Life may have survived in ocean pockets 700mn yrs ago
A new study has revealed that life may have survived a cataclysmic global freeze in the ocean pockets some 700 million years ago.
London: A new study has revealed that life may have survived a cataclysmic global freeze in the ocean pockets some 700 million years ago.
Researchers have apparently found evidence in Australia that turbulent seas still raged during the period, where microorganisms may have clung on for life.
Conditions on what is dubbed ``Snowball Earth`` were so harsh that most life is thought to have perished.
Researchers in Britain and Australia have claimed that they have found deposits in the remote Flinders Ranges in South Australia, which bare the unmistakable mark of turbulent oceans.
They said the sediments date to the Sturtian glaciation some 700 million years ago, one of two great ice ages of the Cryogenian period associated with the ``Snowball Earth`` hypothesis.
These sediments have proved pockets of open ocean waters must have existed during the period, perhaps supporting microscopic life.
The snowball earth hypothesis has suggested the land and oceans of our planet were thrown into a deep freeze, the like of which has never been seen before or since.
"For the first time, we have very clear evidence that storms were affecting the sea floor," the BBC quoted Dan Le Heron of the University of London, who lead the research, as saying.
"That means we have to have pockets or oases within this ``Snowball Earth`` that are free of ice.
"We see a very particular type of feature in sedimentary rocks called ``hummocky cross-bedding``. These features can only form where storm waves sweep up sand from the ocean floor, slosh it back and forth and create a bed of sandstone," said Heron.
This could also explain how some microorganisms survived the period and went on to flourish and diversify during the later Cambrian period.
The details were published in the journal Geology.