Researchers led by Anna Musolino have identified a new type of impact glass—ananguites—in South Australia. Argon dating places these beads at about 11 million years, distinct from the much younger australites (~788,000 years) tied to the Australasian strewnfield. Ananguites show lower silica but higher iron, magnesium and calcium oxides, plus different physical properties. Despite evidence for a large impact, no crater has been found; burial, erosion or misidentification are possible explanations. The findings appear in Earth & Planetary Science Letters.
11-Million-Year-Old "Ananguites" Reveal a Previously Unknown Massive Meteor Impact in Australia
Researchers led by Anna Musolino have identified a new type of impact glass—ananguites—in South Australia. Argon dating places these beads at about 11 million years, distinct from the much younger australites (~788,000 years) tied to the Australasian strewnfield. Ananguites show lower silica but higher iron, magnesium and calcium oxides, plus different physical properties. Despite evidence for a large impact, no crater has been found; burial, erosion or misidentification are possible explanations. The findings appear in Earth & Planetary Science Letters.
11:50, 04.11.2025Science
Ancient impact glass points to a lost meteor strike
Researchers led by geoscientist Anna Musolino (Aix-Marseille University) have identified a previously unrecognised type of impact glass in South Australia. These tiny, spherical glass beads—now named ananguites—carry a unique chemical fingerprint indicating they formed in a powerful meteorite impact about 11 million years ago.
The find is striking because, despite clear mineral evidence for a large collision, no matching crater has been located. The ananguites were identified after Musolino and colleagues re-examined decades-old chemical data from unusual australites first flagged by Dean Chapman and Leroy Scheiber in 1969, then screened a museum collection for matches.
How ananguites differ from australites
Compared with typical australites (the tektites tied to the much younger Australasian strewnfield, ~788,000 years old), ananguites show:
- Lower silicon dioxide (SiO2) content
- Higher oxides of iron, magnesium and calcium
- Greater density and higher magnetic susceptibility
- Distinct bubble textures and different trace-element ratios
Using this fingerprint, the team identified six matching specimens in the South Australian Museum and conducted argon dating on two samples. The results cluster around ~11 million years, confirming these beads are far older than the australites and therefore come from a separate impact event.
“These glasses are unique to Australia and have recorded an ancient impact event we did not even know about,” said Fred Jourdan, geochronologist and geochemist at Curtin University. “They are like little time capsules from our planet's violent past.”
Where is the crater?
Locating the source crater remains a major challenge. Possible explanations for its absence include:
- Intense weathering and erosion over millions of years
- Burial beneath sediments since the event
- Misidentification as volcanic features in rugged regions (for example, parts of Papua New Guinea)
The team also notes preliminary geochemical differences between western and eastern ananguites that, if confirmed with more samples, could help narrow down the impact location. However, it's also plausible the crater has been destroyed or buried during the last 11 million years.
The study, led by Musolino and collaborators and published in Earth & Planetary Science Letters, highlights how small, durable pieces of impact debris can preserve dramatic episodes of Earth history that leave little other geological trace.
Why it matters: Discovering ananguites expands our record of meteorite impacts on Earth and underscores how museum collections and archival data can reveal major events long after they occurred. Finding the source crater would help constrain the impact’s size, location and environmental consequences.