The University of New Mexico

01/28/2025 | Press release | Distributed by Public on 01/28/2025 16:06

It’s (Probably) Not Rocket Science podcast rocks the Grand Canyon’s geological mysteries

It's (Probably Not) Rocket Science (IPNRS), the podcast, says we may need to carve a few years off the Grand Canyon's age after the Arizona National Park was found to be younger than previously thought. This revelation challenges long-held assumptions about one of the world's most iconic natural wonders.

The Grand Canyon stretches more than 270 miles long and up to 18 miles wide, boasting an enormous scar on the Earth's western hemisphere. Its stunning views and towering rock formations are celebrated worldwide, but how well do we understand the history behind its layers? For years, scientists thought they had a firm grasp on the canyon's age - but as it turns out, the timeline isn't exactly what we thought.

University of New Mexico geology experts are now weighing in on the question. Their recent research suggests that the canyon may be much younger than previously believed. Karl Karlstrom and Laura Crossey, both distinguished professors at UNM, are at the forefront of this discovery, offering fresh insights into the canyon's geological history.

Karlstrom, who specializes in structural geology in the Department of Geology, and Crossey, an expert in geochemistry and sedimentology from the Department of Planetary Earth and Sciences, have dedicated much of their careers to studying the Grand Canyon. Their work delves into the layers of rock that tell the story of the Earth itself.

Both professors have a personal connection to the canyon. Karlstrom's passion for the Grand Canyon began when he was a teenager in Flagstaff, Arizona.

"I grew up in Flagstaff, Arizona, and learned to love the Grand Canyon when I was a teenager hiking down and learning the layers," Karlstrom said. "The Grand Canyon has got to be one of the most spectacular geologic laboratories anywhere on Earth."

This personal connection underscores his deep investment in unraveling the canyon's secrets.

For Crossey, whose roots are in the flatlands of Illinois, the Grand Canyon left an equally profound impression when she visited as a college student.

"I always had a yearning to go to the Southwest of the United States… I took a visit as a college student to the rim of the Grand Canyon on a camping trip and was just taken away by the incredible view," Crossey said. Her journey from the Midwest to the Grand Canyon marked the beginning of her career as a geoscientist.

With such a well-known geological site at their doorstep, it's hard to believe that scientists haven't yet figured out exactly how old the canyon's layers are. However, in the digital age, new technologies like geochronology are allowing researchers to more accurately date the canyon's rock layers. Karlstrom explains that recent findings have revealed the canyon itself to be far younger than expected, while the rocks that form its layers are ancient.

"We've completely redated, as Laura said, all the basement rocks and what their ages were and how they represented how the continent was assembled," Karlstrom said. "[The canyon] has only been carved in five or six million years. So the canyon's young, the rocks are old."

This new understanding suggests that the canyon's dramatic landscape is a relatively recent phenomenon, formed by processes that began millions of years after the rocks themselves had already formed.

But the canyon's layers are more than just geological records - they are a mirror to Earth's ancient past. As part of their ongoing research, Karlstrom and Crossey have redated the Cambrian timescale, which helps us understand how old the canyon's rocks are.

"The Cambrian is the earliest part of the visible record of life in our rocks, you know, all around the world… and one of the most amazing creature features of the Cambrian would be the trilobite," Crossey said. "The Grand Canyon just has fantastic exposure." Through this research, the canyon reveals critical insights into life on Earth millions of years ago.

In their efforts to map out the canyon's geological history, new tools have played a crucial role. Technology like three-dimensional scanning has allowed Karlstrom and Crossey to create detailed, accurate models of the canyon's rock formations.

"We are able as geoscientists to go in and get a real good three-dimensional picture of the distribution of the sedimentary environments…" Crossey said. This technological advancement helps researchers visualize the geological processes that have shaped the canyon, allowing them to uncover insights that were previously hidden.

Their research is not only reshaping our understanding of the Grand Canyon but also inspiring the next generation of scientists. Their work is being used in classrooms and textbooks, igniting the curiosity of students - particularly those at UNM, where both professors are highly regarded for their commitment to education.

Beyond the classroom, Karlstrom and Crossey's work extends to public education through the Trail of Time, a geological walking path at the Grand Canyon that brings millions of years of Earth's history to life for visitors. The path provides a tangible connection to the canyon's deep past, allowing the public to engage with science in a new and immersive way.

The professors' groundbreaking research and dedication to education are helping both the scientific community and the public view the Grand Canyon in a new light. Their findings are opening up fresh avenues of discovery, and as they continue to uncover the canyon's mysteries, one thing is clear: there's still much to learn about this iconic natural wonder.

With this deeper dive into the Grand Canyon's timeline, Karlstrom and Crossey are leading the charge in unearthing its mysteries - and showing the world that even the most famous geological features still hold untold secrets waiting to be discovered.