Powering primordial life – endogenous-exogenous interactions in Earth’s oldest habitats

Hydrothermal activity, triggered by endogenic processes, distributes and redistributes organic matter through diffuse flow networks and may lead to a production of organic matter via abiotic synthesis. Today, hydrothermal seepage, especially at seafloor spreading zones, induces oases for diverse microbial communities in otherwise relatively hostile environments. Furthermore, hydrothermal fluids can deliver organic molecules as building blocks and/or substrates for primeval microorganisms and thus probably played a central role in the emergence of life on Earth. In this talk I will briefly outline evidence for traces of early life on Earth associated with hydrothermal processes from the 3.5 Ga old Dresser Formation (Pilbara, Western Australia). Recent findings strongly support the idea that microbial life in the Dresser Formation was linked to, and perhaps locally fuelled by, hydrothermal seepage. I will demonstrate that integrative study designs including analytical imaging techniques (e.g., Raman spectroscopy), biogeochemical approaches (e.g., catalytic hydropyrolysis and gas chromatography – mass spectrometry), stable isotope analysis and experimental approaches provide important insights into the complex interplay between biological and abiotic processes in early Archean hydrothermal habitats. Thus, they allow us to catch a glimpse into the earliest record of life on Earth.