| Autor: |
Teece BL; Australian Centre for Astrobiology (ACA), School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, Sydney, Australia.; Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, Sydney, Australia., Havig JR; Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA.; BioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA.; Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA., George SC; School of Natural Sciences, Macquarie University, Sydney, Australia., Hamilton TL; Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA.; BioTechnology Institute, University of Minnesota, St. Paul, Minnesota, USA., Baumgartner RJ; Australian Centre for Astrobiology (ACA), School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, Sydney, Australia.; Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, Sydney, Australia.; CSIRO Mineral Resources, Kensington, Australia., Hartz J; School of Natural Sciences, Macquarie University, Sydney, Australia., Van Kranendonk MJ; Australian Centre for Astrobiology (ACA), School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, Sydney, Australia.; Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, Sydney, Australia. |
| Abstrakt: |
Active hot springs are dynamic geobiologically active environments. Heat- and element-enriched fluids form hot spring sinter deposits that are inhabited by microbial and macroscopic eukaryotic communities, but it is unclear how variable heat, fluid circulation, and mineralization within hot spring systems affect the preservation of organic matter in sinters. We present geological, petrographic, and organic geochemical data from fossilized hot spring sinters (<13 Ka) from three distinct hot spring fields of Yellowstone National Park. The aims of this study were to examine the preservation of hydrocarbons and discern whether the hydrocarbons in these samples were derived from in situ communities or transported by hydrothermal fluids. Organic geochemistry reveals the presence of n -alkanes, methylalkanes, hopanes, and other terpanes, and the distribution of methylheptadecanes is compared to published observations of community composition in extant hot springs with similar geochemistry. Unexpectedly, hopanes have a thermally mature signal, and Raman spectroscopy confirms that the kerogen in some samples has nearly reached the oil window, despite never having been buried. Our results suggest that organic matter maturation occurred through below-surface processes in the hotter, deeper parts of the hydrothermal system and that this exogenous material was then transported and emplaced within the sinter. |
