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

Explorers have dreamed of harvesting deep-sea metals since the 1870s, when the British scientific ship HMS Challenger pulled up mineral-laden rocks on its round-the-world voyage. The first ...

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 ...