Alaska VMS zinc discovery excites Aussie
Last updated 8/31/2018 at 4:53am
White Rock Minerals Ltd. Aug. 20 reported high-grade zinc grades were encountered in a second hole at the Hunter discovery on the company's Red Mountain project in Alaska.
Hunter was discovered during a reconnaissance exploration program seeking new volcanogenic massive sulfide prospects across White Rock's 35,300-acre Red Mountain property. While mapping and sampling an area about 5,200 meters southeast of Dry Creek, one of two zinc-lead-copper-gold-silver deposits on the property, crews identified a two-foot massive sulfide outcrop rich in sphalerite (zinc mineralization) and galena (lead mineralization) at Hunter.
Further prospecting at Hunter mapped massive sulfide mineralization for about 500 meters along strike that is associated with carbonaceous phyllite that can be traced more than 1,000 meters.
Rock chip sampling of the massive sulfide from the discovery outcrop, as well as trenching along strike to define the position of the mineralization, returned assays of up to 18.6 percent zinc, 5.4 percent lead, 2.3 percent copper, 147 grams per metric ton silver and 0.7g/t gold.
The first two holes drilled at Hunter – HR18-01 and HR18-02 – cut the massive sulfide mineralization up to 80 meters down-dip from the outcrop.
Hole HR18-01 cut 1.4 meters of massive sulfide averaging 17.4 percent zinc, 3.9 percent lead, 90 g/t silver and 1.6 percent copper 48.2 meters down-hole. This equates to 25.8 percent zinc-equivalent when you consider the value of all the metals encountered.
Hole HR18-02, which was drilled from the same pad at a shallower angle, cut 1.8 meters averaging 13.8 percent zinc, 3.1 percent lead, 56 g/t silver and 0.9 percent copper, or 19.5 percent zinc-equivalent, 60.8 meters down-hole.
"There aren't many places in this world where you find outcropping zinc-rich massive sulfide (with lead, copper, silver and gold) and then promptly drill test that and get a positive response," said White Rock Minerals CEO Matt Gill.
A third hole tested – HR18-04 –cut a narrow band of massive sulfide mineralization a further 80 meters down dip from hole 2; assays are pending.
"While the third hole intersected a narrower band of massive sulfide, we know from the West Tundra deposit (9,000 meters to the west) that occasionally the VMS horizon pinches locally, but the potential remains high for good thickness and grade along strike and further down dip," said Gill.
When White Rock acquired Red Mountain in 2016, the project was known to host two zinc-rich VMS deposits, West Tundra Flats and Dry Creek.
A maiden Australian Joint Ore Reserves Committee- (JORC) compliant resource calculated in 2017 found that Dry Creek and West Tundra Flats host 16.7 million metric tons of inferred resource averaging 4.1 percent (1.49 billion pounds) zinc; 1.7 percent (630 million lb) lead; 0.2 percent (57.3 million lb) copper; 99 grams per metric ton (53.5 million ounces) silver; and 0.7 g/t (352,000 oz) gold.
Recognizing that these deposits may be a part of a larger VMS district, White Rock expanded the property to cover around 30 prospects identified with sampling and geophysics.
"The discovery of a new massive sulfide occurrence at Hunter goes a long way to supporting the thesis that the Red Mountain project has the potential to host multiple deposits and expand into a true VMS camp," said Gill.
To further test this thesis, the drill rig that discovered Hunter is now testing South Platypus prospect, a prospect about 3,000 meters east of Hunter.
In addition to making new discoveries, this year's drills have tapped exceptional mineralization at Dry Creek and West Tundra Flats.
The best hole drilled so far this year at Dry Creek, DC18-79 cut 4.72 meters averaging 19.5 percent zinc, 7.8 percent lead, 466 g/t silver, 6.9 g/t gold and 1.5 percent copper, or 49.7 percent zinc-equivalent. This was part of a 16-meter intercept that averaged 6.4 percent zinc, 2.6 percent lead, 152 g/t silver, 2.2 g/t gold and 0.5 percent copper, or 16.1 percent zinc-equivalent.
WT18-28, drilled at West Tundra Flats, cut 3.45 meters averaging 15.1 percent zinc, 6.7 percent lead, 518 g/t silver, 2.1 g/t gold and 0.2 percent copper, or 35.2 percent zinc-equivalent.
Both holes were drilled early in the season and assays were reported earlier this year.
"We are excited by the success of our first field season in Alaska at the Red Mountain project," said Gill. "Through an aggressive approach – deploying a drill rig early on the tail of geological prospecting, surface sampling and ground geophysics – we have been rewarded with the discovery of massive sulfide mineralization in outcrop within three months of starting our very first program."
Thanks to an AU$1 million funding agreement with Sandfire Resources NL, a mid-tier Australian mining company that operates a high-grade copper-gold mine in Western Australia, this program will be even more aggressive and run later into the 2018 season.
"With this funding, we have now been able to extend our drilling campaign into September and ramp-up our reconnaissance mapping and geochemical sampling works three-fold, this work already credited with one massive sulfide discovery – Hunter," said Gill.
This funding agreement consists of two AU$500,000 loans – one that is completely interest free and a second that begins accruing a 5 percent annual interest beginning on Feb. 28, 2019.
Under an agreement reached in July, Sandfire has the option to earn up to a 90 percent interest in Red Mountain by investing AU$30 million into the high-grade zinc project and then funding a feasibility study.
If Sandfire exercises its option to enter into a joint venture arrangement on Red Mountain, the AU$1 million loans would be applied toward the Aussie miner's expenditure commitments. Otherwise, the non-interest loan would convert to White Rock shares. The interest-bearing loan can also be converted to White Rock shares but would require shareholder approval.
"This funding will help White Rock continue implementing key exploration and development activities at Red Mountain and sets us up well for next year's campaign," Gill said.