The presence of Paleoproterozoic glacial diamictites deposited at low latitudes on different continents indicates that three or four worldwide glaciations occurred between 2.45 and 2.22 Ga. During that time period, the first atmospheric oxygen rise, known as the Great Oxidation Event (GOE), occurred, implying a potential connection between these events....

Microbial mat growth can produce diagnostic delicate structures in low-energy environments, but mat morphology, and thus preservation of delicate structures as morphological biosignatures, is affected by mud accumulation. In Lake Joyce, Antarctica, varying rates of siliciclastic mud deposition affected the morphology of partially calcified microbial...