Terrestrial system response to North Atlantic climate oscillations during the last glacial cycle: high resolution loess-palaeosol sequences from Remagen-Schwalbenberg (Middle Rhine Valley, Germany) - TerraClime

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Our understanding of climate variability and forcing during the Quaternary is largely derived from marine and ice core records. The response of terrestrial systems to climate change through time, by contrast, remains poorly defined. Nevertheless, understanding landscape response to climate variability is of critical importance: not only because we as people live on and interact with the land, but also because land interacts differently with the atmosphere than do the oceans and ice sheets. Consequently we must investigate the nature of feedbacks and forcings between terrestrial and atmospheric systems.The TERRACLIME project will investigate terrestrial system response to northern hemisphere climate change during the last glacial cycle (LGC), based on novel loess-palaeosol sequences (LPS) from Remagen-Schwalbenberg (Middle Rhine Valley, Germany). Pilot core REM 3A, conducted during preparatory studies, yields the thickest and most complete sequence of landscape response to palaeoclimate in Central and Western Europe, spanning much of the LGC. The records of profiles and cores from earlier studies were not as long and complete as the new core, and they lacked high resolution palaeoclimate reconstruction using state of the art methods now available, as well as reliable high resolution chronological frameworks.Systematic geophysical prospection of the Schwalbenberg area will be the base to identify the thickest deposits for a further key core and several screening cores. The TERRACLIME research design will yield an understanding of loess response to climate based on the catena principle; variabilities between different (key and screening) cores will enable us to decouple local, regional and supra-regional processes acting on the deposits and to elucidate the nature of loess deposition and formation in three dimensions.TERRACLIME will combine established methods (sedimentology, mineralogy and environmental magnetism) with recently developed proxy approaches (inorganic and stable isotope geochemistry, and biomarker analyses). LPS core analyses will provide data on past climatic conditions, sedimentation and post-sedimentary alteration processes, and vegetation history. Geochemical data generated will furthermore be used to investigate possible shifts in sediment source areas through time.Pivotal to the project is high resolution luminescence dating to establish a reliable and independent age model for the Schwalbenberg sequences. The resulting age model, based on paired quartz OSL and polymineral pIR-IRSL dating, will facilitate direct comparison of the new Schwalbenberg LPS with regional and global palaeoclimate archives to elucidate terrestrial response to North Atlantic climate oscillations during the LGC. Synchronicity or lags between the age models from the different archives will further improve our understanding of the links between marine, ice core and terrestrial recorders of climate change in the northern hemisphere over the LGC.