Drilling underway at Unga gold project
2021 program expanding high-grade gold, testing new targets North of 60 Mining News – May 14, 2021
Last updated 5/27/2021 at 3:41pm
Heliostar Metals Ltd. May 13 announced the start of a 7,000-meter drill program focused on expanding high-grade gold mineralization and testing new targets at its Unga project in Alaska.
Covering roughly 93 square miles (240 square kilometers) of the Unga and Popof islands off the southern coast of the Alaska Peninsula, the Unga project hosts the historic Apollo and Sitka mines, which produced roughly 150,000 ounces of gold from high-grade epithermal veins from around 1886 to 1922.
Much of Heliostar's exploration in recent years has focused on two high-grade gold trends – Apollo-Sitka and Shumagin – that each cut roughly six miles across Unga Island. Apollo-Sitka hosts the historic Apollo Mine and Shumagin is a parallel high-grade gold trend about 2,000 meters to the northwest.
SH-1, which is found along the Shumagin trend, hosts 866,015 metric tons of inferred resource averaging 13.8 grams per metric ton (384,318 ounces) gold and 35.4 g/t (986,321 oz) silver.
The initial phase of Heliostar's 2021 program at Unga has four objectives:
• Expanding the SH-1 resource to depth.
• Define previous identified but unmined zones of gold-, silver-, and base metal-rich mineralization at the Apollo-Sitka Mine.
• Expand the Aquila target at the southwest end of the Shumagin trend.
• District-scale exploration to advance high-priority targets and the highest ranked opportunities.
The 2021 drilling at Unga got underway in April and Heliostar has already completed five holes at the SH-1 and Apollo targets.
"With three drill rigs operating, the company plans to complete an initial 7,000-meter program to follow-up and extend the open gold intersections defined last year at SH-1, Apollo, and Aquila," said Heliostar Metals CEO Charles Funk.
This program employs two reverse circulation drills and a diamond drill core rig.
Diamond drilling will be focused on SH-1 to match previous drilling for confidence in any future resource estimation.
The RC rigs will test the large, earlier stage targets such as Aquila, Apollo, and the broader district prospects.
Drilling at SH-1 is targeting the down-dip extension of high-grade gold mineralization below the Main zone. The 2020 results from shallow drilling support the interpretation that the high-grade zone dips more steeply than previously recognized, an interpretation that will guide the deeper drilling planned for 2021. BM-1, the deepest hole included in the current resource, cut 5.48 meters averaging 23.99 g/t gold and is open to depth.
The drilling at Apollo-Sitka is initially testing the Apollo Shaft 2 area before expanding to include drilling at Sitka Mine, to the east, and the Apollo Shaft 1, to the west.
The Apollo Shaft 2 area has never been drilled despite being the focus of significant historic exploration at the time of original mining. This historical work included the sinking of a shaft, drifting, and cross cutting to discover veins. Historic reports note that many drifts and crosscuts encountered veins with gold, silver, and base metals. These zones of defined mineralization were not mined due to the lack of flotation technology to treat sulfide ore, technology that has now been industry-standard for multiple decades.
Historic exploration reached depths of more than 225 meters below surface by way of a vertical mine shaft, from which hundreds of meters of horizontal drifts and crosscuts were run. Reports from historic sources provide information on the presence of veins in these developments but give much less information on their exact locations and orientations. Available data suggest panels of steeply dipping veins that project from Shaft 2 to the northeast and southwest.
The company is testing this area by drilling fences of holes to clearly define the location and orientation of veins before stepping out along strike and at depth to define the extent of mineralization.
The 2021 drilling at Sitka will test the extents of a stockwork zone of quartz veins encountered by Heliostar last year. One such hole, APS20-04, cut 24.99 meters of 0.3 g/t gold, 11.9 g/t silver, 0.8% zinc, and 0.7% lead from a depth of 5.8 meters.
The Aquila drill program will principally test the Amethyst vein encountered during the 2020 drill program. This hole, AQ20-01, cut 31.6 meters averaging 1.8 g/t gold, including 5.75 meters of 5.56 g/t gold.
Heliostar says a recently completed compilation and digitization of historical trenching results indicates that this mineralized structure is continuous at surface over a strike length of more than 700 meters. Mineralized widths from trenching range from 5 to 15 meters and mineralization is unconstrained at depth by drilling.
In addition to drilling at the Amethyst Vein, the 2021 drill program will further expand upon the 2020 discovery by systematically stepping along strike and to depth to determine the full size of the mineralized vein zone.
While the drills test these targets, Heliostar's geological team will be carrying out field reconnaissance to identify new targets across the historic and mineral-rich Unga project.
"The company has C$7.2 million in cash and investments and closing the recent capital raise has allowed us to expand the phase 1 program," said Funk. "Heliostar looks forward to some of the earliest assay results from summer projects in Alaska and Canada in 2021 due to this early start."
Learn more about the history of Unga Island and the Apollo-Sitka mines at Forgotten chain of Alaska mining history in the April 30, 2021 edition of North of 60 Mining News.