Massive glaciers from Earth’s past reshaped the planet in ways that paved the way for complex life.
As they moved, they carved into the crust, releasing minerals that altered ocean chemistry and set off a chain reaction of life-supporting changes. This research not only unlocks secrets of Earth’s deep history but also offers insights into how climate shifts — both ancient and modern — can dramatically impact the planet.
Ancient Glaciers: Earth’s Great Bulldozers
New research from Curtin University shows that massive ancient glaciers reshaped Earth’s surface much like giant bulldozers, carving the landscape and setting the stage for complex life to emerge.
By analyzing crystals in ancient rocks, scientists discovered that as glaciers moved across the land, they scraped deep into the Earth’s crust. This process released key minerals, which then flowed into the oceans, altering their chemistry.
These changes had a significant impact on the planet’s composition, creating conditions that made it possible for more complex life forms to evolve.
Lead researcher Professor Chris Kirkland, from the Timescales of Mineral Systems Group at Curtin’s Frontier Institute for Geoscience Solutions, explained that the study highlights Earth’s deeply interconnected natural systems.
Ice, Floods, and Ocean Chemistry
“When these giant ice sheets melted, they triggered enormous floods that flushed minerals and their chemicals, including uranium, into the oceans,” Professor Kirkland said.
“This influx of elements changed ocean chemistry, at a time when more complex life was starting to evolve.
“This study highlights how Earth’s land, oceans, atmosphere and climate are intimately connected- where even ancient glacial activity set off chemical chain reactions that reshaped the planet.”
Lessons for Today’s Climate Challenges
Professor Kirkland said the study also offered a new perspective on modern climate change, showing how past shifts in Earth’s climate triggered large-scale environmental transformations.
“This research is a stark reminder that while Earth itself will endure, the conditions that make it habitable can change dramatically,” Professor Kirkland said.
“These ancient climate shifts demonstrate that environmental changes, whether natural or human-driven, have profound and lasting impacts.
“Understanding these past events can help us better predict how today’s climate changes might reshape our world.”
Reference: “The Neoproterozoic glacial broom” by C.L. Kirkland, R.A. Strachan, D.B. Archibald and J.B. Murphy, 25 February 2025, Geology.
DOI: 10.1130/G52887.1
The research was conducted in collaboration with the University of Portsmouth and St. Francis Xavier University, Canada.
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1 Comment
“By analyzing crystals in ancient rocks, scientists discovered that as glaciers moved across the land, they scraped deep into the Earth’s crust.”
How deep is “deep?” Certainly not even 10% of the thickness of the crust. During the Neoproterozoic, there were no plants or animals yet living on land. Thus, biological forces to turn regolith into soil were not what they are today. That means that crustal rocks and regolith derived from them by mechanical and chemical weathering were the dominant agents of weathering and glaciers would not have to scrape very deep to move material towards the oceans. And without vegetation and soil, floods would have been more frequent and powerful than today. I think that the quote is a bit of a stretch.
“Understanding these past events can help us better predict how today’s climate changes might reshape our world.”
Except that the Earth today, wrought by the evolution of life, has created a very different world than what existed during the Neoproterozoic. The development and evolution of life is one of the very few examples that I’m aware of that fulfills the implications of a Tipping Point. After the Great Oxygenation event, animals could move to land and new minerals — oxides — could form readily. That is, a relatively sudden and irreversible change in the Earth processes.
Anything that the authors may learn from “these past events” will have limited application to Today or the near future. Instead, it will mostly lead to a better understanding of what, why, and how things changed in the distant past, with little predictive value for a world that has gone well beyond the ‘Blank Slate.” It sounds like rationalization of basic research to make the grants funding it more palatable as applied research. Were it otherwise, the authors would have been prudent to specify exactly what things they learned that would allow prediction of the results of frequent climate changes throughout geologic history, instead of generalized arm waving.