Earth’s capacity to sustain complex life is the most paramount feature that distinguishes it from all other planets. This is largely attributed to the high oxygen content of the Earth’s atmosphere, which began to grow after the onset of what is known as the Great Oxygenation Event (GOE). But what happened to the environment after the GOE is a subject of much debate among scientists, and is the topic that Kärt Paiste’s thesis entitled “Reconstructing the Paleoproterozoic sulfur cycle: Insights from the multiple sulfur isotope record of the Zaonega Formation, Karelia, Russia” has set out to investigate.
The study assess the microbial communities and sulfur cycle as recorded in the fossilized sediments of the ~2.0 Ga Zaonega Formation in the lake Onega area in Russian Karelia. This area is considered one of the best archives of Paleoproterozoic rock, allowing researchers to decipher environmental conditions after the GOE. The results of the study indicate a restructuring of the microbial community as a response to ongoing changes in local environmental conditions and modern type sulfur cycling at ~2.0 Ga.
Paiste successfully defended her thesis on November 8th, 2018 at UiT The Arctic University of Norway, which was funded by the centre for Arctic Gas Hydrate, Environment, and Climate (CAGE). She had previously received both her Bachelor’s and Master’s degrees in geology from the University of Tartu in Estonia.