Auroch Minerals is heading for the metals-rich and under-explored Adelaide Geosyncline in South Australia following the acquisition of two zinc projects with historical drill hits of up to 26.9% zinc.
The company announced this week it had entered into binding agreements to acquire 90% of the Arden Zinc project near Quorn in the Flinders Ranges and 100% of the Bonaventura Zinc project on Kangaroo Island.
The projects are separated by almost 600km but lie within the same rift complex known as the Adelaide Geosyncline, which has produced multiple zinc, lead and copper mines.
This deposit style is known for its large-scale, stratiform orebodies and will be a key target of Auroch’s new exploration push in South Australia.
Existing mines include the Beltana zinc mine that boasts 972,000 tonnes at 29.8% zinc for almost 300,000 tonnes, the Angas zine mine with 1.29Mt at 5.75% zinc and lead and the Kanmantoo copper mine with 34.5Mt at 0.6% copper and 0.1 g/t gold.
The Adelaide Geosyncline was actually host to Australia’s first base metals mine in 1842 in what is now the Adelaide foothills suburb of Glen Osmond, however, it is still vastly underexplored compared to many West Australian regions.
Auroch’s new acquisitions, which will be satisfied by the issue of 8.3 million Auroch shares and various classes of performance shares if certain JORC resource targets are met, are subject to due diligence and shareholder approval.
The Arden project comprises a large tenement of 710km² containing small historic mines for zinc, lead, copper, iron and manganese that were worked at various times between 1850 and 1920.
Between 1966 and 1972, Kennecott (Rio Tinto) undertook zinc mining and exploration and delineated over 10km of strike of potential Sedex zinc mineralisation via trenching, resulting in anomalous zinc intersections up to 40m wide and individual samples of up to 10% zinc. However, only 200m of the 10km of strike was drill-tested by 4 holes in 1968, none of which reached the target depths to test for primary sulphide mineralisation.
Since 1980, the Arden Project area has been the focus of diamond exploration, and no further zinc or other base-metal exploration has occurred. Sampling completed last year by the vendors confirmed Kennecott’s historic zinc results and presented a new gossan which assayed up to 10% zinc, a further 1,500m along strike from the last Kennecott trench. Further sampling in 2017 also resulted in assays of up to 2.5% cobalt from rock chips taken from the Kanyaka target, providing some serious blue sky for Auroch in the burgeoning clean tech battery metals space.
The Bonaventura Project comprises a large tenement of 234km² in the northern part of Kangaroo Island and includes a number of small historic zinc, copper and gold mines. Previous exploration produced impressive drill hits, including 5m @ 26.9% zinc and 10% lead from 26m.
Auroch executive chairman, Glenn Whiddon, said: “The Arden Project and Bonaventura Project in South Australia comprise a substantial zinc, lead and copper play supported by excellent infrastructure. The projects cover several historical mines and provide multiple targets. This acquisition provides Auroch with multiple drill-ready targets for large scale base-metal mineralisation that will be systematically evaluated in 2018”.
The company has planned an aggressive systematic exploration program for both the Arden and Bonaventura Projects, with a budget of about $1.1 million in the first 12 months.
At Arden, site reconnaissance mapping, rock chip and soil-sampling will begin immediately in the known target areas. All existing open-file geophysics data will be processed, followed by a high-resolution aeromagnetic survey over the whole tenement. A maiden drill program is targeted for the September quarter after permitting and access agreements are in place.
At the Bonaventura Project, re-processing and interpretation of the existing high-resolution geophysical data will begin immediately. Site reconnaissance mapping, rock chip and soil-sampling of the known target areas will take place in parallel. Drilling is targeted as early as the June quarter after permitting and access agreements are completed.
By Matt Birney
