The initiation of the caving process in block/panel caving is critical to the success of mines. However, there is no widely adopted methodology for modeling the onset of caving. This study proposes a methodology to model the initial stages of caving using the Discrete Element Method, in which the rock mass is represented using the Bonded Particle Model, and the undercut material is modeled with non-cohesive discrete particles. The collapse of the rock mass was replicated following a parameter calibration process, and the results were compared with actual mining data of the observed initial fragmentation. Key parameters were identified, such as allowable normal and shear stresses, which are essential to accurately represent the collapse of the rock mass and the evolution of the early stage of rock fragmentation. Low allowable stress values led to premature collapse and finer fragmentation, whereas higher values delayed cave back failure and resulted in coarser initial fragmentation. The results showed the formation of large rock fragments between 14 and 15 m during the initial cave back failures. Subsequently, larger fragments ranging from 2 to 9 m were observed detaching from the cave back as draw progressed, with sizes comparable to those reported in some block/panel caving operations. The main contribution of this work is a methodology that demonstrates the feasibility of modeling caving initiation, which is crucial in a context where increasing rock mass strength and deposit depth require design changes at the production level and pose significant uncertainty in the rock mass response.

The hydrojet-shield machine, a rapidly advancing shield machine type, uses slurry for excavation and muck removal via a pipeline system. The pipeline includes a flushed feeding system that injects slurry into areas at risk of obstruction. This study provides a computational fluid dynamics (CFD) analysis of the flow characteristics of a large hydraulic shield machine, proposing the Particle Lifting Coefficient (L) and Regional Improvement Ratio (I) as innovative criteria to evaluate the effects of flow rate distribution and cutting wheel rotational velocity. By adjusting the proportion of scouring flow in the lower part of the chambers to 30%, 50%, and 100%, three flow distribution strategies, labeled as FC1, FC2, and FC3, were obtained to suit normal slurry transport conditions, address cutterhead mud accumulation, and deal with the deposition of rock and soil particles at the bottom of the chamber, respectively. The FC3 strategy amplifies the flow of symmetric jets in the lower scouring region, strengthening the upward flow that entrains surrounding fluid, thereby significantly increasing the L and I values in the targeted area and showing great potential for inhibiting the settlement and deposition of rock and soil debris. This study also emphasizes the need to integrate slurry jet distribution strategies with real-time monitoring of cutterhead mud accumulation and chamber deposition, while adjusting cutterhead rotation speed based on geological conditions.

Objectives: High-resolution aero-radiometric data of Igumale and Nsukka of Southeastern Nigeria, were used in this study to ascertain the local proportion levels of uranium (U), thorium (eTh) and potassium (K). Methods: Obtained data were grid and subjected to Geosoft analysis using Oasis Montaj Package. Findings: The analysis's findings showed that the potassium concentrations vary from 0.00% to 0.6%. The average thorium concentration was 13.6 ppm, having value spanning from 4.3 to 22.9 ppm. The uranium concentration level varies between 0.5 to 7.0 ppm with average value of 20.86572 ppm. There is a very clear discountunity seen in the middle of the research area trending north to south allowing the passage of low concentration of all three radioactive substances towards the southeastern region. The ternary map revealed radioactive mineral compositions which are exceedingly high in the southeastern part and associated with Esh and Arish formation resulting from felsic volcanic rock deposits greater than the usual average value of radioactive materials a reliable geothermal energy source in the environment. The low concentration combined effect of the three radioelement falls within longitude 7o20ʹ to 7o40ʹ and found in areas within the false bedded sandstone, coal and shale (FSS), sandstone (ESS), coal, sanstone and shale (LCM) formation where as high concentration combined effect is located within latitude 6o30ʹ and 6o47ʹ and longitude 7o47ʹ and 8o00ʹ are associated with Esh and Arish formation. Spot for RHP is seen to be very high in the north western and extending towards the south eastern part of the study area whereas low radiogenic heat production (RHP) is evident at the boundary between Nsukka and Igumale central part of study area trending NS between longitude 7o 30ʹ and 7o 60. Novelty: The research revealed spot of high RHP which will guide geoscientists, miner and investors in choosing the optimal locations for installing an exploratory well to harness high generated heat. Keywords: Aeroradiometric, Radioelements, Igumale-Nsukka, Total count map, Ternary map, Radiogenic heat production

The study determined the effect of selected environmental variables (Cr, Ni, Ba, Zn and Cu) on the potential peroxidation of biomarker fatty acids (FAs) in snails Cepaea nemoralis, both in in situ and in vivo (in laboratory conditions). The following panel of biomarker FAs was used: C16:0; C18:0; C23:0; C18:1 n-9; C20:1 n-9; C18:2 n-6; C18:3 n-3; C20:2 n-6; C20:4 n-6; C20:5 n-3; C22:4 n-6; and C22:5 n-3. Field studies included samples obtained from a location potentially affected by anthropogenic sediment, containing a deposit of waste rock, and from a location without this influence. Waste rock, which is mining waste produced during extraction of bituminous coal, was treated as a potential source of metals. The study tested whether metals deposited in an anthropogenically contaminated environment whose main element is a waste rock deposit can be transferred to the body of land snails. In laboratory conditions, Cr³ ⁺, Ni²⁺, Zn²⁺ and Cu²⁺ ions were administered to snails separately, per os, using a pipette, in a volume of 10 µl per snail, in the form of independent solutions of prepared salts (CrCl3x6H2O; NiSO4x6H2O; ZnCl2; CuSO4). Separate experimental groups were created for each metal, in which three metal concentrations were used: 0.0005 mg Met/ml redistilled water; 0.00075 mg Met/ml redistilled water; and 0.001 mg Met/ml redistilled water. Due to the high toxicity of soluble barium compounds, poorly soluble BaSO4 was used as the source of this element, which in solid form, in an amount proportional to the other metals, was added to the agar constituting the base of the medium. Regardless of exposure to individual metals, three additional experimental groups were also created in which snails were supplemented with a mixture of the tested metal ions, administered together in equal proportions, corresponding to the three concentrations used. The results indicate that metals affect the physiological response in snails associated with changes in the composition of biomarker FAs, peroxidation (PI) and unsaturation (UI) indices, including potential lipid peroxidation. It is possible to identify a group of FAs which can be useful biomarkers of exposure of snails (Gastropoda, Pulmonata) to these variables, in both natural and laboratory conditions. The search for this type of biomarkers in invertebrates is important in ecotoxicology even in the case of subthreshold levels of environmental pollutants. When using snails as a source of biomarkers in situ, after determining the levels of the pollutants in their natural habitat, in order to determine the synergy or antagonism of these pollutants with elements of the environmental background, for example climate and soil factors, it is worth carrying out comparative testing in a laboratory using supplementation with the same substances in controlled conditions.

The Jurassic lacustrine oil shale in southwest China has become a primary production layer due to its high yield and substantial reserves. However, influenced by the lacustrine environment, the vertical profile of the lacustrine shale reservoir shows alternating deposits of shale and carbonate rock. This complex lithological combination results in significant heterogeneity in reservoir types, reservoir distribution, and internal structure. Currently, research on micro-pore structure and hydrocarbon storage mechanisms in lacustrine shales is insufficient, necessitating the elucidation of their micro-characteristics to support future exploration and development. This research focuses on the Da’anzhai Member of Jurassic Ziliujing Formation. Various techniques—including organic geochemical analysis, X-ray diffraction, physical property testing, gradient centrifugation, and gradient drying NMR monitoring—were employed to investigate the micro-pore structure and fluid storage mechanisms of the lacustrine shale reservoir. The following insights were gained from this research. The organic matter pores (OMP) and inorganic pores (IP) developed within the Da’anzhai lacustrine shale reservoir together create the storage space for shale oil, while micro-fractures further enhance the reservoir’s storage capacity and flow performance. Lacustrine shale oil exists in three storage states: mobile oil, bound oil, and adsorbed oil. Mobile oil is primarily located within the micro-fractures and large pores (greater than 350 nm) of the shale reservoir and is the main target for industrial extraction. Bound oil is mainly found in the meso-pores, micropores, and narrow pore structures between rock grains (30 nm to 350 nm), and, theoretically, could potentially be developed through engineering methods such as hydraulic fracturing. Adsorbed oil, due to its close binding with organic matter and clay mineral surfaces, is difficult to release effectively using conventional techniques. The OM abundance, the mineral composition of lacustrine shale, and the pore structure all influence the storage states of shale oil. While a high TOC value increases the amount of mobile oil, the strong adsorption properties of kerogen and organic matter lead to the accumulation of adsorbed oil, which inhibits oil flow. Clay minerals further restrict oil flow by enhancing adsorption, while brittle minerals facilitate the movement of mobile oil by expanding pore space. Based on fractal geometry theory and multi-scale testing results, the large pores in the Da’anzhai lacustrine shale have a high fractal dimension and exhibit complex shapes. However, as pore complexity increases, the amount of adsorbed oil rises significantly, which in turn reduces the proportion of movable oil.

Combined analysis of magnetic investigations and geological mapping of the Babouri-Figuil Basin (Northern Cameroon): Implications for hydrocarbon prospects

This study is based on field observations and sample collections from the Panjinbulak, Qiongbulak, and Qunjisayi outcrops in the Yining Sag of the Ili Basin. Using organic geochemical analysis methods, the characteristics and hydrocarbon generation potential of the Permian Xiaoshansayi Formation (P2x) and Tamqisayi Formation (P2t) source rocks in the Yining Sag were compared and analyzed. The results indicate that the Permian source rocks in the Yining Sag of the Ili Basin exhibit high organic matter abundance and good types, among which the P2t source rocks are overall superior to the P2x. The P2t source rocks in the Panjinbulak outcrop section on the northern margin are dominated by Type II1-II2 kerogen, while those in the Qunjisayi and Qiongbulak outcrop sections on the southern margin show a transition to Type II2-III kerogen. The maturity of Permian source rocks presents a pattern of “higher in the south and lower in the north”, and all have reached the hydrocarbon-generation threshold. The northern margin is in the oil window, mainly dominated by oil generation; the southeastern margin has higher maturity, mainly producing oil/condensate gas. The Permian source rocks were deposited in a saline-reducing environment, with mixed input of aquatic organisms and terrestrial plants. During the deposition of P2t source rocks in the northern margin, the water salinity was higher, and plankton such as cyanobacteria made prominent contributions. The P2t source rocks in the Panjinbulak outcrop section on the northern margin have relatively better organic matter abundance and type, making it the main hydrocarbon-generation-potential area. The source rocks in the Qunjisayi outcrop section on the southeastern margin are slightly poorer, but their maturity is higher, currently in the main oil window, representing a secondary hydrocarbon-generation-potential area.

In the Jinshan aulacogen on the southern margin of the Ordos Basin, volcanic rocks of the Mesoproterozoic Changchengian System Xiong'er Group were first encountered by Well PT1, and the drilling operations have revealed the complete strata of Changchengian System within the basin. A systematic analysis of Well PT1 data, including lithological assemblage, zircon U–Pb dating, and geochemical testing, provided the following key findings. (1) The Mesoproterozoic Changchengian System shows a typical sequence consisting of three parts: the Xiong’er Group (volcanic and volcaniclastic rocks) at the bottom, the Ruyang Group (clastic rock) in the middle, and the Luoyu Group (fine clastic–carbonate rocks) at the top. (2) The Xiong’er Group experienced multiple stages of basaltic magma eruptions, dated at 1731 ± 27 Ma and 1756 ± 19 Ma. This suggests that the Ordos Basin was rifted along with the breakup of the Columbia supercontinent, indicating that the Jinshan aulacogen functioned as a rift system. (3) A 28-m-thick dark mudstone, interval with a total organic carbon (TOC) content of up to 1.58%, was encountered in the Changchengian System Cuizhuang Formation. This mudstone has been identified as the oldest source rock discovered in the Ordos Basin. The tensional tectonic environment associated with the breakup of the Columbia supercontinent created favorable conditions for the deposition of Mesoproterozoic source rocks, making them promising targets for Proterozoic exploration in the Ordos Basin.

The objective of this research is to identify and analyze the changes in vegetation cover, agricultural lands, and barren lands in Northern Kirkuk Governorate over the period from 1993 to 2023. The study seeks to understand the dynamics of these changes and their underlying causes, while also creating detailed maps that visually represent the results. To achieve this, a validated classification methodology, using satellite imagery and Geographic Information Systems (GIS), was used to effectively analyze and classify the land cover and land use in the area. This approach allows for an in-depth assessment of the shifts in land use patterns, providing valuable insights into the environmental and socio-economic factors driving these changes.To achieve this, satellite imagery collected from satellites, such as Landsat 5 and Landsat 7, was utilized using TM, ETM+, and OLI-TIRS sensors. These images are an effective source that saves significant time and effort, as well as providing accurate and reliable results. Six land cover and land use patterns were identified in the region. Agricultural land, natural vegetation, water cover, and built-up land witnessed significant increases in 2023, reaching 23.37%, 21.15%, 0.32%, and 4.62%, respectively. In contrast, rock deposits and barren lands covered vast areas in 1993, representing 58.12%, but experienced a significant decline in 2023, falling to 27.23%. This change was the result of natural and human factors that positively impacted the region. These findings constitute a critical information database for monitoring land cover changes in the region, facilitating the tracking of these changes, analyzing their causes, and predicting their future developments. These results will help develop strategic plans to address future challenges related to land and natural resource management in northern Kirkuk Governorate.

ABSTRACT The protracted tectonic history concerning the northern edge of the pre‐Himalayan proto‐Indian plate margin during the Neoproterozoic time has been a long‐standing subject of debate, with various hypotheses enduring over several decades. Although a continental rift to passive margin setting has been proposed for the deposition of Neoproterozoic rocks of the Outer Lesser Himalayan Sequence (OLHS), the similarity in detrital zircon age peaks and Nd isotope values of OLHS rocks with those of the Higher Himalayan Crystalline Sequence (HHCS) led to the proposition of an arc‐related setting. So far, there is no such report of Neoproterozoic arc‐related magmatism from the Lesser Himalayan Sequence. In the present study, an interbedded volcaniclastic horizon has been identified from the basal stratigraphic level of the Nagthat Formation, OLHS. Geochemistry and U–Pb zircon geochronology are used to understand the provenance and tectonic setting of the Nagthat volcaniclastic rock. The angularity of the framework minerals, moderate degree of weathering (avg. Chemical Index of Alteration value 62), and immature nature (Index of Compositional Variability 1–1.1) suggest that a contemporaneous volcanic province was probably the main source. Whole rock geochemical analysis shows high Th/Sc (1.67–3.40, avg. 2.71), La/Sc (4.74–8.21, avg. 7.14), and low Cr/Th ratios (1.78–5.45, avg. 3.02). It supports that the volcaniclastic was supplied from an acid to intermediate source rocks, such as rhyolite and dacite/andesite. U–Pb detrital zircon analysis yielded a major age peak around 775 Ma. However, comparison of the U–Pb zircon age data with published datasets from the Lower (Chandpur Formation) and upper (Nagthat Formation) stratigraphic horizons suggests a timing of volcanism between 800 and 700 Ma. Geochronological and geochemical characteristics of the volcaniclastic rock suggest a signature transitional from passive to active continental margin setting, indicating that at least subduction was ongoing during the Tonian (800–700 Ma) at the northern proto‐Indian plate margin.

This article discusses the issue of substantiating the geomechanical model of well No. 300 at the Chinarevskoye field before drilling. The main purpose of the study is to ensure the stability of the borehole, to make a preliminary prediction of the geomechanical risks that arise during drilling (collapse, compression of rocks, anomalies of absorption and reservoir pressure) and to identify ways to reduce them. The paper comprehensively analyzes the geological and structural features of the deposit, the physical and mechanical properties of rocks, reservoir pressures and the initial stress state. The geomechanical model was constructed using one-dimensional and three-dimensional approaches and the change in the stress-strain state over the drilling depth was estimated. Based on the simulation results, a window of safe drilling fluid density was determined, recommendations were given for optimizing the well trajectory and selecting technological parameters. The results obtained will ensure safe and efficient drilling of wells at the Chinarevskoye field, as well as reduce production costs and the risk of accidents.

A study was conducted on the use of opoka from the Shipovskoye deposit in the Republic of Kazakhstan and thermolite obtained from opoka in road construction. The aim of the study is to develop new technologies for the production of building materials - opoka and thermolite, and their use in road construction. The object of the study is opoka from the Shipovskoye deposit in the Republic of Kazakhstan. The subject of the study is the properties of opoka and thermolite and their work in the composition of the road pavement of category III highways. Scientific hypothesis - opoka from the Shipovskoye deposit in the Republic of Kazakhstan can be used as an independent material or as a thermolite in the composition of the road pavement of category III highways. Scientific novelty - using modern research methods, new data were obtained on the physical and mechanical properties and meneralogical composition of opoka from the Shipovskoye deposit; new data were obtained on the physical and mechanical properties and chemical composition of thermolite obtained from opoka. The theoretical significance of the study lies in obtaining experimental data on the properties of opoka and thermolite, the practical significance of the work lies in using the research results to develop the composition of asphalt concrete mixture based on thermolite and its application in road construction. The main physical and mechanical properties of opoka from the Shipovskoye deposit in the West Kazakhstan region were established. The use of opoka in the construction of a road on the section Uralsk (Republic of Kazakhstan) - the village of Ozinki (Russian Federation) was studied. As a result of the work carried out to study the state of the road section after six years of operation, the advantage of using opoka for the construction of the road base was established compared to clay. A technology for producing thermolite was developed, for which a product quality certificate was received based on the results of the tests. The development of a technology for the production of asphalt concrete mixture based on thermolite for road construction, especially in those areas where there are no deposits of hard rocks for the production of crushed stone, is very relevant. An asphalt concrete mixture composition has been developed using thermolite, which has an advantage in terms of indicators compared to existing analogues, which is confirmed by the results of tests conducted in accredited testing laboratories, permitting the use of the developed asphalt concrete mixture composition for the construction of road surfaces of category III highways.

Geoacoustic emission is a phenomenon of seismic energy radiation caused by changes in rock structure. Passive seismic observations were conducted by continuously recording accelerograms at four observation points on a landslide slope area on the left bank of the Vorkuta River valley opposite the Vorkutinskaya mine. The accelerograms were processed using adaptive mode signal decomposition (the Hilbert–Huang method). For each observation point, 10–12 empirical modes were obtained. Of these, the first two are significant: the first modes are high-frequency noise, the second contain a useful signal. In the Hilbert–Huang spectra, the main oscillation energy is in the spectral range of 180–250 Hz, with elastic wave energy emission occurring in semi-rocky soils. Intense fracturing was detected in the semi-rocky, clayey, and loamy deposits of the study slope at the southern end of the research site in the area of observation point (OP) 2. It was shown that, within the geological space of the separated rock block, the main stress release occurred during the preparatory stage and at the moment of block separation from the slope. The results of the data analysis indicate that in the future, rock deposits may be involved in the process of detaching the next block of rocks from the slope. When planning the monitoring of crack formation dynamics in order to predict the location and time of destruction of the integral structure of the slope geological massif, instrumental observations are required at existing OP1–3 and at new PNs constructed in the southern, southeastern and eastern parts of the slope research site.

The results of studying the possibilities of extracting strategic metals (Au, Ti) from gold-ilmenite placers located in the south of the Russian Far East are presented in this article. The need to apply hydrofluoride techniques in order to create a basis for technology to enrich titanium-bearing deposits is justified. The experience gained through the deep processing of gold ilmenite mineral resources will help us to identify ways to develop complex deposits in the Russian Far East in accordance with the principles of sustainable use of natural resources and environmental protection.

Introduction. Exhaustion of large oil and gas deposits leads to exploring smaller geological structures, from which large amount of core cannot be extracted. Therefore, value of trace fossils analysis increases due to necessity of receiving more geological information from less core material. Therefore, new core processing practices must be implemented. The paper is devoted to the study, description and systematization of the trace fossils that have been found in the Serpukhovian stage of Carboniferous system inside of Mospanivska geological structure. Analysis of previous publications. There are only a few Ukrainian publications, that have been written over past decades, that briefly touch the topic of trace fossils analysis. Such mentions can be found in works of V. Dernov, A. Menasova, A. Matveev and a few others. Last complex work on trace fossils in Ukraine was written over fifty years ago by O. Vyalov. On the contrary, in world sedimentology practice trace fossils analysis doesn’t lack attention. Some important publications were made by Seilacher, Ecdale, Bromley, Knaust, Hasiotis and others. The main goal of this publication is to highlight prospects of using trace-fossils analysis as an important aspect of core description. Material and methods. Full-lenth core from four different wells was used. The scientific search was based on the analysis of literature, as well as own field, laboratory and analytical studies. Trace fossils were described from longitudinal core cutting plains. To create images of trace fossils, core panoramic photographs in white light were done. Systematization of trace fossils was done in accordance with ichnotaxobasis method, described by D. Knaust. For each trace fossil morphology description included orientation, bifurcation, overall form, lining presence or absence, visible sizes and typical cutting projections. Results and discussion. Lithological composition of the studied beds includes sandstones, siltstones, siliclastic mudstones, thin beds of coal and carbonate mudstones. Taxonomical composition of studied Serpukhovian trace fossils in Mospanivska structure consists of 10 genes. They are Arenicolites, Gastrochaenolites, Lingulichnus, Macaronichnus, Palaeophycus, Planolites, Skolithos, Teichichnus, Thalasinoides and plant roots traces. Such ichnodiversity is considered to be high, which points out to miscellaneous rock deposition conditions, varying from continental to distal-marine. It is highly important to notice, that all described trace fossils, which are typical for sandy nearshore deposits (Arenicolites, Lingulichnus and Skolithos) have producer organisms that can tolerate fluctuations in water salinity. It can be considered as an indicator of salinity fluctuations during sedimentation in nearshore facies. For every genus high-resolution photos and conceptual schemes are provided. These graphics are considered to be essential as trace fossils appearance in core and in the outcrop, where they were first described, may vary significantly. Every genus is described in terms of its morphology, ethology, palaeoecological value and probable producers. It helped to rule out significant facial diversity and justify subsequent detailed facial analysis of studied Serpukhovian beds.

Critical minerals, such as rare earth elements (REEs), lithium, and cobalt, are essential for modern technologies, including renewable energy, electronics, and advanced manufacturing. The increasing demand for these minerals has led to a surge in exploration and extraction efforts. However, their mineralogy and geochemistry are not well understood, hindering sustainable extraction and supply chain management. This review examines the current state of knowledge on the mineralogy and geochemistry of critical minerals, highlighting exploration, extraction, and sustainability challenges. Research has identified new mineral deposits and improved understanding of critical mineral geochemistry. Ion adsorption clay deposits and pegmatites are significant sources of REEs, while lithium is often extracted from brines and hard rock deposits. Cobalt is commonly associated with copper and nickel deposits. Advanced analytical techniques, such as machine learning and spectroscopy, are enhancing exploration and extraction efficiency. However, environmental concerns, such as water pollution and land degradation, accompany extraction activities. Sustainable practices, like recycling and urban mining, are being explored to mitigate these impacts. The mineralogy and geochemistry of critical minerals are complex and not yet fully understood. While advances in exploration and extraction technologies are improving supply chain resilience, sustainability remains a pressing concern. Future research should focus on developing eco-friendly extraction methods, improving recycling rates, and promoting responsible sourcing practices to ensure the long-term availability of these critical minerals.

The Ordovician Magnolia Formation in Odors Basin is one of the core horizons of oil and gas exploration. The third member of Magnolia Formation ( Ma3 member ) is an important part of this formation, and its facilitates choreographically pattern profoundly controls the development and distribution of high-quality reservoirs. In recent years, the predecessors have made many new understandings on the study of the third member of the Madman Formation, but the overall research degree is weak, and the accumulation law and main control factors of the natural gas in the third member of the Madian Formation have not been clarified, resulting in difficult well deployment and high risk, which restricts the exploration and development process of deep natural gas under salt to a certain extent.In this paper, the main research goal is to restore the lithofacies paleogeography of the Masan Formation in the Ordos Basin.Based on the geological, logging, and seismic data, the' trichotomy ' of the Masan Formation was established. The pre-depositional paleogeomorphology was restored by the impression method. Combined with sedimentology, paleogeomorphology restoration and lithofacies paleogeographic analysis, the lithofacies paleogeographic characteristics of each layer of the Masan Formation were systematically described, and the changes of the internal uplift and depression of the Masan Formation and the resulting sedimentary microfacies evolution were analyzed. The study shows that the internal area of the platform in the sedimentary front of the Masan member is also relatively flat, accounting for about 70 % of the area, of which the low-lying area in the eastern platform accounts for about 45 % of the area. The southern platform margin area and the western denudation ancient land slope area account for about 30 % of the area ; the Ma3 member is dominated by the evaporative platform facies under the regression system, mainly developing the intra-platform lagoon and the evaporative tidal flat subfacies. The intra-platform lagoon is mainly the salt rock lagoon microfacies, and the evaporative tidal flat subfacies is further divided into ash dolomite flat, dolomite flat, mud dolomite flat, gypsum dolomite flat and other microfacies. During the deposition period of the third member of the Mashan Formation, the eastern Ordos Basin belonged to the transgressive system tract of the second stage of the Mashan Formation to the regressive system tract of the third stage of the Mashan Formation, and the seawater depth became shallow, but the low-lying areas along the Shenmu-Yichuan area still existed. Coupled with the strong evaporation of paleoclimate conditions, the low-lying areas became sulfates, that is, the favorable place for the deposition of gypsum-salt rocks, thus forming a relatively closed platform lagoon environment. The lagoon area is very large, from the Shenmu area Shuang 176 well-Shen 74-M 1 to the southern Yu 152-Yi 68 well line, becoming a salt rock sedimentary area ; from the lithofacies paleogeographic distribution map of each sub-layer of the Masan Member, the favorable microfacies intra-platform shoals are mainly distributed in the Masan 1 and Masan 2 sections, and the distribution of Masan 3 is limited.

Abstract. This article presents the new version of the map of critical raw materials hard rock deposits that has been produced in the frame of the GSEU project (Geological Service for Europe). The map displays over 800 medium to very large deposits for 30 Critical Raw Materials (CRM) from the 2023 list of the European Commission, in 33 European countries. We explain the objective of this work and the process and methodology for collecting, compiling and harmonizing CRM data from multiple providers. We also describe the map itself, the information it carries and its availability. As an example of added-value output, we present a pan-European assessment of CRM potential, classified in 4 categories of confidence from “historical or non-compliant resource estimates” to “mineral reserves”. This assessment provides an image of the current known potential for CRM in Europe. Based on this exercise, we discuss the challenges and barriers of compiling and harmonizing mineral resources data at continental scale, and the future perspectives of this work we envision through the EGDI (European Geological Data Infrastructure). We also discuss the limitations of the map and dataset to raise awareness on their proper interpretation and use.

Identification of regolith-hosted Nb-REE deposits in alkaline rocks using multisource spectroscopic system: A case study of the Puxiong deposit, Yunnan Province, China

Abstract Rockslides and their cascading hazards, such as river blockage and outburst flooding, pose significant threats to infrastructure and human lives, particularly in mountainous and seismically active regions. To enhance hazard forecasting and risk mitigation, it is helpful to develop accurate numerical models for analysing the failure mechanisms of rock slopes under external loadings. Traditional two-dimensional numerical simulations have constraints in capturing the anisotropic stress distribution and complex evolution of failure mechanisms in three-dimensional space. Moreover, most three-dimensional numerical models typically treat rock slopes as homogeneous media, rarely accounting for the natural fractures within rock blocks. To address these limitations, this study introduces a novel three-dimensional material point method (MPM), combined with the discrete fracture network (DFN) to dynamically simulate the initiation and evolution of rockslides under seismic loading, along with the subsequent river blockage phenomenon. The DFN is explicitly incorporated into MPM using a projection algorithm by mapping fracture geometries onto the computational domain and then assigning the physical properties of fractures to specific material points, enabling a more realistic representation of fractured rock masses. The reliability of the proposed framework in addressing complex dynamic contact problems is verified through four numerical case studies. The motion of rockslides under seismic loading and the deposition of fragmented rock blocks within a river channel are then studied, revealing that fracture intensity and fracture orientation significantly influence the failure modes of rock slopes and the extent of river blockage. This research provides valuable insights into the complex failure processes of fractured rock slopes and interactions between rockslides and river systems, contributing to the advancement of hazard assessment and mitigation strategies.