Earthen constructions of the Yamnaya culture kurgans in the Orenburg region: a case study of applying soil science approaches to archaeological challenges

The determination of drying period, compressive strength, and air-dry density represent crucial parameters for assessing the quality and performance of earthen construction materials. This paper explores the possibilities of using the ultrasonic method as a non-destructive testing technique applied to earthen materials (specimens, elements, or structures) to determine these properties. The method relies on the measurement of ultrasonic pulse velocity (UPV), which is influenced by factors such as density, elasticity, and curing process. By analyzing the propagation of ultrasonic waves through earthen samples, valuable insights can be gained regarding their drying period, compressive strength, and density. The drying period of earthen samples can be determined using the ultrasonic method by monitoring the changes in pulse velocity over time. As the moisture content decreases during the drying process, the velocity of ultrasonic waves increases due to the reduced presence of water. This allows for the estimation of the drying period without the need for time-consuming and destructive testing methods. Compressive strength is also a critical parameter in assessing the structural integrity of earthen materials. The UPV method offers a non-destructive approach to determine the compressive strength of earthen samples. This provides a valuable tool for quality control and assessment of earthen construction materials. Density is another important property that influences their performance and the UPV method can be used to determine the density of earthen materials by measuring the ultrasonic pulse velocity and analyzing its relationship with density. This non-destructive approach allows for quick and efficient estimation of the compactness and quality of earthen mixes. Overall, the ultrasonic method offers a non-destructive and efficient approach in determining the drying period, compressive strength, and density of various soil compositions. By measuring the pulse velocity and analyzing its relationship with these properties, valuable insights can be gained regarding the quality and performance of earthen construction materials. This method has the potential to significantly improve the assessment and quality control processes in earthen construction, leading to more sustainable and reliable structures associated with the earthen techniques.

The assessment of compressive strength, and air-dry density constitutes essential parameters for evaluating the quality and performance of earthen construction materials. To ascertain these properties, this study investigates the potential application of ultrasonic testing as a non-destructive evaluation technique for earthen materials, including specimens, elements, or structures. The methodology is predicated on the measurement of ultrasonic pulse velocity (UPV), which is affected by various factors such as density, elasticity, and the curing process. By examining the propagation of ultrasonic waves through earthen samples, significant insights can be obtained regarding their drying duration, compressive strength, and density. Compressive strength is a pivotal factor in evaluating the structural integrity of earthen materials. The UPV method provides a non-destructive means to ascertain the compressive strength of earthen samples, thereby serving as a valuable instrument for quality control and assessment of earthen construction materials. Density, another critical property influencing the performance of earthen materials, can also be evaluated using the UPV method. By measuring ultrasonic pulse velocity and analyzing its correlation with density, this non-destructive approach enables rapid and efficient estimation of the compactness and quality of earthen mixtures. The ultrasonic method presents a non-destructive and efficient strategy for determining the compressive strength, and density of various soil compositions. By quantifying pulse velocity and examining its relationship with these properties, substantial insights can be garnered regarding the quality and performance of earthen construction materials. This technique holds the potential to enhance assessment and quality control processes in earthen construction, ultimately contributing to the development of more sustainable and reliable structures utilizing earthen techniques.

In the ceramic collection of Turganic settlement in the Orenburg region there is a group of bronze age pottery, which by its morphological and technological indicators stands out sharply from the main group of dishes. They are large size vessels with massive aureoles and distended body. The authors called these vessels «hums». The aim of this study is to identify cultural-chronological position of the specified group of dishes in the system of the antiquities of the early - middle bronze age. Within this group the authors distinguish two types. The basis for type selection was the particular design of the upper part of the vessel. The first type is ceramics from Turganic settlement and the vessel from the burial mound Perevolotsky I. Morphological and technological features, and a series of radiocarbon dates has allowed to date these vessels to the time of the yamnaya culture formation in the Volga-Ural region (Repinsky stage). The authors suggest that the appearance of such vessels should be an imitation of the Maikop pottery. It could be penetration of small groups of craftsmen or the intensification of contacts with the population of the North Caucasus. The second type of pottery from Turganic settlement is similar to the burial mound Kardailovsky I (mound 1, burial 3) in Orenburg region, in the Northern pre-Caspian, region of the Samara river, Kuban and the Dnieper. Researchers have noted the scarcity and originality of this dish. The chronological and cultural position of such vessels is determined within the III Millennium BC (calibrated values).

The aim of the study. To study the Bronze Age paleosols (Yamnaya and Srubnaya cultures), perform paleoclimatic reconstructions and comparison with previously studied synchronous paleosols in the Cis-Urals steppe. Location and time of the study. The studied site is located in the Orenburg region in the steppe area of the Southern Cis-Urals. In July 2019 and 2021 together with researchers from the archaeological laboratory of the Orenburg Pedagogical University, rescue excavations were carried out at the Tashla IV kurgan cemetery, located near the Tashla village. Kurgans 1 (Yamnaya culture) and 2 (Srubnaya culture) were studied. Methods. A comprehensive morphogenetic analysis of the soils buried beneath the kurgans and surface soils of the studied site was carried out; the soils were described in detail and classified in the field. Soil samples were analyzed for particle size distribution, loss of ignition, pH of the water extraction, content of organic and carbonate carbon, exchangeable bases and magnetic susceptibility. To carry out the paleoclimatic reconstructions, the chronosequence and comparative geographic methods were used. Results. It was established that the studied soils were buried under the kurgans at the beginning of the development of both cultures, when the stages of climatic aridization were close to their ending or ended in the first half of the 4th millennium BC (Yamnaya culture) and at the turn of the 3rd and 2nd millennia BC (Srubnaya culture). The climatic aridization during the Early stage of the Srubnaya culture was more significant than in the Early (Repinsky) stage of the Yamnaya culture, and this conclusion was made for the first time for the studied region. Conclusions. The studied soils properties could be grouped according to the characteristic times of their response to changes in external conditions: magnetic susceptibility, associated with microbiological activity, refers to rapidly changing properties, i.e. in the first decades, whereas changes in other studied properties require from several decades to hundreds of years. Comparison of the Srubnaya paleosol buried under kurgan 2 in the studied site with other soils of the same culture in the region made it possible to place it more accurately on the time scale, attributing to the very beginning of the 18th century BC, and additionally to characterize in detail the climate change within the time span of the Srubnaya culture of the Cis-Urals steppe.

The aim of this paper is to publish new radiocarbon dating data for three complexes stratified under one mound (mound No. 1 in the Boldyrevo IV burial ground in the Western Orenburg region), which are distinguished by the unusual nature of the burial in comparison with the known, reference necropolises of the Yamnaya culture. Kurgan 1, one of the largest in the Volga region and the Southern Urals, was investigated in 2019–2020. The early horizon was represented by two small mounds above the burials of children, surrounded by ditches consisting of separate pits. Later, between the mounds for children, a collective burial of five adults took place in a huge burial chamber with a complex design, over which a large mound was built, which also covered both children’s mounds. All the main burials under the early mounds and burial 5 under the large mound represent a single cultural and epochal complex and belong to the Yamnaya culture. According to archaeological and paleo-soil data, the construction of mound 1 occurred systematically over a time interval that is approximately 200 years. Radiocarbon dating showed that the construction of the mound occurred within the calibrated interval of 3200–2600 BC years. The site, apparently, before and during the creation of the mound, was the site of sacred ceremonies and public meetings of many clans of the Yamnaya culture. The induction burial of two women took place at the top of the mound at the end of the Bronze Age.

<p>In 2019, kurgan 1 in the Boldyrevo IV kurgan cemetery in the Orenburg region, Russia was studied. The kurgan was built by the population of the Yamnaya culture of the Early Bronze Age (about 5500 years ago). Within the kurgan, four earthen structures built-in succession have been revealed. Under each of the kurgan structures, the buried soil has been studied. According to archaeological data, the kurgan was built over several decades; radiocarbon dating showed an interval of 300 years.</p><p>During the construction of the kurgan, the morphology and physicochemical properties of the soils and materials of the kurgan structures changed, namely, the content of organic matter decreased, while the content of carbonates, gypsum, exchangeable sodium in the composition of exchangeable bases and the value of magnetic susceptibility increased. It can be suggested that the studied interval of the kurgan building, like the entire early (Repino) stage of the Yamnaya culture, was characterized as more arid in comparison with the present.</p><p>Based on the micromorphological analysis and physicochemical properties of the materials of the kurgan structures and buried soils, it can be assumed that the monument was built from local soils using anthropogenic material. The construction technology consisted of rough kneading and tamping of raw sandy loam material with the addition of river silt, rare coal dust, and bones. For facing the ritual site around the main burial river silt was exclusively used.</p><p>Previously, in the study of short-term pedo-chrono-sequences under the structures of big kurgans of the Early Bronze Age of different ages in the Stavropol and Krasnodar Territories, it has been also compared the properties of paleosols and earthen structures. It allowed confirming the use of local soils in the construction of the monuments and carrying out paleoclimatic reconstruction. In addition, for all three studied big kurgans, a comparison was made of technical and technological approaches used by ancient builders for the construction of monumental facilities of earthen architecture.</p>

Chemico-microstructural changes in earthen building materials containing calcium carbide residue and rice husk ash

A geoarchaeological study of the large Essentuksky 1 kurgan in the Stavropol region of Russia analyzed the chemical composition and micromorphological features of the kurgan's earthen materials and established their relationships with buried soils in the context of previously conducted paleoclimatic reconstructions. The kurgan was 5.5–6.0 m high and more than 60 m in diameter, and consisted of four earthen and three stone constructions. It was built in the second quarter of the 4th millennium BC (the Early Maykop culture) using a precise plan and utilizing the building skills and technologies available at that time. The earthen constructions consisted of alternating layers of dark‐colored slightly compacted humified and pale‐colored dense carbonate‐rich materials, which, in the moist state, were rammed down by ancient builders. These materials were sourced mainly from local soils and contained admixtures of river silt and, at the final stage of building, dung. The physicochemical properties of the earthen constructions as well as the paleosols buried under them are indicative of a short‐term aridization of the climate within the period of building. A gleyed earth with strong iron staining at the kurgan's base and mortar that held the stone constructions was produced by thoroughly mixing and compacting in a wet state, indicating that they were special construction materials. This kurgan is an example of the ancient earth architecture in the steppe zone of Russia over 5500 years ago.

Gölcük in Kocaeli city is located in the northwestern region of Turkey on the Anatolian fault line. It has been subjected to various civilizations according to archeological evidence and historical sources. Among 23 villages located in Gölcük district, Saraylı, Örcün, and Selimiye that have a long history dated back to around 1326 when the region was conquered by Ottomans are known for their well-preserved rural architectural heritage. The rural houses show architectural design properties that increase the structural resistance for earthquakes due to their various characteristics such as construction materials’ properties. The study involves the determination of raw material characteristics of earthen construction materials of vernacular houses of Saraylı, Örcün, and Selimiye villages.Archaeometric investigation carried out on samples from earthen bricks, mud plasters, and mortars of representative houses in the mentioned villages. The earthen materials were investigated from the mineralogical and chemical point of view including particle size distribution, aggregate/binder ratio, total soluble salt content, X-ray diffraction (XRD) analysis, Fourier transform infrared analyses (FTIR), and X-ray fluorescence (XRF) analyses.The results of the study allowed an understanding of the building technologies and the properties of raw materials employed in the houses in different locations. The determination of the original construction materials would help to develop appropriate restoration strategies and restoration materials compatible with the principles of sustainable architecture.KeywordsVernacular architectureRaw material characteristicsHımış-type housesEarthen materialsSustainable architecture

Vernacular construction techniques like earthen practices have a greater role in post-disaster self-recovery and rehabilitation efforts that utilize indigenous knowledge, skills, and locally available resources. The present review aims to examine the positive and negative effects of various hazards on earthen structures in brief, and further investigate the opportunities and best practices of earthen construction techniques for disaster resilience. Through case studies, this study demonstrates that in some countries, various modifications and adaptations have led to a disaster-resistant earthen construction design. In contrast, in many other regions where such measures were not incorporated, the vulnerabilities of the earthen-built environments in rural settings increased. Further, this study investigates the relationship between earthen-building techniques and the aspiration to achieve relevant targets of various United Nations Sustainable Development Goals (UN-SDGs) by utilizing a scoring matrix. As a study outcome, this paper presents a conceptual framework for disaster-resilient recovery planning with the vernacular housing approach highlighting “engineered for disaster resilience” as the key component for adopting vernacular techniques. This study also found that earthen materials and methods have a visible positive contribution for achieving the relevant targets of SDGs 01, 07, 09, 11, 12, and 13. Such studies on the interconnectedness between adopting indigenous knowledge and locally sourced building (earthen) materials, and SDGs can help inform and inspire policymakers, practitioners, and developers to formulate strategies for disaster reconstruction and resilience that are community-centric.

Introduction The Pit-Grave culture spread on huge territory of Eastern Europe steppe from Kazakhstan and south Ural to the Dniestr region. The eastern Pit-Grave artefacts were found in the Volga-Ural interfluve and in the south Ural region on the territory of the Astrakhan, Volgograd, Saratov, Samara, and Orenburg oblasts, Russia. The environmental conditions of the steppe existed on the most part of the territory and forest steppe--in the north (Fig. 1). Today, natural conditions are determined by the continental climate, which corresponds to hot summers with low precipitation and severe winters with a lot of snow. The flora of watersheds is typical for the Volga sheep fescue-feather grass steppe (the type of steppe where sheep fescue and feather grass flourish). Various kinds of meadow grass, bushes, and streamside forests grow in river valleys and gulches. The paleoclimatic conditions of the Pit-Grave culture are different to the modem climate. Eneolithic and Pit-Grave culture existed in the favourable natural conditions practically all the time. The precipitation was 50 mm higher compared to the humidity today. The environmental conditions and temperature drops were milder than we had in past decades (Spiridonova & Aleshinskaya 1999; Khokhlova et al. 2006; 2010; Khokhlova 2012). Many scientists think that the climate change and the emergence of aridity period coincided with the start of the Late (Poltavka) stage of the Pit-Grave culture and the Catacomb culture spread to the west of Volga (Demkin et al. 2006; Shishlina 2007; Khokhlova et al. 2010; Khokhlova 2012). [FIGURE 1 OMITTED] V. V. Golmsten, P. S. Rykov, I. V. Sinitsyn, K. F. Smirnov, N. Ya. Merpert, V. P. Shilov, N. K. Kachalova, I. B. Vasilyev and other archaeologists studied the Pit-Grave sites in the Volga-Ural interfluve in the 20th century. During the Smirnov expedition the first Pit-Grave culture barrows (kurgans) were discovered at the end of the 1950s and beginning of the 1960s. Smirnov (1965) compared the Ural materials with the Lower Volga graves and found that there are skeletons in right lateral crouched position. After considering unique metal finds (a knife and a hammer) archaeologists came to the conclusion that during the Pit-Grave period an independent metallurgy center appeared on the base of the Kargala copper deposit (80-90 km to the north of Orenburg) in the south Ural region (Chernykh 1966, 68 f.). Later, at the end of the 20th century, the research by E. N. Chernykh proved the above-mentioned statement. This added the original character of the Ural group of the Pit-Grave culture and historical area (Chernykh 2002, 7 ff). At the beginning of the 1970s N. Ya. Merpert published the monograph, in which he summarized all the data concerning the Pit-Grave culture (Merpert 1974). The scholar singled out three local groups of sites within the Volga-Ural Pit-Grave cultural and historical area: the Ural, the Lower Volga, and the Middle Volga. Since 1977 the Pit-Grave research has been carried out under the guidance of N. L. Morgunova in the Orenburg oblast. She discovered diverse Pit-Grave complexes. In the second part of the 1980s the Pit-Grave culture research became well targeted and systematic. It resulted in considerable growth in the number of analysed Pit-Grave barrows (Morgunova & Kravtsov 1994). The first periodization of the Ural Pit-Grave culture was put forward. Scholars raised some questions concerning the economy and the structure of the Early Bronze Age society (Morgunova 1991). We formed the hypothesis of singling out the Middle Volga-Ural local type of the Pit-Grave culture (Turetskij 1999). Results of various kurgan studies in the area together with a lot of finds--various metal artefacts substantially changed the popular opinion that the Ural Pit-Grave culture had peripheral character. However, by the end of the 20th century it had become quite clear that the Pit-Grave sites were essential for applying new methods so that archaeologists could exploit new sources to find solutions for different complicated problems first of all the issues concerning the origin, the periodization and the chronology of the culture. …

The installation of the Protective Barrier around the Ekofisk Tank in the Summer of 1989 significantly altered the wave environment as affecting the three immediately adjacent platforms and the four inter-connecting bridges. The change in environmental conditions provided a locally enhanced wave condition to the extent that the maximum free field wave height (crest to trough) was increased from 23.8 metres to around 37.0 metres at the leading edge of the Protective Barrier. Whilst all the bridges had previously been elevated by 6.0 metres, during the major Ekofisk jacking operation in the Summer of 1987, this revised elevation was inadequate in terms of maintaining an adequate air gap for the four bridges immediately adjacent to the Tank after the Protective Barrier had been installed. The change in environmental conditions after the installation of the Protective Barrier meant that two of the inter-connecting bridges would be submerged close to the mid-span by as much as 9.0 metres during a 100-year storm. This changerepresented a unique design condition for the interconnecting bridges, which in turn support large product pipelines, and in turn form an essential part of the overall Ekofisk Transportation System. This paper describes the changes in environmental loading on one of the bridges and supporting pipelines, together with a description of the necessary strengthening measures carried out. INTRODUCTION Because of an anticipated level of subsidence at Ekofisk of about 6.0 metres, the installations within the Ekofisk complex had to be protected against severe environmental action. Figure 1 shows the field layout of the existing platforms and inter-connecting bridges within the Ekofisk complex. In the Summer of 1987 the steel platform decks, and bridges were all elevated by6.0 metres in order to protect those structures against environmental wave loading, and this project has beenpreviously described as the Ekofisk Jacking Project (1,2,3). In the Summer 1989 the Protective Barrier was installed around the Ekofisk Tank in order to provide protection to the equipment on the Tank decks located at +90 metres and +100 metres above seabed level. Figure 2 shows a plan and elevation of the Protective Barrier around the Tank. An account of the main design and installation aspects of this structure has been given previously (4). The installation of the Protective Barrier significantly altered the wave environment as affecting the platforms and inter-connecting bridges immediately adjacent to the Tank. The effects of this installation on the adjacent2/4R, 2/4P and 2/4G platforms have been described previously (5). Generally, the effect was to increase theenvironmental wave loadings on the platforms by 50%, 20% and 15% for the 2/4R, 2/4P and 2/4G platforms, respectively. The purpose of this paper is to describe the changes in environmental design conditions for the inter-connecting Ekofisk bridges between the Tank and the 2/4R, 2/4P, and 2/4G platforms, and to outline the method of strengthening that was required in order to resist the new environmental loading.

Mediterranean sediments are known for their major shifts in sedimentary composition associated with dramatic changes in environmental and climate conditions. A typical expression for this in Holocene sediments is the occurrence of a distinctly organic-rich unit, sapropel S1, thought to be related with humid climate conditions. The S1 is accompanied by major changes in Ba content and in other elemental composition, respectively related to biological upper water column productivity and shifts in detrital sediment provenance. Here, we focus on changes in Ba and in its various phases to unravel shifts in environmental conditions around S1.Using selective extractions for sediments in cores MP37PC, MP39PC and MP50PC, respectively at 1908, 1359 and 775m water depth, we distinguish different Ba-phases: detrital Ba (Ba-det), barite Ba (Ba-bar), Mn-oxide-related Ba (Ba-ox), carbonate- and pyrite-associated Ba (Ba-carb and Ba-pyr). The predominant Ba-phase during S1 is Ba-bar (∼70%), whereas before and after S1 it is Ba-det (>90%). All other phases are mostly relatively small but have diagnostic value for environmental conditions and processes.The detrital (Ba/Al) is distinctly lower during S1 than before and after. The (Ba/Al). det variability, and enhanced values for Ba-carb and Ba-ox may have substantial influence on the traditional way to derive barite-Ba or excess-Ba content.The steep gradients in Ba-bar at onset and ending of S1and its high level during S1, clearly identify this period. In addition, and due to the exclusive nature of extraction results, we unequivocally demonstrate for the first time that there is a small gradual ‘early onset’ Ba-bar preceding the major increase in sapropel S1 formation sensu stricto.The ending of S1 formation is relatively abrupt with a well-defined reventilation event (’6 ka reventilation event’). This reventilation is associated with a rapid change in environmental conditions such as oxygenation and related remineralization of organic matter and recrystallization of carbonate. This rapid change and associated diagenetic processes are authentically recorded in Ba-carb and Ba-ox. For the period during sapropel S1 formation, the Ba-carb and Ba-ox results point to different levels of ventilation in the Eastern Mediterranean, i.e. a relatively mixed water mass down to ∼800m, a moderately mixed water mass from ∼800-to ∼1500 m, and a more stagnant water mass below 1500 m.

Unlike most non-human social animals, the social status of humans does not consistently correlate with higher fertility and in many cases appears to suppress fertility. This discrepancy has been employed as an argument against the use of evolutionary biology to understand human behavior. However, some literature suggests that social status and its implications for survival during high-mortality events may imply that status-seeking at a cost to fertility may be an optimal strategy over the long term. Here, we propose a theoretical model, in which each generation trades-off between social status and fertility under different economic and environmental constraints. To our knowledge, the model we present here is the first to connect individual decisions of generations, strategies to maximize long-term biological fitness, and key environmental and economic conditions in a coherent stylized modeling framework. We use it, in particular, to explicate the conditions, under which the strategy of having a lower number of offspring with higher social status may result in higher biological fitness over the long term. Furthermore, we delineate sets of economic and environmental conditions, for which the dynasty shrinks and grows. As adaptation of individual preferences is costly, limited and may take generations, we argue that a sudden change in environmental or economic conditions may shift a dynasty from a growing to a declining trajectory, which may be irreversible. Also, we show that in some cases, a slight change in environmental conditions can lead to a regime switch of an optimal strategy maximizing biological fitness.

The natural and sustainable ability of earthen building materials makes them highly valuable. Bio-stabilization involves using biological materials or processes in earthen construction to enhance the performance and characteristics of earthen materials. The main objective of bio-stabilization is to substitute high-energy-intensive building materials with more green, thermally efficient substitutions, ultimately reducing indirect emissions. The large-scale use of earth presents a viable alternative due to its extensive availability and, more importantly, its low embodied energy. The aim of this work is to investigate the thermal conductivity of earth stabilized with Opuntia Ficus-Indica (OFI), a natural biopolymer, and to assess how these properties vary based on mix design. A comparative analysis is performed to evaluate the thermal performance of bio-based polymer-stabilized earthen materials (S-30, S-40, D-30, and D-40) alongside natural biopolymer-stabilized earth (OFI-30 and OFI-40) under dry conditions, employing an experimental method. A scanning electron microscope was employed to examine the microstructure of bio-stabilized earthen materials from the samples. Statistical analysis was conducted on the collected data using ANOVA with a significance level of 0.05. The Tukey test was applied to identify specific mean pairings that demonstrate significant differences in the characteristics of the mixtures at each replacement level, maintaining a confidence interval of 95%. The experimental and statistical findings reveal that the OFI-30, D-40, and S-40 mixtures exhibit strong bonding with earthen materials and high thermal performance compared to all other mix designs in environmental samples. Additionally, these mix designs show further improvement in thermal performance in the dry conditions.