Paleohygrometry and reconstruction of lake evaporation history based on compound-specific hydrogen and oxygen isotope analyses of biomarkers – principle of the coupled isotope approach, advances and limitations
- 1Heisenberg Chair of Physical Geography with focus on paleoenvironmental research, Technische Universität Dresden, Dresden, Germany (michael.zech@tu-dresden.de)
- 2Department of Soil Biogeochemistry, MLU Halle-Wittenberg, Germany
- 3Thermo Fisher Scientific, Bremen, Germany
- 4Chair of Physical Geography, Friedrich-Schiller University of Jena, Germany
- 5Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland
The oxygen and hydrogen isotopic composition δ2H and δ18O of leaf and lake water reflects the isotopic composition of source water/precipitation modified by evapo(transpi)rative enrichment. This later enrichment can be illustrated and quantified using δ2H- δ18O diagrams and the deuterium-excess. The enrichment of leaf water thereby depends primarily on relative air humidity (RH) and can be investigated using biomarkers being produced in leaves. The enrichment of lake water depends on lake evaporation and can be investigated using biomarkers being produced by aquatic macrophytes or algae. Provided that unambiguous terrestrial and aquatic biomarkers can be identified in lake sediments, the coupling of δ2H and δ18O hence allows reconstructing RH (paleohygrometry approach) and lake evaporation history. In our contribution, we discuss the potential, the advances and the limitation of the coupled isotope approach based on leaf wax-derived n-alkane and hemicellulose-derived sugar biomarkers (δ2Hn-alkanes- δ18Osugars).
References
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How to cite: Zech, M., Hepp, J., Tuthorn, M., Lemma, B., Bittner, L., Zech, R., Rozanski, K., and Glaser, B.: Paleohygrometry and reconstruction of lake evaporation history based on compound-specific hydrogen and oxygen isotope analyses of biomarkers – principle of the coupled isotope approach, advances and limitations, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-16430, https://doi.org/10.5194/egusphere-egu23-16430, 2023.
