In 1869, John Wesley Powell was studying layers of rock in the Grand Canyon when he noticed an unconformity in the layers. Around a billion years were missing, and the problem turned out to be global.

Here’s what you’ll learn when you read this story: Usually, geologic layers build on one another, with younger rocks piling on top of older ones. A new study, however, shows that this process is ...

Geology in our middle Colorado River watershed isn’t a simple affair, but it’s not remarkably complicated or incredibly obscure, either. It follows the general principles of geology, with young layers ...

Big Four Mountain's mystery: 82-degree tilted rock layers defy geology's horizontal rule. There’s a basic rule in geology: Sedimentary rock layers build up horizontally. So how did the slabs of Big ...

The devastation from the earthquakes in Haiti and Chile is a reminder of ever-present, powerful geologic forces. Aspen is a long way from the present day’s colliding plates of converging continents, ...

I love the Grand Canyon, both personally (because of all the good memories I have of my adventures there), and as a scientist. I first saw it in the early summer of 1981 when I went on a six-week-long ...

Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4.6 billion years. Mountains have been built and eroded, continents and oceans have moved ...

MUNISING, MI -- The layers of sandstone not only give Pictured Rocks National Lakeshore its name and its looks, it also reveals chapters of Michigan’s geological history. Every week, Pictured Rocks ...

What kid hasn’t had some sort of rock collection? Discovering hidden gems is always a treat. Western Colorado is perfect for exploring geology with your kids. Look around — there is evidence of eons ...