The joint venture property is located in the Northwest Territories of Canada, 300 km east-northeast of Yellowknife, on the traditional territories of Tłįchǫ, Dene, and Métis people. The mine site lies on the edge of the continuous permafrost zone in an area known as the barren lands due to its lack of forests.

The surface is characterised as heath/tundra, with occasional knolls, bedrock outcrops, and localised surface depressions interspersed with lakes. A thin, discontinuous cover of organic and mineral soil overlies bedrock, which typically occurs within a few metres of surface. Small stands of stunted spruce dot the area. Numerous lakes cover the landscape. Kennady Lake, under which the kimberlites were discovered, is a local headwater lake with a minimal catchment area.

The mine is located only 230 kilometers south of the Arctic Circle, with just six hours of daylight at winter solstice. On many clear winter nights, the northern lights are visible over the mine.

Four kimberlites are presently mined in an open pit scenario: 5034, Hearne, Tuzo, and Wilson. Mining began in 2016 with the 5034 kimberlite, with Hearne and Tuzo subsequently incorporated into production. Mining at Hearne will be completed in 2024, while production at Tuzo will continue to increase. Near-mine discoveries since production began include the NEX and SWC extensions to 5034, the Wilson kimberlite adjacent to Tuzo, and the Northwest Extension below Hearne. These discoveries have extended the open pit life of mine at Gahcho Kué to 2031. 

The main Gahcho Kué kimberlite cluster comprises five kimberlite bodies:  5034, Hearne, Tuzo, Wilson and Tesla. Tuzo and 5034 are positioned over the GK dyke, which dips roughly 25 degrees north-northeast. Hearne is located on the separate Dunn dyke which dips to the North. These dykes are believed to have been the feeder systems that were repeatedly active during kimberlite emplacement, resulting in a complex geology of the kimberlite bodies as shown in the images. In the near-surface, the kimberlite bodies are steep-sided with several texturally distinct phases of kimberlite that vary in texture from hypabyssal kimberlite (HK) to diatreme facies tuffisitic kimberlite (TK). In the images provided, the blues are HK and the other colors are variants of TK.

There are several smaller kimberlites that are not presently part of the mine plan. These include Curie, a small kimberlite blow feature connected to the Dunn Sheet, which is a northeast-trending shallow-dipping kimberlite dyke that is believed to be the feeder kimberlite to Hearne.

The summaries above provide a technical overview of the Assets at the Gahcho Kué Mine. For more detailed information, please access the NI 43-101 Technical Reports on www.sedar.com, or download them from the links provided below.

Gahcho Kue Mine NI 43-101 Technical Report - October 2 2024
Gahcho Kue Mine NI 43-101 Technical Report - March 28 2022
Gahcho Kue Mine NI 43-101 Technical Report - March 1 2020
Gahcho Kue Mine NI 43-101 Technical Report - March 16 2018
Gahcho Kue Mine NI 43-101 Technical Report - March 31 2014