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Each nuclear weapon test contributes to a global burden of released radioactivity. Between 1945 and 1996, more than 2,000 nuclear tests were conducted, three-quarters of which were underground. Underground nuclear tests involved placing the nuclear device in a cavity drilled or excavated beneath the surface. The goal was to contain the explosion and its effects to the immediate vicinity of the detonation point, ultimately minimizing the release of radioactive materials into the atmosphere. While these tests successfully curtailed the atmospheric release and radioactive fallout, they created dynamic responses within crustal formations caused by local shock waves from the explosion. This paper discusses the legacy of underground nuclear testing, addressing issues from containment failure to the phenomenological effects after underground detonations and the pathways of subsequent dispersal of radionuclides to the environment. [ABSTRACT FROM AUTHOR]

Underground hydrogen storage has emerged as a strategy to address the challenge of large-scale, long-term, and economically viable hydrogen preservation, fulfilling energy demands and balancing supply intermittency in renewable energy systems. This paper seeks to enrich the discourse on sensitivity analyses concerning underground hydrogen storage processes by reviewing the influence of wettability. In this work, we present our review of wettability in geological formation for hydrogen storage starting with sandstone formations, carbonates, shale, and finally basalt. Results show that published water/hydrogen contact angle measurements indicate strong water-wet to intermediate water-wet conditions at ambient conditions for most formations. • Sandstone and basalt show consistent water-wet state at various conditions, thus considered ideal for hydrogen storage. • Microbial activity alters wettability and increases contact angle, posing risks for certain lithologies like carbonate. • Increased organic matter in carbonate and shale increases contact angle measurements, especially at high pressure. [ABSTRACT FROM AUTHOR]

Due to the inherent unpredictability of geological conditions, tunnelling operations are often at risk of encountering water inrushes. Such incidents can lead to construction delays, impose financial strains and pose significant safety threats to the workers involved. Water‐bearing geological formations are the main triggers for such incidents, with factors such as the positioning, water quantity and permeability distribution of these formations being key to predicting the occurrence and severity of water inrush disasters. By leveraging the complex interplay among relaxation time, P‐wave velocity and permeability within the rock's physical properties, a series of indoor tests were conducted on 40 artificial reef limestone cores to extract the necessary parameters. Through the analysis of the data, the comprehensive permeability prediction model was established, and the correlation coefficient was 0.9420 between the model's predictions and actual measurements. At the same time, through theoretical and mechanism analysis, the relationship between permeability and relaxation time and the relationship between permeability and P‐wave velocity were analysed. Finally, 10 natural reef limestone samples were used to verify the accuracy of the model. The prediction model enables an accurate evaluation of tunnel permeability, thus providing a scientific basis for the mitigation of tunnel water inrush hazards. [ABSTRACT FROM AUTHOR]

Introduction: The drilling industry is one of the main sectors of the oil industry, and oil drilling is one of the most specialized industrial activities. Large-scale production of sugarcane bagasse in Khuzestan Province creates an environmental opportunity to utilize this agricultural byproduct in different sections as a valuable byproduct. This study aimed to investigate the ability of the raw form of bagasse and its transformed structure in heavy metal fixation in drilling mud and to investigate the efficiency of crude bagasse, processed bagasse, and biochar adsorbents in removing heavy metals from the drilling mud residues of Ahvaz oil field. Methods: Sampling of drilling mud waste from Mishan Geological Formation (MGF) and Aghajari Geological Formation (AGF) was done on a vibrating sieve. The treatments examined in this research include the contact time in six levels (30, 60, 90, 120, 150, and 180 min), amount of the adsorbent in three levels (0.1, 0.5, and 1 g), adsorbent type in three levels (crude bagasse, processed bagasse, and biochar), and the formation type in two levels (Aghajari and Mishan). After chemical digestion, the samples were placed in contact with crude bagasse, processed bagasse, and biochar according to the designed conditions. Then, the removal percentages of Ba, Ni, V, Cd, Fe, and Pb were calculated. Means were compared using Duncan's test at the 1% level. Results and Discussion: The results showed that the biochar adsorbent is the most efficient compared to other adsorbents. The maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 72.53%, 68.89%, 79.49%, 76.88%, 49.42%, and 85%, respectively. In addition, the results showed that the maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 81/72%, 83/89%, 86/67%, 83/44%, 64/41%, and 90.72%, respectively. The maximum efficiency of biochar for adsorbing heavy metals Ba, Ni, V, Cd, Fe, and Pb is 90.70%, 91.84%, 88.89%, 88.75%, 78.59%, and 97.75%, respectively. The maximum amount of heavy metals adsorbed by all adsorbents was 1 gr/L, and the adsorption efficiency increased by increasing the amount of the adsorbent from 0.2 to 1 gr/L. In examining the effect of contact time, the maximum removal percentage of heavy metals barium and cadmium was obtained in 120 min, nickel and lead in 90 min, and vanadium and iron in 60 min. After the above contact times, there was no increase in the maximum percentage of metal removal. [ABSTRACT FROM AUTHOR]

The dissolution of CO2 in seawater in the form of bicarbonate ions is an attractive alternative to storage in geological formations, on the condition that the storage is stable over long periods and does not harm the marine environment. In this work, we focus on the long-term chemical stability of CO2 absorbed in seawater as bicarbonate by monitoring the physico-chemical properties of the solutions (pH, dissolved inorganic carbon and alkalinity) in six different sets of experiments on both natural and artificial seawater lasting up to three months. The bicarbonate treatment of natural seawater consists of mixing it with pre-equilibrated solutions obtained from the reaction of CO2 and Ca(OH)2, with the same pH as natural seawater. This was achieved with a pilot plant working with tons of seawater, while small-scale laboratory experiments were carried out by adding sodium bicarbonate to artificial seawater solutions. If the increase in the overall carbon concentration in the final mixture does not exceed a critical threshold (about 1000–1500 μmol/L), the resulting bicarbonate-rich solutions are found to be stable for over three months. [ABSTRACT FROM AUTHOR]

The composite strata structure is a common geological formation in western China. The study of the failure characteristics of the composite structure is of great help to the stability evaluation of stope and the prediction of coal mine dynamic disasters. In order to study the influence of different hard rock coefficients on the instability characteristics of composite samples, the triaxial tests with progressive varying confining pressure simulating the field loading condition were conducted on eight groups of composite samples with different hard rock coefficients. The bearing capacity of different samples was tested using the RMT-150B triaxial compression equipment, while the DS-5 type eight-channel acoustic emission monitoring system was employed for simultaneous monitoring of acoustic emission parameters. Additionally, the multifractal theory in mathematics is applied to the analysis of acoustic emission signals, exploring the multifractal characteristics of the time series of acoustic emission signals. The results show that the peak strength of the composite sample decreases first and then increases as the hard rock coefficient increases, which is consistent with the trend of the multifractal spectrum parameter $\Delta f\left(\alpha \right)$ Δ f α of the acoustic emission time series. A significant increase in the low-frequency and high-amplitude signal ratio can be used as a precursor to early indicate the instability in composite samples. The dynamic changes of multifractal parameters at different stages of the progressive varying confining pressure can reflect the influence of axial pressure and confining pressure on the crack propagation in the composite samples, and the two parameters at the hydrostatic pressure stage can be used as a rule-of-thumb for screening the testing samples. Simultaneously, the multifractal parameters can early warn the rock failure much more ahead of time than the conventional approach associated with the warning point obtained in the acoustic emission curves, and its head of time can be reaching 0.015 failure progress. HIGHLIGHTS: The influences of hard rock coefficient on the peak strength and failure mode of composite samples were studied. The multifractal characteristics of acoustic emission time series were analysed for composite samples with different hard rock coefficients. The multifractal parameters can be used to screen the testing sample with internal defects. Multifractal parameters can be used for early warning of rock failure. [ABSTRACT FROM AUTHOR]

Our increased reliance on fossil fuels and its environmental effects have led us to prioritize transitioning to a carbon-free economy and using renewable sources of electric power. Hydrogen is an environmentally friendly, non-carbon-based energy source that can replace fossil fuels. It is critical to create a long-term storage medium to balance its intermittent supply and demand. Developing a full-scale H 2 economy requires large-scale H 2 storage. H 2 storage in geological formations is being explored as a possible option where it can be withdrawn again at a larger stage for utilization. This study examines global underground operational and prospective locations to provide a comprehensive overview of the current state of hydrogen storage worldwide. Underground geological formations have effectively stored H 2 , as shown in the literature review. Geochemical, microbiological, hydrodynamic, and geomechanic factors affected by injected hydrogen are some of the key challenges in storing hydrogen in deep geological formations. These factors have a significant impact on the project's performance and operating efficiency. A roadmap for the implementation of underground hydrogen storage (UHS) is presented. The economic aspects of UHS were analyzed. Research is still ongoing on the potential effects of storing hydrogen in salt caverns, depleted oil and gas reservoirs, and saline aquifers, subsurface geological media. This study also encompasses the state-of-the-art hydrodynamic, geo-chemical and geo-mechanical modeling studies in the UHS domain, as well as several modeling software tools. Finally, conclusions, recommendations and further investigations were provided. • Major kinds of underground hydrogen storage (UHS) are assessed. • UHS either pure or in the form of a gas mixture, is a promising approach. • UHS is not yet ready for complete industrial and nationwide integration. • Modeling techniques improve understanding of underground reservoir dynamics. • UHS in salt caverns is seen as technically mature. [ABSTRACT FROM AUTHOR]

The geological formation of the Muschelkalk is widespread in the center of the North German Basin (NGB) and is increasingly attracting interest for application of geothermal energy extraction or high-temperature aquifer thermal energy storage (HT-ATES). This study investigates the Middle Triassic "Rüdersdorfer Schaumkalk", which was the former injection horizon of the natural gas storage facility in Berlin, Germany. For the first time, detailed chemical and microbiological analyses of formation water of this Lower Muschelkalk limestone formation were conducted and hydrogeochemically characterized. In addition, a hydrogeochemical model was developed to quantify the potential reactions during HT-ATES focusing on calcite dissolution and precipitation. The main objectives of this study are: (1) to determine the origin of the water from the three wells targeting the Muschelkalk aquifer, (2) to understand changes in hydrochemistry after system operation, and (3) to evaluate the long-term sustainability of a potential HT-ATES system with increasing temperature. The target formation is encountered by several wells at about 525 m below the surface with an average thickness of 30 m. Two hydraulic lifting tests including physical, chemical, and microbial groundwater as well as gas monitoring were carried out. In addition, several downhole samples of formation fluid were collected from the aquifer at in situ pressure and temperature conditions. Fluid analysis of the saline formation water indicate a seawater origin within the Muschelkalk with subsequent evaporation and various water–rock interactions with anhydrite/gypsum, dolomite, and calcite. With a salinity of 130 g/L, dominated by Na–Cl, a slightly acidic pH between 6 and 7, and a low gas content of 3%, the formation water fits to other saline deep formation waters of the NGB. Gas concentrations and microbial communities like sulfate-reducing bacteria and methanogenic archaea in the produced water indicate several geochemical alterations and microbial processes like corrosion and the forming of biogenic methane. Geochemical simulations of calcite equilibrium over 10 HT-ATES cycles indicated a pronounced propensity for calcite precipitation up to 31 mg/kgw, within the heat exchanger. At the same time, these models predicted a significant potential for calcite dissolution, with rates up to 21 mg/kgw, in both the cold and hot reservoirs. The results from the carbonate aquifer characterized in this study can be transferred to other sites in the NGB affected by salt tectonics and have provided information on the microbiological-chemical processes to be expected during the initial use of old wells. [ABSTRACT FROM AUTHOR]

Geological Culture Villages Towns (GCV(T)s) serve as rich repositories of geological resources, embodying significant historical and cultural values that mirror the dynamic interplay between Earth's evolution and human societies. Despite their importance, the theoretical underpinnings of GCV(T)s have not been thoroughly explored and elucidated. This study explores the relationship between geological culture and societal development, revealing the linkage between geological culture and societal advancement with the aim of promoting a harmonious coexistence between humanity and the environment. Focusing on 96 GCV(T)s in China, this study employs spatial analytical techniques such as the nearest-neighbor index, kernel density analysis, geographic connectivity, and geographic detector to scrutinize the spatial distribution patterns and identify key influencing factors. The findings reveal that (1) GCV(T)s exhibit uneven distribution, with concentrations in the Yangtze River Delta region, Beijing-Tianjin-Hebei region, and Shanxi-Gansu and Ningxia Provinces. (2) These sites tend to be situated in areas characterized by active geological formations, abundant geological relics, higher elevations, gentle topography, and ample rainfall. (3) The establishment and evolution of GCV(T)s are shaped by a complex interplay of geological heritage, natural factors, and human interventions. While the selection and spatial arrangement of these sites are predominantly influenced by geological and natural factors, the innovative development of their geological cultural heritage is driven by humanistic considerations. Overall, the distribution and evolution of GCV(T)s stem from multifaceted interactions among diverse factors. Recognizing this intricate web of influences is crucial for safeguarding geocultural diversity and formulating conservation strategies for geoheritage protection. The development of GCV(T)s transcends mere geoheritage preservation, it embodies a pivotal stride toward safeguarding the varied and multi-dimensional global geoheritage. [ABSTRACT FROM AUTHOR]

This study provides a critical review of Underground Hydrogen Storage (UHS), emphasizing its potential as a viable energy storage option despite several associated challenges. These challenges include microbial degradation, chemical reactivity, unique thermophysical characteristics, and geomechanics considerations. Effective and secure UHS operation requires careful site selection, management, and a thorough understanding of hydrogen's behavior under various geological and operational conditions. Our review examines the significance of hydrogen's physical properties, H 2 -fluid-rock dynamics, redox-driven geochemical interactions, microbial activities, and geomechanical risks influencing UHS performance, safety, and containment. Additionally, we discuss the importance of optimal material selection and operational strategic development to maximize UHS efficiency and minimize associated risks. While global projects and ongoing research form a solid foundation for UHS development, ensuring UHS effectiveness and safety requires further investigation. This article also identifies the main knowledge gaps and future research directions for effective deployment of UHS projects. [Display omitted] • Assessment of geological formations suitable for UHS, including salt caverns, depleted reservoirs, and saline aquifers. • Insights derived from global UHS projects inform best practices. • H 2 physical properties and the complex H 2 -fluid-rock dynamics are crucial for ensuring UHS efficiency and safety. • Geochemical reactions, microbial activities, and geomechanics may affect UHS performance and integrity. • Geologic and operational parameters are keys to achieving optimal UHS performance. [ABSTRACT FROM AUTHOR]

Worldwide, silicified woods are found in many geological formations. Significantly, the organic materials of wood are no longer dominant; almost all wood fossils have been mineralized into inorganic silica materials. These unique geological processes must be understood to develop better understanding on organic material fossilization, particularly in the micron scale. Therefore, our aim was to characterize the composition of silicified wood using comprehensive microanalysis. The methods utilized were XRF, ICP-MS, XRD, FTIR, and FE-EPMA. Specimens are from Jasinga, West Java, Indonesia. The results showed that wood silicification was controlled by the infiltration of silica from the host rock into the spaces of the wood structure. In Jasinga, they are controlled by Pliocene tuffaceous sedimentary rocks. The ratio of silica phases revealed a trend in the degree of silicification. Besides silica, the distribution of trace elements also demonstrates the geochemical interaction between the wood fossil and host rock. Wood fossils are affected by the gradual replacement of organic carbon-based materials with silica through silicification. Silica enrichment occurs in the internal of wood, facilitates permineralization and recrystallization. Silica replaces organic material and preserves the wood structures. The microanalytical approach provides comprehensive perspectives on wood petrification, leads to better insights for paleontological studies. [ABSTRACT FROM AUTHOR]

Despite the elevated heat flow known in the Western part of the South Slave Region (Northwest Territories, Canada), a continuous and equilibrium geothermal gradient was never measured in boreholes below the communities where geothermal energy could be developed. This paper aims to predict the geothermal gradient and assess the Earth's natural heat flow below the communities of Fort Providence, Kakisa, Hay River, and Enterprise. Temperatures from drill-stem tests and bottom well logs were corrected for drilling disturbance and paleoclimate. The thermal conductivity and heat generation rate of the geological formations were determined from the literature and with new laboratory measurements. Original 1D models were developed to evaluate subsurface temperature through the sedimentary formations based on a thermostratigraphic assessment. The results indicate a geothermal gradient that varies from 44.1 ± 10.6 °C km−1 to 59.1 ± 14.9 °C km−1 and heat flow that varies from 105.5 mW m−2 to 160.2 mW m−2 below the communities. These estimates were in agreement with the equilibrium geothermal gradients measured in Cameron Hills, south of the four communities, and were used to verify our predictions. The highest geothermal gradient (59.1 ± 14.9 °C km−1) was estimated at Hay River, which, therefore, has the most favorable geological conditions for geothermal development. [ABSTRACT FROM AUTHOR]

Commercial scale decarbonization through carbon capture and storage may likely involve many CO2 storage projects located in close proximity. The close proximity could raise concerns over caprock integrity associated with reservoir pressure buildup and interference among adjacent projects. Commercial-scale injection will also require large prospective CO2 storage resource and high injectivity in the targeted storage formations. To accommodate the need for both large resource and high injectivity, project operators could consider injecting CO2 into a stacked sequence of formations. This analysis investigates the benefits of injecting CO2 into a vertically stacked sequence of saline formations, over injecting the same amount of CO2 into a single saline formation, in addressing these challenges. Our analysis shows that injecting into the stacked sequence mitigates the extent of pressure buildup among the stacked formations, while still achieving the same or greater target CO2 storage volumes. Among cases modeled, the resulting pressure buildup front is most reduced when each storage site distributes injection volumes over several wells, each of which injects a portion of the total CO2 mass across the stacked sequence. This favorable case not only results in the smallest CO2 aerial footprint, but also shows the largest reduction in the pressure buildup at the top of perforation at the injection wells (upwards of approximately 46% compared to the single-formation storage), the result of which is crucial to maintain caprock integrity. This analysis provides insights into required decision-making when considering multi-project deployment in a shared basin. [ABSTRACT FROM AUTHOR]

Barium (Ba) dissolution and mobilization in groundwater are predominantly controlled by sulfate because of the low solubility of barium sulfate (BaSO4) minerals. Naturally present at low concentrations in groundwater, elevated concentrations of Ba can occur as a result of anthropogenic activities, including use of barite in drill operations, and geogenic sources such as leaching from geological formations. No toxicity data exist for Ba with groundwater organisms (stygofauna) to assess the risk of elevated Ba concentrations. The present study measured Ba toxicity to two stygobiont Cyclopoida species: one collected from Wellington and the other from Somersby, New South Wales, Australia. Toxicity was measured as cyclopoid survival over 2, 4, 7, 14, 21, and 28 days in waters of varying sulfate concentration (<1–100 mg SO4/L). When sulfate was present, dissolved Ba concentrations decreased rapidly in toxicity test solutions forming a BaSO4 precipitate until dissolved sulfate was depleted. Barium in excess of sulfate remained in the dissolved form. The toxicity of Ba to cyclopoids was clearly attributed to dissolved Ba. Precipitated Ba was not toxic to the Wellington cyclopoid species. Toxicity values for dissolved Ba for the Wellington and Somersby cyclopoid species included a (21‐day) no‐effect concentration of 3.3 mg/L and an effective concentration to cause 5% mortality of 4.8 mg/L (at 21 days). Elevated dissolved Ba concentrations due to anthropogenic and/or biogeochemical processes may pose a risk to groundwater organisms. Further toxicity testing with other stygobiont species is recommended to increase the data available to derive a guideline value for Ba that can be used in contaminant risk assessments for groundwaters. Environ Toxicol Chem 2024;00:1–14. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

This study presents a detailed compilation of hydrogen losses in porous media from various literature. In addition, it models the expected recovery factors and productivity indices in three types of geological water-bearing formations – shallow reservoirs with normal geothermal gradients, shallow reservoirs with high geothermal gradients, and deep saline aquifers. The study considers and applies the estimated losses reported in the literature to 30-day, 90-day, and 180-day storage cycles. The findings show that hydrogen recovery from water-bearing formations when potential losses are accounted for could range from 13% to 83% for both sandstone and carbonate reservoirs. This also depends on the storage cycle duration and the type of aquifer. Deep saline aquifers have larger hydrogen recovery factors for all cycles but have smaller productivity indices compared to shallow reservoirs. When maximum possible losses are considered, deep saline aquifers have better productivity indices beyond 150-day storage cycles. Reservoirs with large geothermal gradients and temperatures exceeding 120 °C are okay for hydrogen storage as long as there is sufficient cushion gas. Such reservoirs show great potential for larger hydrogen recovery and productivity indices if long-duration storage (>180 days) is required. Mineralogy was not as significant as depth, temperature, and salinity in contributing to hydrogen losses. [ABSTRACT FROM AUTHOR]

Qinghai Province, as a core component of the Qinghai-Tibet Plateau, shares similar geological and geomorphological formations as well as an evolutionary history of its natural ecosystem with the entire Qinghai-Tibet Plateau. Within Qinghai, there exist 97 families, 595 genera, and 3 558 species of wild seed plants. Based on the author's extensive field research and data accumulation, this article presents a classification and analysis of the distribution area types of all plant families, genera, and species in Qinghai. The key findings are as follows: (1) Qinghai hosts all 15 areal-types described in Mr. Wu Zhengyi's "Distribution Area Types of Chinese Seed Plant Genera" indicating the richness of its floral components and the complexity and diversity of its ecological and geographical environment. (2) Tropical types, primarily represented by pan-tropical distributions, are characterized by marginal distribution within Qinghai, with the absence of woody types. (3) At the genus level, the core components of Qinghai's flora are predominantly warm-cold genera gen originating from the Northern temperate zone and East Asia. However, at the species level, species distributed in Temperate Asia and East Asia dominate. (4) The unique Chinese type of flora in Qinghai reflects its close affinity with the flora of Southwest China (Hengduan Mountains) and the Himalayas, and exhibits distinct alpine flora characteristics of the Qinghai-Xizang Plateau. (5) The southwest and northern floras of China have great influences on Qinghai with different extents. (6) Qinghai has three distinct ecological zones in Qinghai: the warm and humid Qilian Mountains, the alpine southern Qinghai Plateau, and the temperate and arid Qaidam Basin, and each zone exhibits distinct and prominent characteristics. Intersection of the three zones reveals the transitional nature of the flora. (7) The terminal or marginal distribution areas of many plant species in Qinghai are particularly evident, marked by the westernmost extent of their distribution ranges and the highest altitudinal limits. (8) Qinghai's flora exhibits a youthful and derived taxonomic nature, primarily consisting of perennial herbaceous species and a paucity of woody types. This analysis concludes that Qinghai's flora is dominated by northern temperate components, particularly those endemic to the temperate and cold zones of Eurasia. Qinghai possesses the temperate flora attributes of warmth, cold, and alpine types, reflecting the complexity of its flora. For the first time in China, a "species-level" distribution area type system for wild seed plants in Qinghai has been established. [ABSTRACT FROM AUTHOR]

The article presents the discussion on career and academic achievements of Professor Tomasz Zieliński, born on October 3, 1952, in Starachowice, who specialized in Quaternary geology and held prominent positions at the University of Silesia and Adam Mickiewicz University. Topics include his educational background, significant research contributions leading to his habilitation degree; and his roles in administrative and scientific functions.

This work aims to explore the Lower Silurian shale gas and tight sandstone gas accumulation conditions in the Gongtan Syncline, southeastern Sichuan Basin. The sedimentary environment, organic geochemical characteristics, reservoir characteristics, gas content, and preservation conditions of the reservoir were comprehensively analyzed. The results show that the Wufeng–Longmaxi Formation shale formed in a deep-water shelf characterized by a large thickness (50–70 m), appropriate total organic carbon content (0.5–5.47%), high maturity (2.38%), high brittle mineral content (67.10%), and large gas content (0.71–1.64 m3/t), and the formations show the good resource potential of the shale gas. The Xintan Formation formed in a lower shore phase, and the tight sandstone is locally developed with a small thickness. The Xiaoheba Formation formed in an upper-middle shore phase, and the tight sandstone is stably distributed with large thicknesses. The porosity and permeability of the two sets of sandstone are small and some natural fractures are developed in the sandstone, but the fracture filling degree is higher. The results of well logging show that there are abnormally high values of total hydrocarbon in both the Xintan Formation and Xiaoheba Formation; this indicates that tight sandstone gas is developed in the Lower Silurian strata. A comprehensive study indicates that the Lower Silurian of the Gongtan Syncline has the geological conditions for the formation of shale gas and tight sandstone gas, which are the "Two gases" with good co-exploration prospects. [ABSTRACT FROM AUTHOR]

Numerical simulation of multiphase flow in porous media is an important step in understanding the dynamic behavior of geologic CO 2 storage (GCS). Scaling up GCS requires fast and accurate high-resolution modeling of the storage reservoir pressure and saturation plume migration; however, such modeling is challenging due to the high computational costs of traditional physics-based simulations. Deep learning models trained with numerical simulation data can provide a fast and reliable alternative to expensive physics-based numerical simulations. We propose a Stochastic pix2vid neural network architecture for solving multiphase fluid flow problems with significant speed, accuracy, and efficiency. The Stochastic pix2vid model is designed based on the principles of computer vision and video synthesis and is able to generate dynamic spatiotemporal predictions of fluid flow from static reservoir models, closely mimicking the performance of traditional numerical simulation. We apply the Stochastic pix2vid model to a highly-complex CO 2 -water multiphase problem with a wide range of reservoir models in terms of porosity and permeability heterogeneity, facies distribution, and injection configurations. The Stochastic pix2vid method is first-of-its-kind in static-to-dynamic prediction of reservoir behavior, where a single static input is mapped to its dynamic response with a fixed number of timesteps. The Stochastic pix2vid method provides notable performance in highly heterogeneous geologic formations and complex estimation such as CO 2 saturation and pressure buildup plume determination. The trained model can serve as a general-purpose, static-to-dynamic (image-to-video) alternative to traditional numerical reservoir simulation of 2D CO 2 injection problems with up to 6,500 × speedup compared to traditional numerical simulation using the MATLAB Reservoir Simulation Toolbox. [ABSTRACT FROM AUTHOR]

This study is conducted within the Gambia River Basin Development Organization Energy Project (OMVG) framework. The construction of a high voltage interconnection network fed by a hydropower station to supply electricity to OMVG Member States was done on stable ground. During the installation pits for the pylons in Labé Prefecture, Republic of Guinea, cavities were discovered in the geological formations during the initial planned route. Structurally, the study area is bounded by two major faults to the east and west of northeast direction. The geomorphology is made up of a central plateau, intermountain depressions, piedmont plains, talwegs, and glacis. Geological investigations were obtained by a geophysical Two-dimensional Electrical Resistivity Tomography (ERT) method. The results show that the synthetic lithological profile from top to base was sandy-clayey soil, hard cuirass, and a layer of gravel followed by a mottled zone comprising an indurated part and an imbibed part just before the source rock. The cavities were observed probably because of the dissolution of certain minerals constituting the weathering crust due to the infiltration, underground waters, and the seasonal variation in the level of the surface watercourses. Geophysical results showed a very good agreement with the visual observations. [ABSTRACT FROM AUTHOR]

Saturn's mid-sized icy moons have complex relationships with Saturn's interior, the rings, and with each other, which can be expressed in their shapes, interiors, and geology. Observations of their physical states can, thus, provide important constraints on the ages and formation mechanism(s) of the moons, which in turn informs our understanding of the formation and evolution of Saturn and its rings. Here, we describe the cratering records of the mid-sized moons and the value and limitations of their use for constraining the histories of the moons. We also discuss observational constraints on the interior structures of the moons and geologically-derived inferences on their thermal budgets through time. Overall, the geologic records of the moons (with the exception of Mimas) include evidence of epochs of high heat flows, short- and long-lived subsurface oceans, extensional tectonics, and considerable cratering. Curiously, Mimas presents no clear evidence of an ocean within its surface geology, but its rotation and orbit indicate a present-day ocean. While the moons need not be primordial to produce the observed levels of interior evolution and geologic activity, there is likely a minimum age associated with their development that has yet to be determined. Uncertainties in the populations impacting the moons makes it challenging to further constrain their formation timeframes using craters, whereas the characteristics of their cores and other geologic inferences of their thermal evolutions may help narrow down their potential histories. Disruptive collisions may have also played an important role in the formation and evolution of Saturn's mid-sized moons, and even the rings of Saturn, although more sophisticated modeling is needed to determine the collision conditions that produce rings and moons that fit the observational constraints. Overall, the existence and physical characteristics of Saturn's mid-sized moons provide critical benchmarks for the development of formation theories. [ABSTRACT FROM AUTHOR]

When seismic waves propagate through the geological formation, there is a significant loss of energy and a decrease in imaging resolution, because of the viscoacoustic properties of subsurface medium. This profoundly impacts seismic wavefield propagation, imaging and interpretation. To accurately image the true structure of subsurface medium, the consensus among geophysicists is to no longer treat subsurface medium as ideal homogeneous medium, but rather to incorporate the viscoacoustic properties of subsurface medium. Based on the generalized screen propagator using conventional acoustic wave equation (acoustic GSP), our developed method introduces viscoacoustic compensation strategy, and derives a one-way wave generalized screen propagator based on time-fractional viscoacoustic wave equation (viscoacoustic GSP). In numerical experiments, we conducted tests on two-dimensional multi-layer model and the Marmousi model. When comparing with the acoustic GSP using the acoustic data, we found that the imaging results of the viscoacoustic GSP using the viscoacoustic data showed a significant attenuation compensation effect, and achieved imaging results for both algorithms were essentially consistent. However, the imaging results of acoustic GSP using viscoacoustic data showed significant attenuation effects, especially for deep subsurface imaging. This indicates that we have proposed an effective method to compensate the attenuated seismic wavefield. Our application on a set of real seismic data demonstrated that the imaging performance of our proposed method in local areas surpassed that of the conventional acoustic GSP. This suggests that our proposed method holds practical value and can more accurately image real subsurface structures while enhancing imaging resolution compared with the conventional acoustic GSP. Finally, with respect to computational efficiency, we gathered statistics on running time to compare our proposed method with conventional Q-RTM, and it is evident that our method exhibits higher computational efficiency. In summary, our proposed viscoacoustic GSP method takes into account the true properties of the medium, still achieves migration results comparable to conventional acoustic GSP. [ABSTRACT FROM AUTHOR]

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This study is the first attempt to characterize the quality status of El Fahs aquifer by combining graphical tools, multivariate statistical techniques and traditional geostatistical methods. Water samples are collected from thirty-six observation wells during April 2016 to characterize the physicochemical properties of the aquifer. Subsequently, these samples are partitioned into three hydrochemically distinct water classes (i.e., C1, C2, and C3) using the K-means clustering method. Principal Component Analysis is used to reduce the dimensionality of the dataset prior performing the clustering computations, resulting in clusters of higher quality than the non-reduced case in terms of Silhouette coefficient. Piper diagram is used to display the chemical composition of the samples, revealing the dominant role of Mg–Ca–Cl water type for all three classes, whereas Sodium and Sulfate were found to be the second most important cations and anions respectively. Indicator kriging (IK) is used to identify the probability of occurrence of the hydrochemical classes beyond the sampling locations. It is found that Class 1, associated with fresh groundwater component, is most probable to occur at the central part of the plain, mainly due to the presence of a dense hydrological network, whereas Classes 2 (agricultural activities) and 3 (dissolution of evaporate geological formations) are expected to occur at the southern and northern regions respectively. IK also identified the regions associated with high levels of uncertainty, mostly occurring in a large portion of the northern area due to the absence of available hydrochemical information. The results showed that integration of graphical methods, multivariate statistical techniques and geostatistical modeling, is an efficient approach for characterizing the hydrochemical status of the aquifer system, to spatially optimize the groundwater monitoring well networks and quantify the uncertainty levels of the water classes in a systematic way. [ABSTRACT FROM AUTHOR]

Assessment of the current state of the near-surface part of the geological environment and understanding of its layered structure play an important role in various scientific and applied fields. The presented work is devoted to the application of phasometric modifications of geoelectric control methods to solve the problem of the detailed complex study of the underground layers of the environment in the process of drilling operations with the use of special equipment. These studies are based on the analysis of variations in phase parameters and characteristics of an artificially excited multiphase electric field to assess poorly distinguishable details and changes in the layered structure of the medium. The proposed method has increased accuracy, sensitivity and noise proofness of measurements, which allows for extracting detailed information about the heterogeneity, composition and stratification of underground geological formations not only in the zone where the drill makes contact with the medium, but also in the entire control zone. This paper considers practical mathematical models of phase images for basic scenarios of drill penetration between the layers of the near-surface part of the geological medium with different characteristics, obtained by means of approximation apparatus based on continuous piecewise linear functions, and also suggests the use of modern machine learning methods for intelligent analysis of its structure. Studying the phase shifts in electrical signals during drilling highlights their value for understanding the dynamics of soil response to the process. The observed signal changes during the drilling cycle reveal in detail the heterogeneity in soil structure and its response to changes caused by drilling. The stability of phase shifts at the last stages of the process indicates a quasi-equilibrium state. The results make a significant contribution to geotechnical science by offering an improved approach to monitoring a layered structure without the need for deep drilling. [ABSTRACT FROM AUTHOR]

In order to scientifically and rationally evaluate the susceptibility to landslide hazards in Tekes County, Yili State. This paper takes Tekes County in Xinjiang as an example, on the basis of a comprehensive analysis of the regional geological environment conditions and the distribution pattern and formation conditions of geological disasters, using the data of geological disaster points (landslide center points), and through the correlation matrix calculation of the evaluation factors, the nine evaluation factors with larger absolute values of correlation coefficients were determined to construct the evaluation system of the susceptibility to landslide geological hazards in Tekesi County. Combining the information quantity method and the entropy value method, using the weights determined by the entropy value method, the information quantity method is used to calculate the information quantity value of each factor within the factor, calculate the susceptibility index of landslide geological disasters within the territory of Tekes County, and then carry out the landslide susceptibility evaluation. The susceptibility of landslide disasters was evaluated by ArcGIS. The results show that the landslide disaster susceptibility level in Tekes County can be divided into four levels: high susceptibility, medium susceptibility, low susceptibility, and not susceptible, with areas of 491.3276 km2, 1181.5171 km2, 1674.7609 km2 and 5295.2976 km2 accounting for 5.68%, 13.67%, 19.38% and 61.27% of the total area of Tex County, respectively. The AUC number obtained by the success curve method (ROC) is 0.8736, reflecting the evaluation accuracy of 87.36%, indicating that the model method used in this paper is effective. The results are expected to provide practical data support for landslide disaster control in Tekes County and provide a reference for geological disaster monitoring, early warning and engineering prevention and control deployment in Yili Valley. [ABSTRACT FROM AUTHOR]

The Carpathian belt is one of Europe's major metallogenic provinces, where magmatic ore mineralization is associated with the past subduction environment. The upper crust is mapped for the first time in the Northeast Carpathian Volcanic Arc using magnetotelluric data inversion. The obtained 3‐D electrical resistivity model is interpreted in conjunction with geological information and magnetic anomaly data. The model illustrates the deep magmatic plumbing system including kilometer‐scale plutonic bodies at a depth of 2–7 km. The model implies that the transport of magma and fluids in the uppermost crust was controlled by pre‐existing faults and décollement horizons. Present ore mineralization, mined since historical times, can be attributed to an electrically conductive conduit that is mapped from the surface to a depth of about 30 km. It is suggested that this conduit connected a shallow magmatic chamber to a deep source region in the southeast during late Miocene time. An observed northwest deflection of the deep magmatic conduit at a depth of more than 10 km may explain the spatial gap in the distribution of the Miocene volcanic activity along the Eastern Carpathians. Plain Language Summary: The Carpathian Mountains have long been exploited for their metal ore deposits, which have been associated with the subduction of tectonic plates. Studying the natural variations of the regional electric and magnetic fields, we estimate the distribution of subsurface electrical resistivity. Subsurface electrical structures are interpreted as deep magma systems and large plutonic bodies. The interpretation implies that regional volcanic activity has been controlled by faults, large fractures in geologic formations, and detached strata. Specifically, historic mining can be attributed to a large conductive body that can be mapped from surface to about 30 km. Data suggest that this body, which could represent a pathway of magmatic fluids, connects to a deep, southeastern mantle source region. Key Points: 3‐D magnetotelluric survey in northeast Carpathian Mountains elucidates the structure of the Miocene volcanic provinceNew data reveal shallow magmatic‐hydrothermal system connected to a deep source region via an inclined conductive conduitCenturies‐old mines align with an electrically conductive layer interpreted as a clay alteration related to hydrothermal activity [ABSTRACT FROM AUTHOR]

Inorganic arsenic species exist in the environment as a result of both natural sources, such as volcanic and geothermal activities, and geological formations, as well as anthropogenic activities, including smelting, exploration of fossil fuels, coal burning, mining, and the use of pesticides. These species deposit in water, rocks, soil, sediments, and the atmosphere. Arsenic-contaminated drinking water is a global public health issue because of its natural prevalence and toxicity. Therefore, chronic exposure to arsenic can have deleterious effect on humans, including cancer and other diseases. This work describes the mechanisms of environmental exposure to arsenic, molecular regulatory factors involved in its metabolism, genetic polymorphisms affecting individual susceptibility and the toxic effects of arsenic on human health (oxidative stress, DNA damage and cancer). We conclude that the role of single nucleotide variants affecting urinary excretion of arsenic metabolites are highly relevant and can be used as biomarkers of the intracellular retention rates of arsenic, showing new avenues of research in this field. • Inorganic arsenic exposure and its impact on the human health. • Genetic polymorphisms and it role on urinary excretion of arsenic metabolites. • Susceptibility and potential risk of toxic effects by ingestion of inorganic arsenic. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the characteristics of slates and metamorphosed shales in Hamadan province for their potential use in brick production. Firstly, the slatey and shaley units of geological Formations in Kabudar Ahang, Razen, Hamedan, and Tuserkan with a scale of 1:100,000 were identified, and their geological and petrological data of metamorphic units were collected. Following field visits, five sampling locations were selected. The results of the chemical analysis of the main oxides and X-Ray Diffraction analyses confirmed that the lithological composition of the sampling sites is slate and metamorphosed shales. According to the results of the data obtained from the chemical analysis, the composition of the studied rocks meets the required standards for brick preparation (Standard No. 7 of the National Standards Organization of Iran). After preparing the samples, physical, chemical, and mechanical tests were conducted on the bricks. The density values of the manufactured bricks indicate they are lighter than regular bricks. Water absorption of the produced bricks is within the acceptable range for facing bricks and pressed bricks according to Iran's national standard. All the slate and metamorphosed shale bricks are in good condition in terms of strength and can be used for engineering, facing, and pressed bricks. Results of the freezing test on the bricks subjected to 50 cycles of freezing and thawing show that the weight loss percentage of the samples falls within the permissible limit of Iran's national standard (No.7). Also, the amount of soluble salts in the bricks is at the optimal level. Overall, all the properties examined in the slate bricks comply with relevant standards, indicating their suitability for use in the brick-making industry, which is economically and environmentally significant. [ABSTRACT FROM AUTHOR]

Copyright of REMAH Journal is the property of Research & Development of Human Recourses Center (REMAH) 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 Geology & Exploration is the property of Geology & Exploration 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.)

Radon is present in most groundwater hosted by geological formations rich in uranium. It is a gas that dissolves easily in water, poses a potential health risk when present in water used in homes. For this purpose, an exploring study of radon concentration in groundwater was conducted in three selected areas in Morocco (the Anti-Atlas, the High Atlas and the Bahira areas) using RAD-7 detector. The radon contents measured in the 34 groundwater samples, range from 0.36 to 577.1 Bq L− 1, with average of 52.99 Bq L− 1. Among them, only three samples exceed the accepted limit of 100 Bq L− 1, established by the world health organization and the European Commission. Considering the level recommended by U.S. environmental protection agency, 67.64% of the samples measured had concentrations greater than 11.1 Bq L− 1. These results indicate significantly higher 222Rn concentrations in the groundwater of the Anti-Atlas compared to the High Atlas and occidental Meseta. This disparity could be attributed to the variation in lithology between these three different regions, as the granites are mainly the primary sources of radon in the region. The obtained annual effective doses show values ranging from 0 mSv y− 1 to 2.10 mSv y− 1 for the three regions, with samples in the Anti-Atlas and Bahira exceeding the safety limit of 0.1 mSv y− 1 proposed by both the WHO and the European Commission. This exploring study is important for both the environment and human health since it can provide important information for radon-related regulations and programs. [ABSTRACT FROM AUTHOR]

Geothermal energy, recognized as a clean energy source, has attracted widespread attention for its extraction. However, it is located in deep and complex geological formations, presenting a significant challenge to the drilling operations of existing Polycrystalline Diamond Compact (PDC) drill bits. To further understand the rock-breaking mechanism of PDC cutters in deep geological formations and improve rock-breaking efficiency, a finite element model employing the cohesive zone method was developed for a saddle-shaped PDC cutter (SC). This model was validated against experimental simulations, proving its capability to capture real rock crack initiation during the simulation process accurately. By analyzing the formation of cracks under cutting forces, the SC's rock-breaking mechanism was explored and compared with conventional cutters (CCs), clarifying its advantages. Additionally, the model analyzed the effects of different confined pressures, back rake angles, and structural parameters on crack formation in SC rock-breaking, highlighting directions for structural optimization. Full-scale drill bit rock-breaking simulations were conducted to verify the effectiveness and optimization of single cutter usage. The results indicated that the total number of cracks and the generation of tensile cracks determine the rock-breaking efficiency of the cutter. A lower total number of cracks and a higher proportion of tensile cracks lead to better rock-breaking performances. Due to its unique ridged and curved structure, the SC can generate concentrated and tensile stresses on the rock more effectively, resulting in fewer total cracks and a higher proportion of tensile cracks. The increase in confined pressure suppresses the generation of tensile cracks during rock-breaking, dispersing the rock-breaking energy, increasing the total number of cracks, and reducing rock-breaking efficiency. However, under the same conditions, using SC can effectively address these issues and enhance efficiency. For deep formation drilling, a back rake angle range of 15° to 20° is recommended for SC. The arc radius significantly impacts the SC's tensile cracks and total number of cracks, with a recommended arc radius range of 50 mm to 60 mm, and the SC structure could be modified from an arc to a straight line and back to an arc. The results contribute to enhancing the efficiency of deep drilling and theoretical research on drill bits. [ABSTRACT FROM AUTHOR]

Fracture is an important factor that affects the oil and gas productivity of carbonate reservoirs. Much researches have been done on the origin of high-angle fractures in carbonate reservoirs, but few efforts have been made on the genetic mechanical mechanism of low-angle fractures. Based on the seismic data, core data, conventional logging data and rock mechanics experimental data, combined with three-dimensional in situ stress field simulation methods, the features, formation geological conditions and genetic mechanical mechanism of low-angle fractures (LAFs) were analyzed by applying Coulomb–Moore criterion, Griffith criterion and non-coordination criterion. The proportion of the number of shear fractures is as high as 90.2%, while that of tensile fractures is only 9.8% in the study area. Shear fractures are mainly unfilled fractures, and tensile fractures are mainly partially filled fractures. The LAFs were formed in the second tectonic movement, in which the knee-fold structure with high in the west and low in the east developed in the study area. The buried depth of most parts of the KT-I formation is 800 m when the study area develops the knee-fold structure, with a maximum depth of 1800 m and a minimum buried depth of 70 m, and the dip angle of the steepest part of the stratum is about 20°. A large number of LAFs were formed in the study area under the joint influence of tectonics and abnormally high pressure of water, including near-horizontal LAFs in the non-weak fabrics section (type I low-angle shear fractures), the LAFs having a certain angle with bedding in the non-weak fabrics section (type II low-angle shear fractures) and near-horizontal LAFs in the weak fabrics section (type III low-angle shear fractures). The formation of type I and type II low-angle shear fractures follows the Coulomb–Moore criterion. Type I low-angle shear fractures are formed in strata with a certain dip angle, while type II low-angle shear fractures are formed in near-horizontal strata. Type III low-angle shear fractures are formed under the comprehensive influence of pre-existing weak fabrics and strong horizontal extrusion, which follows the non-coordination criterion. Low-angle tensile fractures are mainly caused by abnormally high pressure and reverse faults in the study area, following Griffith's criterion. The research in this paper not only reveals the formation mechanical mechanism of LAFs in pre-salt carbonate reservoirs but also provides guidance for the prediction of LAFs and solving the problem of water channeling caused by LAFs in oil fields. [ABSTRACT FROM AUTHOR]

The Taoudéni Basin, spanning 20% of Burkina Faso, holds vital aquifers for the Sahel's water security and development. However, limited understanding of these aquifers' hydrodynamics, including the flow patterns, mineralization processes, and renewal rates, hinders sustainable management practices in this arid region. Therefore, this study aims to investigate the aquifer hydrodynamics, mineralization processes and groundwater renewal in the transboundary Taoudéni Basin. Through a combination of hydrogeochemical and isotopic analyses, alongside existing data, this study examines 347 physicochemical samples, 149 stable isotope samples, and 71 tritium samples collected from 2013 to 2022. The findings reveal mineralization and stable isotopes (δ18O, δ2H) spatially aligned with the groundwater flow direction, validating this and indicating potentially multiple independent aquifers. The predominant mineralization mechanisms involve silicate hydrolysis and carbonate dissolution, supplemented by minor processes like evaporitic dissolution and cation exchange. The anthropogenic influence suggests potential groundwater recharge with potential pollution in the "SAC1", "SAC2", "GFR", "GGQ", and "GKS" geological formations. The stable isotopes (δ18O, δ2H) indicate recharge occurred over 4.5 kyr B.P., while tritium (3H) analysis confirms the presence of old, mixed waters, indicating slow renewal. Overall, this study highlights the minimal recent recharge and limited renewal rates, questions tritium's efficacy for old water detection, and emphasizes the need for sustainable management. [ABSTRACT FROM AUTHOR]

Geological formations with fractures are frequently encountered in various research fields. Accurately characterizing these fractured media is of paramount importance when it comes to tasks that demand precise predictions of liquid flow and solute transport within them. Since directly measuring fractured media poses inherent challenges, data assimilation (DA) techniques are typically employed to derive inverse estimates of media properties using observable state variables. Nonetheless, the considerable difficulties arising from the strong heterogeneity and non‐Gaussian nature of fractured media have diminished the effectiveness of existing DA methods. In this study, we formulate a novel DA approach known as parameter estimator with deep learning (PEDL) that harnesses the capabilities of DL to capture nonlinear relationships and extract non‐Gaussian features. To evaluate PEDL's performance, we conduct three case studies, comprising two numerical cases and one real‐world case. In these cases, we systematically compare PEDL with three widely used DA methods: ensemble smoother with multiple DA (ESMDA), iterative local updating ES (ILUES), and ES with DL‐based update (ESDL). Notably, in the problems characterized by highly non‐Gaussian features, ESMDA and ILUES produce significantly divergent results. Conversely, employing the DL‐based update, ESDL demonstrates improved performance. However, its estimation uncertainty remains high, potentially attributable to ESDL's updating mechanism. Comprehensive analyses confirm PEDL's validity and adaptability across various ensemble sizes and DL model architectures. Moreover, even in scenarios where structural difference exists between the accurate reference model and the simplified forecast model, PEDL adeptly identifies the primary characteristics of fracture networks. Key Points: A deep learning‐based data assimilation method, named parameter estimator with deep learning (PEDL), is proposed to characterize fractured media with highly non‐Gaussian featuresPEDL outperforms three popular data assimilation methods based on deep learning or the Kalman formulaComprehensive analyses confirm PEDL's validity and adaptability across various ensemble sizes and DL model architectures [ABSTRACT FROM AUTHOR]

The objective of this paper is to determine whether the flood-spreading system at the Tasuj station in east Azerbaijan, Iran, has caused inappropriate chemical alterations to the properties of the soil. One question is whether the flood-spreading system was constructed at an inappropriate location leading to unintentional consequences. Composite soil samples were taken from three flooded areas, from three grids in each flooding area, and from two depths. Chemical characteristics of the soil including electrical conductivity, pH, concentrations of bicarbonate, chloride, sodium, calcium, and magnesium ions, and the sodium adsorption ratio in the flooded areas were measured. Because of calcareous, gypsum, shale, and marl formations in the first flooded area, dissolution of solutes of these formations increased the concentration of ions in the runoff (especially sodium and chlorine, to 19.50 and 21.90 mmol (charge) L−1, respectively). These high ion concentrations caused the electrical conductivity of the runoff to increase significantly (up to 2.03 dS/m) compared to the other areas. High amounts of lime in the soil caused increasing buffering capacity of the area soil, as a consequence the flood-spreading did not cause significant changes to the soil pH and showed a difference of only 0.3–0.2 in the first flooded area compared to other areas. HIGHLIGHTS Soil samples were extracted from grids in multiple flood areas and from multiple depths.; Chemical characteristics in the flooded areas were measured.; It is concluded that the flood-spreading system was constructed in an appropriate location.; There is a minor problem associated with salts in the initial parts of flooded area.;

Labuan, Miri, Kundasang and Raub regions of Malaysia have very different geological formations and settings that could result in different levels of natural radioactivity. Hence, this study determines the influence of different geological formations on radioactivity in these locations using field measurements, petrology and geochemistry. A total of 141 gamma dose rates and 227 beta flux measurements were collected using Polimaster survey meters (PM1405) in these four regions. The gamma dose rate values range from 0.37 to 0.05 µSv/h with a mean value of 0.11 µSv/h. Beta flux values range from 3.46 to 0.12 CPS with a mean value of 0.57 CPS. Mineralogy and elemental composition of the different rock types were analysed using thin-section petrography, XRD, ICP and pXRF methods. Felsic igneous rocks such as syenite and granite have higher natural radioactivity and contain more radionuclide-bearing minerals such as apatite, zircon, allanite, K-feldspar, titanite, muscovite and biotite. Metamorphic rocks have the second highest natural radioactivity and contain fewer radioactive minerals. The natural radioactivity of sedimentary rocks mostly depends on their clay content. The gamma dose rate maps show that igneous and metamorphic regions around Raub have higher radioactivity compared to the sedimentary-dominated regions around Miri and Labuan. Annual effective dose (AED) and excess lifetime cancer risk (ELCR) were calculated to evaluate the potential health risk for inhabitants of these regions. Labuan and Miri are considered to be safe zones with respect to natural radioactivity as the results show little to no risk for the public, compared with the Raub region, which is medium to high risk. [ABSTRACT FROM AUTHOR]

Karst regions are characterized by unique geological formations that pose challenges to soil fertility and plant nutrition. In this study, we investigated the distribution and interactions of selenium (Se) in soils of Zheng'an County, a representative karst region in subtropical China. The results showed that the Se enrichment in the soils of Zheng'an County was high, with total contents ranging from 0.49 to 3.87 mg/kg and an average of 1.22 mg/kg, making the area Se-rich. Despite the abundance of Se, the effective percentage of Se uptake by plants was relatively low due to the generally moderately acidic nature of the soils in the region (pH: 5.98–6.60), which encourages the conversion of the available Se into forms that are not readily accessible. In addition, the high organic matter (OM) content (21.92–127.66 g/kg) promoted Se retention by interacting with Ca2+ in carbonate rocks. In addition, the clay content (50.73% to 76.19%) enhanced Se adsorption and limited Se availability. In conclusion, this study provides a basis for soil management and ecological restoration strategies in karst landscapes, highlights new insights into the dynamics of Se, and calls for further research to elucidate the Se availability mechanism and improve the efficiency of Se uptake by plants. Meanwhile, this study provides the first systematic study of Se transport and transformation, as well as Se-enriched Gastrodia elata in karst regions, and provides a preliminary understanding of the geochemical behavior of Se in karst regions. [ABSTRACT FROM AUTHOR]

Converting surplus renewable energy into hydrogen is considered an efficient technique to balance renewable energy generation and demand, which necessitates large-scale underground hydrogen storage (UHS) in geological formations. While the H 2 trapping mechanisms and fluid flow behavior have been rigorously reported in past studies, the performance of UHS is strongly influenced by the formation conditions and well configurations, which have not been explored thoroughly. To this end, this study investigated the sensitivity of UHS efficiency to variations in formation temperature, brine salinity, well placement, and well perforations. For each scenario, key aspects such as plume migration dynamics, residual trapping, dissolution trapping, structural trapping, H 2 recovery factor, and water production were thoroughly analyzed. The results indicate that factors such as formation temperature, brine salinity, and well perforations have a negligible impact on the shape of the overall H 2 plume. However, these significantly influence local H 2 saturations. Formations with higher temperatures, central dome well placement, and production wells in the top layers exhibit a higher H 2 recovery factor (as high as 69.93 %), whereas salinity plays a minor role in H 2 trapping and withdrawal (maximum change observed is ∼1.7 % and ∼1.4 % for trapping and withdrawal respectively with a 20 wt % increase in salinity). In addition, brine production is strongly influenced by the formation conditions and well configurations (e.g., ∼3965 m3 brine produced under at 343 K and ∼26,000 m3 for non-central well placement), due to variations in H 2 /brine properties, such as density and viscosity, and the extent of H 2 accumulation. [Display omitted] • Higher temperature reduces residual trapping and enhances the H 2 recovery factor. • Higher salinity observes a decrease in brine production. • Well placement strongly influences plume migration behaviors. • Well placement away from the central dome increases brine production. • Wells produced at the bottom layers demonstrate the highest percentage of mobile H 2. [ABSTRACT FROM AUTHOR]

The ongoing global energy shift from fossil fuels to renewable sources highlights the importance of underground hydrogen storage (UHS) as a sustainable mechanism to counterbalance the seasonal inconsistencies of renewable energy. Comparable to geological CO2 sequestration, UHS necessitates precise subsurface imaging and a thorough understanding of hydrogen behavior within geological formations, including its location and migration patterns. Since direct subsurface measurement is unattainable, there is a pronounced need for robust subsurface characterization and monitoring techniques. This research focuses on UHS feasibility in enduring storage scenarios, employing seismic monitoring strategies adapted from CO2 storage practices. Specifically, we integrate Continuous Active Source Seismic Monitoring (CASSM) and Time-Lapse Full Waveform Inversion (TLFWI) to scrutinize UHS. The study employs synthetic crosshole surveys that initially model the coexistence of hydrogen and water within fractured reservoirs, aiming to pinpoint hydrogen-related velocity alterations in acoustic waveforms. Subsequently, we utilize a time-lapse synthetic model of hydrogen injection to emulate CASSM observations. Utilizing TLFWI in conjunction with White's model, we successfully process the CASSM data to discern and quantify temporal variations in velocity and saturation, which effectively maps the spatial and temporal distribution of mobile hydrogen. The results affirm the capabilities of TLFWI and CASSM as proficient monitoring systems for UHS. This study aspires to offer a dependable methodology for the administration of large-scale and long-term geological hydrogen storage. • New method links seismic monitoring with waveform inversion. • Imaging shows changes in underground hydrogen storage. • Monitoring accurately pinpoints hydrogen in fractured reservoirs. • Patchy White's model tracks hydrogen saturation through velocity changes. [ABSTRACT FROM AUTHOR]

The stability of rock cliffs is a longstanding issue and is of practical significance. This case study demonstrates the application and use of advanced 3D modeling techniques, concentrating on the geological formations of the Xrobb l-Ġħaġin peninsula on the south-east coast of Malta, where the Xrobb l-Ġħaġin Neolithic site is located. In order to utilize a static and dynamic analysis of the investigated scenario, a 3D finite element model (FEM) of the geological formation in which the monument is set had to be created. To this end, 3D scanning, unmanned aerial vehicles (UAVs), and oblique photogrammetry were first used with state-of-the-art commercial packages for mesh reconstruction. As a result, a geometric and finite element model (FEM) was created, suitable for both static and dynamic analysis. In the second stage, a parametric investigation of the material properties of the structural system of the geological substrate was sought. The structural response of the system was evaluated for different loading scenarios assuming nonlinear finite element analysis. Collapse case scenarios were investigated for standard and weakened materials, predicting which components would collapse first and under which case of weakened materials the collapse occurs. Among other aspects, the main novelty of this paper lies in the integrated approach and multidisciplinary paradigm that supplement the available historical knowledge for this specific cultural heritage Neolithic site towards its conservation. [ABSTRACT FROM AUTHOR]

This study focused on determining the stratigraphic phenomena of the sequences of the Kirkuk group, within the Tertiary age, in the study area at the Buzurgan oil field within the Maysan governorate. In addition to various seismic lines from the completed seismic survey of the study region, data from the Buzurgan oil field wells was utilized. The stratigraphic interpretation results showed that the seismic sections of the Kirkuk Group formations are deposited in the form of a sigmoid configuration through the continuous deposition of shallow-shelf carbonates. Periodic rises in sea level led to episodes of deeper-water sedimentation, including shelf and shelf margin facies. Clastic (sandstone) was deposited as the sea receded from the Ghar formation, which represents the alluvial fan in the outer-shelf basin (slop and basin fan), through periods of sea-level (LST) and in a shallow-marine environment, leading to an overlap between sediments and the presence of sand lenses, onlap, and down lap. The current study shows the phase change in reflectors and perfect hydrocarbon indexes. The study detected a stratigraphic trap in the formation's eastern part and a large lens in the Southeast parts of the study area. [ABSTRACT FROM AUTHOR]