Posters on site: Thu, 1 May, 16:15–18:00 | Hall X4
Soil magnetometry, encompassing measurement techniques based on the magnetic properties of soils, particularly magnetic susceptibility, represents a rapidly evolving field within pedological research. These measurements, performed on the soil surface and within vertical soil profiles, provide valuable supplementary information to traditional geochemical and geophysical analyses. Soil magnetometry is a practical, cost-effective approach for investigating soil properties. While numerous studies have examined the shape of magnetic susceptibility profiles, significantly less attention has been given to analyzing the spatial correlation of this parameter within vertical soil profiles.
A key tool for spatial correlation analysis is the semivariance function, which can provide deeper insights into the vertical variability of magnetic susceptibility in soil profiles. Parameters derived from the semivariance function along with additional correlation measures might enhance our understanding of soil variability and its structure. However, their systematic application in soil classification remains underexplored.
This study aims to fill this gap by systematically analyzing spatial correlation measures and their parameters in magnetic susceptibility profiles for selected soil types in Northern Poland. Particular emphasis is placed on assessing the utility of these measures in soil classification.
How to cite: Zawadzki, J. and Fabijańczyk, P.: Exploring Spatial Correlation of Magnetic Susceptibility in Vertical Soil Profiles of Northern Poland, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2771, https://doi.org/10.5194/egusphere-egu25-2771, 2025.
Ochric soils are characterized by thin, light-colored surface horizons with low organic matter and nutrient content, commonly found in arid and semi-arid regions. These soils exhibit limited water and nutrient retention and are prone to erosion, making them challenging for agricultural use without significant management. However, their clear stratification and minimal organic interference make ochric soils a valuable subject for studying soil processes and their development.
Magnetic susceptibility is an efficient, non-destructive tool that complements traditional soil analysis methods, enhancing our understanding of the processes shaping soil stratification and development, reflecting the concentration and type of magnetic minerals, such as magnetite or hematite. It serves as a reliable proxy for studying soil genesis, mineral composition, and pedogenic processes.
The vertical distribution of magnetic susceptibility in soil profiles provides valuable insights into processes like mineral weathering, sediment deposition, and soil horizon development. It also helps detect environmental changes, such as shifts in vegetation or climate, and anthropogenic impacts, including land use changes or pollution.
This study focuses on measuring magnetic susceptibility in ochric soil profiles to assess its variability at different depths. The findings contribute to advancing soil classification methodologies and improving environmental monitoring and land management.
How to cite: Fabijańczyk, P. and Zawadzki, J.: Assessing ochric soil profiles using magnetic susceptibility measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2726, https://doi.org/10.5194/egusphere-egu25-2726, 2025.
Black soils play a vital role in the global carbon cycle due to their high carbon stocks derived from their formation under specific environmental conditions. Black paleosols in landscapes, where under the present climate other soils dominate, provide valuable information about former environments and pedogenesis.
Here, we investigated black layers preserved in the floodplain of the Aue Creek, a tributary of the Leine River in Southern Lower Saxony, Central Germany. Its catchment is mainly made up of Triassic sandstone, and Triassic and Jurassic limestone, covered by Pleistocene periglacial slope deposits and loess, in which typically Luvisols have developed. In parts of the catchment, Luvic Phaeozems on the slopes testify former climatic conditions suitable for Phaeozem formation, which then shifted to conditions suitable for Luvisol formation. We took nine drill cores from the floodplain, in which black layers occurred, and analyzed them for pedomorphological features, radiocarbon ages of bulk soil organic matter (SOM), carbonate contents, dithionite-extractable Al, Fe, Mn, and Si, grain size distribution, total elemental and mineralogical composition. The majority of the calibrated radiocarbon ages of the bulk SOM of the black horizons fell into the Atlantic period (8545-5661 cal BP), while a few ages fell into the Subboreal-Subatlantic transitional (4519-3725 cal BP) and Subatlantic period, coinciding with the Iron Age (2314-2175 cal BP). These ages exceeded those of the underlying layers, which mostly dated to around 1600-1900 cal BP. One possible explanation for this phenomenon could be the hardwater effect which should, however also have affected the overlying and underlying layers. Another explanation is that the formation of the black horizons originally took place on the adjacent slopes, where it started already during the early Holocene. This hypothesis is supported by the relict Luvic Phaeozems that occur in the catchment. Thereby, the radiocarbon ages of the black material reflect the formation time of the biomass that was subsequently turned into SOM in a dynamic equilibrium of SOM accumulation and decomposition. The later a black soil was eroded, the later this dynamic SOM equilibrium stopped. On its way towards the floodplain, the eroded black soil material was most likely halted for some time as a colluvial deposit on the foot slopes. Only around 1600-1900 cal BP, when human influence led to enhanced erosion, some of the black sediments were remobilized, transported to the floodplain and redeposited there. Such cascade-wise erosion-deposition process may explain, how black material characterized by older SOM may have got embedded in between considerably younger sediments.
For a more comprehensive understanding of the formation of such black layers embedded in alluvial sediments, which have been reported from various regions of Germany, we recommend that future studies also include novel proxies such as vegetation biomarkers, in order to get a clearer picture of the vegetation, under which the black soils developed and test the above hypothesis.
How to cite: Siddig, M., Assida, O., Schwindt, D., Birk, J., and Sauer, D.: Black layers in the floodplain of the Aue catchment, Central Germany – paleosols or black sediments?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15687, https://doi.org/10.5194/egusphere-egu25-15687, 2025.
Parent material for soil formation (subsolum geological substrate, SSGS), represents an essential link between geology and soil science. This study evaluates the applicability of geological and SSGS maps for understanding soil formation processes in Austria. Geochemical characterization derived from traditional geological maps at scales 1:200.000 and 1:50000 are compared with a novel SSGS map based on a recent mapping campaign. The analysis focuses on the geochemical characteritics based on mineral components including carbonates, silicates and clay minerals, and its genesis and/ or deposition type, which have significant influence on pedogenesis.
The comparison reveals that geological maps often overlook surficial sedimentary deposits, such as quaternary loess deposits, which are crucial for understanding soil formation and plant growth. For example, surficial carbonate free rocks covered by carbonate substrates or vice versa result in entirely different soil characteristics, therefore soil development processes and related nutrient capacity. Furthermore, the geochemical evolution from geological bedrock to SSGS in areas of autochthonous weathering may reveal distinct shifts in mineral composition and geochemical properties, underscoring the transformative processes involved in soil genesis.
The study spans large parts of eastern Austria, including major tectonic units of the alpine region and its foreland basins, encompassing crystalline, sedimentary and Neogene rock formations.
These findings underscore the importance of SSGS maps for improving our understanding of soil formation, plant nutrient supply and ecosystem modeling.
How to cite: Brandstätter, J., Wagner, T., Vremec, M., Löberbauer, M., Klebinder, K., Keßler, D., Englisch, M., Wilhelmy, M., Szentivanyi, J., Gruber, J., and Winkler, G.: Comparison of geochemical characterization derived from geological versus subsolum geological substrate maps as basis for soil formation in Austria, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20174, https://doi.org/10.5194/egusphere-egu25-20174, 2025.
Volcanism plays a crucial role in maintaining the stability of Earth’s terrestrial ecosystems through soil rejuvenation. When tephra is incorporated into the soil system, the secondary minerals and micronutrients generated by weathering positively affect soil structure and fertility. Northeast China is home to a vast expanse of highly fertile Mollisols, with numerous volcanoes scattered throughout the region. However, it remains unclear whether volcanic activity and the associated denudation of volcanic materials contribute to the parent material source for Mollisols and thereby alter their physical and chemical properties. This study used mineralogical and geochemical methods to confirm, for the first time, the contribution of tephra to Mollisols and evaluate the effect of tephra addition on soil properties. The TESCAN Integrated Mineral Analyzer (TIMA) identified the presence of volcanic glass, characterized by angular and vesicular shapes, in typical profiles of the northern Songnen Plain. The elemental composition of volcanic glass indicates that it originated from the nearby Wudalianchi and Keluo Volcanic Cluster. The mercury (Hg) content, phosphorus (P) retention, and Alo+1/2Feo jointly indicate that the northern and eastern parts of the study area have been significantly affected by tephra materials, whereas the central and southern areas remain largely unaffected. Tephra proxies are significantly correlated with soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and cation exchange capacity (CEC), indicating the substantial effect of tephra input on key soil properties.
How to cite: Shi, Y., Qiu, Z., Long, H., Sauer, D., Yang, F., and Zhang, G.: Identification of tephra and its pedological significance in Mollisols of Northeast China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1729, https://doi.org/10.5194/egusphere-egu25-1729, 2025.
Agricultural terraces are labor-intensive to build and maintain but often serve as key productive areas due to their potential for irrigation and enhanced soil depth in challenging terrains worldwide. However, their cultural and historical significance as records of past events is often overlooked, despite historical terraces being potential hotspots of soil memory because of intensive human-environment interactions.
The terraced landscape of Monti Lucretili in Central Italy was selected to apply the soil memory framework to agricultural terraces. This area has long been used for pastoral and agricultural practices and is likely culturally connected to the Medieval castle of Montefalco. A multi-scalar approach is being applied, from landscape to molecular level, through a set of high-resolution techniques. Six limestone-wall bench terrace soils were described in the field (WRB, 2022), with undisturbed blocks collected for soil micromorphology and bulk samples for phytoliths, geochemistry, lipids, and sedaDNA analyses. For dating the features, bulk sediment samples were collected and subjected to optically stimulated luminescence (OSL) profiling in the field using a portable luminescence reader, and subsequent OSL dating in the laboratory.
Preliminary results suggest that five of the studied terrace walls in Monti Lucretili were constructed near karstic dissolution holes where vertic and proto-vertic soil properties are buried by the wall stones and younger terrace sediments. In contrast, the closest terrace to the castle of Montefalco lacks buried clayey horizons, with the karstic hole filled with chert artifacts. This possibly indicates early land management strategies that eroded the paleo-Vertisol. The terrace soils often include gravels and rocks from both slope processes and artifacts (mainly cherts and bricks). Vitric properties are also present, along with poorly-weathered pyroxenes, indicating volcanic deposits stratigraphically correlated to the first stages of the terrace construction.
Furthermore, finer stratifications and bioturbation (with crumb structures) in the superficial horizons are identified, which might indicate the period of terrace abandonment. The OSL profiling in the field showed net signal intensities displaying similar trends for each terrace soil, with normal signal-depth progression. This indicates the gradual burying of the materials behind the terrace walls and might be related to minimum historical plowing.
How to cite: Cerón González, A., Rossi, M., Egberts, E., Alonso Eguiluz, M., Farinetti, E., Vervust, S., Vandam, R., and Devos, Y.: Behind the stones - Soil memories of Medieval terraces in Monti Lucretili, Central Italy, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18244, https://doi.org/10.5194/egusphere-egu25-18244, 2025.
Posters virtual: Fri, 2 May, 14:00–15:45 | vPoster spot 3
EGU25-12841 | ECS | Posters virtual | VPS15
Analysis of relationships among variables in nationwide big data of geotechnical information in JapanFri, 02 May, 14:00–15:45 (CEST) | vP3.1
Recent advancements by national institutions in Japan have significantly enhanced the accessibility of geotechnical information, enabling researchers to utilize extensive datasets via online platforms. While these datasets have been widely employed in various studies, systematic analyses of relationships among variables within large-scale geotechnical data remain limited. This study aims to address this gap by analyzing relationships between variables using a comprehensive nationwide dataset of soil tests provided by the National Geo-Information Center (NGIC). The analysis of soil hydraulic conductivities revealed a strong dependence on the proportion of fine-grained components, such as clay and silt fractions. However, correlation analysis indicated that the strongest relationship, observed with the clay fraction, yielded a correlation coefficient of -0.51, suggesting a moderate association. Further investigation into variables such as dry density, natural water content, and void ratio demonstrated their dependence on the proportion of fine-grained fractions. Notably, the upper and lower bounds of these variables were influenced by fine particle content. A particularly significant finding was the observation that as the proportion of fine particles decreased, the void ratio also declined, leading to an increase in the permeability coefficient. These results provide valuable insights into the relationships between geotechnical properties and particle-size composition, offering a novel perspective on soil behavior. This study highlights the potential of utilizing extensive geotechnical datasets to advance our understanding of soil properties and their dependencies. The findings contribute not only to the theoretical understanding of geotechnical systems but also to practical applications in geotechnical engineering, providing a foundation for future research and data-driven approaches to soil analysis.
How to cite: Teruya, S., Ishida, K., and Sato, A.: Analysis of relationships among variables in nationwide big data of geotechnical information in Japan, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12841, https://doi.org/10.5194/egusphere-egu25-12841, 2025.
