As the snows melt in the Canadian province of British Columbia (BC), Australian exploration play Blackstone Minerals (ASX: BSX) looks to re-commence field activities at the company’s BC cobalt project.
The company’s attention will be focused on the impressive copper, gold and cobalt targets it identified by way of a soil sampling program previously undertaken on the project.
“We will be commencing our northern hemisphere exploration season in May once the snow starts to melt allowing us access to the ground,” Blackstone Minerals managing director Scott Williamson told The Resources Roadhouse.
“We have a good number of targets at the BC cobalt project that we are keen to start testing.
“Besides the Little Gem target we have identified another, sitting between Little Gem and the previously identified Erebor target, that we feel demands attention.
“We have already encountered high-grade gold and cobalt at Little Gem and at Erebor, so we feel the new target is very interesting and well worth a look.
“Besides these, we also have the Jewel prospect, which is a very big target that we consider having a lot of potential.”
Blackstone has not even had to park the drill rig at Jewel for it to be gathering some attention from astute market watchers.
Basically, the company didn’t have to do anything, thanks to the heavy lifting done by industry heavyweight, Newcrest, which recently made news with a $1.14 billion acquisition for a 70 per cent Joint Venture stake in the Red Chris mine of Toronto-listed Imperial Metals Corp.
Newcrest is no stranger to extracting maximum gain from low-grade, porphyry systems, it has been doing it with a fair rate of success for some time at the Cadia mine in New South Wales, one of the world’s biggest gold mines – after copper credits – that has similar low-grade Resources to Red Chris.
Newcrest mines Cadia at a rate of 30 million tonnes per annum, producing 240,000 ounces of gold – just in the December 2018 quarter alone.
Red Chris has Measured and Indicated Resources of 1 billion tonnes at 0.35 per cent copper and 0.35 grams per tonne gold.
These grades are the norm for BC-style porphyries and, although they may seem low-grade, they are akin to what is being mined by Newcrest at Cadia.
Newcrest has gone into the deal, and the district, with eyes wide open, knowing it has the expertise to make such deposits work and providing plenty of encouragement for others to follow suit.
“The Newcrest deal has really changed our view of the Jewel prospect, as we believe it has similar geology to Red Chris,” Williamson said.
“The Jewel target has potential to be associated with a copper-gold porphyry with cobalt.
“That deal has now put British Columbia copper-gold porphyries on the map.
“To establish such a project does require large capex; however, once underway they practically print money over a twenty to thirty-year mine life.
“We don’t know whether we have one…yet, but there is a chance we could have.”
Blackstone’s 2018 field work at the BC cobalt project consisted an extensive soil sampling program that identified several copper-gold-cobalt targets.
The program resulted in the identification of the Jewel copper-gold-cobalt prospect, located 1.1 kilometres north-northeast of the project’s original focus, the Little Gem prospect.
The new soil anomalies are greater than 1.5km long and coincide with IP targets, indicating a possible large sulphide bearing body at depth.
These copper, gold and cobalt soil anomalies are located within a structural setting near the contact between the granodiorite and serpentinite, that Blackstone considers to be analogous in geological setting to the deposits of the Bou-Azzer primary cobalt district in Morocco.
“We consider there to be forty-eight kilometres of that particular geology that delivered the Little Gem target,” Williamson explained.
“We have only tested one target – Little Gem – out of the entire belt at this stage.
“The key target that has now emerged for testing is the Jewel copper-gold-cobalt prospect.”
Surface rock chip samples taken at the Jewel prospect returned grades of up to 5.6 per cent copper and 5.1 per cent copper.
The BC project took further shape with the discovery of the Erebor cobalt-gold discovery, located 900 metres along an interpreted ultramafic trend to the south-west of the historic Little Gem adits.
Results from surface rock chip samples taken from the Erebor discovery returned assays recording grades of up to 2.3 per cent cobalt and 32 grams per tonne gold.
High-grade cobalt assays from surface rock chip samples taken from the Erebor discovery included:
2.3 per cent cobalt, 32 g/t gold and 1.1 per cent nickel;
1 per cent cobalt;
1 per cent cobalt;
0.6 per cent cobalt;
0.6 per cent cobalt;
0.5 per cent cobalt; and
0.4 per cent cobalt.
These were complemented by high-grade gold and copper assays recorded from surface rock chip samples from Erebor, including:
16.7 g/t gold and 1.6 per cent copper;
10.4 g/t gold; and
1.5 per cent copper.
Blackstone claims Erebor as the first discovery of significant cobalt-gold mineralisation in the region since prospectors discovered similar mineralisation at Little Gem in the 1930s.
The company believes the Erebor discovery further suggests the potential for the BC project to host multiple deposits, akin to the Bou-Azzer primary cobalt district in Morocco.
Blackstone remains encouraged by the fact there has been very little modern-day exploration undertaken across the BC cobalt project since the activities carried out by the early prospectors at Little Gem.
Even since then, the main activities have involved airborne geophysical surveys (including magnetic, radiometric and electromagnetic (EM) surveys) in the 1970s and a further two drill holes completed in 1986.
The mineral occurrence at the Jewel prospect supported some gold production from 1938 to 1940.
Although Blackstone Minerals’ southern hemisphere winter focus is on the company’s BC cobalt project, it also has the emerging Silver Swan South gold project, located eight kilometres along strike of the five million-ounce Kanowna Belle gold mine near Kalgoorlie in Western Australia.
The Silver Swan South project comprises one exploration licence application E27/545 and six granted prospecting licences, P27/2191 – 2196 covering an area of 47.2 square kilometres and are located approximately 40 kilometres northeast of Kalgoorlie.
Results from Blackstone Minerals’ 2018 drilling campaign at the Silver Swan South gold project produced several encouraging results.
The company’s second phase aircore drilling program at Silver Swan South demonstrated its potential as being an emerging gold discovery hosting extensive gold mineralisation and basement geochemical anomalism.
The basement geochemical anomalisms at the Black Eagle deposit as well as at the Black Hawk prospect are located along the interpreted extension of the Fitzroy Shear Zone, which hosts the Kanowna Belle gold mine.
The drilling encountered gold mineralisation and extensive basement geochemical anomalism at the Black Eagle prospect, providing a result of:
10 metres at 3.2 grams per tonne gold from 68m within 15m at 2.2g/t gold from 64m to end-of-hole (EOH).
On the back of this result, Blackstone was able to promote the Black Eagle prospect to priority drill target status.
Blackstone Minerals remains keen to identify the extent and source of the gold mineralisation at Silver Swan South, and to follow-up results of surface sampling of the target ultramafic unit that previously confirmed the presence of nickel sulphides (pentlandite).
“When we originally acquired this ground, we actually did so for its nickel potential,” Williamson said.
“This is the project the company originally listed on, because we liked what we saw in terms of nickel sulphide potential, so we are now going to revisit that nickel sulphide potential.”
Directors: Hamish Halliday, Scott Williamson, Andrew Radonjic, Steve Parsons, Michael Konnert