Jeremiah Berneau. Credit: Chevron

It has been long assumed that Utah’s Bonneville Salt Flats was formed as its ancient namesake lake dried up 13,000 years ago. But new research from the University of Utah has gutted that narrative, determining these crusts did not form until several thousand years after Lake Bonneville disappeared, which could have important implications for managing this feature that has been shrinking for decades to the dismay of the racing community and others who revere the saline pan 100 miles west of Salt Lake City.

This salt playa, spreading across 40 square miles of the Great Basin Desert, perfectly level and white, has served as a stage for land-speed records and a backdrop for memorable scenes in numerous films, including “Buckaroo Banzai” and “Pirates of the Caribbean.”

Relying on radiocarbon analysis of pollen found in salt cores, the study, published Friday in the journal Quaternary Research, concludes the salt began accumulating between 5,400 and 3,500 years ago, demonstrating how this geological feature is not a permanent fixture on the landscape.

“This now gives us a record of how the Bonneville Salt Flats landscape responds to environmental change. Originally, we thought this salt had formed here right after Lake Bonneville and it was a static landscape in the past 10,000 years,” said the study’s lead author, Jeremiah Bernau, a former U graduate student in geology. “This data shows us that that’s not the case, that during a very dry period in the past 10,000 years, we actually saw a lot of erosion and then the accumulation of gypsum sand. And as the climate was becoming cooler and wetter, then the salt began to accumulate.”