Hidden in plain sight in the middle of the Australian desert, an ancient coral reef has been preserved for millions of years.
The Nullarbor Plain in South Australia is now an extremely flat and nearly featureless expanse of limestone rock but once contained a huge prehistoric ocean that led to coral formation when the plain was underwater.
An extraordinary landscape in the past
Using satellite imagery, an international team of scientists led by geologist Matej Lipar of the Slovenian Academy of Sciences and Arts has found an ancient landform that appears to have been a coral reef, or part of one. The reef-like landform consists of a raised circular ring about 1,300 meters wide with a dome in the center.
Unlike many parts of the world, large areas of the Nullarbor Plain have remained virtually unchanged due to the processes of weathering and erosion over millions of years, making it a unique geological canvas that records ancient history vividly. remarkable,” explained Milo Barham of Curtin University in Australia in his study published in the scientific journal Earth Surface Processes and Landforms.
” Through high-resolution satellite imagery and fieldwork, we have identified the clear remnant of an original seafloor structure preserved over millions of years, which is the first such landform discovered on the Nullarbor Plain,” the authors point out.
What was this ocean like?
The ocean that covered the Nullarbor began to dry up about 14 million years ago, exposing shallow-water limestones deposited during the middle Cenozoic (the Cenozoic era began about 66 million years ago).
It’s funny how most of Australia today is a dry, arid area, with large interior deserts. But nevertheless, millions of years ago, during the Miocene, the continent teemed with life; not only dense and thriving forest ecosystems, but also huge inland seas.
“Evidence of long -vanished river channels , as well as sand dune systems imprinted directly into limestone, preserve an archive of ancient landscapes and even a record of prevailing winds,” added Barham.
“On the surface, due to relatively stable conditions, the Nullarbor Plain has preserved large numbers of meteorites, allowing us to look back in time to the origins of our solar system. These features, along with the million-year-old landscape feature we have now identified, make the Nullarbor Plain a land that time forgot and allow for a deeper and more fascinating understanding of Earth’s history.”
Referencia: Enigmatic annular landform on a Miocene planar karst surface, Nullarbor Plain, Australia Matej Lipar, Mateja Ferk, Andrej Šmuc, Milo Barham
First published: 29 July 2022 Earth Surface Processes and Landforms.
DOI: https://doi.org/10.1002/esp.5459
