In a recent study, geologists say Michigan is home to the oldest known rock in the nation. Watersmeet gneiss is found in Michigan's Upper Peninsula. Minnesota's Morton gneiss previously held the ...

Wyoming geologist Carol Frost and three of her colleagues have identified a new oldest rock in America. Found in Michigan, ...

Exactly what caused the collapse of the mighty Roman Empire has been hotly debated practically since the fall itself. Was economic stagnation primarily to blame, or was it societal decay? Did ...

A weathered sign in the Minnesota River Valley proudly proclaims: “World’s Oldest Rock.” Erected in 1975, it marks a 3.8-billion-year-old gneiss — or so scientists thought. Turns out, it ...

Fluorides occur naturally in the earth’s crust, where they are found in rocks, coal, clay and soil. Lately, though, fluoride ...