Reaktionen des terrestrischen Systems auf nordatlantische Klimaschwankungen im letzten glazialen Zyklus: Hochauflösende Löss-Paläoboden-Sequenzen aus Remagen-Schwalbenberg (Mittelrheintal, Deutschland) - TerraClime
Zusammenfassung der Projektergebnisse
Understanding landscape and ecosystem response to climate change is not only of great importance under challenges of recent anthropogenic warming but also for the past in order to identify potential feedbacks and forcings between land and atmosphere. The climate variability and forcing in the northern hemisphere during the Upper Pleistocene (from c. 126,000 to 11,700 years before present) is best documented in high resolution from marine and ice core records, but the response of terrestrial systems to climate over this period, however, still requires intensive research. One of the main reasons for our poor understanding of terrestrial system response is the relative paucity of long, continuous terrestrial sediment archives with which we can correlate the high-resolution deep sea and ice core records. With the TERRACLIME project, we aimed at filling a part of this gap investigating Upper Pleistocene Loess-Palaeosol-Sequences (LPS) from the Schwalbenberg in the Middle Rhine valley in western Central Europe. We present the first comprehensive reconstruction of the formation of LPS in four dimensions, based on the combination of surface-based geophysical prospection, in situ borehole hydraulic and geophysical profiling, sedimentological, geochemical, geoecological and geochronological data. Based on this approach we show that the LPS preserved in interfluve position provides the most detailed record for the Schwalbenberg sequence, and has experienced the least truncation by erosion, in average containing less than 5 ka/m. This resolution is exceptional for Upper Pleistocene terrestrial archives. Correlation of combined lithostratigraphic features and Total Organic Carbon contents from Schwalbenberg with the Sofular and NGRIP δ18O-records suggests a close match with both, the millennial timescales of climatic oscillations as well as the amplitudes of such events. As such, the synthetic Schwalbenberg record can be used to document the sensitivity of western European LPS to northern hemispheric climate oscillations. We found that the Schwalbenberg LPS resolves the Atlantic-driven Upper Pleistocene climate oscillations in more detail than any other terrestrial archive in the region so far. In the frame of the TERRACLIME project, we tested a multivariate strategy to decode geochemical signatures in LPS that applies a combination of Principal Component Analyses and Linear Discriminant Analyses on subdatasets of defined stratigraphic units separately. Based on this, we were able to increase the sensitivity of the analysis allowing for process-based interpretation of geochemical signals and a re-evaluation of existing approaches. Ongoing studies are related to provenance shifts based on isotope analyses, palaeomagnetic investigations, luminescence characteristics and chronology as well as plant leaf-wax derived n-alkanes, yielding further insights into the palaeoenvironmental development of the Schwalbenberg key site and associated landatmosphere feedbacks. Finally, the new TERRACLIME age model confirmed and refined the chronostratigraphic position of a Palaeolithic horizon discovered in the late 1970s, dated to the very beginning of the Mid-Upper Palaeolithic ‘Gravettian’ period in Central Europe. Use-wear analyses of the lithics has begun to address the question whether or not the Upper Palaeolithic tool types were dedicated to tasks different from those generally classified as Middle Palaeolithic. The results will be evaluated against the background of palaeoenvironmental proxy data produced within the TERRACLIME project and a new age model based on high-resolution dating of ECG, which is realized in the frame of an associated project on radiocarbon dating of the Schwalbenberg LPS. Already available results yield a robust chronostratigraphy between 40 and 21 ka confirming and refining the TERRACLIME age model. Overall, we show that the Schwalbenberg provides the long, high resolution terrestrial palaeoclimate archive that was still lacking for our understanding of the complex interplay between global climatic and environmental systems. The TERRACLIME outcome contributes to better understand mechanisms controlling the relationship of sediment build up, soil formation, vegetation dynamics, sediment relocation and associated preservation of climate signals, resulting in the unique resolution of studied LPS. The newly developed approaches, for instance related to subsurface characterisation based on Direct Sensing techniques in combination with geophysics or related to sophisticated statistical data analyses, can easily be transferred to other settings in the terrestrial realm to further enlarge our understanding of how ecosystems react(ed) on natural and human induced climate changes.
Projektbezogene Publikationen (Auswahl)
- 2020. Combining Inorganic and Organic Carbon Stable Isotope Signatures in the Schwalbenberg Loess-Palaeosol-Sequence Near Remagen (Middle Rhine Valley, Germany). Front. Earth Sci. 8
Vinnepand, M., Fischer, P., Fitzsimmons, K., Thornton, B., Fiedler, S., Vött, A.
(Siehe online unter https://doi.org/10.3389/feart.2020.00276) - 2021. Millennial-scale terrestrial ecosystem responses to Upper Pleistocene climatic changes: 4D-reconstruction of the Schwalbenberg Loess-Palaeosol-Sequence (Middle Rhine Valley, Germany). Catena 196, 104913
Fischer, P., Jöris, O., Fitzsimmons, K.E., Vinnepand, M., Prud’homme, C., Schulte, P., Hatté, C., Hambach, U., Lindauer, S., Zeeden, C., Peric, Z., Lehmkuhl, F., Wunderlich, T., Wilken, D., Schirmer, W., Vött, A.
(Siehe online unter https://doi.org/10.1016/j.catena.2020.104913) - Luminescence Sensitivity of Rhine Valley Loess: Indicators of Source Variability? Quaternary 2022, 5(1)
Fitzsimmons, K.; Perić, Z.; Nowatzki, M.; Lindauer, S.; Vinnepand, M.; Prud'homme, C.; Dave, A.K.; Voett, A.; Fischer, P.
(Siehe online unter https://doi.org/10.3390/quat5010001)
