Martin Homann

Carb-Factory: Petrographic and geochemical characterization of Earth's earliest carbonate platfrom

PostDoctoral Fellow: Dr Martin Homann
Scientific Sponsors: Dr Stefan Lalonde (LGO)
LabexMER Research Axis 3: Geobiological interactions in extreme environments

One of the most dramatic geobiological events in Earth’s history was the evolution of oxygenic photosynthesis, whereby cyanobacteria evolved the capacity to obtain energy from sunlight while releasing free oxygen. Since at least ~2.5 billion years ago oxygen first began accumulating in Earth’s atmosphere. However, during the Archean (3.8 - 2.5 Ga) and prior to atmospheric oxygenation, coupling between the cycling of carbon and oxygen and the regulation of global climate by the activity of photosynthetic life is poorly understood. Carb-Factory will analyse samples from Earth’s oldest carbonate platform, preserved in the 2.94 Ga Ball assemblage of the Red Lake greenstone belt (Ontario, Canada), in order to provide the first insights into operation of the carbon and nitrogen cycle at the initiation of widespread carbonate precipitation on Earth, as well as examine the onset of oxygen production by the ancient phototrophs, which likely formed the stromatolites that comprise this platform.