Abstract
Calculations are presented of the extent to which chemical disequilibria are generated when submarine hydrothermal fluids mix with sea water. These calculations involve quantifying the chemical affinity for individual reactions by comparing equilibrium compositions with the compositions of mixtures in which oxidation-reduction reactions are inhibited. The oxidation-reduction reactions that depart from equilibrium in these systems provide energy for chemotrophic microbial metabolism. Methanogenesis is an example of this phenomenon, in which the combination of carbon dioxide, hydrogen and methane induced by fluid mixing is far from equilibrium, which can be approached if more methane is generated. Similarly, the production of other organic compounds is also favorable under the same conditions that permit methanogenesis. Alkanes, alkenes, alcohols, aldehydes, carboxylic acids and amino acids are among the compounds that, if formed, would lower the energetic state of the chemical composition generated in mixed fluids. The resulting positive values of chemical affinity correspond to the thermodynamic drive required for abiotic organic synthesis. It is also possible that energy release accompanies biosynthesis by chemotrophic organisms. In this way, hydrothermal ecosystems differ radically from familiar ecosystems at Earth's surface. If captured, the energy released may be sufficient to drive biosynthesis of carbohydrates, purines, pyrimidines and other compounds which require energy inputs.
Original language | English (US) |
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Title of host publication | Frontiers in Geofluids |
Publisher | Wiley-Blackwell |
Pages | 161-192 |
Number of pages | 32 |
ISBN (Print) | 9781444333305 |
DOIs | |
State | Published - Feb 9 2011 |
Keywords
- Affinities for Abiotic Organic Synthesis
- Affinities for Biosynthesis
- Diversity of Submarine Hydrothermal Fluids
- East Pacific Rise (EPR)
- Energetics of organic synthesis and biosynthesis
- Extrapolating beyond the present study
- Mixing of Submarine Hydrothermal Fluids with Sea Water
- Quantifying Disequilibria
- Trans-Atlantic Geotraverse (TAG)
ASJC Scopus subject areas
- General Earth and Planetary Sciences