Johannesburg - Two University of Johannesburg (UJ) researchers have contributed to a study which suggests that oxygen began to appear in the ocean and the atmosphere much earlier than generally thought.
“The earth was formed about 4.6 billion years ago and, until now, scientists believed that oxygen began accumulating in the planet's atmosphere about 2.3bn years ago,” the geology department's Prof Nic Beukes said in a statement.
Beukes and researcher Stefanus Kruger participated in the study with a group of researchers from Denmark and Germany. Their findings were published in the science journal, Nature.
“There was no oxygen in the atmosphere for at least hundreds of millions of years after the earth formed,” Beukes said.
“This study now suggests that the process began very early in earth’s history, supporting a much greater antiquity for oxygen-producing photosynthesis and aerobic life.”
The researchers looked at the chemical composition of rock and soil samples from the Pongola Supergroup in South Africa, and used mathematical models to determine the age of trace amounts of oxygen.
The study found that the oxygen began to appear in the atmosphere and ocean three billion years ago, which was 700 million years earlier than was commonly believed. - Sapa