While the Earth has experienced countless climate variations during its long history, a longstanding hypothesis known as Snowball Earth, which postulates that Earth was almost completely covered in ice between 720 to 635 million years ago, has puzzled scientists for years. Now, a recent study published in the Proceedings of the National Academy of Sciences investigated how the level of planetary ice coverage could have been more than previously hypothesized. This study holds the potential to help scientists better understand the past climates on the Earth and how this contributed to life evolving on our planet.
“You have the climate evolving, and you have life evolving with it,” said Dr. Liam Courtney-Davies, who is a postdoctoral researcher at the University of Colorado Boulder (CU Boulder) and lead author of the study. “All of these things happened during Snowball Earth upheaval. We have to better characterize this entire time period to understand how we and the planet evolved together.”
For the study, the researchers examined Tava sandstones that reside in Colorado’s Front Range that have been shoved down the surface over time. Using radiometric dating techniques, which help put absolute ages on objects by calculating the decay of uranium within the substance, the researchers estimated these sandstones were produced during the time of Snowball Earth, suggesting the ice coverage reached as far south as Colorado, and possibly farther. These findings indicate that the ages of the sandstones range between approximately 690-660 million years old.
Image of the Tava sandstone that was examined for the study. (Credit: Liam Courtney-Davies)
Going forward, the researchers aspire to find other evidence of these sandstones to broaden their understanding of Snowball Earth and how this could have influenced the history of life on the Earth.
"We're excited that we had the opportunity to unravel the story of the only Snowball Earth deposits that have so far been identified in Colorado,” said Dr. Rebecca Flowers, who is a professor of geological sciences at CU Boulder and a co-author on the study.
What new discoveries about Snowball Earth will scientists make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Proceedings of the National Academy of Sciences, EurekAlert!, CU Boulder