Revised Age of the Planet’s Most Ancient Impact Site
June 25, 4:00 PM. Fresh research has recalibrated the age of Earth’s oldest known meteorite crater—the North Pole Dome, located in Western Australia’s Pilbara region—from 3.47 billion years down to just over 3 billion years. Despite this significant correction, the structure still holds the title of the planet’s most ancient impact crater, surpassing the second-oldest, Yarrabubba, by roughly 800 million years.
Earlier estimates for the crater’s age were off by nearly half a billion years. The updated findings, published in the journal Geology, rely on advanced mineral dating techniques. A team led by Professor Kirs Kirkland from Curtin University’s School of Earth and Planetary Sciences examined rock samples featuring shatter cones and a shock-deformed quartz vein.
Research Methods
The study analyzed several minerals, including:
- apatite
- calcite
- muscovite
- zircon
Zircon analysis provided the primary evidence for the crater’s age, with some grains displaying a distinctive skeletal, branching form. The age readings from zircon matched those from apatite, reinforcing the new conclusions.
“Dating impact craters of such immense antiquity is an incredibly difficult task,” the researchers note.
This discovery is the only recognized example of a meteorite impact from the Archean eon, highlighting both the importance and the challenges of work in this scientific field.
The implications extend beyond geology, offering fresh insights into Earth’s early history. Pinpointing the age of the North Pole Dome could help scientists better understand planetary formation and development during the Archean era. Such findings may also shape future research into meteorite impacts and their role in the evolution of life on Earth.
The recalibration of the North Pole Dome's age not only alters our understanding of this ancient site but also invites further exploration into the broader implications of such findings. For instance, researchers have recently identified the precise age of another significant impact crater, providing additional context for the evolution of Earth’s geological history and the processes that shaped our planet during the Archean eon.