Jakarta –
The first evidence of the oldest glaciers found in the world, was found in a South African gold field. This remarkably well-preserved glacial deposit lies beneath the world’s largest gold deposit. These findings provide convincing evidence of the environmental conditions of ancient Earth.
The exact conditions of the Earth during this period are still not widely known. But these 2.9 billion year old glacial remains can provide evidence for a number of theories about conditions so far.
“Perhaps this area is close to the poles. Another possibility is that the entire Earth was in a ‘snowball Earth’ period, when low atmospheric concentrations of CO2 and CH4 caused the ‘reverse greenhouse effect’, causing large parts of the planet to freeze over,” said Professor Axel Hofmann , quoted from IFL Science.
Scientists believe that this may have happened on several occasions in the past. If so, this would be the earliest recorded period of global cooling. Both possibilities are scientifically interesting.
Along with physical evidence of fossilized glacial moraines, the debris left behind by glaciers, the team also analyzed oxygen isotope concentrations in the ancient rocks to determine the climatic conditions at the time they were deposited.
“We looked at the relative amounts of the three oxygen isotopes, 16 O, 17 O, and 18 O. These are all types of oxygen but have slightly different weights. We found that these rocks have very low amounts of 18 O, and low amounts of 17 O. very high, indicating that they formed at cold temperatures,” explained study co-author Professor Ilya Bindeman.
“The geochemical evidence pairs with the moraine evidence, and that means these glaciers are the oldest glaciers ever found on Earth.”
The locational significance of the find beneath Earth’s largest sedimentary gold deposit could also trigger further investigation, Hofman explained. “It is possible that the change from icehouse to greenhouse conditions may have aided the formation of these gold deposits, but this needs to be confirmed and requires further work.”
Using three oxygen isotope analyzes in this way could open new avenues for finding evidence of early Earth glaciation. Discoveries like these introduce new lines of inquiry and investigation into Earth’s climatic history.
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2023-07-13 23:15:29
#Worlds #Oldest #Glacier #Barren #Goldfields #Africa
