US geoscientists update Grand Canyon's ancient history using cutting-edge technology

The Grand Canyon, with its iconic layers of sedimentary rock, has long been a treasure trove for geologists seeking to unravel the mysteries of Earth's ancient past.

For anyone from the Baby Boomer generation to Gen Alpha who has studied geology, Edwin Dinwiddie McKee’s groundbreaking research on the Grand Canyon's sedimentary record has likely shaped their understanding—whether or not they immediately recognize his name, Caliber.Az reports via foreign media.

McKee, a renowned scientist who lived from 1906 to 1984, dedicated over 50 years to studying and documenting the stratigraphy and sedimentation of Colorado Plateau geology, particularly the Grand Canyon's Cambrian Tonto Group. His enduring contributions have influenced generations of geoscientists. “The Tonto Group holds a treasure trove of sedimentary layers and fossils chronicling the Cambrian Explosion some 540 million years ago, when the first vertebrates and animals with hard shells rapidly proliferated and sea levels rose to envelop continents with emerging marine life,” explains Carol Dehler, a professor at Utah State University.

“McKee marveled at this pivotal geologic period, yet had no knowledge of plate tectonics or global sea level change, and his ideas were often shunned by the scientific community of his time.” But what if McKee had the opportunity to fast-forward through time and benefit from modern stratigraphic, depositional, and paleontological models, along with the advanced technology available today?

Carol Dehler, along with colleagues James Hagadorn from the Denver Museum of Nature & Science, Frederick Sundberg, Karl Karlstrom, Laura Crossey from the University of New Mexico, Mark Schmitz from Boise State University, and Stephen Rowland from the University of Nevada, Las Vegas, along with their students and interns, have used these modern tools to create a refined and insightful framework based on McKee’s pioneering ideas. 

Their work is detailed in a recent paper featured as the cover story of the November 2024 print issue of the Geological Society of America’s GSA Today.

“The Grand Canyon is an epic Rosetta Stone for geology,” says Hagadorn, Tim & Kathryn Ryan Curator of Geology at DMNS. “And we’re helping to further decode it. Because Grand Canyon rocks record global changes in climate and tectonics, our work helps us understand strata that were deposited worldwide during the Cambrian period.” Studying the Tonto Group, he explains, is akin to being a detective at a crime scene. “You can see clues and discern at least part of what happened,” Hagadorn says.

By Naila Huseynova