Found: A reef, 650 million years old

September 22nd, 2008 - 11:45 am ICT by IANS  

Sydney, Sep 22 (IANS) Three scientists have located in the middle of a desert the remains of a giant underwater reef - with a plateau 10 times higher than the Great Barrier Reef - in the Northern Flinders Ranges in outback South Australia. The 20-km wide reef is about 650 million years old and is the only known reef complex of this age. The next closest aged series of reefs found to-date are around 800 million years old and located in Arctic Canada.

The discovery is particularly significant because the reef existed for five to 10 million years during a period of tropical climate squeezed between two major ice age events where ice was present even at equatorial latitudes, reports Sciencealert.

Scientists Jonathan Giddings, Malcolm Wallace and Estee Woon of the School of Earth Sciences, University of Melbourne believe that peculiar fossils of possible multi-cellular organisms found in the reef could be the earliest examples of primitive animal life discovered to date.

“Unlike the Great Barrier Reef, this reef was not made by coral. It was instead constructed by microbial organisms and other more complex organisms that have not been previously discovered,” said Wallace, an associate professor.

“The discovery is already attracting significant interest from leading scientists around the world. A lot of people will be intrigued as to why this once underwater reef is now located in a very barren part of inland Australia,” said Giddings.

“With the movement over millions of years of Australia’s tectonic plates, the reef has now been turned 90 degrees skywards from its once horizontal position. This has exposed the whole one km depth of the reef, from what was once its shallow water section right down to its deep water section.

“In effect, these tectonic forces have resulted in very ancient history being pushed up to the present. Today’s advances in satellite imagery are also helping us to see the reef very easily. Geologists had seen this mass before but had not really recognised it as once being a reef,” Giddings added.

This extreme climate change from ice age to tropical conditions and back to ice age occurred approximately 750-550 million years ago, hundreds of millions of years before the advent of dinosaurs.

These findings will be presented at the Geological Society of Australia’s Selwyn Symposium in Melbourne Sep 25.

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