The Grand Canyon Is Missing an Entire Billion Years of Earth's History

The rock layers of the Grand Canyon are missing more than a billion years of geological record — over half of the canyon's entire history simply isn't there, as if someone ripped the middle chapters out of a book.

For more than 150 years, ever since explorer John Wesley Powell first spotted the gap in 1869, the "missing" era was blamed on erosion carved out by the Colorado River.

The twist: new research published in 2026 shows the canyon floor was actually exposed roughly 800 million years before the modern Colorado River ever started flowing. The real culprit was a far older event — the breakup of the supercontinent Rodinia, when a kilometer-high cliff swept across North America, retreating over tens of millions of years and stripping away as much as 8 kilometers of rock in places.

That missing rock is still somewhere on Earth — nobody just knows exactly where. And this is still only one hypothesis: a competing explanation ties the gap to glaciers from the "Snowball Earth" era, 720 to 635 million years ago.