Description

The Slave Geological Province contains numerous lithium-cesium-tantalum (LCT) and niobium-yttrium-fluorine (NYF) pegmatites, which are important potential sources of various critical minerals, including lithium.  Although the occurrence of mineralised rare metals pegmatites in the Slave Geological Province has long been known, the factors that control the formation and mineralisation of these pegmatites are poorly understood. The goal of the project is to de-risk investment in the exploration and development of pegmatites-hosted critical minerals and other rare metals in the Northwest Territories (NWT). This includes generating new public geoscience knowledge on the geology, mineralogy, geochemistry, geochronology, and processing of rare metals in the pegmatites.

Location

The study area comprises the NWT portion of the Slave Geological Province, with plans to extend the project to the Cordillera along the Yukon border, where mineralised pegmatites are also reported.

Justification

Rare metals pegmatites are an important source of lithium, tantalum, niobium, rare earth elements, and high-purity silica, which are vital components of the global transition to zero-carbon emission and modern technology systems such as electric cars and renewable energy. Granitic pegmatites are also important sources of beryl, gemstones, and museum-quality mineral specimens.

Approach

This is a multi-year project with both field and laboratory components. The project is a collaboration between the Northwest Territories Geological Survey, summer and graduate students, university professors, and other researchers. Summer fieldwork includes sampling of pegmatite clusters, host rocks, and any spatially associated granitoids. Selected samples will be analysed for various aspects, including mineralogical and chemical compositions, age, and mineral chemistry. The results from the various analyses will be interpreted in the light of the objectives of the project.

Schedule

The project began in 2021 with the Northwest Territories Geological Survey geoscientists and university partners visiting historic Best Bet and DeStaffany (Moose II) pegmatite occurrences. Subsequently, research was extended to other pegmatite fields throughout the Slave Craton and is ongoing, with plans to include pegmatite occurrences in the Cordillera. Preliminary findings are being presented at conferences, including the Yellowknife Geoscience Forum, GAC-MAC, and PDAC.

Partners and Support

• The project is partially funded by a grant from Natural Resources Canada’s Critical Minerals Geoscience Data program and the Northwest Territories Geological Survey.
• University partners include Dr. David Lentz and Gilles Ngoran from the University of New Brunswick in Fredericton, New Brunswick.