The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
A productive year: studies, exploration, expansion, success North of 60 Mining News - November 22, 2023
HighGold Mining completed 7,648 meters of drilling in 33 holes during the 2023 exploration program at its Johnson Tract gold project in Southcentral Alaska.
HighGold Mining Inc. Nov. 20 announced an update for its 2023 exploration and development program, as well as the final drill results from its Johnson Tract project in Southcentral Alaska.
"We had a busy and productive field season this year," said HighGold Mining President and CEO Darwin Green. "We completed a significant drill program aimed at expanding existing zones and targeting new discoveries. Results from the drill program are encouraging and will serve to inform ongoing drill planning and targeting as we continue to evaluate the multi-deposit potential of the project."
This year's program at Johnson Tract included 7,648 meters drilled in 33 holes to test various targets –JT Deposit, Ellis Zone, DC Prospect, and the recently targeted South Valley and Double Glacier prospects.
In addition to drilling, the program included the initiation of preliminary scoping work to evaluate conceptual direct-shipping-ore scenarios; completion of a comprehensive work program to support the permitting of an underground exploration ramp; infill drilling that returned typical results from its high-grade JT deposit; various results ranging between narrow high and broad low from step-outs at Ellis Zone; and finally, encouraging new zones discovered for future exploration.
"Thick, high-grade deposits in desirable jurisdictions with a path to relatively rapid and cost-efficient development are a rare prize in the mining sector," added Green. "In conjunction with our drilling efforts, HighGold has also turned to assessing the development potential for the JT Deposit and demonstrating the intrinsic value of the project."
While the company has initiated a multi-year program to determine the best course of action for a mine at Johnson Tract, drill results continue to outline just how prospective this property is.
The 2023 drilling included six holes for hydrogeological and geotechnical studies along an alignment of a proposed 1,800-meter-long underground exploration ramp at JT Deposit, which hosts 3.49 million metric tons of indicated resource averaging 5.33 grams per metric ton (598,000 ounces) gold, 6 g/t (673,000 oz) silver, 5.21% (400.8 million pounds) zinc, 0.59% (43.1 million lb) copper, and 0.67% (51.5 million lb) lead.
GT23-004, which was drilled as an infill hole to characterize ground and water conditions for future mine modeling at JT, cut 56.6 meters averaging 4.87 g/t gold, 0.61% copper, and 3.5% zinc, including two subintervals cutting 33.6 meters averaging 7.93 g/t gold, 0.9% copper, and 4.8% zinc, and 4.9 meters averaging 33.03 g/t gold, 1.2% copper, and 0.6% zinc.
"Infill hole GT23-004 is a reminder of the exceptional width and grade that characterizes the JT Deposit," said Green.
Separate from the geotechnical drilling, two exploration holes were stepped out 100 to 200 meters south of the JT Deposit for potential extensions along strike. These holes intersected broad zones of strong alteration with local silver-lead-zinc mineralization, including six meters averaging 76 g/t silver, 0.4% lead, and 1.2.% zinc in hole JT23-153.
Most of HighGold's 2023 program targeted the Ellis and DC zones about 2.5 miles (four kilometers) north of JT. The drilling in this area included 50- to 100-meter step-outs on Ellis to sketch in resource potential and first-time tests of new targets between the two prospects.
Drilling in 2023 has now defined two distinct and overlapping styles of mineralization at the Ellis Zone: a steep-dipping, structurally-controlled, high-grade quartz vein and sulfide breccia zone and a zone of shallow-dipping, broad, lower-grade, potentially stratigraphically-controlled mineralization with VMS-style characteristics.
The current interpretation is of a broad zone of stringer-style mineralization with local structurally controlled high-grade shoots. HighGold states that mineralization has now been intersected over a length of 200 meters and to a depth of 225 meters.
Narrow high to bonanza-grade as well as broad low-grade mineralization have been intersected in 2023 step-out drilling at Ellis Zone, including:
• 2.2 meters averaging 49.9 g/t gold, 25 g/t silver, 1.5% copper, and 8.4% from a depth of 59.2 meters in hole DC23-070.
• 1.4 meters averaging 4.51 g/t gold, 16 g/t silver, 1.9% copper, 1.1% lead, and 7% zinc from 67.3 meters in DC23-071.
• 47.1 meters averaging 0.29 g/t gold and 0.5% zinc from 50.2 meters in DC23-087.
• 64.1 meters averaging 0.31 g/t gold and 0.7% zinc from 67.9 meters in DC23-088.
Finally, eight reconnaissance holes were completed across a 1,000-meter east-west trend between Ellis and the East DC prospect area. Targeting mapped structures, alteration, and mineralization, as well as blind geophysical and geological targets that project beneath an area of landslide cover, significant new zones of quartz-sulfide stockwork veining were intersected in five holes at East DC, with anomalous silver-copper geochemistry that warrants additional follow-up. Significant results include:
• 3.9 meters averaging 97 g/t silver in DC23-075.
• 1.3 meters averaging 23 g/t silver and 2.7% copper in DC23-076.
• 1.2 meters averaging 1.6% copper in DC23-080.
Aside from exploration, HighGold has begun preliminary scoping work to evaluate conceptual direct-shipping-ore (DSO) scenarios. This includes studies and investigations into potential mining methods, mine designs, and the logistics and infrastructure required for shipping mineralized material to an existing, off-site milling facility.
The project's location near tidewater offers the potential for DSO via bulk marine transport (the lowest cost form of bulk shipping) either direct to Asia or to existing coastal mills at mines in Alaska and British Columbia.
Advantages of a DSO mine over a conventional mine include project simplicity, lower capital expenditures and execution risk, and the potential for an expedited timeline to production. A DSO mine at Johnson Tract would also have the attractive environmental benefits of a small surface footprint and minimal long-term management and closure concerns.
Under such a scenario, development rock (waste rock) would likely be integrated into the mining plan as a backfill for permanent underground storage within the mine, and tailings would be stored at a pre-existing off-site facility, resulting in no on-site tailings.
In Alaska, a DSO mining joint venture agreement is in place between Kinross Gold and Contango Ore, in which ore from the Mahn Choh deposit will be trucked 240 miles (380 kilometers) for off-site processing at Kinross Gold's Fort Knox mine.
With studies in place to determine the viability of a DSO mine, additional preliminary work is determining the likelihood of a proposed underground ramp at JT.
The exploration ramp will provide a platform to conduct cost-effective, tightly spaced definition drilling in the highest-grade portions of the known deposit to support future engineering and economic studies. The calculated 1,800-meter-long ramp, which is parallel to and slightly outboard of the trend of mineralization, will also provide access to efficiently test multiple deep exploration targets.
Over the coming months, the data from its 2023 studies will be incorporated into the project design and form the basis of the exploration ramp permitting that is planned to commence in early 2024.
In connection with the exploration ramp plan, a Section 404 permit application was submitted earlier this year to the US Army Corps of Engineers for a 2.6-mile (four kilometers) portal access road and expanded airstrip.
This process is tracking well, with no significant deficiencies identified to date.
"The company is well capitalized to continue advancing these important value-added activities through 2024 and beyond," finished Green.
Reader Comments(0)