Geobiology studies Earth as a system and explores the past, present and future of the interaction of life with its environment. This GRC assembles biofilm and microbial mat researchers, early life paleontologists, stromatolite sedimentologists, coastal engineers, and molecular biologists with the aim to explore the living Earth and its ancestry. We hope that this fruitful engagement inspires the next generation of geo- and astrobiologists. The GRC documents biofilms, and sediment-stabilizing microbial mats that form typical sedimentary structures such as microbially induced sedimentary structures or stromatolites. In the fossil record such structures are found in banded iron formations, cherts, sandstones, and carbonate rocks. Isotope geochemistry and the study of biomolecules reveal metabolic pathways of early life, and allow conclusions on the evolution of main prokaryotic groups. Astrobiologists apply these concepts for the exploration of life on other planets.