Magdalen Islands, Quebec – The dozen Magdalen Islands stretch for about 65 kilometres in the heart of the Gulf of Saint Lawrence. What is amazing is that they actually floating on giant salt domes. 320 million years ago these islands were down near the equator, in a basin below sea level. Seawater flowing in and evaporating (the temp was about 38 °C (100 °F) created salt.
Over time the salt accumulated to a depth of 5 km! Then this mass migrated north and was covered a layer of rock and lava about 4 km thick. Eventually pressure caused the rocky layer to heat up to nearly 300°C (572°F) and the salt rose creating domes.
The salt is mined at a depth of 300 metres at Rocher-du-Dauphin on the dune linking Grosse Île Island to Pointe aux Loups Island. Visitors cannot enter, but there is a visitors information centre on Grosse Île. About 1.5 million metric tons of salt is exported each year. It’s used to de-ice roads throughout eastern Canada and the United States.
Many of the residents of Grosse-Île are English speaking of Scottish decent. The islands overall are 94% French-speaking Acadians. There are about 300 km of beautiful beaches, it’s popular for windsports, and there’s a wonderful bounty of lobster and seafood to enjoy. You can reach them by flying, by ferry from Prince Edward Island (5 hours) and on weekly cruise-ferry from Montreal.
Mines Seleine Kiosque Touristique, 56 Ch Principal Grosse Isle Quebec (Magdalen Islands / Iles de la Madeleine)