Has the Earth ever completely frozen? New evidence found in Colorado Rocks

New research into unique sandstone formations in the Colorado Rocky Mountains may confirm that Earth experienced a massive, planet-wide freeze known as ‘Snowball Earth’. About 700 million years ago, the Earth’s surface was covered in ice, creating an extreme climate in which early life not only survived but later developed into complex multicellular organisms.

For decades, the Snowball Earth hypothesis was mainly supported by coastal sedimentary rocks and climate models. But solid evidence that ice sheets reach the planet’s equatorial interior has remained elusive until now. The recent study, published in the Proceedings of the National Academy of Sciences, identifies unusual sandstone deposits called Tava, found in the Pikes Peak granite formations in Colorado. These sandstones likely formed under the pressure of ice sheets, supporting the Snowball Earth theory with new geological evidence.

Tava sandstone formation linked to ancient glacial pressure

Pikes Peak, a sacred site known to the Ute people as Tavá Kaa-vi, is the source of these Tava sandstone formations. Researchers discovered that the sandstones formed when sandy, water-saturated sediment was forced into weakened rock by the immense weight of the ice sheets. The study’s lead authors, Christine Siddoway and Rebecca Flowers, used advanced radiometric dating to determine that Tava sandstones developed about 690 to 660 million years ago, in line with the Cryogenic period.

Using iron minerals found near the sandstone, Siddoway’s team used uranium-lead dating to confirm the origins of the Tava Sandstone within the Snowball Earth time frame. The team suggests that the ice sheets covering the equatorial landmass of Laurentia, now part of North America, created the pressure needed to form these sandstone injectites.

Implications for understanding Earth’s climate history

This discovery strengthens the Snowball Earth hypothesis while shedding light on other geological phenomena, including ‘unconformities’ where erosion has removed large portions of Earth’s rock. The findings at Pikes Peak indicate that similar anomalies may be older than Snowball Earth, indicating complex erosion processes over millions of years. Scientists hope these insights will lead to a deeper understanding of Earth’s climate history and the processes that shaped our habitable planet.