A translation by Judith Turcotte
The Magdalen Islands rest on enormous salt domes and the origin of these domes is surprising. A good description can be found on the Seleine Mines website. The Islands are situated on a plateau baptized the Magdalen Shallows. Difficult to believe but this plateau was situated at the Equator 360 million years ago. It formed a valley and this valley periodically filled with sea water. The water would evaporate in the sun and leave salt deposits. Over millions of years, this salt accumulated and formed salt domes. With the continental drift, the plateau found itself in its current position and became the Magdalen Islands. It is thanks to these salt domes that the Magdalen Islands were found on the surface of the water.
These salt domes are enormous and were not discovered until 1972. Today, the mining of the salt is carried out at Gosse-Île by heavy equipment that circulates through galleries and underground chambers. More than 1,300,000 metric tons are mined every year and this exploitation is carried out to a depth of 489 metres. This salt is used to de-ice Québec roads. In recent years, the Islands produce cooking salt; however, this salt is obtained through the evaporation of seawater.
When I visited the Magdalen Islands and discovered the Seleine Mines for the first time, I would have liked to descend and see firsthand the immense caves and the exploitation of these salt deposits but I had to settle with the Seleine Mining Interpretation Center. It seemed to me then that a visit to the mine’s interior could become a destination with an international potential. A resident of the Islands told me that there had already been visits of the mine but they had discontinued 25 years ago as a result of an important infiltration of seawater accompanied by disturbing ground movements in the mine. The situation was serious enough to force the shutdown of the mine’s operations for two years. More than 200 employees were then laid off. It is realistic to think that the authorities would have stopped the visits to the mine by the tourists.
It is only in 1972 that the Société Québécoise d’exploitation minière (SOQEM) announced the discovery of the mine. The exploitation of the only salt mine in Québec only began in 1978. The société Canadienne de sel (Sel Windsor) purchased the mine in 1988. In 2009, the German group K+S Windsor Salt became the owner of the Seleine Mine and in 2021, the American holding company, Stone Canyon Industries Holding of Los Angeles acquired K&S mining assets.
I find it unfortunate that such a unique natural resource not be owned by a Québec company.