In the 19th century, many people believed that landscapes like the Grand Canyon were shaped by volcanoes and earthquakes. But one American geologist named John Newberry had different ideas.

"Scroll Down through History" displays the layers of rock exposed within the Grand Canyon and shows when in earth's history they formed. The region where the Grand Canyon now lies begins to shift ...

And rather than being fully marine, these sequences were formed in a varied ... are a reminder that science is a process. He concluded: "Our work in the Grand Canyon—one of the world's most ...

LIZ BONNIN: Hi, I'm Liz Bonnin, and I'm digging through the BBC's amazing archives to find out all about physical geography. Now there are a few things you need to know for this next clip.