The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
Sampling expands gold-copper beyond the porphyry deposits North of 60 Mining News – March 22, 2019
A rainbow arcs over Freegold Mountain, a road-accessible gold-copper project in the Yukon where placer mining has exposed gold-rich bedrock.
Triumph Gold Corp.'s 2018 surface sampling provides further evidence that the already large gold-copper deposits outlined so far at its Freegold Mountain project in the Yukon may be just portions of an even greater mineralized system on the property.
The sampling identified gold-copper mineralization in three zones outside the Nucleus and Revenue deposits, including bonanza grade gold in a grab sample collected from bedrock exposed by placer mining in one of the streams cutting across the property.
The Nucleus deposit hosts 74.74 million metric tons of indicated resource averaging 0.54 grams per metric ton (1.3 million ounces) gold and 0.06 percent (105.3 million pounds) copper; plus 63.79 million metric tons of inferred resource averaging 0.4 g/t (800,000 oz) gold and 0.05 percent (491,800 lb) copper.
The Revenue deposit, located about 3,000 meters east of Nucleus, hosts another 80.8 million metric tons of inferred resource averaging 0.39 g/t (1 million oz) gold and 0.14 percent (241.4 million lb) copper.
Further east, the Tintina Hill deposit hosts an additional 2.16 million metric tons of inferred resource averaging 1.89 g/t (131,000 oz) gold, 54.9 g/t (3.8 million oz) silver, 0.27 percent (13 million lb) copper, 1.41 percent (67.2 million lb) zinc and 0.99 percent (47.1 million lb) lead.
Together with the delineated deposits, Freegold Mountain hosts around 20 earlier staged exploration targets, including the Keirsten, a zone west of Revenue that was drilled last year.
Triumph Gold geologists believe that a 6,000-meter-long multi-element encompassing these zones and deposits is underlain by rocks affected by a gold-rich hydrothermal system related to a large buried porphyry intrusion that has yet to be tested by drilling.
The 2018 surface sampling program tested three main areas – Drone Zone, Blue Sky and Granger – with a total of 164 linear-chip or channel samples collected from bedrock and 35 grab samples.
Results released by the company on March 21 show that this sampling encountered intriguing mineralization in all three zones.
"As we advance exploration in underexplored portions of the six-kilometer-long soil anomaly that surrounds the Revenue and Nucleus deposit areas, we are continually impressed by the world-class scale of the of the underlying gold-rich hydrothermal system," Triumph Gold Vice President of Exploration Tony Baressi said. "Each of the surface exploration target areas yielded exciting results."
Bonanza gold at Drone
Drone Zone is a new prospect identified when a roughly 100- by 25-meter area of bedrock was exposed by the removal of gravel during placer mining in Mechanic Creek.
Situated about midway between high-grade drill intercepts in the Nucleus gold deposit and the Keirsten Zone porphyry system, the bedrock exposed at Drone Zone consists of disseminated sulfides and quartz-sulfide veins with pyrite, chalcopyrite, and lesser arsenopyrite and bismuthinite with visible gold.
Drone Zone was tested with 49 chip samples and 21 grab samples.
One grab sample collected from locally sourced rock debris on the eastern edge of the placer mine exposure contained 450 g/t gold and 19 g/t silver.
While this sample, grabbed for its abundant visible gold, is particularly high-grade, Freegold said chip sampling shows that gold and copper concentrations is consistent at Drone Zone.
Highlights from the two-meter chip samples collected include 1.2 g/t gold and 0.077 percent copper; 4.82 g/t gold and 0.017 percent copper; and 0.56 g/t gold and 0.105 percent copper.
Freegold said the zone appears to extend beneath the overburden beyond the placer gold mining cut, is open in all directions and has never been drilled or previously explored.
Testing Blue Sky potential
The sampling program also tested the Blue Sky discovery area at the eastern end of the 6,000-meter-long Revenue-Nucleus soil anomaly.
Drilling carried out at this zone over the past two years has confirmed a wide zone of porphyry gold-copper mineralization on the western slope of Bowlidden Ridge. One such hole drilled last year, RVD18-19, cut 316 meters averaging 1.1 g/t gold and 0.27 percent copper.
Surface sampling in 2018 focused on the eastern slope of Bowlidden Ridge, roughly 400 to 800 meters from the Blue Sky porphyry discovery area.
The 2018 surface sampling program included 86 chip and channel samples from three trenches and 13 grab samples collected mainly from disturbed bedrock along new access roads.
Eight of the grab samples contained greater than two g/t gold, with the best containing 16.8 g/t gold.
Trenches returned anomalous gold concentrations, including 1.46 g/t gold over one meter in trench BST18-01 and 0.31 g/t over eight meters in BST18-02. The full 52.5-meter length of BST18-02 averaged 0.15 g/t gold.
Triumph said these new samples, as well as two grab samples of quartz veins collected from the area in 2017 that graded 3.76 and 5.77 g/t gold, define a roughly 400-meter-long corridor of mineralization that is open in all directions and is untested by drilling.
"Newly discovered mineralization at the Drone Zone and in the Blue Sky Zone reinforce our belief that Revenue and Nucleus are only small parts of a much larger mineralized body," said Baressi. "Both of the new showings represent high quality drill ready targets with potential for high grade gold intersections."
Golden center
The third area tested, Granger, is a shallow oxide gold between the Revenue and Nucleus deposits that has been previously investigated with limited drilling and sampling, including one grab sample containing 45.5 g/t gold.
Historical drilling at this zone at the center of the Revenue-Nucleus soil anomaly, encountered multiple shallow oxide gold intercepts, including one hole that cut 13.71 meters of 5.29 g/t gold from 3.05 meters to the bottom of the hole.
Drilling in 2018 intersected variably oxidized near-surface mineralization in every hole, delineating a mineralized corridor over 200 meters in strike-length and to a depth of at least 74 meters.
Highlights of the results from 2018 Granger Zone drilling include:
• 18.39 meter of 0.98 g/t gold from a depth of 2.95 meters in hole RVD18-33;
• 18 meters of 0.61 g/t gold from a depth of 53 meters in RVD18-29; and
• 55.21 meters of 0.45 g/t gold from a depth of 18.84 meters in RVD18-30.
Twenty-nine chip and channel samples covering 46.8 meters in two newly excavated trenches tested strongly oxidized rock in the center of the mineralized corridor. Samples from the trenches contain a similar tenor of gold mineralization as that intersected at depth by drilling, indicating continuity from surface to a depth of approximately 45 meters.
Trench results include 3.5 meters of 1.04 g/t gold in TR18-03 and 3.5 meters of 1.72 g/t gold in TR18-04. Freegold said the southern edge of TR18-04 has some of the highest grade mineralization, including one meter of 3.26 g/t gold, indicating the zone is open and highly prospective to the south.
"(N)ew trenches in the Granger Zone demonstrate continuity of oxide gold mineralization between surface and underlying drill intersections, building a case for a near-surface heap leachable oxide gold resource," said Barressi.
Over his more than 16 years of covering mining and mineral exploration, Shane has become renowned for his ability to report on the sector in a way that is technically sound enough to inform industry insiders while being easy to understand by a wider audience.
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