Nighthawk Gold (TSX: NHK; US-OTC: NIMZF) has released an updated resource estimate for its Colomac gold deposits as well as a maiden underground resource for the Damoti deposit, 28 km to the south, which lie within the company’s wholly owned, 899-sq.-km Indin Lake gold property in the Northwest Territories, 200 km north of Yellowknife.
At Colomac, total indicated resources now stand at 25.9 million tonnes grading 2.01 grams gold per tonne, for a total of 1.7 million oz., with additional inferred resources of 5.7 million tonnes at 2.03 grams gold, totalling 372,500 ounces. This compares with the prior 50.3 million inferred tonnes grading 1.62 grams gold, containing 2.6 million oz. gold.
Within these updated numbers, there are 9.9 million indicated open-pittable tonnes at 1.7 grams gold and 15.9 million tonnes indicated tonnes in the underground classification grading 2.2 grams gold.
The maiden underground resource estimate for Damoti includes an additional 736,000 inferred tonnes at 4.97 grams gold, for 117,800 contained oz. gold.
The updated resources for Colomac include an open-pit and underground component (the prior estimate only included open-pittable mineralization), which are now constrained by pit shells and manually constrained into optimized shapes, respectively. The resource also incorporates 50,000 metres of drilling completed in 2018 and 2019.
“This latest resource is the most refined and accurate representation to-date, and for the first time includes constrained open-pit and underground indicated resources at Colomac with an average grade of 2.01 g/t gold,” Michael Byron, the company’s president and CEO, said in a release. “We are confident that this latest resource represents a giant step forward in terms of increasing project robustness and value and provides a solid platform from which to rapidly add ounces and to develop Colomac quickly and efficiently.”
Byron added that there remains substantial exploration upside for Colomac, with the potential to add ounces to the company’s resource inventory through additional drilling. The company is planning a 25,000-metre drill program this year.
The Colomac Main sill expands at depth over 3.5 km of strike and additional deeper drilling is expected. On a regional basis, the Leta Arm and Treasure Island projects are two priority underexplored areas.
The updated resource will be used by JDS Mining and Energy to prepare a preliminary internal scoping study for Colomac.
The latest resources were derived using cut-off grades between 0.6 gram gold (open-pit) and 1.3 grams gold (for underground resources). A 2 gram per tonne cut-off grade was used for Damoti. The 2018 resource estimate is based on cut-off grades between 0.6 gram gold and 0.7 gram gold. Indin Lake is 200 km northwest of Yellowknife and is accessible by a winter road or by chartered aircraft. The construction of an all-season road is underway, which would allow better winter road access to the property.
Colomac is within the central part of Indin Lake and includes five gold deposits, one of which produced 527,908 oz. gold between 1990 and 1997 from three shallow open pits.
— This article first appeared in the Canadian Mining Journal.