The talk will be streamed. You can watch the stream at Realfagsbiblioteket YouTube-channel.
Abstract:
Earth is currently the only planet in the universe known to support life. The question of how life emerged and evolved here has fascinated scientists since the time of the ancient Greeks and remains one of the greatest scientific challenges today. A crucial part of solving this mystery lies in understanding the environments where early microbial life may have thrived and evolved over 3 billion years ago. While the geological record from this time in Earth’s history is sparse, the preservation of certain key minerals has offered geochemists valuable time capsules that provide insights into surface conditions of the early Earth.
In this seminar, I will explore what we have learned about Earth’s earliest environments through the study of sulfate and sulfide minerals preserved in greenstone belts of South Africa, Australia and India. I will highlight how rare occurrences of the sulfate mineral barite have provided key information on the chemistry of the early atmosphere and the emergence of the first landmasses, thanks to the robustness of barite against alteration and metamorphism. In addition, we will examine how sulfide minerals found together with barite yield clues about early microbial sulfur cycling in localized marine sulfate oases, shedding light on some of the earliest habitats of life.