Yooperlites are a variety of sodalite-rich syenite found in the Upper Peninsula of Michigan.

Sodalite forms in igneous rocks that crystallized from sodium-rich ... per year on state-owned and public trust lands. Agates are formed when gas bubbles in lava leave a hole in the "vesicle" ...

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

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

"Dating zircon grains using ... techniques is now celebrated as the optimal method for determining when igneous rocks formed," the report said. The technique involves measuring the decay of ...

Smithsonian researchers trekked to a remote site in northern Canada to collect four-billion-year-old rock samples that could ...

Instead, researchers are now exploring the possibility that Skull Hill could be a chunk of igneous rock, formed from cooling magma and potentially ejected by an impact event or uncovered by erosion.