Minnesota River Valley's 3.6-billion-year-old rocks
Go Deeper.
Create an account or log in to save stories.
Like this?
Thanks for liking this story! We have added it to a list of your favorite stories.
In The Daily Circuit's letters segment this week, a professor mentioned that the Minnesota River Valley is home to 3.6-billion-year-old rocks, some of the oldest rocks on earth. We follow up on why that would be and what they signify about Minnesota's past and future.
Turn Up Your Support
MPR News helps you turn down the noise and build shared understanding. Turn up your support for this public resource and keep trusted journalism accessible to all.
