Das Projekt "Internationales Kontinentales Bohrprogramm (ICDP) - Biogeochemie von mikrobiellen Ökosystemen in der 'Tiefen Biosphäre' der Mallik 5L-38 Gashydrat-Bohrung, Mackenzie-Fluss-Delta, Kanada" wird vom Umweltbundesamt gefördert und von GeoForschungsZentrum Potsdam durchgeführt. In recent years the discovery of ubiquitous microbial life in the deep subsurface has changed our perception of the Earth's biosphere. First assessments suggest the biomass of this so-called 'deep biosphere' is approximately comparable to that of the Earth's surface, thereby outlining the importance of this widely disseminated hidden world for global geochemical cycles. The opportunity to explore a microbial ecosystem in the deep biosphere in a terrestrial setting near a gas hydrate deposit using organic geochemistry is provided by the Mallik Gas Hydrate Research Well 5L-38, which is located at the northern edge of the Mackenzie River delta (Northern Territories, Canada) in a permafrost region. Our main goal, co-ordinated with a partner project on feedstock generation and networked with colleagues from Canada, USA, India and other scientists at GeoForschungsZentrum Potsdam, is to elucidate the occurrence and nature of deep microbial ecosystems in the well using biogeochemistry. Both the chemical and isotopic compositions of individual biomarkers will be employed to identify the sources of organic matter detritus and the type of living biomass. Sediments and bacterial cultures will come under detailed investigation.