Scientists have discovered traces of the world’s oldest glaciers in South Africa. These glaciers are 2.9 billion years old and gold deposits have been found in the underlying rocks. The discovery suggests that ice caps existed on the continent in the past. Scientists say that this region was either close to the Earth’s pole or some parts of the Earth were frozen in extremely cold ‘Snowball Earth’.
A study published in the journal Geochemical Perspectives Letters states that along with oxygen isotope concentration in ancient rocks, physical evidence has also been found. This evidence suggests that these glaciers are 2.9 billion years old.
Professor Ilya Bindeman from the University of Oregon in the US said, ‘We found a glacial deposit close to the gold fields of South Africa. It is one of the few areas of the earth, which has not changed. They said that this glacial moraine is made up of fossil deposits. It is the debris left by the glacier, which slowly melts and shrinks. It is the oldest moraine deposit ever found.
“We found that 180 oxygen was extremely low in these rocks, while 170 was very high,” Bindemann said. This suggests that they must have been formed at icy temperatures.
At the same time, Professor Axel Hoffmann of the University of Johannesburg says that the largest gold reserves in the world are found in the small hills above the studied rocks. In such a situation, it may be that the change in greenhouse conditions from ice has helped in the formation of those gold reserves. However, this has not yet been confirmed and further work is needed in this direction.
According to the report, researchers have also analyzed oxygen isotopes from these rocks, which has shown that the climate must have been cold at the time the rocks were deposited here. During the analysis, the researchers also studied the amounts of three oxygen isotopes, 16O, 17O, and 18O.