A 500 million-year-old trilobite fossil left ladder-like traces, and Cambrian worms left tube-like trails in the mud of the shallow ocean that are preserved as trace fossils. Credit: Laurie Crossey, UNM Newsroom
SciTechDaily reports on a discovery that may reshape our understanding of the Cambrian Period. New research, published in the journal GSA Today, focuses on Cambrian rock formations at the base of the Grand Canyon. The study, a collaborative effort led by Carol Dehler, a professor at Utah State University, and Fred Sundberg, a paleontologist and adjunct professor at UNM, revisits the McKee Model, a foundational concept in marine transgression studies. Developed 50 years ago by Eddy McKee based on these same rock formations, the model has been widely taught to geologists around the world. This new research refines and updates McKee's classic framework.
“Our new model for deposition of the Tonto Group is much more nuanced, showing a mixture of marine and non-marine settings, breaks or unconformities when no sediment was being deposited, and a much faster tempo of evolution. Even more than before, the Tonto Group of Grand Canyon remains one of the most important Cambrian-type sections in the world because of its complete exposure,” says UNM Distinguished Professor Karl Karlstrom.
Note: this article was sent in by ESCONI member George Witaszek!
