A 56,000-year-old meteor impact in Arizona may have triggered both the formation of Meteor Crater and a landslide-dammed lake in the Grand Canyon, according to a recent study published in Geology. The research, led by University of New Mexico Distinguished Professors Emeritus Karl Karlstrom and Laurie Crossey, reveals a surprising connection between two of the Southwest’s most iconic geological features.
Around 56,000 years ago, a meteor struck the Earth, creating Meteor Crater. At roughly the same time, a massive landslide formed a natural dam in the Grand Canyon, temporarily halting the flow of the Colorado River and creating an ancient lake. The study also traces the efforts of multiple generations of scientists and showcases recent breakthroughs in dating techniques that helped piece together the story.
The researchers found that driftwood and sediment from high above the river level, including a piece of driftwood that initially tested as being more than 35,000 years old, dated back to 56,000 years. Advanced techniques and data from laboratories in New Zealand and Australia updated this estimate to 56,000 years.
The team involved Chris Bastien, David Kring, Jonathan Palmer, and others, who worked together to analyze the evidence. They used two dating methods, which both returned statistically indistinguishable dates of 55,600-year-old. The findings suggest that the meteor impact, landslide, lake formation, and driftwood high above river level are all rare and unusual occurrences that converge into a narrow window of time at 56,000 years ago.
The research also explores the possibility of a rockslide near Nankoweap Canyon that could have formed a dam and a paleolake that backed up water and allowed driftwood to float into Stanton’s Cave. The combined results support this hypothesis and provide evidence for a temporary lake and massive dam in the Grand Canyon.
While the study does not claim final proof, the mean of dates from various samples converges into a narrow window of time at 56,000 years ago, which gives credence to the hypothesis that they were causally related.
Source: https://scitechdaily.com/did-a-cosmic-collision-dam-the-grand-canyon-a-56000-year-old-mystery