Professor Alan Collins, who studies the evolution of the deep Earth at the University of Adelaide, said, “The rock of the Twelve Apostles is like a library, a history of what happened in the past.” I’m here.

Most of Port Campbell sits on the same limestone. The entire area was once a shallow sea bay where the sea was slowly eroding. However, only the Twelve Apostles have their histories fully open and available for study.

Nevertheless, they had received little serious scientific research until Gallagher began working on them last year.

“They’re on every tourist brochure. You might think everyone knows all about layers, but it turns out there really isn’t.”


And they cover what Gallagher calls important “pivot points” in our recent history.

Each layer of limestone represents tens of thousands of years. The entire stack records millions of years of history, and its length is so vast that modern humans are only 315,000 years old, which geologists call “deep time.” .

Colors mark the depth of the sea, with a yellowish brown laid down by shallow water. Trace the dark layers of clay laid down by the deep sea at the base of the chimneys to 13 million years ago.

The Earth was much warmer and sea levels were much higher. Antarctica was almost ice-free. Gallagher has been working on rocks at the base and has found microfossils that are not out of the ordinary in the tropics.


These microfossils show the major changes necessary for life to adapt to warming. But life had a lot of time to make that change.

“As far as we know, this is a difficult thing to grasp, but the temperature of the Earth has never changed as fast as it does now,” says Collins.

The fossils and limestone that make up sea stacks are carbon. Coal is formed from a similar process. But burning it releases its carbon into the atmosphere, warming the planet and causing sea levels to rise.

Those rising seas are scraped away, eventually claiming the rest of the Apostles.

That adds to the urgency of Gallagher’s work.

“We might as well make the most of it,” he says. “Because they are gone.”

Liam Mannix’s Examine newsletter explains and analyzes science with a strict focus on evidence. SIGN UP TO GET EVERY WEEK.