Modern Soil–Palaeosol Proxy Relationships in European Loess: Implications for Quantitative Climate Transfer Functions

Quantitative climate and environmental reconstructions for continental surfaces require well-calibrated proxies inclusive of knowledge about how soil and sediment properties are actually linked to climatic and hydrological conditions via processes. While widespread terrestrial archives- like Loess–Palaeosol Sequences (LPS) covering more than 10 % of our planet preserve soils and sediments that formed under changing environmental conditions, the quantitative performance and transferability of commonly applied cost-efficient geophysical proxies remain incompletely constrained across climatic gradients. This strongly limits the valorization of these key-archives for terrestrial paleoclimates with implications for our knowledge about past and ongoing changes in our climate system and associated response processes.

Here, we evaluate the sensitivity and predictive accuracyof multiple soil property proxies—rock magnetic parameters, colorimetric indicators, and grain-size distributions—using modern topsoil samples from the Upper (Germany) and Middle (Serbia) Danube Basin. These regions provide well-defined gradients in temperature and moisture availability and serve as controlled framework for developing and testing transfer functions based on modern climate. Our results indicate that single-proxy models capture climate-related variability with moderate success, whereas multi-proxy regression substantially improves predictive performance, highlighting the nonlinearity and complementary nature of individual soil formation intensity indicators.

Building on this calibration effort, ongoing work extends the analysis along a transect covering the Danube catchment (Germany, Austria, Hungary, Serbia, and Romania). This dataset integrates modern soils with interglacial palaeosols, with a particular focus on units attributed to the last interglacial, (Marine Isotope Stage 5e). Rather than directly comparing fossil soils with modern meteorological parameters, we are trying to investigate whether climate- and moisture-sensitive relationships among soil properties persist through time and can be used to derive quantitative palaeoenvironmental information.

By combining modern calibration, multi-proxy transfer functions, and spatial integration, our study advances the quantitative use of geophysical soil proxies for reconstructing Quaternary palaeoenvironmental variability and clearly addresses both the potential and limitations of these approaches.