Curtin University and NASA identify Earth’s oldest crater

zircon Erickson

Earlier this year, researchers at NASA and the John de Laeter Centre at Curtin University identified what they think is the oldest meteorite crater known to man, and they used electrodynamic fragmentation to do it.

The article in Nature Communications shows that the ages of shock recrystallised and shock reset monazite and zircon are coeval and agree on a age for the crater of 2229 ± 5 Ma, making the 70km wide Yarrabubba crater in West Australia the oldest impact structure on Earth. 

Zircon, Erickson, Curtin, monazite
Monazite and zircon recrystallisation textures

Interestingly, the age of the crater coincides with the end of the palaeoproterozoic ice age, the ‘Snowball Earth’ where the planet was entirely frozen. This leads to the hypothesis that the massive impact played a role in ending that ice age.

The method used to extract and isolate the zircon and monazite grains using the Curtin Lab system is as follows:

To separate zircon and monazite grains ~1 kg splits of each sample were processed with a Selfrag electric pulse disaggregator in the John de Laeter Centre (JdLC), Curtin University, Western Australia. The heavy mineral fraction was then separated using the heavy liquid methylene iodide. Further concentration of zircon and monazite was achieved with a Frantz isodynamic magnetic separator. Grains were then handpicked and mounted in a 25.4 mm epoxy round.”

Read the full article on nature.com

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We’re glad to see SELFRAG represented and utilised successfully in such a high profile study, and that our novel fragmentation system is providing critical, high quality sample preparation to complement the increasingly sensitive analytical systems such as the SHRIMP. To find out how SELFRAG can support your research, see some of our other articles on sample preparation and diamond recovery and visit our application notes page.#australia