EGU22-2653, updated on 08 Jan 2024
https://doi.org/10.5194/egusphere-egu22-2653
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Trace metal availability in extreme microbial habitats of the Miocene Oberpullendorf Basin, Austria

Sebastian Viehmann1,2, Robert Kujawa2, Simon V. Hohl3, Nathalie Tepe4, Alexandra S. Rodler1,5, Thilo Hofmann4, and Erich Draganits2
Sebastian Viehmann et al.
  • 1University of Vienna, Dept. of Lithospheric Research, Vienna, Austria (sebastian.viehmann@univie.ac.at)
  • 2University of Vienna, Dept. of Geology, Vienna, Austria
  • 3Tongji University Shanghai, State Key Laboratory of Marine Geology, Shanghai, P.R. China
  • 4University of Vienna, Department of Environmental Geosciences, Vienna, Austria
  • 5Austrian Academy of Sciences, Austrian Archaeological Institute, Vienna, Austria

Stromatolitic carbonates were formed in ancient microbial mats, and, thus, provide unique geochemical archives to reconstruct palaeo-environments in which microbial life thrived and evolved. In this study, we report the first geochemical data of Miocene stromatolites from the Oberpullendorf Basin (Austria) that were formed during the Badenian salinity crisis at the north-western coast of the Paratethys Sea. The combined approach of trace element data obtained by quadrupol ICP-MS with C-O isotopes of individual stromatolite laminae is used to reconstruct short-term variations of palaeo-environmental conditions in microbial habitats of the Oberpullendorf Basin.

Stromatolitic carbonates in the lower stromatolite units show negative δ13Ccarb values and typical shale-normalized seawater-like rare earths and yttrium (REYSN) patterns with positive LaSN, GdSN anomalies, super-chondritic Y/Ho ratios, and heavy REYSN enrichments to light REYSN, indicating an open marine-dominated depositional setting. Stratigraphic upwards, stromatolitic carbonates show suppressed seawater-like REYSN signatures and increasing δ13Ccarb values that argue for the development of a restricted environment. Seawater-like REYSN patterns and homogenously distributed negative δ13Ccarb values in the stratigraphic uppermost part resemble the transition to fully marine environmental conditions again. Enrichment factors of bio-essential elements (Fe, Mn, Co, Zn, Mo, W) reflect sufficient element availability during marine conditions but limitation during the development of the (semi)closed lagoon.

We show that combined REY, C isotopes, and enrichment factors of bio-essential elements bear the unique potential to reconstruct temporal changes in paleo-environments and determine the availability of bio-essential elements in microbial habitats. This approach provides the groundwork for a better understanding of the evolution and development of microbial metabolisms under severely different atmospheric-hydrospheric on planet Earth and beyond.

How to cite: Viehmann, S., Kujawa, R., Hohl, S. V., Tepe, N., Rodler, A. S., Hofmann, T., and Draganits, E.: Trace metal availability in extreme microbial habitats of the Miocene Oberpullendorf Basin, Austria, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2653, https://doi.org/10.5194/egusphere-egu22-2653, 2022.