A team of researchers from the University of Manchester's School of Earth, Atmospheric and Environmental scientists, through their recent breakthrough study, have possibly uncovered the mystery behind what may have caused the Earth's first ever Ice Age.
A few water bubbles trapped in quartz grains may help them do just that.
When tested, the air bubbles were found to contain a much higher amount of argon gas (Ar) than present today in the atmospheric air.
The researchers also found that the levels of two isotopes of argon - 40Ar, and 36Ar - were much higher back in time, compared to the levels we observe in the water today.
This discovery may help shed light on how there may have been a gradual release of the argon, from the rocks and land into the atmosphere.
Also, the argon isotope ratio may further reveal how the continents grew over the time, the volume of the continental crust, and many other important factors.
"The water samples come from the Pilbara region in north-west Australia and were originally heated during an eruption of pillow basalt lavas, probably in a lake or lagoon environment," Dr Ray Burgess, author of the study explained.
"The signs of the Earth's evolution in the distant past are extremely tenuous, only fragments of highly weathered and altered rocks exists from this time, and for the most part, the evidence is indirect. To find an actual sample of ancient atmospheric argon is remarkable and represents a breakthrough in understanding environmental conditions on Earth before life existed."
It was already known how high levels of greenhouse gases, like carbon dioxide, in the atmosphere, may have prevented the Earth from freezing over.
"The continents are a key player in the Earth's carbon cycle because carbon dioxide in the atmosphere dissolves in water to form acid rain. The carbon dioxide removed from the atmosphere by this process is stabilised in carbonate rocks such as limestone and if a substantial volume of continental crust was established, as revealed by our study, then the acid weathering of this early crust would efficiently reduce the carbon dioxide levels in the atmosphere to lower global temperatures and lead to the first major ice age," Dr. Burgess added.
