“They may have documented [the United States’] oldest known rock,” he says, “but the challenge to young readers will be to discover an even older rock.” Frost agrees. The 3.8-billion ...

The Search for America’s Oldest Rock: The Watersmeet Gneiss The new title-holder for the oldest rock in the United States is the Watersmeet Gneiss in Michigan, which dates back 3.6 billion years ...

The oldest rock in the United States has been discovered in Michigan, with zircons dating back 3.82 billion years.

Geologists recently dated the age of Watersmeet gneiss, a type of rock in the Upper Peninsula, as the oldest in the U.S. Here's what to know.

"Taken together, the Archean rocks of the Wyoming-Minnesota-Michigan block represent the oldest continental crust in the United States, the nucleus around which the younger rocks of the nation ...

"Taken together, the Archean rocks of the Wyoming-Minnesota-Michigan block represent the oldest continental crust in the United States, the nucleus around which the younger rocks of the nation ...