Author name: Axel Hofmann

Stromatolites are widespread in Precambrian sedimentary successions and provide important insights into life, environmental processes, and surface conditions on the young Earth. Shaped by interactions among microbial processes, sediment deposition, and mineral precipitation, stromato- lites have a record spanning most of Earth’s history and are sensitive indicators for past hydrodynamic conditions and water chemistry. Significant variations in the composition, texture, and structure of stromatolites and associated sedimentary facies occur throughout the geological record, constraining the evolution of surface conditions. The ability of microbial communities to build large carbonate platforms in turn actively influenced the Precambrian hydro- sphere and atmosphere. Stromatolites are direct, visible evidence of microbial ecological success that shaped the Precambrian Earth’s surface.