Tektites are nearly pure glasses (practically no crystalline inclusions) created when a space rock slams into Earth, melting surface material and hurling it hundreds or even thousands of km.
Map of the ananguites strewn field, based on the tektite locations. Image credit: Musolino et al., doi: 10.1016/j.epsl.2025.119600.
“Tektites are a specific type of impact-produced glass, defined in particular by their occurrence within large strewn fields lying at long distances from their source crater,” said Curtin University’s Professor Fred Jourdan and his colleagues.
“Only five different strewn fields are known: the four ‘classic’ ones known for nearly a century, from Central Europe (14 million years old), North America (35 million years old), Ivory Coast (1 million years old), and a large area spread from China to Australia (780,000 years old) and a more recently discovered strewn field in Central America (800,000 years old).”
“The corresponding tektites are called moldavites, bediasites-georgiaites, ivorites, australasites, and belizites, respectively.”
The newly-discovered type of tektite, named ananguite, have so far been found exclusively in an area mainly within South Australia.
“Finding a new tektite field is like opening a fresh chapter in Earth’s violent geological past,” Professor Jourdan said.
“These glasses are unique to Australia and have recorded an ancient impact event we did not even know about.”
“These tiny pieces are like little time capsules from deep in our planet’s history.”
“What makes the discovery even more intriguing is that, although the impact must have been immense, scientists are yet to locate the crater.”
“Understanding when and how often large asteroids have struck Earth also helps us assess the risk of future impacts, which is important for planetary defense.”
Picture of six tektites studied by Musolino et al. Scale bars – 2 mm. Image credit: Musolino et al., doi: 10.1016/j.epsl.2025.119600.
“The glasses were distinct from all other known tektites,” said Anna Musolino, a Ph.D. student at Aix-Marseille University.
“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.”
“While the Australasian tektites formed about 780,000 years ago and are spread across half the globe, these tektites are much older and their discovery suggests a previously unrecognized giant impact.”
The team’s paper was published in the journal Earth and Planetary Science Letters.
_____
Anna Musolino et al. 2025. A new tektite strewn field in Australia ejected from a volcanic arc impact crater 11 Myr ago. Earth and Planetary Science Letters 670: 119600; doi: 10.1016/j.epsl.2025.119600
