[Rockhounds] Earth’s oldest impact crater was just found in Australia – exactly where geologists hoped it would be

[Kreigh Tomaszewski]

We have discovered the oldest meteorite impact crater on Earth, in the very
heart of the Pilbara region of Western Australia. The crater formed more
than 3.5 billion years ago, making it the oldest known by more than a
billion years
<https://theconversation.com/how-the-worlds-oldest-known-meteorite-impact-structure-changed-the-chemistry-of-earths-crust-201228>.
Our discovery is published today in Nature Communications
<https://doi.org/10.1038/s41467-025-57558-3>.

Curiously enough, the crater was exactly where we had hoped it would be,
and its discovery supports a theory about the birth of Earth’s first
continents.

The oldest rocks on Earth formed more than 3 billion years ago, and are
found in the cores of most modern continents. However, geologists still
cannot agree how or why they formed.

Nonetheless, there is agreement that these early continents
<https://www.annualreviews.org/content/journals/10.1146/annurev-earth-040722-093345>
were
critical for many chemical and biological processes on Earth.

Many geologists think these ancient rocks formed above hot plumes
<https://www.nature.com/articles/372063a0> that rose from above Earth’s
molten metallic core, rather like wax in a lava lamp. Others maintain they
formed by plate tectonic processes
<https://www.sciencedirect.com/science/article/pii/S0301926821001066> similar
to modern Earth, where rocks collide and push each other over and under.

Although these two scenarios are very different, both are driven by the
loss of heat from within the interior of our planet.

We think rather differently.

A few years ago, we published a paper
<https://www.nature.com/articles/s41586-022-04956-y> suggesting that the
energy required to make continents in the Pilbara came from outside Earth,
in the form of one or more collisions with meteorites many kilometres in
diameter.

https://theconversation.com/earths-oldest-impact-crater-was-just-found-in-australia-exactly-where-geologists-hoped-it-would-be-250921