A research team from the University of Cologne has detected organic molecules and gases trapped in 3.5 billion-year-old rocks. the scientists examined about 3.5 billion-year-old barites from the Dresser Formation in Western Australia. The barite thus dates from a time when early life developed on Earth. In the fluid inclusions, the team identified organic compounds such as acetic acid and methanethiol, in addition to gases such as carbon dioxide and hydrogen sulfide. These compounds may have been important substrates for metabolic processes of early microbial life.
— source University of Cologne | Feb 18, 2021