Paleosol horizons preserved in loess-palaeosol sections (LPS) provide valuable archives of Quaternary palaeoenvironmental changes over time and spatial palaeoenvironmental gradients during the same period. Here, we present the characteristics of paleosol horizons in two LPS near the western edge of the Rhône Rift Valley in southeastern France: (1) the LPS “Baix” (total thickness: 14 m), located about 17 km north of Montélimar (44°42’36”N, 4°43’21”E), thus, in the transition zone between the presently temperate and the Mediterranean region of Europe; (2) the LPS “Collias” (total thickness: 9 m), located in the Uzès Basin, about 15 km northeast of Nîmes (43°57’11.94”N, 4°27’56.71”E), thus, in presently fully Mediterranean climate. Investigation of the paleosol horizons in the main profile at Collias was complemented by those of three smaller nearby LPS, “Collias-North_D112” (43°57’12.55”N, 4°27’55.83”E), “Collias-South_D112” (43°57’12.44”N, 4°27’53.36”E), and “Collias-North” (43°57’21.67”N, 4°28’6.99”E), in order to capture the spatial variability of the characteristics of some key horizons.

To our knowledge, no LPS have been analysed yet in such a transitional position between the presently temperate and Mediterranean climate. Primarily the LPS Baix may provide a crucial link between the rigorously analysed LPS in the presently temperate regions further north (e.g., in northern France, the Alsace region and Germany) and the LPS in the Mediterranean region (e.g., in southern France, Catalonia, Italy and Croatia), including the LPS Collias. Therefore, we aimed to decipher the paleoenvironmental record of the LPS Baix and Collias, and to identify similarities and differences between them. Optically stimulated luminescence (OSL) dating provided a chronological frame for both LPS.

The basal part of the LPS Baix starts with reddish Bt(g) horizons of a Stagnic Luvisol, representing the remains of an Eemian to Early Würmian (MIS 5) pedocomplex formed under warm and - at least temporarily - relatively moist conditions. The corresponding pedocomplex in the profile Collias-North_D112 displays an intensive red (chromic) Bt horizon overlain by several Bw horizons formed in reworked soil sediment and underlain by a massive calcrete. In the main profile at Collias, this red horizon has been entirely reworked by slope processes and has regained an angular blocky structure afterwards. Thus, it appears as a dark orange-red Bw horizon. Both, the LPS Baix and Collias include a prominent brown Bw horizon of a truncated Cambisol that developed in middle Pleniglacial (MIS 3) deposits. It is associated with large, elongated, vertically oriented calcium carbonate nodules, indicating that considerable amounts of calcium carbonate must have been leached from the former middle Pleniglacial Cambisol and accumulated in the underlying loess unit. No distinct palaeosols were observed in the Late-Pleniglacial deposits of the LPS Baix and Collias; a slightly brownish colour indicates very weak weathering (several BCk horizons) in the Late-Pleniglacial sediments of both LPS.

How to cite: Sauer, D., Pfaffner, N., Kadereit, A., Kreutzer, S., Karius, V., Kolb, T., Bertran, P., and Bosq, M.: Palaeosols in the loess section of Baix (Rhône Rift Valley, SE-France), compared to those of Collias: a unique Late-Pleistocene record of the transition zone between the presently temperate and the Mediterranean region of Europe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15899, https://doi.org/10.5194/egusphere-egu23-15899, 2023.

In the present study we report paleopedology of the fluvial sequences of the Siwalik Group in the Himalayan Foreland Basin, NW Himalaya that formed during ~12 Ma -5.5 Ma. The paleosols formed during this time period are critical to understand weathering and paleopedogenic processes during the evolution of foreland basin over the entire Himalayan range. This work highlights field-characteristics, micromorphology, clay mineralogy, and geochemistry of the ~0.5 km thick Lower Siwalik and ~1.7 km thick Middle Siwalik successions along the Katilu Khad, Kangra sub-basin. In the field, the paleosols are characterized by 1-2 m thick Bw, Bt, Bk, Bss, and BC horizons, blocky and wedge-shaped pedogenic structures, root traces, color mottling, Fe-Mn oxide concretions, slickensides, pedogenic CaCO₃ (PC), and bioturbation features. 

Micromorphological observations show the dominance of moderate to well-developed paleopedofeatures in paleosols of the Lower Siwalik in contrast to the moderately to weakly-developed paleopedofeatures in paleosols of the Middle Siwalik. The comparative analysis of various pedogenic features i.e., PC, illuvial clay, mottles, Fe-Mn concretions, microstructures, and bioturbation features confirmed varying degree of the paleopedogenic maturity in the paleosols at different intervals of the Siwalik successions.

Clay mineralogy of the total clay (<2 μm) and fine clay fraction (< 0.2 μm) of the Lower and Middle Siwalik paleosols suggests varying chemical weathering of silicates and change of paleoclimatic conditions during paleopedogenic processes during this time period. The clay mineral assemblage of the total clay and fine clay fraction show the varying distribution of illite, chlorite, kaolinite, smectite, vermiculite and interstratified clay minerals in these paleosols. Large amounts of smectite together with pedogenic carbonates in part of the Lower Siwalik at 12.0 Ma, and at 10.9 Ma and in Middle Siwalik at 9.2 Ma, and at 5.5 Ma suggest arid to semiarid dry climatic conditions Whereas, dominance of kaolin, illuvial features, and dissolution of pedogenic carbonates suggests sub-humid to humid climatic condition at 11.6 Ma, 8.5 Ma, 7.1 Ma, and at 6.5 Ma.

The bulk geochemistry of the paleosols also confirmed varying degree of pedogenic weathering showing high CIA and CIA-K (CIW) values and ~ 800 mm to 1400 mm MAP for paleosols of the Lower and Middle Siwalik. The high MAP (~ 1200 mm to 1400 mm) at ~11.6 Ma, ~8.5 to 8.0 Ma, and 7.1 to 6.5 Ma in paleosols of the Lower Siwalik and Middle Siwalik correspond to increased chemical weathering and paleopedogenesis. While the intervening periods correspond to less MAP (~800 mm to 1100 mm) with large amount PC and less chemical weathering. Based on micromorphology, clay mineralogy, and geochemical characteristics of the paleosols it is interpreted that climate change during ~12 Ma to 5.5 Ma is characterized by humid (11.6 Ma) to semiarid (11.0 Ma to 8.5 Ma), and humid-subhumid (8.5 Ma to 6.5 Ma) in response to Himalayan orogeny and its linkage to regional and global atmospheric conditions.

Keywords: Himalayan Foreland Basin, Paleosols, Siwalik, Micromorphology, Clay mineralogy, Geochemistry

How to cite: Hameed, A., Yadav, P., Kumar, R., and Srivastava, P.: Paleopedological evolution of Siwalik succession from Kangra sub-Basin, NW Himalayan: Implications for climate change and weathering conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-838, https://doi.org/10.5194/egusphere-egu23-838, 2023.

Based on surveys and three excavation seasons, we report details on one of the first major utilizations of loose aeolian sand for construction and (hypothesized) vegetable agriculture at the Early Islamic Plot-and-Berm (P&B) agroecosystem south of Caesarea Maritima, along the Mediterranean coast of Israel. P&B agroecosystems are an innovative initiative to reconstruct sand bodies and dunefields into agricultural plots sunken between sand berms. These agroecosystems are sporadically found between Iran and Iberia and some are still in use. The plots, usually ~1 m above the groundwater table allowed easy access to the water via shallow wells for irrigation.

Research methods included pedological and sedimentological analyses, micromorphology and compositional analyses such as Fourier Transform Infrared Spectroscopy to detect heating of cultural additives (e.g., fired clays, pyrogenic lime); plant ashes (e.g., deliberate enrichment of fuel and/or recycling of former crop cycles as part of plot maintenance); and pollen and phytolith analysis to detect micro-botanical proxies of crops. Relative chronologies were obtained from portable luminescence profiling (pOSL). OSL ages along with artifacts analysis indicate that the agroecosystem was established during the late 9^th or 10^th century and functioning until the early decades of the 12^th.

Refuse, including ash, carbonate, trace elements and artifacts, extracted from the dumps of Caesarea was combined with local sand to stabilize the berm surface but also partly altered the physical and chemical properties of the sand and increased its fertility, mainly in the plots, to form grey sandy to sandy loam anthrosols. This refuse was combined in different mixtures along the ~5 m thick berm fill and upon its slope and crest surface to stabilize the earthwork and comprise an anti-erosive agent. Similar mixtures were used to support berms and foundations of structures that served for lime production, agroecosystem management and local farming utilities. A 5 m high mound constructed out of interchanging anthrosediments was also piled up within a plot to support a presumable guarding structure. 

Plot anthrosols appear to include a basal, dark grey 20-40 m thick unit, ~ 1 m above the groundwater table that was enrichened with carbonate overlaid by a ~1 m thick grey sand anthrosol. The lower unit probably served for preserving infiltrating irrigation water that was applied to the crops grown atop the light grey anthrosol.

The agroecosystem remained well-preserved and untouched until the mid-20th century. Its pristine preservation is evidence of the ingenious and widespread utilization of refuse for construction and agriculture in sand. The untouched shape of this agrotechnological earthwork in the last millennia is intriguing and may be due to either lack of knowledge, or resources per revenue for similar endeavors.

How to cite: Robins, L., Roskin, J., Grono, E., Bookman, R., and Taxel, I.: Construction and Agriculture in Sand at the Early Islamic Plot-and-Berm Groundwater Harvesting Agroecosystem South of Ancient Caesarea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10982, https://doi.org/10.5194/egusphere-egu23-10982, 2023.

A multi-element and multivariate geochemical analysis has been carried out at a medieval farm site and village settlement, which belonged to the Cistercian monastery of Plasy (in W Bohemia). The results of our geochemical survey have been evaluated in context of the LiDAR survey covering the same area and the available historic maps (Habsburg Military surveys), which helped to locate relict landscape features and land-use changes. Approximately 300 samples were taken in a grid point pattern within the courtyard of the farm, as well as randomly, in the surrounding areas, in order to identify geochemical signals related to the observable surface phenomena. We have applied different analytical techniques, including PCA, log-transformation and isometrical log-transformation, and through spatial interpolation (IDW) it was possible to link  signals of both anthropogenic and geogenic character to archaeological, cultural and land-use phenomena. The results illuminated more intensive anthropogenic impact in connection to the courtyard area, and the intravillain area of the village, and additionally helped to locate different land-use activities in the  surrounding area (agricultural and possibly industrial). In that regard, this methodology was successfully applied to trace anthropogenic impact beyond narrowly defined archaeological sites. This abstract has been reformulated on the basis of our recently published paper (Horák et al 2023).

Horák, J., Janovský, M.P., Klír, T., Malina, O., Ferenczi, L., 2023. Multivariate analysis reveals spatial variability of soil geochemical signals in the area of a medieval manorial farm. Catena 220. https://doi.org/10.1016/j.catena.2022.106726

This abstract is part of the research project: “Monastic manors and the landscape impact of Cistercian estate management: A landscape archaeological and historical ecological study on Plasy Abbey“ financed by the GAČR - Czech Science Foundation, grant No. 21-25061S.

How to cite: Janovský, M., Horák, J., Klír, T., and Ferenczi, L.: Geochemical analysis in the area of a medieval Cistercian manorial farm, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14576, https://doi.org/10.5194/egusphere-egu23-14576, 2023.

Soil marks are detectable by airborne images due to the difference in soil colour between the archaeological feature and the surrounding background soil. Colour of the soil only represents the visible part of the soil spectrum which contains physical and chemical information of the soil. This study will present a spectral analysis method to prospect soil mark features and buried archaeological remains using airborne image data. This method statistically calculates the difference between the targeted spectrum and the background (non-archaeological) soil spectrum. The difference is quantified by an R-value. If the R value is larger than 1, then the spectral behaviour of the targeted spectrum is different from the spectrum of the background soil and, thus, likely to be an archaeological soil spectrum (soil mark). In this study, the spectral analysis method will be applied to APEX imaging spectroscopy data collected from an archaeological site in Sárvíz Valley, Hungary. Previously, the method was successfully applied to the same archaeological site using soil spectra gathered by a portable hand-held VIS-NIR spectrometer. Here, the results showed clear spectral difference between soil mark features and background soil. This study will 1) compare the results of the method from hyperspectral image and ground-based spectral data, and 2) investigate the most effective waveband for identifying archaeological spectral signatures to verify the effectiveness of the method.

How to cite: Choi, Y. J.: Detection of archaeological soil marks using airborne hyperspectral images, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11168, https://doi.org/10.5194/egusphere-egu23-11168, 2023.

As sea levels rose since the end of Last Glacial Maximum (LGM) ancient coastal communities were often forced to abandon their settlements and move inland. Today, many of these abandoned sites are covered by sand or lay in shallow water. Examining these can shed light on past coastal communities as well as settlement patterns in ancient times. Archaeological excavation along the coast is particularly tricky and often sporadic in nature. Thus, high‐resolution shallow geophysical methods, which have become a standard in archaeological studies since they provide a noninvasive way of imaging the subsurface before an excavation, would seem like a perfect solution. However, most methods are limited in their ability to work near the shoreline – the transitional zone between classical land-based methods and standard marine ones. Ground penetrating radar (GPR), for example, is greatly affected by moisture and salinity and is therefore limited in its ability to work in areas saturated with seawater. Seismic reflection is time consuming to overcome issues of poor vertical and spatial resolution and sensitive to urban noise, while magnetics would provide poor results for sand covered sandstone. Other techniques, such as electrical resistivity tomography (ERT) have been shown to work in coastal areas and in shallow water. However, this method can be slow, as it involves setting up complex arrays for each cross section measured. This study will present the frequency domain electromagnetic (FDEM) method, which has the potential to overcome these problems and can bridge the gap in knowledge by measuring in the nearshore environment. The ease of use and quick scanning capability means that large areas can be covered in a relatively short time. There are no electrodes or loops to set up. Since it measures swaths, results are obtained in map-view and not cross-section, with little interpolation. Different frequencies penetrate to different depths (lower frequencies corresponding to deeper penetration). Therefore, the result is a series of frequency maps corresponding to the integration of all subsurface data in a specific sampled volume (i.e. down to the frequency-related depths), providing important information on shallow subsurface properties. The use of multiple frequencies allows for the resolving of internal structures within the depth range. Overall, the FDEM method has proven to be a valuable tool for studying coastal archaeology, and it is likely to continue to play an important role in the field in the coming years. Its ability to detect buried objects and structures and to study the geomorphology of submerged landscapes makes it an essential tool for researchers working in this field.

How to cite: Lazar, M. and Basson, U.: Frequency domain electromagnetic methods for coastal archaeology – a new(ish) approach for the detection of ancient settlements, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5919, https://doi.org/10.5194/egusphere-egu23-5919, 2023.

Kurgans are funeral chambers, evidence of burial tradition dating back to the first thousand years BCE, of nomadic populations that covered a vast area in-between Europe and Asia. In Azerbaijan, past archaeological explorations revealed numerous large kurgans from the Early Bronze, which correspond to Kura-Arexed period (ca. 3500-3000 BCE), and relatively smaller burials of Late Bronze/Early Iron Ages. To improve the efficiency of the excavation process, geophysical methods have been widely and effectively applied for many years to provide clear and useful images of archeological targets hidden underground such as kurgans.

In this work, we introduce a multi-method archaeo-geophysical survey done in May 2022 to investigate Early Bronze Age kurgans located in Uzun Rama Steppe of Goranboy region in Azerbaijan. Applied method cover different depth of investigation and resolution to provide a wealth of information on the structure of three kurgans aligned in a North-South direction. It comprises coincidental DC-resistivity and seismic refraction tomographies of 70.5 m with a 1.5 m spacing going over all kurgans, a Ground Penetrating Radar (GPR) 40 m long profile using a 500 MHz antenna on the northern kurgans going from East to West and a magnetic map 24 x 25 m on the southern one.

The DC-resistivity profile shows two layers, a medium resistivity layer (500 to 600 W.m) from the surface to 6 m depth and a very conductive layer (> 10 W.m) under it. The first layer contains three areas of lower resistivity (~ 60 W.m) that are limited in thickness and length. As these three spots are marked by higher height on-site, we interpret them as the three kurgans. The coincidental seismic profile is a lot less detailed (due to physical properties and higher spacing between receiver) and define only three homogeneous layers, a first layer from the surface to 1 m depth with a P-wave velocity of 300 m/s, a second layer of higher velocity (1000 m/s) from 1 m depth to approximately 6 m depth and a final third layer of 2000 m/s velocity. Even though, the resolution is lower, we interpret the first layer as an attempt of the model to represent the kurgans. The GPR profile give a high attenuate image due to low resistive layer. However multiple diffractions can be seen in the first meter of the subsurface that can indicate the presence of ancient artefact related to the kurgans. Finally, the magnetic map defines the limit of the kurgan as a positive-negative anomaly probably due to the burning ritual that ended the implementation of a kurgan.

This geophysical campaign allowed us to accurately locate the kurgans as well as provide information on the environment. DC-resistivity and magnetic mapping seem to get the best results in our case. A future archaeological investigation will be put in place based on these results.

How to cite: Bayramov, K., Jodry, C., Alizada, G., Mammadov, S., Azimov, V., and Abdullayev, M.: Geophysical investigation of kurgans in Uzun Rama steppe, Goranboy region, Azerbaijan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10838, https://doi.org/10.5194/egusphere-egu23-10838, 2023.

The characterization of the shallow subsoil at complex archaeological sites requires sufficient spatial coverage and resolution as to provide the necessary information. This is all but trivial, particularly where historical superposition of layers requires also sufficient depth investigation and resolution. The Scrovegni Chapel in Padua, with its Giotto's fourteen century frescoes, and recently added to the list of UNESCO World Heritage Sites, stands on the remains of the local Roman amphitheater. The hypogeum located under the chapel shares its western wall with a part of the wall of the amphitheater. To date, no information is available about the soil below the apse of the chapel. Over the past decade, several ERT and GPR measurements have been conducted outside the chapel, straddling the amphitheater structure for archaeological and geomorphological characterization of the area. In 2021, a first 3D active and passive seismic survey was conducted using about 1500 wireless sensors, aiming at using surface waves to provide a 3D image of the subsurface in terms of shear wave velocity. In 2022 three 20 m deep boreholes were drilled around the chapel and equipped with fiber optics, ground deformation sensors, and electrodes for cross-hole ERT, and about 200 1-C and 3-C wireless seismic sensors were placed around the drilling area. During the drilling, additional 3D seismic data were acquired from the surface, which completed the datasets acquired in 2021. The geophysical data thus acquired and the time-lapse monitoring that will be possible around the area of the Scrovegni Chapel in Padua will allow reconstructing the geomorphology of the subsurface on which the chapel rests, but also to better study and analyze the possible interactions between the structure of the chapel and the buried structure of the Roman amphitheater from the mechanical point of view as well as from the perspective of the seismic response of this specific site.

How to cite: Cassiani, G., Barone, I., Pavoni, M., Boaga, J., and Deiana, R.: Geophysical characterization of the shallow subsoil at a heavily urbanized archaeological site: the Roman Amphitheater and the Scrovegni Chapel in Padua., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8737, https://doi.org/10.5194/egusphere-egu23-8737, 2023.