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To address the practical problem of decreased anchoring effect due to the detachment of the exterior bolt head from the cave wall under dynamic loads, this paper developed a partially recoverable displacement energy absorption (RDEA) bolt. On the basis of preliminary static loading performance tests, a field comparative test was conducted on the blast resistance performance of the cavern reinforced by RDEA bolt. The overall damage and dynamic response of the RDEA-bolt-reinforced test section and the conventional steel-bolt-reinforced test section were compared. The research found that under the same test conditions, the macroscopic damage to the conventional steel-bolt-reinforced test section was more severe than that of the RDEA-bolt-reinforced test section. When the scaled distance was 0.93 m/kg1/3, the ratio of the rebound displacement to the displacement peak at the arch top of the conventional steel-bolt-reinforced test section was 9.09%, while that of the RDEA-bolt-reinforced test section was 31.1%. The energy consumption characteristics of the RDEA bolt were described by the pressure peak value at the third working condition of the arch top. The pressure peak value of the RDEA-bolt-reinforced test section was 76.4%, lower than that of the conventional steel-bolt-reinforced test section. The arch top acceleration of the conventional steel-bolt-reinforced test section was about 1.35 times that of the RDEA-bolt-reinforced test section. The good blast resistance performance of the cavern reinforced by RDEA bolt was reflected from various aspects, such as macroscopic damage and the wall displacement, indicating that the RDEA bolt can not only weaken the effect of explosion load at the cavern location but also enable the reinforced cavern to have a good ability to resist deformation recovery after explosion, thereby having good application prospects. [ABSTRACT FROM AUTHOR]

Halite beds in the upper Permian Zechstein Group represent an opportunity for the future development of underground storage caverns. However, geological factors such as lithological heterogeneities, cap rock characteristics and depth can affect the sealing capacity and the integrity of the cavern or contaminate the stored fluid. The main objective of this paper is to evaluate these factors focusing on the compositional variation of the Zechstein Group in different salt structures in the Norwegian North Sea, and related opportunities and challenges for salt cavern storage. Based on deformation style, geometry, height and thickness of the salt structures, we have divided the Zechstein Group into four main categories: (1) thin beds, which can be either carbonate‐anhydrite or clastic dominated. Halite is absent and therefore there is no potential for the development of salt caverns. (2 and 3) bedded to weakly deformed evaporites and intermediate size salt structures, where thick halite beds of more than 300 m are present, but they are usually deeper than 2000 m. Lithological heterogeneities in the halite consist of a mix of competent and incompetent (K‐Mg salts) lithologies. (4) Tall diapirs, characterized by shallower structures (<2000 m), with large deformation and poor seismic image. Thin layers of incompetent K‐Mg salts are observed in these diapirs. The composition, thickness and deformation of the cap rock vary greatly in the area. Thick halite beds are recognized in most salt structures, suggesting an opportunity for underground storage. The challenges are related to the depth of the halite, amount and type of heterogeneities, characteristics of the cap rock and deformation in the different salt structures. These results also have implications for the distribution of reservoir and source rocks, and the evolution of the Northern Permian Basin. [ABSTRACT FROM AUTHOR]

Projects Starting the second tunnel boring machine at the Brenner construction site Sillschlucht‐Pfons / Andrehen der zweiten Tunnelbohrmaschine am Brenner‐Baulos Sillschlucht‐Pfons Contracts for caverns and gallery system for Forbach pumped storage power station awarded / Kavernen und Stollensystem für Pumpspeicherkraftwerk Forbach beauftragt Brenner north approach: gallery construction between Schaftenau and Radfeld / Brenner‐Nordzulauf: Stollenbau zwischen Schaftenau und Radfeld First part of the Fehmarnbelt tunnel concreted / Erster Teil des Fehmarnbelt‐Tunnels betoniert EU funds Brenner Base Tunnel with another 700 million euros / EU fördert Brenner Basistunnel mit weiteren 700 Mio. Euro Four international consortia have been selected for railway equipment of the Fehmarnbelt Tunnel / Vier internationale Konsortien für bahntechnsiche Ausrüstung des Fehmarnbelt‐Tunnel ausgewählt Porr wins a major contract for the SuedLink Elbe crossing / Porr gewinnt Großauftrag für SuedLink Elbquerung Lucerne through station: preliminary project completed / Durchgangsbahnhof Luzern: Vorprojekt abgeschlossen Call for papers – Topics for the next issues of Geomechanics and Tunnelling / Themen für die nächsten Ausgaben der „Geomechanics and Tunnelling" [ABSTRACT FROM AUTHOR]

At present, there are very few remaining cases of wooden buildings of the Tang Dynasty preserved in China, and what have been left of these buildings do not show an overall layout. Information on the preserved buildings and their groups in the southwestern grottoes themed on sukhabati is a key historical source to support the study. However, the sources of architectural elements, the evolution of composition rules and the components of artistic processing have not been systematically and fully explained. Taking the grottoes themed on sukhabati as the object, this paper explores the adaptive development process of the architectural image and the complex relationship of Chinese wooden architecture in the artistic conception of expressing sukhabati, sorts out the real and valid architectural information between them, and establishes a new perspective and historical basis for "demonstrating history through images". [ABSTRACT FROM AUTHOR]

Copyright of Intersecciones en Antropología is the property of Universidad Nacional del Centro de la Provincia de Buenos Aires, Facultad de Ciencias Sociales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zephyrus is the property of Ediciones Universidad de Salamanca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Študijné Zvesti AU SAV is the property of Institute of Archaeology SAS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A large part of our material culture is made of organic materials, and this was likely the case also during prehistory. Amongst this prehistoric organic material culture are textiles and cordages, taking advantage of the flexibility and resistance of plant fibres. While in very exceptional cases and under very favourable circumstances, fragments of baskets and cords have survived and were discovered in late Pleistocene and Holocene archaeological sites, these objects are generally not preserved, especially in tropical regions. We report here indirect evidence of basket/tying material making found on stone tools dating to 39–33,000 BP from Tabon Cave, Palawan Philippines. The distribution of use-wear on these artefacts is the same as the distribution observed on experimental tools used to thin fibres, following a technique that is widespread in the region currently. The goal of this activity is to turn hard plant segments into supple strips suitable as tying material or to weave baskets, traps, and even boats. This study shows early evidence of this practice in Southeast Asia and adds to the growing set of discoveries showing that fibre technology was an integral part of late Pleistocene skillset. This paper also provides a new way to identify supple strips of fibres made of tropical plants in the archaeological record, an organic technology that is otherwise most of the time invisible. [ABSTRACT FROM AUTHOR]

In view of the broken rock mass in the surrounding rock of large underground caverns, the 3D distribution model of the joints is obtained through the on-site investigation of the joints and the digital imaging technology, and the image processing software. Based on the analysis of the mutual cutting degree of the joints and the geometric shape of the block, the concepts and calculation methods of the degree of fragmentation and the degree of bite are proposed, and the degree of rock mass fragmentation is quantitatively described. Furthermore, the multi-factor analysis method is used to establish the quality evaluation method and the standard of broken rock mass based on the degree of rock fragmentation and the degree of bite, and the failure mode and safety criterion of broken rock mass of surrounding rock are proposed. Applying the discrete element numerical analysis method, the mechanical parameters of different broken rock masses are obtained. The reinforcement analysis of the surrounding rock of different broken rock masses shows that the degree of fragmentation, the degree of bite, and the classification of surrounding rock proposed in this paper can implement precise reinforcement measures for the surrounding rock of different broken rock masses, as it provides an important theoretical basis for the surrounding rock safety of large underground caverns in the broken rock mass and has wide applicability. [ABSTRACT FROM AUTHOR]

Copyright of Carsologica Sinica is the property of Institute of Karst Geology, CAGS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

During the Middle Devonian, reef growth reached an acme, and corals and stromatoporoids colonized depositional niches commonly considered unfavourable for reefal organisms. This paper documents the detailed facies architecture and palaeoecology of a stratigraphically thin (ca 12 m, 'carpet reef'), lower Givetian reefal body exposed along the walls and ceilings of the labyrinthine passages in the Klutert Cave in western Germany. The cave exposures (ca 26 000 m2 of rock surface) and data from short cores, neighbouring caves and outcrops document the growth and demise of an autoparabiostrome. The reef forms part of a parasequence with a lower carbonate and an upper clastic unit, bounded by flooding surfaces. Despite the comparatively small study area (ca 1 km2), the exceptional exposure quality reveals facies changes over relatively short distances both vertical and lateral. The sedimentary matrix of the reefal build‐up contains between 20 to 95 wt.‐% of clay and quartz of silt to sand fraction. Based on this observation, the corals and stromatoporoids thrived in murky waters and under sediment‐stressed conditions. Stromatoporoids, for example, display irregular ragged flanks, a feature that is in agreement with a sediment‐stressed environment. No evidence of reduced growth rates, decreased calcification rates, or lower numbers of species is found. In fact, coral diversity and density are highest within one of the two biostromal units that show peak clastic matrix values, indicating a remarkable adaptation of reef builders to sediment‐stressed conditions. The initial settlement of rugose phaceloid corals took place on a mixed clastic–carbonate substrate (the basal flooding surface). Up‐section, a succession of coral–stromatoporoids is present that is here described in great detail. Reef collapse occurred when much of the accommodation space was filled, and argillaceous sediments suffocated stromatoporoids and corals in a protected, low‐energy environment. [ABSTRACT FROM AUTHOR]

The genus Crossiella contains two species, C. equi, causing nocardioform placentitis in horses, and C. cryophila, an environmental bacterium. Apart from C. equi, which is not discussed here, environmental Crossiella is rarely reported in the literature; thus, it has not been included among "rare actinobacteria", whose isolation frequency is very low. After C. cryophila, only five reports cover the isolation of Crossiella strains. However, the frequency of published papers on environmental Crossiella has increased significantly in recent years due to the extensive use of next-generation sequencing (NGS) and a huge cascade of data that has improved our understanding of how bacteria occur in the environment. In the last five years, Crossiella has been found in different environments (caves, soils, plant rhizospheres, building stones, etc.). The high abundance of Crossiella in cave moonmilk indicates that this genus may have an active role in moonmilk formation, as evidenced by the precipitation of calcite, witherite, and struvite in different culture media. This review provides an overview of environmental Crossiella, particularly in caves, and discusses its role in biomineralization processes and bioactive compound production. [ABSTRACT FROM AUTHOR]

One of the most significant challenges of construction of underground large size structures is to determine the effect of the geological discontinuities. Fault is a natural discontinuity which allows significant displacement of the rock mass along the fault plane and increases the plastic zones around the underground structure. For instance, an underground hydropower plant comprising more than two underground caverns and large distance between the underground cavern incurs the higher cost because of connecting tunnels or transfer of electricity from powerhouse cavern to transformer cavern. However, presence of the fault would result in the increase of the plastic zone and shear displacement along the fault. Thus, with regards to the effect of the fault on the stability of the two parallel caverns, in this paper different numerical models were simulated to study the effect of the fault on plastic zone around the cavern group and pillar between the caverns, and shear displacement along the fault plane under different scenarios such as fault location, fault dip angle, fault friction angle and in-situ stress conditions. The results are produced graphically and discussed. These results offer advance guidelines in construction of the two parallel large size caverns. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the process of top coal caving mining, the caving time and the tail beam swing angle have an important impact on the evolution of the coal gangue boundary, which determines the top coal recovery rate and gangue content rate. Therefore, it is necessary to study the influence of the caving time and the tail beam swing angle on the top coal caving effect. For this purpose, based on Hertz–Mindlin contact theory, this paper established a simulation model of top coal caving and carried out a coal caving simulation with different caving times and tail beam swing angles. In the process of coal caving, under a specific tail beam swing angle and different caving times, this work studied the evolution characteristics of the coal gangue boundary. A simulation model of coal caving with variable time is established, and the influence mechanism of time on the coal caving effect is analyzed. Then, the evolution characteristics of the boundary are studied under different tail beam swing angles and the same caving time. A simulation model of coal caving with variable angles is established, and the influence mechanism of the tail beam swing angle on the coal caving effect is analyzed. Finally, the effects of caving time and tail beam swing angle on coal gangue discharge are studied, and the effect of coal gangue release under different working conditions is analyzed. The boundary data and the discharge data are extracted through the simulation, and contrast curves are drawn. The results show a limit position of the coal gangue boundary under the fixed working condition, which is the middle line position of the coal caving outlet. When the coal gangue boundary does not reach the limit position, there are two characteristics. First, the greater the tail beam swing angle is, the faster the deformation speed of the coal gangue boundary is. At the same caving time, the position of the coal gangue boundary will be closer to the coal caving outlet, which leads to excessive mixing of coal and gangue. Second, the longer the drawing time, the greater the deformation of the coal gangue boundary, and the easier the coal gangue is mixed, resulting in an increase in the gangue content of the discharged coal. When the coal gangue boundary reaches the limit position, the boundary will be basically stable near the top of the coal caving outlet. The limit position and shape of the coal gangue boundary are mainly affected by the density difference of coal gangue particles but not by the coal caving time and the tail beam swing angle. After the end of coal caving, the coal gangue boundary finally presents a double arch structure. The research in this paper has important reference significance for the selection of caving time and tail beam swing angle and further research. [ABSTRACT FROM AUTHOR]

Context: A landscape is defined as a "system of ecosystems" and this is a model in which karst areas can easily be integrated. In karst areas, much of the connectivity between the units of the landscape is underground, with aquifers and caves forming a continuous layered tissue. However, underground environments are among the least studied landscapes on Earth because of limited accessibility and the difficulty of performing surveys. Objectives: The aim of this paper is to provide a conceptual framework for applying principles of landscape ecology to research on karst environments. Methods: By adapting the standard patch-corridor-matrix model to a 3d model, the main issues that need to be addressed were identified. These include identifying the main morphological (surface and underground) karst features; determining the landscape structure through its features, composition, and configuration; and developing adequate indices. Results: The landscape spatial structure of different karst areas influences fundamental ecological functions and biodiversity patterns. Determining how structure, biodiversity, and functions relate reveals important insights into the functioning of karst systems. Emphasizing the provisioning of ecosystem services is essential in supporting the concept that karst regions are vital for human well-being because they host valuable resources and fundamental ecosystem processes. The paper discusses how this framework helps address anthropogenic impacts and conservation issues on karst. Conclusions: The potential of applying a landscape approach to karst systems lies in developing models that provide ecological information relevant to understanding karst systems and understanding their implications for natural resources management. [ABSTRACT FROM AUTHOR]

Copyright of Nasleđe is the property of University of Kragujevac, Faculty of Philology & Arts and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper presents an analysis of the long-term stability of a large unsupported cave excavated in granular cohesionless material in Ficulle, Italy. The stability of the cave arises from a 'cohesive' term in the shear strength criterion and this paper investigates the source of this cohesive term. Contrary to expectations, the material appeared to be granular (cohesionless) at the touch. The investigation started by determining whether the stability of the cave was attributable to any cementation bonding the soil particles. Microstructural analyses, together with geomechanical testing, produced enough evidence to suggest that the material was not naturally cemented. On the other hand, water-undrained direct shear tests on unsaturated intact specimens indicated the presence of significant apparent cohesion, which was then linked to the existence of suction in the material. In this way, the stability of the cave was assessed accounting for the beneficial effects of suction and partial saturation on shear strength. A three-dimensional analysis based on the upper bound theorem of plasticity was successful in confirming the stability of the cave in terms of the state of the structure at the time of field investigation. In addition, it was shown that 24 and 48 h rainfalls of 100 years return period are not sufficient to relieve suction sufficiently to bring the cave to collapse, thus justifying the observed long-term stability of the cave. Suction is rarely included in geotechnical design under the assumption that it cannot be relied upon owing to the potentially adverse effect of rainwater infiltration. This case study demonstrates that suction can indeed remain 'active' naturally for a long time, contributing to the long-term stability of geo-structures. [ABSTRACT FROM AUTHOR]

This paper focuses on a reassessment of the emergence of herding in Africa seen from the Tadrart Acacus and neighbouring regions in the Libyan central Sahara. The paper examines whether the presence of wild animals in the Early Holocene 'green' Sahara could have represented a 'disease challenge' to the spread of domestic livestock, as proposed for sub-Saharan Africa. Analysis of the zooarchaeological record and Saharan rock art highlights this potential threat also in North Africa, where it has hitherto been disregarded. Old and new data from the study area in SW Libya, with a focus on Takarkori rock shelter, highlight the presence of herding activity at a very early stage. Direct dating on bones of sheep/goat and cattle secures this chronology, providing evidence of a rapid ingression of small groups of herders who crossed Africa's north-eastern quadrant around ~ 8300 years cal BP. This rapidity defies the 'disease challenge' hypothesis and suggests alternative scenarios. In the central Sahara, the cultural complexity of local Early Holocene hunter-gatherers and their delayed return system of resource exploitation could have facilitated the incorporation of new practices, including the herding of small numbers of domestic animals. The societal implications of the transition from hunting and gathering to herding are archaeologically better visible in the funerary record and in rock art. By contrast, both material culture and the subsistence basis seem to demonstrate continuity with the former foraging groups' phase. Taken together, the Saharan evidence suggests a punctuated process of acculturation for the inception of food production in North Africa. [ABSTRACT FROM AUTHOR]

Five decades ago, Usategi Cave (Basque Country) yielded a small Gravettian series that included an Isturitz-type bone point. This paper presents the first 14C dates for the assemblage and new data obtained by the study of the lithic raw materials, a high proportion of which came from north of the Pyrenees. The discussion of this new information leads to the hypothesis that the occupants of the cave were a group that travelled from the continental Basque Country across the Pyrenean mountain passes and the Ebro basin to procure flint from the nearest outcrop at Urbasa. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zoological Systematics & Evolutionary Research is the property of Hindawi Limited and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The existence of giant karst cave can cause collapse and water inrush hazards during the excavation of the karst tunnel, causing serious economic losses. In this paper, based on the FEA software MIDAS, a numerical simulation model for the backfilling of a large karst cave through a large cross-section tunnel was established. The distribution characteristics and change rules of the displacement field, stress field, horizontal support stress, and plastic zone of the tunnel surrounding rock and backfill were explored. The first stage of tunnel excavation leads to a sharp increase in the displacement of the tunnel's surrounding rock and the deterioration of the plastic zone, which should be strengthened and monitored. The tunnel arch, waist, and wall footing areas were prone to stress concentration. The two layers of horizontal support force show a certain regularity, showing a sharp increase and a gradually smooth growth trend. Meanwhile, the site monitoring results for arch settlement and horizontal convergence of the mega cavern tunnel were analyzed. The results show that the numerical calculation results were in good agreement with the values of site monitoring data. The average errors of final crown settlement and horizontal convergence were 8.6% and 15.9%, respectively, which verified the correctness of the numerical modeling method. This project can provide reliable experience for the construction of similar large cavern tunnels. [ABSTRACT FROM AUTHOR]

Monitoring and providing warnings for coal mine rockburst disasters is a worldwide problem. Several rockburst accidents have occurred in a 1301 belt transport chute near a 1300 fully mechanized caving mine face. To address this issue, an empirical study of the occurrence mechanism of rockbursts in the adjacent area of the fully mechanized top-coal caving face was carried out. This paper mainly addresses the following issues: (1) based on microseismic monitoring technology, the distribution characteristics of the host-rock-supported pressure of the 1300 working face were measured, and the evolution and distribution of the deep-well caving working face host-rock-supported pressure were analyzed. It is revealed that the occurrence mechanism of rockburst in the adjacent area is actually caused by the evolution and superposition of the lateral abutment pressure of the 1300 stope, and the stress of the original rock along the 1301 belt transport down chute; (2) a theoretical calculation model of dynamic and static abutment pressure in longwall stope is built, and an example is tested. The results show that the peak position of lateral abutment pressure of the coal body outside the 1300 goaf is around 63 m, and the peak value of abutment pressure is around 47 MPa; (3) coal body stress monitoring, bolt dynamometer detection, and other means are compared and analyzed. At the same time, with the help of CT geophysical prospecting and drilling cutting measurements, it is concluded that the 1301 belt transport down chute is in the bearing pressure influence zone (superimposed zone), which further verifies the validity of microseismic analysis results and the accuracy of the above theoretical model. Based on this, the early warning system and prevention measures for rockburst based on microseismic monitoring are proposed. The engineering practice shows that the dynamic and static bearing pressure distribution and evolution law of the working face can be dynamically obtained by using microseismic technology, which provides a basis for the accurate prediction and treatment of rockbursts. [ABSTRACT FROM AUTHOR]

Copyright of Architectural Journal / Jian Zhu Xue Bao is the property of Architectural Journal Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although research on the natural ventilation of single-sided buildings is progressing, research on the natural ventilation of the Mogao Grottoes, which have special shapes and structures, is relatively limited. The purpose of this paper is to develop a correlation for calculating the natural ventilation rates of such grottoes. Field experiments were carried out on two typical caves to measure their meteorological parameters and natural ventilation rates to verify the validity of the proposed correlation. The results show that our correlation has good reliability and stability when predicting the natural ventilation rates of the caves. First, the new correlation has a small average deviation of 16.35%. The average deviations in the natural ventilation rates predicted by seven established correlations are as low as 17.85% and as high as 59.39%, revealing a large gap compared with the correlation proposed herein. Second, the maximum deviation in the outputs of the proposed correlation is only 7.70% between each case. Finally, a comparison between the calculated results and the values measured in Cave 328 shows that the correlation is also suitable for large-volume caves. The developed correlation provides theoretical support and a scientific method for preventive protection and a quantitative analysis method for the study of natural ventilation in caves. [ABSTRACT FROM AUTHOR]

Cave carbonates, seemingly growing in defiance of gravity, have attracted the community's interest for more than a century. This paper focusses on 'helictites', contorted vermiform speleothems with central capillaries. Petrographic, crystallographic and geochemical data of calcitic and aragonitic helictites (recent to 347 ka) from three caves in Western Germany are placed in context with previous work. Aragonitic helictites from one site, the Windloch Cave, form exceptionally large and complex structures that share similarities with the celebrated helictite arrays in the Asperge Cave in France. Aragonitic and calcitic helictites differ significantly in their crystal fabrics and internal geometry. Calcitic helictites are best described as a composite crystal fabric consisting of fibrous mesocrystals. Aragonite helictites display a complex fabric of acicular to platy crystals, some of which show evidence for growth‐twinning and perhaps crystallisation via a monoclinal precursor stage. The micro‐tomographic characterisation of several orders of channels and their complex architecture raises important questions regarding fluid migration and helictite architecture. In terms of their isotope geochemistry, helictites are depleted in 13C to various degrees, isotope values that are controlled by the mixing of fluids and mineralogy‐related fractionation. Regarding their δ18O values, most helictites overlap with other calcitic and aragonitic speleothems. Previous models explaining the twisted morphology of helictites are discussed from the viewpoint of fluid migration and CO2 degassing rates, mineralogy and helictite petrography. For the complex aragonitic helicities documented here, the most likely mechanisms to explain the contorted growth forms include the internal capillary network combined with localised (sector) growth at the helictite tip. The morphologically simpler calcitic helictites are best explained by capillary and surface flow. Future work should include geomicrobiology to assess the significance of induced mineralisation and transmission electron microscopy analysis to more quantitatively assign crystallographic properties. [ABSTRACT FROM AUTHOR]

In 2021, a patient died from Marburg virus (MARV) disease in Guinea and it was the first confirmed case in West Africa. The origin of the outbreak has not been identified. It was revealed that the patient didn't travel anywhere before the illness. Prior to outbreak, MARV had been found in bats in the neighboring Sierra Leone, but never in Guinea. Therefore, the origin of infection is unclear: was it an autochthonous case with spillover from a local population of bats or an imported case with spillover from fruit bats foraging/migrating from Sierra Leone? In this paper, we studied Rousettus aegyptiacus in Guinea as the possible source of MARV infection caused the patient death in 2021 in Guinea. We caught bats in 32 sites of Guéckédou prefecture, including seven caves and 25 locations of the flight path. A total of 501 fruit bats (Pteropodidae) were captured, including 66 R. aegyptiacus. The PCR screening showed three positive MARV R. aegyptiacus, roosting in two caves discovered in Guéckédou prefecture. After Sanger sequencing and phylogenetic analyses it was shown that found MARV belongs to the Angola-like lineage but it is not identical to the isolate obtained during the outbreak of 2021. Author summary: In 2020, MARV was first detected in fruit bats in Sierra Leone (West Africa). One year later, first outbreak of MARV in West Africa was registered in the neighboring Guinea after a man's death in the Temessadou M'bokét village. The source of the outbreak has not been identified. It is known, that the reservoir animal of MARV is the cave-dwelling bat Rousettus aegyptiacus, and typically, MARV disease outbreaks emerge after a visit of the index patient to a cave or mine. In our work, we studied bats in the vicinity of this village for the presence of the MARV. A cave hosting a colony of R. aegyptiacus was found close to the Temessadou M'bokét village (~4.5 km). Sampling and PCR screening of the bats from the colony identified three MARV-positive bats. The cave is inaccessible to humans; therefore, the index patient could not have been infected upon visit. We assume that the patient was infected outside the cave after direct or indirect contact with an infected bat of the same colony. These results provide the basis for preventive measures against new MARV outbreaks in Guinea. [ABSTRACT FROM AUTHOR]

Neanderthals were widespread during the Middle Palaeolithic (MP) across Europe and Asia, including the Caucasus Mountains. Occupying the border between eastern Europe and West Asia, the Caucasus is important region regarding the Neanderthal occupation of Eurasia. On current radiometric estimates, the MP is represented in the Caucasus between about 260–210 ka and about 40 ka. Archaeological record indicates that several culture diverse MP hominin populations inhabited the Caucasus, but the region complex population history during this period remains poorly understood. In this paper, we identify for the first time the archaeological evidence indicating contacts between two culture diverse MP Neanderthal populations in the North Caucasus and discuss the nature of these contacts. Basing on the lithic assemblages that we excavated at Mezmaiskaya cave in the north-western Caucasus (Kuban River basin) and Saradj-Chuko grotto in the north-central Caucasus (Terek River basin), dating from MIS 5 to MIS 3, and comparative data from other MP sites in the Caucasus, we identify two large cultural regions that existed during the late MP in the North Caucasus. The distinctive toolkits and stone knapping technologies indicate that the MP assemblages from Mezmaiskaya cave and other sites in the west of North Caucasus represent a Caucasian variant of the Eastern Micoquian industry that was wide spread in central and eastern Europe, while the assemblages from Saradj-Chuko Grotto and other sites in the east of North Caucasus closely resemble the Zagros Mousterian industry that was wide spread in the Armenian Highlands, Lesser Caucasus and Zagros Mountains. The archaeological evidence implies that two culture diverse populations of Neanderthals settled the North Caucasus during the Late Pleistocene from two various source regions: from the Armenian Highlands and Lesser Caucasus along the Caspian Sea coast, and from Russian plain along the Sea of Azov coast. [ABSTRACT FROM AUTHOR]

As precious cultural heritage sites, the state of preservation of cave temples is closely related to the geological and climatic conditions in which they are located. This paper constructed an analytical method of sized slate stability based on the equivalent support stiffness method. The stability analysis of the roof slab of Yuanjue Cave was carried out by establishing a three-dimensional numerical calculation model. Through comparative analysis of the results of stress and displacement fields under different conditions, the stress and deformation characteristics of the roof slab of Yuanjue Cave were revealed, as well as the study of the main factors affecting the stability of the roof slab of Yuanjue Cave and the key slate to be monitored. The main research results are as follows. The stress deformation of the roof plate of Yuanjue cave is mainly divided into the initial uniform change stage, the medium-term stable change stage or the medium-term accelerated change stage, and the later rapid change stage. With the increase in the number of overhanging and broken slates and the increase in the damage factor of cracked slates, the vertical stress extremum of the stones increases continuously, and the equivalent support stiffness decreases, which aggravates the uneven stress deformation of the roof of the Yuanjue Cave. This study provides a reliable reference basis for the stability analysis and evaluation of the roof slab of a large number of cave temples existing in the Sichuan and Chongqing areas in China. [ABSTRACT FROM AUTHOR]

Regional offsets from Northern Hemisphere radiocarbon (14C) calibration curves are widely recognized for monsoon Asia and often hinder accurate 14C dating. In this paper, we explore the possible linkage between summer monsoon intensity and 14C offsets using tree-ring δ18O and 14C data from Thailand. We developed a 297-yr floating tree-ring δ18O chronology comprising seven teak log-coffin samples from the Ban Rai rock shelter site, northwestern Thailand. The outermost ring of our chronology was estimated to date from 358–383 CE, within a 95.4% (2σ) probability range, based on a total of 10 14C measurements that were wiggle-matched against a mixed calibration curve evenly weighted from the IntCal20 and SHCal20 curves. Backward trajectory analysis showed that an intensified (weakened) summer monsoon detected in a modern tree-ring δ18O chronology was most likely to be induced by increased (decreased) air mass transport from the tropical Indian Ocean, which is an area of intense upwelling where the 14C concentration is lower than the atmospheric 14C level. However, partly because of the limited sample size and dating uncertainty, the direct linkage between the tree-ring δ18O series and 14C records obtained from our teak log-coffin samples could not be statistically verified. [ABSTRACT FROM AUTHOR]

The problem of registering underground cavities and caves is an older one at national level. With the advent of several legislative initiatives regarding this type of entity, the term cadastre of caves also appeared. The case study is represented by the "Şuticoasa" Cave, which is located in the perimeter of the archaeological site, the Şinteu Fortress "Piatra Şoimului", being an integral part of the medieval monument in pestis village, a village belonging to Alesd city in Bihor county. For this purpose, this paper presents the techniques of data acquisition, their processing and a first attempt to refer to this type of entity in an existing land register. [ABSTRACT FROM AUTHOR]

China has abundant coal resources, and the distribution of coal seams is complex. Thick coal seams account for more than 45% of all coal seams. Fully mechanized top coal caving mining has the advantages of large production, high efficiency, and low cost. In fully mechanized caving mining, especially in fully mechanized caving mining of extra-thick coal seams, the mining space is ample, the mine pressure is severe, and the roadway maintenance is complex. As a result, it is necessary to summarize and discuss the gob-side entry driving of fully mechanized caving in theory and technology, which will help to promote the further development of fully mechanized caving gob-side entry driving technology. First, in recent years, the research hotspots of gob-side entry driving have focused on the deformation mechanism and the control method of the roadway surrounding rock. Secondly, this paper discusses the theoretical models of the "triangle-block" and "beam" for the activity law of the overlying strata in gob-side entry driving, including the lateral breaking "large structure" model, compound key triangle block structure model in the middle and low position, the high and low right angle key block stability mechanics model, elastic foundation beam model, low-level combined cantilever beam + high-level multilayer masonry beam structure model, and the vertical triangular slip zone structure model. It introduces the "internal and external stress field theory" and the "stress limit equilibrium zone model". Thirdly, it summarizes several numerical simulation analysis methods in different conditions or research focuses and selects appropriate constitutive models and simulation software. Finally, it introduces surrounding rock control technology, including two ribs, the roof, and under challenging conditions. It provides a method reference for support in similar projects. [ABSTRACT FROM AUTHOR]

In this paper, the organic pigments indigo and isatin were detected by high performance liquid chromatography (HPLC) in The Mural of Four Buddhas which is in Cave 3 from the ancient Chinese Tiantishan grottoes (Ming Dynasty, East Slope). By analysing the preservation conditions of the mural and the environmental conditions of the place where the Tiantishan grottoes are located, we speculated that the isatin detected in this mural was mainly produced by the oxidative decomposition of indigo by ozone (O3), rather than by photodegradation of indigo. We have used theoretical calculation software Gaussian09 (G09) and Amsterdam Density Functional (ADF) module in the Amsterdam Modeling Suite (AMS) software to simulate the reaction mechanism of O3 oxidation of indigo, and the end products of the oxidation of the natural plant dye indigo by O3 were identified as isatin, C16H10N2O3 and C8H6NO3 using HPLC, fluorescence spectroscopy and high performance liquid chromatography-mass spectrometry(HPLC–MS). This finding confirmed the accuracy of the mechanism of indigo fading by O3 oxidation. These findings provided a theoretical basis for subsequent research into the derivation of natural organic dyes in the face of increasing O3 pollution and for better protection of valuable historical and cultural heritage such as ancient Chinese grottoes murals. [ABSTRACT FROM AUTHOR]

The estimation of gangue content is the main basis for intelligent top coal caving mining by computer vision, and the automatic segmentation of gangue is crucial to computer vision analysis. However, it is still a great challenge due to the degradation of images and the limitation of computing resources. In this paper, a hybrid connected attentional lightweight network (HALNet) with high speed, few parameters and high accuracy is proposed for gangue intelligent segmentation on the conveyor in the top-coal caving face. Firstly, we propose a deep separable dilation convolution block (DSDC) combining deep separable convolution and dilation convolution, which can provide a larger receptive field to learn more information and reduce the size and computational cost of the model. Secondly, a bridging residual learning framework is designed as the basic unit of encoder and decoder to minimize the loss of semantic information in the process of feature extraction. An attention fusion block (AFB) with skip pathway is introduced to capture more representative and distinctive features through the fusion of high-level and low-level features. Finally, the proposed network is trained through the expanded dataset, and the gangue image segmentation results are obtained by pixel-by-pixel classification method. The experimental results show that the proposed HALNet reduces about 57 percentage parameters compared with U-Net, and achieves state-of-the art performance on dataset. [ABSTRACT FROM AUTHOR]

Famous for its cliff-carved Buddhist cave-shrines, Longmen was also a burial ground that attracted a few women from the seventh and the eighth centuries. This paper examines the burial caves of two lay women, Lady Lou (d. 661) and Lady Zhang (c. 658–c. 718), in relation to the newly excavated archaeological material and epigraphic evidence. Lady Lou compared her cave burial to the Indian ascetic practice in the forest of Śītavana but did not enact the compassionate offering of flesh. Lady Zhang was later removed from her burial cave by her sons so that she could be interred in a joint tomb with her husband. Through these two cases, I investigate the motivations behind the adoption of cave burials in medieval China. Canonical Buddhist scriptures taught these women that their social gender presented an obstacle to the final release. Dedicatory inscriptions at women's burials and two tales of miraculous events at Longmen further suggest that family ties, an important constituent of women's social gender, were believed to persist posthumously. Married women were expected to maintain their spousal and parental relations in the afterlife, and unmarried girls were imagined as turning into seductive spirits because of their lack of spousal union in their lifetime. I argue that cave burials at Longmen were not a compromise of the Indian ascetic practice but rather presented these lay women with a socially acceptable way to break free from their familial attachments after death. [ABSTRACT FROM AUTHOR]

This paper presents the study's results on beetles (Insecta: Coleoptera) inhabiting caves in the Częstochowa Upland, southern Poland. During two years of research, 2084 specimens, representing 105 species from 19 beetle families, were collected. The obtained results indicate that many beetle species choose to inhabit caves despite lacking specific adaptations for living in such environments. The cave entrance zone is the most attractive place for surface species to inhabit because its climatic conditions are more stable than outside the cave, some sunlight is present, and the availability of organic matter is high. In the deeper parts of the studied caves, the number of occurring species rapidly decreased. Three species were recognised as troglobionts, four as troglophiles and 32 as subtroglophiles. Speonomus normandi hydrophilus, Choleva lederiana gracilenta and Quedius mesomelinus mesomelinus were identified as the most frequent in the studied caves. Speonomus normandi hydrophilus is endemic to the Arize massif in the Central Pyrenees (France) and was experimentally introduced into the Dzwonnica cave (Poland) in 1982, while Ch. lederiana gracilenta is one of two troglobitic beetles native to Polish caves and Q. imesomelinus mesomelinus is a widespread, very common troglophile. [ABSTRACT FROM AUTHOR]

When shield tunnel passes through karst strata, the existence and development of karst caves will inevitably affect the safety of tunnel construction. Therefore, the karst caves in the construction area must be filled, and the backfill strength of karst caves will also affect the stability of surrounding rock. In this paper, the discrete element model of karst stratum is constructed by calibrating the discrete element EDEM mesoscopic parameters. The simulation of shield tunneling process under different karst cave filling intensities is realized. The influence of the ratio of cave filling strength to surrounding rock strength on the stability of surrounding rock is studied. The results show that: (1) Critical normal stress and normal contact stiffness only affect the peak stress, while critical tangential stress and tangential contact stiffness both affect elastic modulus and peak stress. (2) When the ratio of the filling strength of the cave in front of the shield to the strength of the surrounding rock is controlled between 0.8 and 1.2, the stability of the surrounding rock is less affected by the cave. (3) By comparing with the test results, when the ratio of the strength of cave filling material to the strength of surrounding rock is 0.8, the shield machine can safely pass through the front cave without excessive formation deformation. This study provides a basis for the treatment of karst caves when shield tunneling through karst areas. [ABSTRACT FROM AUTHOR]

Longwall mining operation is mainly accompanied by the roof fall phenomenon and out of seam dilution (OSD). These occurrences are strongly dependent on the quality of the face's roof and floor. Therefore, the existence of discontinuities in the floor and roof reduces their quality, increasing the intensity of roof fall and OSD. This paper suggests a synthetic rock mass (SRM) model which is able to simulate roof behavior by initiating and tracking of fractures in cave mining, in order to predict the roof fall and OSD and to evaluate their event risk. For this purpose, longwall mining, including excavation of coal, installation of powered support, and caving the roof, has been successfully established in this numerical model using the PFC2D approach. The risk analysis in a panel of Tabas mine using the matrix risk model indicated that the risk level of roof fall is moderate and the risk level of OSD is high. The results of SRM modeling are consistent with previous studies and field observations at the Tabas coal mine, indicating that the SRM model is a powerful technique for studying the behavior of discontinuities in mining. [ABSTRACT FROM AUTHOR]

Despite the wealth of Late Pleistocene archaeology that exists across southern Africa's open landscape, it is routinely neglected in favour of rock shelter (re)excavation, biasing interpretation of human–environment interaction. This is compounded by the scarcity of open-air studies that use geoarchaeological methods to investigate the history and processes involved in their formation. The open-air archaeology of the Doring River Valley is an example of this, despite nearly a decade of dedicated study and publication. Consequently, there remains a limited and untested understanding of the valley's formation history. This paper rectifies this by providing a sedimentary context for the surface archaeology exposed across one of the Doring River Valley's artefact-baring localities, Uitspankraal 7 (UPK7). Characterisation, particle size, mineralogical, morphometric, and geophysical analysis of UPK7′s sand mantle resulted in the identification of four artefact-bearing sedimentary units, the aeolian and pedogenic processes involved in their formation, and their proposed order of deposition. This provides a stratigraphic, taphonomic, and environmental context against which chronometric dating and an analysis of the taphonomic, spatio-temporal, and technological composition of UPK7′s surface archaeology can be compared. This work is the first vital step towards understanding the depositional and behavioural history of a landscape, irrespective of context type. [ABSTRACT FROM AUTHOR]

The control difficulty of whole coal cavern groups is greatly increased due to the characteristics of soft rock with low strength, large sections, and the mutual influence of crossed cavern groups. The large section gas storage cavern group is taken as the research background. In this paper, the equivalent circle method is used to solve the loose circle of a rectangular roadway, and numerical calculation is used to obtain the deformation and stress distribution laws of the surrounding rock under the excavation conditions of large section whole coal cavern groups (WCCG). The deformation and failure mechanisms of the surrounding rock are revealed under the linkage impact between large section whole coal cavern groups. The stratified reinforcement ring concept of "long cable-bolt-grouting" (LBG) was proposed for the stability control of surrounding rock in the WCCG. On the roof of whole coal cavern groups, the supporting configuration of a high-strength bolt with a high pre-tightening force and the high-strength anchor with a high pre-tightening force were determined. On the two sides and floor of the WCCG, the grouting scheme was determined. These two supporting configurations in both the roof and sidewalls were applied to the large section gas storage cavern group. The results show that the surrounding rock presents asymmetric deformation and failure characteristics due to the large excavation area and complex structure. Tensile failure and mixed tensile-shear failure mainly occur in the shallow part of the surrounding rock, while shear failure mainly occurs in the deep part of the surrounding rock. The roof displacement curves show a symmetric distribution and saddle distribution in the low- and high-negative pressure caverns, respectively. The maximum displacements are on the left and right sides of the cavern roof. The range of the loose rings is 3.34 m and 2.54 m, respectively, on the roof and the two ribs. The stratified reinforcement ring support technology of LBG can effectively reduce the failure depth of surrounding rock, and the surrounding rock is in a stable state. The study can provide a theoretical basis for the layout of large section cavern groups and the stability control of surrounding rock. [ABSTRACT FROM AUTHOR]

The rationale for our research arises from non-regulated use of caves for commercial and sightseeing purposes, which can significantly damage objects of cultural heritage or result in their complete destruction. In this respect, our paper aims to define the factors necessary for the development of nature preserves and tourist centers that provide for the preservation of caves that are properly maintained and used by the public. The paper employs a multidisciplinary approach based on inter-connections among geological, social, and economic research methods. Geological methods provide complex monitoring of cave environments to ensure that they are not being adversely impacted and remain popular tourist destinations. Social and economic methods allow development of a business model to ensure that their operation is economically sustainable. The authors apply a model of step-by-step formation and development of a cave-related nature preserve and tourist center, exemplified with the case study of the Sablinsky tourist center (Leningrad District), including complex research of the geology, establishment of a nature preserve and tourist unit, development of a self-financing operating plan, cave zoning that allots areas for natural and cultural interpretation, but restricts tourists to special routes, and touristic infrastructure. This paper is intended as a practical guide for promoting the development of domestic tourism in Russian regions and creating new tourist clusters around objects of natural and cultural heritage, while implementing an effective protection of the natural geology and limiting anthropogenic impacts. [ABSTRACT FROM AUTHOR]

Achieving a comprehensive and accurate understanding of the anchor reinforcement mechanism and a quantitative evaluation of the surrounding rock's stability for an anchored underground cavern can provide an important theoretical basis for supporting and excavating the cavern. First, the composite bearing structure composed of the anchor and surrounding rock was defined as the surrounding rock reinforcement body by using the homogenization method, and a new method for evaluating the stability of surrounding rock by the surrounding rock reinforcement body deformation and damage degree was proposed. Second, based on the anchor reinforcement effect, the expression of the physical-mechanical parameters of the surrounding rock reinforcement body was deduced, and the analytical solution of stress and displacement of the surrounding rock reinforcement body was obtained. Finally, the stability coefficient of surrounding rock indicating the degree of the surrounding rock reinforcement body damage was defined. The research showed that the theoretical solution agreed well with the results of the numerical simulation, and the difference between the theoretical solution and the monitoring value was less than 10%, which verified the reliability of the method and the results of this paper. The design of the length and spacing of the anchor followed the principle of long but sparse and short but dense, and the pretightening force of the anchor and the stability coefficient of surrounding rock varied linearly. The analytical solution of this paper provides a theoretical reference for understanding the mechanism of anchor support and provides a quantitative evaluation method for the stability of surrounding rock. Compared with the traditional support design, the theory of this paper gives full play to the self-stability of the surrounding rock and the strength of the anchor, which is conducive to saving support costs and avoiding the construction limitations in some projects. [ABSTRACT FROM AUTHOR]