Geoscience and Exploration

Salt Deposits of the Northwest Territories

Wednesday, November 21, 2018 - 12:20 to 15:59 Lobby - Capitol Theatre


D.M. Watson
NWT Geological Survey

S.D. Gervais
NWT Geological Survey

G. Lambiv Dzemua (Presenting)
NWT Geological Survey

Salt (sodium chloride; NaCl) is one of the basic raw materials for various chemical processes and has been used to flavour and preserve food since Neolithic time. Worldwide salt production is over 200 million tonnes. Most of the production comes from sedimentary deposits that are either mined as rock salt or brines. Salt is also produced by evaporation of seawater in traditional solar ponds or using other heat sources including fire and waste heat from power generation.

Salt occurs in several areas of the Northwest Territories (NWT). These include subsurface and surface occurrences. Subsurface deposits occur in Cambrian to Devonian formations including the Saline River Formation, which is widely distributed in the Mackenzie and Franklin mountains as well as in the northern Interior Plains and has been encountered in wells drilled for petroleum exploration in the Fort Liard, Fort Smith, and Norman Wells areas. The Saline River occurrence has the potential for a large-scale solution mining.

Surface occurrences of salts in NWT include salt springs, which are widely distributed in the territory including the Salt Plains of the Wood Buffalo Park and the Fort Smith area. Historic annual production of about four tonnes of salts have been reported from these springs although the exact locations are unknown. Other surface occurrences include seawater along the Arctic Ocean coastline.

In May 2015, six water samples were collected from the Salt River in the Fort Smith area and analysed for sodium (Na), potassium (K), calcium (Ca), and chloride (Cl) among other elements. The samples returned up to 4120 mg/L Na and 7240 mg/L Cl. The concentration of Na and Cl in these samples has probably been diluted by an unknown quantity of fresh surface water. The salt concentration in the springs and water sources varies systematically during the year with spring runoff, rain, and snowfall contributing to lower levels and summer dry spells causing higher salt concentrations.

Although there is no current production of salt in the territory, there is potential for low volume, high value “artisanal or cottage” production in some areas. Any such production could take advantage of natural variations in weather to lower production costs and, leverage the territory’s booming tourism sector to reach the wider national and international clientele.