Hoidas Lake

Hoidas Lake lies in the Northern Rae Geological Province, in the general vicinity of many of Saskatchewan's large uranium mines.[5]

The mineralogy of the Hoidas Lake rare-earth deposit differs from most other such deposits in that it is hosted in veins of apatite and allanite.[6] Hoidas Lake also differs from other deposits in that it contains a significant amount of heavy rare-earth elements, such as dysprosium.[5] This abundance of heavy REEs is significant, as there is a growing demand for the heavier rare earths in high-tech manufacturing (such as the use of dysprosium in the manufacturing of hybrid car components).[7][8] Mineralization is presumably hydrothermal, from an alkali or carbonatitic source at depth.[9]

The main prospective zone is composed of two dominant rock types: a variably deformed monzogranite and a granodioritic to tonalitic gneiss. Both are Paleoproterozoic to Archean in age.[10]

Ongoing work at Hoidas Lake has delineated a vein system (known as the JAK zone), which extends for at least a kilometer along strike.[9] The limits of the system have not been established along strike nor along dip,[9] and the zone's total extension is therefore unknown. The resource zone averages 75 m in width[11] and is composed of individual veins which, though ranging from one to eleven meters in thickness, average about three meters each.[9] Veins are continuous to 300 m depth and follow an anastomosing geometry.[9]

Estimates of the resource, given current delineations and assuming a 1.5% total rare-earth cutoff, have established a presence of at least 286,000 tonnes of rare-earth ore,[12] which is enough to supply more than 10% of the North American market for the foreseeable future.

The Hoidas Lake claims are owned by Great Western Minerals Group, based in Saskatoon.[5]

• United States Geological Survey report on Rare Earths
• Great Western Minerals Group