Goldschmidt 2013 – Deep Subsurface Fluids, Habitability and Microbial Ecosystems

August 25 – 30, 2013 in Florence, Italy – Abstract Submission Deadline: April 12, 2013: Convenors: Matt Schrenk, Barbara Sherwood Lollar, Chris Ballentine – Keynote: Eric Boyd (Montana State University)

The microbial biosphere at the Earth’s surface has long been thought to lack dispersal barriers. The extent to which this is true in the subsurface biosphere remains to be tested. Taking into account the spectrum of subsurface biomes, there are numerous variants impacting microbial dispersal, success, and evolution in the global subsurface. These include a range of dynamics and time scales of fluid mixing (opportunities for dispersal, supply of energy and nutrients), and diverse environmental selective pressures (e.g. temperature, pH, depth). Fluid movement in marine and terrestrial sediments is slow, and diffusive processes play a significant role in materials transport. In contrast, subsurface fluids in basement rock at mid-ocean ridges and ridge flanks have been estimated to circulate the entire volume of the world’s oceans on time scales of <1 Ma. On the continents, Precambrian Shields harbor groundwaters in fractures isolated for millions of years. Timescales of fluid transport, penetration into the subsurface and mixing define the timeframe and extent to which the subsurface is seeded with organisms. Sources and rates of water-rock interaction within the biome provide a key component in habitability and the subsurface energy cycle. This session will highlight the need for concerted investigations of subsurface microbial ecosystems, integrating both genomic and geochemical data, to resolve important questions regarding the age, connectivity and chemistry of habitats, and to permit a global comparison of rates and trajectories of evolution in the deep biosphere. For more information visit: http://goldschmidt.info/2013/