Scientists Have a New Clue to How Grand Canyon Formed
Newser • • science
Key Points:
- A new study published in Science supports the "lake spillover" theory, suggesting that the Grand Canyon's formation began when an ancient lake, Lake Bidahochi, overflowed about 5.6 million years ago.
- Researchers found matching zircon crystals in sandstone from the Bidahochi Basin and early Colorado River sediments, indicating the ancestral Colorado River once fed into the basin.
- The overflow likely spilled westward over the Kaibab Arch, initiating the carving of the Grand Canyon, according to the study led by the US Geological Survey.
- Some geologists find the spillover hypothesis plausible but maintain that other explanations involving different rivers, groundwater, or erosion remain possible.
- Critics also argue that a pre-existing notch in the Kaibab Arch might have prevented water from pooling, challenging the lake spillover scenario.
