previous best results have been 49m at 1.09% lead from 36m, including 14m at 48g/t silver from 56m with 7m at 62g/t silver from 62m; and 21m at 0.32% lead and 0.49% zinc from 108m.
Last year, drilling at Helen East stepped away from locations of prior work and focused on alternate structural and geophysical features considered to be underexplored.
Investigator said the results were “encouraging” and additional step-out work comprising seven drill holes will test basement within a circular gravity low feature associated with cross-cutting Paris-Helen dyke and silver-in-soil anomalies.
Shallow, high-grade project
The shallow, high-grade Paris silver project is located 70 kilometres north of Kimba along South Australia’s Eyre Peninsula.
It hosts a mineral resource estimate of 18.8 million tonnes at 88g/t silver and 0.52% lead for 53.1 million ounces of silver and 97,600t of lead.
Key pre-feasibility financial results include a pre-tax net present value of $202 million; a pre-tax internal rate of return of 54.1%; and capital costs of around $131 million.
Planning is underway to finalise a program of work required to complete the project’s definitive feasibility study.