https://www.newscientist.com/article/mg24032014-700-weird-rocks-in-australia-are-a-missing-piece-of-the-grand-canyon/

To peer into the Grand Canyon is to behold, in its rock layers, a record of Earth’s distant past. The oldest layers at the bottom date back more than 1.5 billion years.

It is some of the most ancient layers in the sequence that interest Jack Mulder, a geologist at Australia’s Monash University. He …