Earth’s Oldest Impact Crater Discovered in Australia – 3.47 Billion Years Old

The North Pole Dome crater in Western Australia is Earth’s oldest known meteorite impact site, dated to approximately 3 billion years ago. According to a study published June 23, 2026, in the journal Geology, the site is roughly 470 million years younger than previously estimated but remains the only recognized impact structure from the Archean eon.

Located in the Pilbara region of Western Australia, the North Pole Dome crater sits among some of the planet’s oldest rocks. Despite the revised age, it remains a record-breaking structure. It predates the Yarrabubba impact structure, also in Western Australia, by roughly 800 million years, according to the researchers.

How old is the North Pole Dome crater?

Current evidence places the impact at a little more than 3 billion years ago. This figure corrects a previous estimate by the same lead author and contradicts a separate study that suggested a much younger date.

The dating history for the site includes three distinct claims:

• A study published in 2025 by Chris Kirkland and colleagues initially claimed the crater was 3.47 billion years old.
• A subsequent study published four months later in Science Advances argued the impact occurred no earlier than 2.7 billion years ago.
• The June 23, 2026, study in Geology concludes the age is approximately 3 billion years.

Chris Kirkland, a professor in the School of Earth and Planetary Sciences at Curtin University and the study’s first author, stated that the site’s exact age had remained uncertain until the use of new mineral dating techniques.

How do scientists date ancient impact craters?

Researchers used a process Kirkland describes as a mineral clock. They analyzed minerals that were either newly grown or remade within rocks damaged by the meteorite strike. The team focused on shatter cones, which are cone-shaped rock chunks formed by shock waves propagating downward during an impact.

The team examined two samples of shatter-cone-bearing rocks and a shocked quartz vein. These veins are sheet-like deposits created when superhot, mineral-rich water flows through cracks in shocked rocks. To determine the age, the researchers analyzed four specific minerals: zircon, apatite, calcite, and muscovite.

The key evidence comes from zircon, a tiny but extraordinarily resilient mineral that can keep geological time for billions of years. Some zircons at North Pole Dome have unusual branching, skeletal shapes. We interpret these as impact-modified crystals, formed when older zircon was disrupted, partly recrystallised, and in places regrown during the intense heating caused by the impact.—Chris Kirkland

The researchers reported that the age recorded in the zircon matched the age locked inside apatite minerals. This alignment gave the team confidence in the 3-billion-year estimate. They noted that the younger shatter cones mentioned in the Science Advances study likely formed later due to thermal and tectonic activity.

Why is the Archean eon significant?

The North Pole Dome crater is the only recognized meteorite impact structure from the Archean eon, which spanned from 4 billion to 2.5 billion years ago. This period marks the era when Earth’s earliest continents were forming.

Dating these structures is difficult because billions of years of heat, pressure, and fluid movement often reset or obscure the original signals of an impact. By pinning down the age of the North Pole Dome, researchers gain a clearer window into the geological conditions of the early Earth.