Does Minnesota really have the 'World's Oldest Rock'?

Historical markers peppered around Minnesota help keep the state’s rich history alive. But few are as intriguing — and controversial — as the landmark for Minnesota’s most ancient artifact: the “World’s Oldest Rock.” Eric Roper and Ash Miller discuss the 3.5-billion-year-old history behind this claim on a historical marker in Granite Falls. And they delve into the reasons why Minnesota boasts some very unique geology. LINKS: Does Minnesota really have the 'World's Oldest Rock'? (August 2022 Curious Minnesota story)