First results from Heron’s second phase of diamond drilling at its 100%-owned Woodlawn project were another positive step towards underground production and will form a key input into the feasibility study, due for completion in the first half a calendar 2016.
The phase-2 program was underway and would likely see 19,000m of drilling completed in total, with the first tranche of 13 holes completed in June for 4200m. This initial sequence has been designed to test the shallow mineralised positions that have potential easily accessible production in the early part of the future underground operation.
The program was also designed to deliver the infill drilling required to upgrade a portion of the 5.5Mt underground mineral resource to indicated status. The program has confirmed the up-and-down plunge extensions of the Kate lens through three particular massive sulphide intercepts.
These three intercepts included 7.3m of polymetallic sulphides from 339.8m; 20.3m of copper and polymetallic sulphides from 383.4m; and 9.6m of copper and polymetallic sulphides from 406.2m. The initial results also included a high-grade intercept on G Lens of 3m at 8.5% zinc, 3.5% copper, 5.2%lead, 6.3gpt gold and 161gpt silver from 30m.
Pioneer Resources has posted its final results from the company’s reconnaissance aircore drilling program at the Fairwater nickel project in the Albany Fraser Orogen. The program included 99 holes for 3616m targeting proof of concept.
Drilling confirmed the presence of ultramafic rocks, which was the prime objective of the work. Anomalous nickel geochemistry was returned from 10 of the holes at the FWNi003 prospect and drilling has extended a priority nickel-copper sulphide target to more than 200m in strike length.
Anomalous nickel-copper assay results were 8m at 0.33% nickel and 109ppm copper from 30m, including maximum values of 0.39% nickel, 336ppm copper and 19% magnesium oxide; 1m at 0.58% nickel and 104ppm copper from 40m; and 12m at 0.35% nickel and 69ppm copper from 32m.
Planning for next phase of drilling is underway and will include deeper RC and diamond holes targeting fresh rock below current shallow drilling. Pioneer has been awarded $129,500 in funding for drilling at Fairwater under the WA state government’s exploration incentive scheme.
Poseidon has put out its first ore reserve estimation for the Maggie Hays mine, at the recently acquired Lake Johnston project, having completed the definition work within seven months of the project being purchased.
The reserve – 1.9Mt at 1.19% 22,600t contained nickel – has been the culmination of geological reinterpretation, resource estimation, detailed mining and engineering studies, contract pricing, plant refurbishment pricing and the completion of the BFS.
This reserve represents an initial 30 months of plant throughput producing 8000tpa of nickel in a smeltable grade concentrate. The reserve number contains 54% of the indicated resources at the project, while further drilling during the production phase will be required to convert the remainder.
This is an initial estimate, as Poseidon has not yet undertaken any further drilling at the site, which it expects to increase the project life given a number of promising resource/reserve extensions are yet to be infill drilled and developed.
Assay results from a diamond drill hole at the Springfield project – part of Sandfire’s joint venture with Talisman Mining – confirm the intersection of a significant zone of high-grade copper-gold mineralisation, about 10km east of Sandfire’s 100%-owned DeGrussa mine.
The assays returned an exceptional massive sulphide intercept of 16.5m at 18.9% copper and 2.1gpt gold from 409.5m. This hole was drilled as a follow-up to a previous drill hole completed last month and was designed to intersect an off-hole EM response detected in a downhole electromagnetic survey.
While exploration of this emerging VMS prospect is still at an early stage, the width, grade and tenor of the copper-gold mineralisation intersected was considered to be very encouraging. This is also the first significant intersection of high-grade copper-gold mineralisation to be discovered outside of the known lenses of VMS mineralisation at DeGrussa.
Additionally, the massive sulphide mineralisation intersected in the latest hole was similar to that seen in the DeGrussa, Conductor 1, 4 and 5 VMS lenses and occurs within a host sequence that bears many similarities to that which hosts the massive sulphide mineralisation at DeGrussa.
Recent diamond drilling at Stavely’s 100% owned Ararat project in western Victoria has offered up some encouraging results for the company, including significant high-grade gold intercepts of up to 11.3gpt and some impressive zones of VMS copper mineralisation grading up to 5.91%.
The drilling has advanced Stavely’s geological understanding of the Ararat project, taking it a step closer to unlocking the potential for a significant bedrock gold discovery adjacent to a prolific historical alluvial goldfield. The company has completed three diamond drill holes targeting the structures controlling hard-rock gold mineralisation at the White Lead prospect.
White Lead is on the western edge of the historical Cathcart Goldfield, part of the Ararat field which is estimated to have produced some 640,000oz of alluvial and deep lead gold production in the period around 1864. Stavely now believes that the source of the alluvial gold is gold mineralised structures of the sort intersected in this recent drilling.
Recent White Lead intercepts were 2m at 6.43gpt gold, including 1m at 11.3gpt gold; and 2m at 1.04gpt gold. Other drilling targeting the Mt Ararat VMS deposit returned 2m at 4.25% copper and 1.15% zinc, including 1m at 5.91% copper and 1.3% zinc; and 3m at 1.77% copper and 0.59% zinc, including 1m at 4.45% copper and 0.66% zinc.
Saracen Mineral Holdings
Saracen’s recent drilling at the Karari deposit, part of its Carosue Dam gold operation in WA, has further expanded the emerging resource. The results included multiple high-grade extensional intersections, which are expected to underpin a significant resource-reserve increase in late 2015.
Karari forms a key part of Saracen’s strategy to establish a five-year-plus mine life at Carosue Dam, with the new results extending the mineralisation at depth below previous drilling. The ongoing results support the case for a underground mine at Karari, where stoping is planned to commence in the current (September) quarter.
Significant results from extensional drilling included 23.4m at 7.5gpt gold from 321m; 41m at 3.3gpt gold from 297m; 18.8m at 5.6gpt gold from 216m; and 21m at 4.8gpt gold from 275m. The deepest intersection to date at Karari (23.4m at 7.5gpt) is just 405m below surface.
In addition to attractive grades, the widths are conducive to high productivity and low unit-cost underground mining, while Karari remains open down-plunge and to the south. Drilling continues with two underground rigs and a maiden underground reserve is anticipated later in 2015.
*A version of this report was first published in the July-August 2015 edition of RESOURCESTOCKS magazine.