Goldschmidt 2013

Goldschmidt 2013
25 – 30 August 2013, in Florence, Italy

Theme 09: Evolution of Earth´s Environment

Session 09i:
Alteration Processes and Geobiochemical Interactions at Mid-Ocean Ridges

Conveners: Esther Schwarzenbach, Chiara Boschi, Tamara Baumberger, Benjamin Eickmann

Keynote: Beth Orcutt

Invited: Wolfgang Bach

Alteration and geobiochemical interactions at mid-ocean ridges, oceanic core complexes and seamounts have profound impacts on the cycling of elements between the lithosphere, hydrosphere, and biosphere. This interplay not only influences the physical and chemical properties of the oceanic lithosphere, but also provides metabolic energy for chemolithoautotrophy-driven ecosystems. Tracing the pathways of fluids and volatiles during hydrothermal circulation at these diverse geological settings provides insights into ongoing processes of water-rock interaction, magma degassing and microbial activity. A key process linking both the production of reduced volatiles (e.g. H2, CH4) and the presence of microbial activity in a deep biosphere is the alteration of oceanic lithosphere (e.g. serpentinization). In addition, subduction of serpentinized rocks may play a major role in the transport of water and carbon into the mantle. This session addresses open questions with regard to global biogeochemical cycles (C, H, S, N, B, Mg, Ca, metals, etc.), mineral reactions or biological activity linked to alteration and hydrothermal circulation at ultraslow to fast spreading mid-ocean ridges. We encourage contributions from the multi-disciplinary research community investigating the complex interplay between abiogenic and biogenic processes in these settings. We also welcome contributions focused on alteration processes in oceanic lithosphere exposed on the continents and their consequences for geochemical cycles, microbial activity as well as microbially-induced mineral formation.

Themes have now been published at:
http://goldschmidt.info/2013/program/programViewThemes