Scientists have uncovered evidence that an enormous ancient cliff system may have helped expose the deepest rocks of the Grand Canyon nearly a billion years before the Colorado River began carving the landscape seen today.
Led by researchers at the University of Southampton in the UK, the new study suggests that a vast "great escarpment" formed about 800 million years ago as the supercontinent Rodinia broke apart.
These towering cliffs may have reached roughly a kilometer in height and extended for thousands of kilometers along western North America. Over time, erosion along this immense rocky boundary removed huge amounts of material, eventually exposing ancient crystalline basement rocks that can now be seen in the Grand Canyon in southern Arizona.
A Billion Years Missing From the Grand Canyon
Thomas Gernon, Professor of Earth Science at the University of Southampton and lead author of the study, explained that the Grand Canyon preserves a geological history stretching back about two billion years. Yet more than half of that rock record appears to be absent.
