caa a22 4500 465744710 CHVBK 20180323111817.0 cr unu---uuuuu 170327e19900501xx s 000 0 eng 10.1007/BF01808115 doi (NATIONALLICENCE)springer-10.1007/BF01808115 Shock Everett Department of Earth and Planetary Sciences, Washington University, 63130, St. Louis, MO, USA aut Geochemical constraints on the origin of organic compounds in hydrothermal systems [Elektronische Daten] [Everett Shock] It is proposed that abiotic synthesis of organic compounds occurs in metastable states. These states are permitted by kinetic barriers which inhibit the approach to stable equilibrium in the C-H-O-N system. Evidence for metastable equilibrium among organic compounds in sedimentary basins is reviewed, and further evidence is elucidated from hydrous pyrolysis experiments reported in the literature. This analysis shows that at hydrothermal conditions, organic compounds are formed or destroyed primarily through oxidation/reduction reactions, and that the role of temperature is to lower the kinetic barriers to these reactions. These lines of evidence allow the development of a scenario in which abiotic synthesis can occur at hydrothermal conditions through the reduction of CO2 and N2. This scenario can be tested quantitatively with distribution of species calculations as functions of temperature, pressure, hydrogen fugacity (fH2) and initial composition. One example of such a test is given for an early, sudden outgassing of the Earth, in which CO2, H2O, and N2 are transported from the mantle to the atmosphere by hydrothermal solutions. Activities of metastable aqueous organic species which form as a consequence of this process are evaluated at conditions appropriate for seafloor hydrothermal systems, and are found to maximize at about 200 °C and between the oxidation states set by two mineral assemblages common in the oceanic crust. Kluwer Academic Publishers, 1990 Origins of life and evolution of the biosphere Kluwer Academic Publishers 20/3-4(1990-05-01), 331-367 0169-6149 20:3-4<331 1990 20 11084 https://doi.org/10.1007/BF01808115 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01808115 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Shock Everett Department of Earth and Planetary Sciences, Washington University, 63130, St. Louis, MO, USA aut NATIONALLICENCE 773 0- Origins of life and evolution of the biosphere Kluwer Academic Publishers 20/3-4(1990-05-01), 331-367 0169-6149 20:3-4<331 1990 20 11084 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer