Researchers have uncovered a new field of 11-million-year-old tektites in South Australia, pointing to a massive asteroid impact whose crater remains undiscovered. These unique glass fragments differ chemically and geographically from known tektites, recording an event previously unknown to science. The finding highlights Earth's violent past and aids planetary defense efforts.
In a breakthrough study, scientists identified rare natural glass formations called tektites across parts of South Australia. These tektites, formed when an asteroid strikes Earth with immense force, melt surface rock and scatter molten debris over thousands of kilometers. Unlike the well-known Australasian tektite-strewn field from about 780,000 years ago, which spans half the globe, these specimens are much older and confined to Australia.
"These glasses are unique to Australia and have recorded an ancient impact event we did not even know about," said Professor Fred Jourdan from Curtin’s School of Earth and Planetary Sciences. He described the tektites as "little time capsules from deep in our planet's history," formed by an asteroid that slammed into Earth around 11 million years ago.
Lead author Anna Musolino, a PhD student at Aix-Marseille University, emphasized their distinctiveness: "These tektites are unique because of their unusual chemistry and their age, which is about 11 million years. They record a completely separate impact event from the famous Australasian tektite-strewn field."
What intrigues researchers most is the absence of the impact crater, despite evidence of a giant event. "What makes the discovery even more intriguing is that, although the impact must have been immense, scientists are yet to locate the crater," Jourdan noted. The study, led by Emeritus Professor Pierre Rochette from Aix-Marseille University, underscores the destructive power of past impacts and their relevance today. Understanding such events helps assess risks from near-Earth objects, crucial for planetary defense.
The research, titled 'A new tektite strewn field in Australia ejected from a volcanic arc impact crater 11 Myr ago,' appears in Earth and Planetary Science Letters (2025; 670: 119600). Materials were provided by Curtin University.