Description

The geology of the Selwyn Mountains in the western Northwest Territories is poorly understood, even though it is rich in critical mineral resources like the Cantung and Mactung tungsten deposits, the Mactung phosphate deposit, and the Howard’s Pass zinc-lead deposits. Since 2015, the Northwest Territories Geological Survey (NTGS) staff have conducted several research projects on the stratigraphy, structure, magmatism, and mineralisation in the region, in collaboration with various universities and other surveys. Other studies have included investigations into the potential of reprocessing historical mine tailings at Cantung to salvage residual W, Cu, and Au values and produce tailings amenable to dry-stack storage, as well as testing the beneficiation of phosphate mineralisation around Mactung and barite ores occurring in the region. Current research is focused on investigating zinc and vanadium mineralisation in the Howard’s Pass and Van Property (Flat Lakes) area.

New research projects are being developed for this resource-rich area. Please contact the NTGS for more information or learn more about opportunities to collaborate.

Download a list of related publications - HERE

*Updated November 2025

Location

The area of interest lies near the western border of the Northwest Territories, in the Selwyn Mountains, from the Mactung deposit in the north (approximately 63.2°N) to the Cantung deposit (located in the Flat River valley) in the south (approximately 61.8°N).

Work in this area benefits from compilations of geophysics data (Mirza and Fischer 2019) and geological mapping data (Okulitch and Irwin 2017), resource assessment studies carried out prior to the expansion of the Nahanni National Park and the creation of the Nááts'įhch'oh National Park Reserve (Rasmussen et al. 2007, Oyzer 2010, Oyzer 2012, Yuvan et al. 2017), and stream geochemical survey data (Falck et al. 2015).

Justification

Although this area has only been lightly explored, it is known to host significant mineral resources. For example, the Cantung mine is a past-producer of tungsten and copper with minor amounts of bismuth, and the Howard’s Pass district contains the world’s largest unmined zinc resource. Other commodities of economic interest that are known to exist in the area include tungsten, lithium, vanadium, barite, phosphate, lead, copper, silver, gold, rare earth elements, and gems (e.g., emeralds). Many of these commodities are on Canada’s list of critical minerals. The sedimentary rocks that host the major deposits have been folded and cut by faults, some of which are thought to have been involved in mineralising processes.  A better understanding of the geology and how different types of mineralisation were formed will support the exploration industry in better focusing its efforts.

Approach

Several collaborative projects, led by NTGS staff, university professors, graduate students, and scientists from other surveys, have been undertaken. Current work is focused on and around Howard’s Pass and the Van Property (Flat Lakes).

Key objectives:

1. Determine the mineralogy, distribution, and genesis of vanadium in the black shales of the Duo Lake Formation;
2. Develop a regional chemostratigraphic framework for the Duo Lake Formation to understand the role, if any, variations in sedimentation and diagenesis played in vanadium and base metals deposition;
3. Characterise the occurrence of by-product critical minerals (e.g., germanium) in zinc-lead mineralisation at Howard’s Pass;
4. Understand the affects of deformation on the distribution and chemistry of zinc-lead mineralisation at Howard’s Pass across multiple scales; and
5. Assess the genetic relationship between giant calcite concretions and zinc-lead mineralisation at Howard’s Pass to determine whether they can be used as an exploration tool.

Schedule

The first projects commenced with fieldwork in 2015, resulting in numerous publications since then. The current work began in 2024 and is funded by a 3-year grant from Natural Resources Canada as part of the Critical Minerals Geoscience and Data Initiative (CMGD), delivered by the Geological Survey of Canada.

Partners and Support

NTGS Participants:

• Hendrik Falck, Edith Martel, Beth Fischer, Gideon Lambiv Dzemua, Merilie Reynolds

Partners: 

• Drs. Ken Hickey and Lori Kennedy, University of British Columbia
• Drs. Jacob Hanley and Erin Adlakha, Saint Mary’s University
• Dr. Michael Melchin, St. Francis Xavier University
• Dr. Stefanie Brueckner, Laurentian University
• Dr. Dan Gregory, University of Toronto
• Dr. Heather Jamieson, Queen's University
• Drs. Pilar Lecumberri Sanchez and Kirsten Rasmussen, University of Alberta
• Drs. Qi Liu and Hao Li, University of Alberta
• Dr. Sarah Schultz, Yukon Geological Survey
• United States Geological Survey
• Rackla Metals Inc.
• Selwyn Chihong Mining Ltd.
• North American Tungsten Corporation Ltd.
• Fireweed Metals Corp.

Funding for these projects has come from a variety of sources and is currently provided by Natural Resources Canada as part of the Critical Minerals Geoscience and Data Initiative (CMGD), delivered by the Geological Survey of Canada.

Photos starting in upper left corner and proceeding clockwise: 1) Project participants look at historical drill core, 2) Historical drill core at Howard’s Pass, 3) Looking south down Flat River Valley at the Cantung townsite and mill, 4) Geologist looking at outcrop, 5) Geologist recording structural data in tablet near Howard’s Pass, 6) Geologists looking at scheelite skarn (the rusty red rocks behind the drill rig) in the Cantung open pit