From Gizmodo · · 1m 20s
Grand Canyon Missing 1.2 Billion Years
Scientists explain why Earth's Grand Canyon lacks 1.2 billion years of geological history.
In brief
Scientists explain why Earth's Grand Canyon lacks 1.2 billion years of geological history. Earth's Grand Canyon shows a 1.2 billion year gap in rock layers due to mantle convection causing continents to sink into the ocean. Originally reported by Gizmodo.
Earth's Geological Book
Earth's geological history is like a book with missing sections covering hundreds of millions to billions of years.
Great Unconformity Discovery
Geologist John Wesley Powell first identified the Great Unconformity at the Grand Canyon in sedimentary rocks from the Cambrian sitting above older igneous and metamorphic rocks.
Mantle Convection Model
Researchers modeled mantle convection over hundreds of millions of years to explain the Great Unconformity at the Grand Canyon.
1.2 Billion Years Missing
The Great Unconformity represents roughly 1.2 billion years of missing rock record at the Grand Canyon.
Earth's Uplift and Sinking
Continents gradually rose due to mantle convection before sinking into the ocean during the Phanerozoic, creating the missing rock layers.
Cambrian Era Connection
The cutoff at 540 million years marks the start of the Cambrian era when life on Earth experienced unprecedented growth.
What This Means
The Great Unconformity shows how Earth's geological history has gaps that may help explain the Cambrian explosion.
What to remember
Earth's Grand Canyon shows a 1.2 billion year gap in rock layers due to mantle convection causing continents to sink into the ocean.
