10/22/2026
🪨 Minnesota’s Geologic History 🪨
1. Minnesota contains some of the oldest rocks on earth; Morton Gneiss which can be found in western Minnesota has been dated to 3.6 billion years old.
2. Minnesota was the location of a continental rift 1.1 billion years ago. The continent attempted to separate, releasing lava across what is now the North Shore of Minnesota down into Iowa and parts of Kansas.
3. While Minnesota lacks dinosaur fossils you can find a wide variety of Marine fossils from 500-225 million years ago, including shark and early archosaur teeth.
4. In the banded iron formations of the Iron Range, you can find fossilized stromatolites; evidence of the first signs of life on the planet.
5. Known as the "Land of 10,000 lakes", Minnesota contains more than 15,000 lake basins. Only 4 of 87 counties in Minnesota are devoid of lakes and 1 county contains a salt lake.