Scientists from the University of Melbourne have uncovered new details about the formation of the Twelve Apostles, revealing that tectonic plate movements over millions of years played a key role in lifting and shaping the iconic coastal structures.
The findings, published in the Australian Journal of Earth Sciences, provide the clearest picture to date of how the limestone stacks emerged from the ocean and evolved into one of Australia’s most recognisable natural landmarks.
Until now, the origins of the Twelve Apostles had not been fully understood. Researchers found that shifting tectonic plates gradually pushed the rock formations upward, while also tilting and fracturing the layers over time. These movements left visible signs that can still be observed in the surrounding cliffs today.
University of Melbourne lead researcher Associate Professor Stephen Gallagher said the discovery highlights the scientific significance of the site.
“Much like an environmental time capsule, each layer of these giant structures preserved information about the Earth’s climate, tectonic activity, plants and animals over millions of years, including a key time about 13.8 million years ago when the climate was much warmer than what it is today,” he explained.
He continued, “We are using this ‘window back in time’ to understand where temperatures and sea levels may be heading on our current path of climate change. With only eight of the twelve Apostles remaining, we need to study and learn from them while we can.”
The research also refined the age of the formations. While earlier estimates suggested the limestone layers were between seven and fifteen million years old, the discovery of microscopic fossils has narrowed this range to between 8.6 and 14 million years.
Scientists say that although tectonic activity lifted the formations, the dramatic coastal pillars visible today were shaped much more recently. Erosion following the last Ice Age, just a few thousand years ago, exposed and sculpted the structures along the coastline.
Researchers are now continuing to study individual rock layers to better understand past climates, ocean conditions and sea level changes, with the aim of applying those insights to modern environmental challenges.
