The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
North of 60 Mining News – January 10, 2020
An aerial view of the Colomac project on Nighthawk's Indin Lake gold property in Northwest Territories.
Nighthawk Gold Corp. Jan. 7 reported that new drill results indicate that the widening of the gold mineralization encountered earlier this year could extend for a least 3,500 meters, which could add significant ounces to this already robust gold project on the company's Indin Lake gold property in Canada's Northwest Territories.
The 899-square-kilometer (222,203 acres) Indin Lake property hosts seven major project areas – Colomac, Leta Arm, Damoti Lake, Treasure Island, JPK, Fishhook and Echo-Indin – each with multiple gold exploration targets.
Colomac is the Indin Lake flagship project and the primary target for roughly 40,000 meters of drilling completed on this district-scale property during 2019.
According to a calculation completed mid-2018, Colomac hosts 50.31 million metric tons of inferred resource averaging 1.62 g/t (2.6 million oz) gold.
The 2019 drilling primarily focused on high-grade areas within the central 3,000-meter portion of the roughly 9,000-meter Colomac Main sill. (A sill is a tabular sheet intrusion, often horizontal, between older layers of sedimentary rock.)
One hole reported by Nighthawk in December, C19-39B, shows the continued widening of the mineralized portion of the sill to depth, where the true width has grown to more than 110 meters at 700 meters below surface. This hole was drilled approximately 270 meters south of the deepest intersection at Zone 1.5, where drilling in 2017 showed a similar widening of the mineralized portion of the sill to 155 meters in true width.
From a depth of 702.3 meters, C19-39B cut 110.5 meters (55 meters true-width) averaging 1.89 g/t gold.
Now, the company has encountered a similar wedge-like widening of the gold mineralization more than 2,000 meters south, in Colomac Zone 3.5.
One hole that encountered this widening gold mineralization at Zone 3.5 was C19-50, which cut 105 meters (45 meters true width) averaging 1.35 g/t gold, including 34.5 meters of 2.38 g/t gold. This hole extended the depth of the gold mineralization in this area by an additional 60 meters.
Nighthawk says C19-50 clearly shows that at a depth of 350 meters, the true width of the mineralized portion of the sill has more than doubled up to 71 meters. This steady increase in thickness of the mineralized portion of the sill to depth is consistent with what was observed throughout drilling at Zones 1.5 and 2.0.
"Previous drilling confirmed that the well mineralized stratigraphic top of the sill (which faces east) at Zone 1.5 and the northern part of Zone 2.0 resembles a wedge form that widens significantly to depth. Recent drilling has now confirmed that the top of the sill also appears to broaden exponentially to depth at Zone 3.5," said Nighthawk Gold President and CEO Michael Byron.
The company said drilling has established Zone 3.5 as a higher-grade gold domain with strong continuity and expansion potential, whose mineralized portion of the sill shows progressive expansion to depth. This widening of the gold mineralization opens the possibility that the entire mineralized sill at Colomac has a similar wedge shape.
"Additional drilling over the 3.5 kilometers (3,500 meters) of sill that separates these two areas is expected to continue to confirm a universal widening of the mineralized portion of the intrusion to depth," said Byron. "Should this hold true, Colomac may become a much larger gold deposit and a stronger prospect for resource development with accelerated growth potential, as some areas have already shown expansions at depth to upwards of three times its near-surface true width."
–SHANE LASLEY
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