Your support helps us to tell the story
The strange limestone formations standing in the middle of Western Australia’s Pinnacles Desert were formed 100,000 years ago, according to a new study that sheds more light on climate change in the continent.
Australia’s Aboriginal Yued people believe the spikes represents the hands of warriors swallowed by the sandy place “Kwong-kan” stretching 1000km across.
Now, researchers from Curtin University have found that the limestone pillars measuring about 5m high and 2m wide were formed 100,000 years ago during what was the wettest period in the area’s past half-million years.
“We found this period was locally the wettest in the past half-million years, distinct from other regions in Australia and far removed from Western Australia’s current Mediterranean climate,” study co-author Matej Lipar said.
Scientists found that an abundance of water during this time caused the limestone to dissolve, forming the distinctive iron-rich pillars.
Researchers say such landscapes are found globally along shorelines, including in the Mediterranean, Middle East, southern and southeastern coastal Africa, as well as the Indian subcontinent, Caribbean, Bermuda, and some Pacific islands.
They say the terrain can serve as sensitive indicators of environmental change but only now a method to study the changes of these formations in depth has been developed.
“Studying them within an accurate timeline helps us understand how Earth’s geological systems respond to climate shifts,” Dr Lipar explained.
The iron-rich nodules in the limestone formations act as geological clocks as they trap helium from the decay of small amounts of radioactive uranium and thorium in the soil.
“Measuring this helium provides a precise record of when the nodules formed,” Martin Danišík, another author of the study, said.
“The innovative dating techniques developed in this study reveal the nodules date back about one hundred thousand years, highlighting an exceptionally wet climate period,” Dr Danisik said.
Scientists hope the new method will allow accurate dating of the climate shifts in such landscapes and help provide a more refined timeline of past environmental changes.
“This research not only advances scientific knowledge but also offers practical insights into climate history and environmental change, relevant to anyone concerned about our planet’s present and future,” Milo Barham, another of the study’s authors said.
