Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 15, issue 5 | Copyright
Biogeosciences, 15, 1535-1548, 2018
https://doi.org/10.5194/bg-15-1535-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Ideas and perspectives 15 Mar 2018

Ideas and perspectives | 15 Mar 2018

Ideas and perspectives: hydrothermally driven redistribution and sequestration of early Archaean biomass – the “hydrothermal pump hypothesis”

Jan-Peter Duda1,2, Volker Thiel1, Thorsten Bauersachs3, Helge Mißbach1,4, Manuel Reinhardt1,4, Nadine Schäfer1,2, Martin J. Van Kranendonk5,6,7, and Joachim Reitner1,2 Jan-Peter Duda et al.
  • 1Department of Geobiology, Geoscience Centre, Georg-August-Universität Göttingen, Goldschmidtstraße 3, 37077 Göttingen, Germany
  • 2“Origin of Life” Group, Göttingen Academy of Sciences and Humanities, Theaterstraße 7, 37073 Göttingen, Germany
  • 3Department of Organic Geochemistry, Institute of Geosciences, Christian-Albrechts-Universität Kiel, Ludewig-Meyn-Straße 10, 24118 Kiel, Germany
  • 4Department Planets and Comets, Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
  • 5Australian Centre for Astrobiology, University of New South Wales, Kensington, New South Wales 2052, Australia
  • 6School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, New South Wales 2052, Australia
  • 7Australian Research Council Centre of Excellence for Core to Crust Fluid Systems, School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, New South Wales 2052, Australia

Abstract. Archaean hydrothermal chert veins commonly contain abundant organic carbon of uncertain origin (abiotic vs. biotic). In this study, we analysed kerogen contained in a hydrothermal chert vein from the ca. 3.5Ga Dresser Formation (Pilbara Craton, Western Australia). Catalytic hydropyrolysis (HyPy) of this kerogen yielded n-alkanes up to n-C22, with a sharp decrease in abundance beyond n-C18. This distribution ( ≤ n-C18) is very similar to that observed in HyPy products of recent bacterial biomass, which was used as reference material, whereas it differs markedly from the unimodal distribution of abiotic compounds experimentally formed via Fischer–Tropsch-type synthesis. We therefore propose that the organic matter in the Archaean chert veins has a primarily microbial origin. The microbially derived organic matter accumulated in anoxic aquatic (surface and/or subsurface) environments and was then assimilated, redistributed and sequestered by the hydrothermal fluids (hydrothermal pump hypothesis).

Download & links
Publications Copernicus
Download
Short summary
The origin of organic matter in the oldest rocks on Earth is commonly ambiguous (biotic vs. abiotic). This problem culminates in the case of hydrothermal chert veins that contain abundant organic matter. Here we demonstrate a microbial origin of kerogen embedded in a 3.5 Gyr old hydrothermal chert vein. We explain this finding with the large-scale redistribution of biomass by hydrothermal fluids, emphasizing the interplay between biological and abiological processes on the early Earth.
The origin of organic matter in the oldest rocks on Earth is commonly ambiguous (biotic vs....
Citation
Share