Geosciences doi: 10.3390/geosciences16030121

Authors: Yanliu Ding Xixi Liu Jing Tian Shiyong Yan Lixin Lin Han Ma

The Bayan Obo Mining District, recognized as the largest rare-earth resource base worldwide, has experienced significant surface instability due to intensive mining and large-scale dumping activities. To address the challenges posed by complex geological conditions and mining-induced disturbances, this study employs dual-ascending Sentinel-1A C-band Synthetic Aperture Radar (SAR) datasets (Path 11 and Path 113) and applies the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique to retrieve time-series deformation along the line-of-sight (LOS) direction for each track. Through temporal normalization and spatial matching, paired LOS observations from the two tracks were established. Based on the SAR observation geometry and under the assumption that the north–south component is negligible, a LOS projection model was constructed and a geometric decomposition was performed to derive the east–west and vertical two-dimensional deformation fields. The results indicate that the study area is generally stable, while significant subsidence occurs in the northern pit and adjacent waste-dump zones, with local maximum rates approaching 50 mm/year, predominantly controlled by the vertical component. The two-dimensional deformation analysis reveals that vertical displacement dominates surface motion, whereas east–west movement shows smaller amplitudes but clear directional concentration. In particular, the east–west slopes exhibit slightly higher velocities, suggesting a lateral adjustment tendency along this direction, likely related to the overall east–west geometric configuration of the open-pit and waste-dump areas. Time-series observations further reveal that precipitation-related surface deformation occurs with an approximate two-month delay, reflecting the hydrological–mechanical coupling processes of rainfall infiltration, pore-water pressure propagation, and dump-material consolidation. Overall, this study reveals the multi-dimensional deformation characteristics and precipitation-driven stage-wise response of the mining area, demonstrating the effectiveness of the dual-ascending SBAS-InSAR for two-dimensional deformation monitoring in highly disturbed environments, and providing a scientific basis for surface stability assessment and geohazard prevention.

Geosciences doi: 10.3390/geosciences16030120

Authors: Isabelle Moretti Alain Prinzhofer Vincent Roche

This study presents the first comprehensive soil gas survey across southern Uruguay’s H2 prospective terranes. A pre-field trip selection was done on the basement rock nature, as well as vegetation anomalies in subcircular depressions and fault presence. The Neoproterozoic terrane, north of Punta del Este, and the Archean Rio de la Plata Craton, north of Montevideo, as well as along the suture zones between the two, were targeted. Our findings reveal substantial H2 concentrations, significantly outperforming many established basins worldwide. The suture zones act as critical migration conduits for H2 coming from a deeper structural level. Slightly abnormal helium signatures confirm an active, deep-sourced fluid system, particularly within the Sierra Ballena and Cordillera shear zones. The Archean Rio de la Plata Craton appears promising but has only been partially sampled and warrants further investigation. These results underscore the high potential of Uruguay as a new frontier for natural hydrogen exploration.

Geosciences doi: 10.3390/geosciences16030119

Authors: Abdullah Kellevezir Ekrem Tuşat Mustafa Tevfik Özlüdemir

The Earth’s lithosphere, the rigid outermost layer of the planet, is composed of numerous tectonic plates of varying sizes that move over the underlying asthenosphere. The motion and interaction of these plates give rise to a wide range of geodynamic processes. Accurate monitoring of these processes is essential for maintaining a stable, up-to-date, and reliable terrestrial reference frame. This study investigates the horizontal and vertical motions of the Antarctic Plate resulting from its interactions with adjacent plates. Tectonic plate movements can be determined using several space-geodetic techniques, including Global Navigation Satellite Systems (GNSS), Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), and Interferometric Synthetic Aperture Radar (InSAR). Among these methods, GNSS is currently the most widely used, as plate motions can be derived from continuous observations recorded at permanent stations and processed using scientific or commercial software. Within the scope of this research, GNSS data collected between 2020 and 2023 were processed using the GAMIT/GLOBK V.10.7 software package to estimate the coordinates and velocities of stations located on the Antarctic, South American, African, and Australian Plates in the ITRF14 reference frame. Furthermore, plate-fixed solutions were generated to analyze the relative motion of the Antarctic Plate with respect to neighboring plates. The results indicate that the Antarctic Plate moves at an average velocity of approximately 4–18 mm/year in the ITRF14 frame. The plate diverges from both the African and Australian Plates and exhibits predominantly strike-slip motion relative to the South American Plate. A comparison with existing global plate motion models demonstrates that the obtained velocities are consistent within 0–5 mm/year.

Geosciences doi: 10.3390/geosciences16030118

Authors: Fei Li Lin Wang Zhifeng Liang Jinan Wang Chuanqi Zhu Ruiyang Yuan

Traditional methods for geostressfield inversion face issues such as weak physical interpretability and insufficient generalization ability. This study pioneers the application of Physics-Informed Neural Network (PINN) to this problem, developing a data- and physics-driven inversion algorithm. The framework incorporates a constitutive-equation-based regularized loss function as a hard constraint during training to ensure physical consistency. To address boundary load uncertainty, two quantification approaches—Bayesian linear regression and surrogate model optimization—are proposed to establish 95% confidence intervals for boundary coefficients. Verification based on simple three-dimensional models and actual geological models of mines shows that PINN inversion achieves a mean absolute relative error as low as 0.0772%, with an error of 15.67% under sparse sampling conditions—significantly lower than the 31.07% error of the traditional Back propagation neural network. This demonstrates excellent robustness and data efficiency. In the practical engineering application of complex geological bodies, the average error of principal stress inversion is 9.35% with a minimum error of 0.137%. All inversion results fall within the permissible accuracy range of engineering, and the stress distribution conforms to basic laws, with an average error of 0.453 in the constitutive relation. Compared with BP neural network and multiple linear regression methods, it shows obvious accuracy advantages. This method provides a new solution for intelligent ground stress prediction with high accuracy, high efficiency, and strong physical interpretability, and also lays the foundation for early identification of geological disasters.

Geosciences doi: 10.3390/geosciences16030117

Authors: Chenge Zheng Yiwei Wang Xiaowei Huang Weijiao Ma Jinzhong Liu Qiang Wang Cui Weng Yong Li

Unconventional shale resources remain crucial to energy security. In situ conversion technology (ICP) offers a promising pathway for exploiting low–maturity shale, yet the distinct roles of kerogen and bitumen during thermal conversion are not fully understood. This study investigates the decomposition behavior of kerogen and extracted bitumen from the Shahejie Formation through gold–tube pyrolysis experiments at 50 MPa and heating rates of 2 °C/h and 20 °C/h. The results show that the yield curves of C1, C2–C5, and C6–C14 generated from kerogen and bitumen exhibited similar trends. In contrast to the C15+ fraction from kerogen, which initially increased and then decreased, the yield of C15+ from bitumen began to decline from the onset of cracking. Additionally, the CO2 generated from the kerogen continued to increase until the end of pyrolysis, whereas the CO2 from the bitumen reached its maximum at an EasyRo of approximately 1.8%. The kinetic results show that bitumen has a higher activation energy for gas generation than kerogen, while kerogen has a higher activation energy for oil generation than bitumen. A heating program of 1 °C/day rate, 324 d duration, and a final temperature of 360 °C was applied to predict oil and gas generation during ICP. Below 326 °C, the proportion of C1 and C2–C5 contributed by kerogen increased and exceeded 90%. Although kerogen’s contribution ratio of C6–C14 exhibited fluctuating variation characteristics, it remained above 50% across most of the intervals. The gas–to–oil ratio increased rapidly above 299 °C and reached 375 m3/m3 by the end of heating.

Geosciences doi: 10.3390/geosciences16030116

Authors: Luciano Telesca Lev V. Eppelbaum Georgios Balasis

Geophysics represents a dynamic research field that delves into the intricate physical properties and processes that shape the Earth and its surrounding space environment [...]

Geosciences doi: 10.3390/geosciences16030115

Authors: Krzysztof Fuławka Bogumiła Pałac-Walko Lech Stolecki

There was an error in the original publication [...]

Geosciences doi: 10.3390/geosciences16030114

Authors: Mason Jacketta Michael S. Thorne Surya Pachhai Ivan Tochimani-Hernandez Tonie van Dam Christian L. Hardwick Ebenezer Adomako-Mensah William P. Johnson Leif S. Anderson

Water levels in the Great Salt Lake (GSL), UT, USA, have been declining overall since 1989, leading to a 70% decrease in surface area. To understand GSL’s future, we seek to image fresh groundwater input and lithologic variation along the lake’s boundary. Determining the amount of groundwater recharge into GSL is crucial for lake management but currently unknown. During the Fall of 2024 and Spring 2025, we conducted 16 electrical resistivity tomography (ERT) and six transient electromagnetic (TEM) surveys along the southern shore of GSL between Burmester Road (to the West), Saltair, and Lee’s Creek (to the East). These measurements indicate a low-resistivity layer consistent with brine pore-water, with variable thickness ranging from 7.1 ± 0.1 m at Burmester to 9.6 ± 0.2 m at Saltair. The Saltair region shows a high-resistivity layer, consistent with a 4.4 ± 0.05 m thick layer of mirabilite. This layer contains vertical conduits that allow saline pore-water to upwell onto the surface forming evaporite deposits. Near Lee’s Creek, we find evidence of high resistivities consistent with fresher groundwater as shallow as 2.8 ± 0.03 m, where increased permeability along the paleo-Jordan River corridor may provide a path for groundwater recharge from the Wasatch Mountains.

Geosciences doi: 10.3390/geosciences16030113

Authors: Marfasran Hendrizan Mutiara Rachmat Putri Fareza Sasongko Yuwono Rubiyanto Kapid Winda Eka Mandiri Puteri Anisa Ulfatu Hasanah Lia Jurnaliah Praptisih Praptisih Harisma Harisma

The Late Miocene is known as a period of long-term Cenozoic global cooling and decreasing concentrations of atmospheric CO2. The conditions provide the opportunity to assess the Earth’s climate sensitivity in altering internal and external drivers in a warmer world with similarity to the modern continental configuration. However, relative warmer Sea Surface Temperature (SST), a deepened thermocline, and reduced upwelling may have occurred in the tropics during the Late Miocene global cooling. Here, we present foraminiferal biostratigraphy data from the Middle Miocene–Pliocene succession in the Halang Formation in the Banyumas Basin in Indonesia. An increase in the planktonic foraminifera Trilobatus trilobus and Orbulina universa during the Late Miocene in the Indian Ocean indicates relative surface temperature warming and reduced productivity inferred from assemblage shifts. Reduced productivity was caused by decreasing upwelling intensity during the Late Miocene based on Globigerinella obesa assemblages. Reduced upwelling in the south of Java is supported by elevated numbers of surface/mixed-layer species (i.e., Trilobatus sacculifer and Trilobatus immaturus). We suppose the distribution of enhanced upper-layer stratification in the eastern Indian Ocean was not only driven by oceanic forcing but was also transferred intensively into the Indian Ocean by atmospheric forcing of strengthening equatorial trade winds. Changes in the Walker circulation controlled a reduction in upwelling over the eastern tropical Indian Ocean and a deeper thermocline during the cooling climate in the Late Miocene.

Geosciences doi: 10.3390/geosciences16030112

Authors: Yuanfa Ji Zijun Lin Xiyan Sun Jing Wang

This study proposes a hybrid landslide displacement prediction model based on multi-strategy integrated optimization to address high nonlinearity and limited accuracy. An improved SFOA with Lévy flight, dynamic exploration adjustment, and stagnation detection enhances global search and convergence. The optimized SFOA (OSFOA) is employed to optimize CEEMDAN using minimum envelope entropy, reducing hyperparameter subjectivity and decomposing cumulative displacement into multi-scale components. The trend term is predicted by a Bayesian-optimized ARIMA, while periodic and stochastic terms are further decomposed by VMD and predicted using Bayesian-optimized SVR. GRA-MIC is applied to select key influencing factors and optimize model inputs. Results show that the proposed method improves accuracy and stability, reducing RMSE by about 82% and 52% compared with SSA-SVR and the baseline single decomposition model, respectively. The study further identifies monthly rainfall change and two-month reservoir level variation as the dominant driving factors for the displacement evolution, providing an effective and interpretable approach for complex landslide early warning.

Geosciences doi: 10.3390/geosciences16030111

Authors: Yulei Tan Jianyu Huang Liyuan Zhang Laijun Lu Baopeng Chen Tongyuan Liang Lin Pan

Sandstone uranium deposits exhibit stratabound mineralization and strong vertical heterogeneity in geological space, which complicates the identification of uranium anomaly layers and their integration into deposit-scale 3D models using borehole datasets. In this paper, we propose a UAPC Fourier layer identification (UFLI) method for uranium anomaly layer identification. The method is based on multi-log feature construction, random forest-based estimation of a depth continuous uranium anomaly probability curve (UAPC), and improved Fourier vertical variation analysis. We used 19 boreholes arranged on four exploration lines (ZKA-ZKD) of the Daying uranium deposit in the northern Ordos Basin (north central China), for the validation. The proposed UFLI method identified 51 uranium anomaly layers at a 5 m sampling interval, forming discrete vertical clusters within the drilled successions. The results indicate that anomalies are overwhelmingly concentrated in the Middle Jurassic Zhiluo Formation, particularly within the lower Zhiluo member, with an anomaly-bearing depth range of approximately 550–745 m. Comparison with known mineralization records shows that both industrial and ordinary mineralization intervals are captured within the anomaly layers. Then, based on inter-borehole continuity of anomaly layers, we reconstructed five uranium orebodies (orebodies 1–5) and describe their distribution characteristics. The proposed method provides a technical means for subsurface visualization and exploration targeting in sandstone uranium systems.

Geosciences doi: 10.3390/geosciences16030110

Authors: Khemruthai Kheamsiri Naofumi Akata Chutima Kranrod Hirofumi Tazoe Tarika Thumvijit Ilsa Rosianna Haruka Kuwata Krit Khetanun Narit Yimyam Yusuke Unno Akira Takeda

Granitic soils in the Highlands support the cultivation of Arabica coffee in northern Thailand; however, their geochemical and radiological properties are inadequately defined. This study examined major oxides, trace elements, natural radionuclides, and extractable phosphorus in granitic-derived coffee soils from the Agricultural Innovation Research, Integration, Demonstration, and Training Center (AIRID) in Chiang Mai. Twenty soil samples were obtained from 10 locations at two depth intervals (0–30 cm and 30–60 cm). Major and trace elements were analyzed via X-ray fluorescence (XRF), natural radionuclides were analyzed through high-purity germanium (HPGe) gamma spectrometry, and extractable phosphorus was determined using the Bray II method. The soils demonstrate remarkably high 40K activity concentrations (1.2–1.9 kBq kg−1) and increased K2O contents (4.9–7.8 wt%), about three to five times more than worldwide soil averages according to Reimann & de Caritat, indicating enrichment from potassium-rich granitic rocks. Major oxide compositions suggest extensive tropical weathering, characterized by elevated SiO2 (>60 wt%) and Al2O3 (>14 wt%), alongside significant depletion of CaO and MgO (<1 wt%). In topsoil, Bray II–extractable phosphorus constitutes 10–25% of total phosphorus and has a robust positive connection with P2O5 (R2 = 0.95, p < 0.001), signifying surface accumulation and restricted vertical mobility. Multivariate analysis indicates lithogenic grouping of trace elements with negligible vertical redistribution. These findings establish a geochemical and radiological baseline for highland coffee soils in northern Thailand, with implications for soil fertility assessment, soil–plant transfer research, and evaluations of natural radioactive exposure related to coffee production.

Geosciences doi: 10.3390/geosciences16030109

Authors: Filipa Moreno Marina Cabral Pinto Orquídia Neves Rosana Neto

Soil provides essential ecosystem services and is pivotal for achieving multiple United Nations (UN) Sustainable Development Goals amid growing population pressures and resource demands. In arid to semi-arid regions such as Maio Island (Cape Verde), nutrient-poor soils and unsustainable land-use practices increase agricultural vulnerability, while volcanic geochemistry introduces elements that are not human friendly, further challenging environmental quality and long-term sustainability. Assessing soil (physical–chemical–biological) condition is therefore crucial for informed environmental and land-use planning. Here, Maio’s topsoil was evaluated using protocols adapted from Santiago, the largest Cape Verdean island. Estimated Background Values (EBVs) indicated naturally elevated V, Cr, Ni, Co, and Cu concentrations, consistent with mafic volcanic terrains. Robust Principal Component Analysis (rPCA) revealed geochemical groupings linked to volcanic–sedimentary units, with the dominant component (PC1) defined by Co–V–Cu–Mn–Ni versus As–Cd. Environmental Risk Indices (ERIs) and Multi-Element ERIs (ME–ERIs) quantified elemental enrichment relative to international land-use standards (residential and agricultural) and subsequently to Maio’s EBVs. The highest exceedances were observed for Cr, Co, Ni, V, and Cu, whereas As, Cd, Hg, Pb, and Zn fell within thresholds. The EBV-based assessment identified fewer exceedances than stricter international guidelines, though a few multi-element “hotspots” persist, highlighting potential land-use constraints and the need for preventive management. Overall, the integrated EBV/ERI/ME–ERI framework establishes an environmental geochemical baseline for Maio and offers a screening tool applicable across the entire archipelago.

Geosciences doi: 10.3390/geosciences16030108

Authors: Yuangui Zhang Jingbin Cui Maoshan Chen Lei Li Ruidong Han Wentao Wang

Stratigraphic forward modeling (SFM) is a numerical approach used to reconstruct sedimentary basin evolution by simulating the infilling and tectonic evolution process of strata. The challenge is that existing approaches inevitably require trade-offs among modeling fidelity and computational cost. We present a novel clastic stratigraphic forward modeling (CSFM) approach to reducing computational cost while retaining key flow and transport behaviors relevant to stratigraphic architecture. In CSFM, Lagrangian water particles affect momentum and sediment, while a fixed Eulerian grid stores topographic elevation and lithologic fractions. A simplified form of the Navier–Stokes equations is proposed to compute the trajectories of fluid particles, which can greatly reduce the computational cost. Sediment dynamics are represented by coupled suspended load and bedload modules. To validate CSFM, we constructed a synthetic alluvial fan model and performed stratigraphic forward modeling on it. Five lake-level cycles were imposed and results showed that cyclic sand–clay couplets and isolated channel sand bodies were formed during repeated progradation and backstepping. These results are consistent with established sedimentological knowledge, confirming the geological plausibility of CSFM.

Geosciences doi: 10.3390/geosciences16030107

Authors: Ke Wang Jianwu Zhang Yang Liu Ziyu Yuan Weiwei Zhao Chao Liu

The Ordos Basin hosts significant shale gas resources in China, yet its marine-continental transitional sedimentary setting causes intense reservoir heterogeneity that severely hinders accurate sweet spot identification in the Permian Shanxi Formation. This study aims to reveal the synergistic controls of lithofacies, mineralogy, and organic matter on shale gas sweet spot formation in the southern Yishan Slope of the eastern Ordos Basin. A multi-dimensional characterization approach was adopted, integrating drilling/logging data and systematic core analyses including X-ray diffraction (XRD), organic geochemical testing, porosity/permeability measurement, and on-site gas content desorption, to quantify reservoir heterogeneity across lithofacies, mineralogy, organic geochemistry, and petrophysical properties. The results show that three lithofacies associations are identified in the target interval: mud-wrapped sand, sand-mud interbedding, and sand-wrapped mud, among which sand-mud interbedding and mud-wrapped sand associations exhibit higher total organic carbon (TOC) contents and strong inter/intra-well heterogeneity. The organic matter in the reservoir is dominated by Type III kerogen, with TOC values ranging from 0.04% to 12.15%, and the Shan 2 Member shows significantly higher average TOC (2.55%) than the Shan 1 Member (1.36%). The reservoir is characterized by ultra-low porosity (average of 0.77%) and low permeability (average of 0.26 × 10−3 μm2), with mesopores and macropores contributing over 99% of the total pore volume and showing a significant positive correlation with gas content. Quartz (average of 34.86%) and clay minerals present strong vertical heterogeneity, with the Shan 2 Member being more heterogeneous than the Shan 1 Member due to differences in sedimentary environment evolution. A TOC threshold of 1.5% is determined for sweet spot identification in the study area, and shale gas sweet spots are synergistically controlled by high TOC abundance, moderate brittle mineral content, and 0.1–3 m thick sandy interbeds. This study enriches the theoretical understanding of marine-continental transitional shale reservoirs and provides a scientific basis for sweet spot prediction and development optimization in similar heterogeneous shale gas systems worldwide.

Geosciences doi: 10.3390/geosciences16030105

Authors: Yang Su Jie Chen Jiao Wang

This study investigates the rare-earth element (REE) geochemistry of twenty-nine clastic rock samples from the Paleogene Liushagang Formation in the Weixi’nan Sag. The primary objectives were to quantitatively evaluate the depositional paleoenvironment, determine the provenance lithology, and constrain the tectonic setting of the source area. Results reveal distinct chondrite-normalized REE distribution patterns characterized by light REE (LREE) enrichment, relatively flat heavy REE (HREE) segments, and pronounced negative Eu anomalies. The cerium anomaly index (Ceanom, normalized to the North American Shale Composite) ranges from −0.06 to 0.00, implying broadly suboxic to anoxic-reducing conditions in the water column during deposition. The chondrite-normalized (La/Yb)N ratio, utilized as a proxy for relative depositional residence time, decreases stratigraphically from member 3 to member 1, reflecting a transition to shorter residence times and higher relative sedimentation rates. Laterally, (La/Yb)N increases toward the basin center, accurately recording progressively lower sedimentation rates basinward. Provenance analysis indicates that the sediments were predominantly derived from felsic igneous rocks of the upper continental crust. Spatially, the northern steep-slope belt reflects a uniform source, whereas the southern gentle-slope belt and the Weixi’nan low-uplift periphery record multisource mixed inputs. Finally, tectonic discrimination reveals an “active continental margin” affinity. This geochemical signature represents the inherited tectonic environment of the Mesozoic parent rocks in the surrounding source uplifts, rather than the Cenozoic extensional rift setting of the Weixi’nan Sag itself.

Geosciences doi: 10.3390/geosciences16030106

Authors: Haotian Fu Guodong Li Honglin Liu Yongqiang Wu Hongzhi Wang Zhiqiang Liu

Addressing the engineering challenge of creep instability in weakly cemented fractured sandstones within extremely soft coal-bearing formations under long-term loading in western mining areas, using weakly cemented sandstone from a coal mine in Xinjiang as the study subject. This research employs uniaxial graded loading creep tests combined with full-information acoustic emission technology and DIC high-speed strain field observation to investigate the creep deformation patterns (The full name of “DIC” is the three-dimensional high-speed dynamic and static stress–strain analysis system of the DIC strain field measurement and analysis system. For the convenience of expression, this system will be uniformly referred to as DIC in the following text), damage evolution characteristics, and failure mechanisms of sandstone under intact, pre-fabricated 30° fractures, and pre-fabricated 60° fractures. Results indicate: Fractures significantly weaken rock strength and long-term stability. Unfractured specimens primarily exhibit columnar splitting tensile failure, while pre-fractured specimens show pronounced shear failure. Shear cracks accounted for 83.67% of failures in 30° pre-fractured specimens and decreased to 63.44% in 60° pre-fractured specimens. Intact specimens exhibited acoustic emission ringing responses during accelerated creep stages, whereas fractured specimens showed ringing responses as early as the first loading stage. During graded loading, ringing counts in pre-fractured specimens continuously accumulated, with cumulative counts significantly exceeding those of intact specimens. Pre-fabricated cracks induced significant stress concentration effects at the ends, causing failure cracks to propagate preferentially along the crack direction and forming a non-uniform deformation field bounded by the crack. The study revealed the micro-macro evolution patterns of progressive damage during creep in extremely weak fractured rock, providing theoretical support for early warning and control technologies against creep instability in tunnel rock masses of weakly cemented strata in western regions.

Geosciences doi: 10.3390/geosciences16030104

Authors: Yuguo Ni Chenbo Xie Zichen Zhang Jianfeng Chen

Atmospheric visibility nowcasting is vital for safety-critical operations but remains challenging due to complex atmospheric dynamics. We propose a compact stacking ensemble merging a multilayer perceptron (MLP) and gradient-boosted regression trees (GBRT). The model, trained on seven months of minute-scale resolution data with a variability-adaptive filter to suppress sensor noise, employs cross-validation. Results demonstrate that the ensemble achieves its peak performance in the operationally critical low-visibility regime (V < 5 km). This range is particularly significant as it encompasses the Category I and II (CAT I/II) operational thresholds defined by the World Meteorological Organization (WMO) for aviation and surface transportation safety. In this regime, the ensemble yields an R2 of 0.82 and an MAE≈385 m, significantly outperforming single learners during rapid weather transitions. Conversely, in the high-visibility regime (V > 20 km), the explanatory power decreases (R2 of 0.46) due to inherent forward-scattering sensor uncertainties and low aerosol concentrations. Despite these range-specific physical limitations, the model maintains high robustness with narrowly centered residuals. This efficient approach, utilizing cost-effective in situ sensors, is highly suitable for airport and road-weather applications and offers strong potential for multi-site scalability.

Geosciences doi: 10.3390/geosciences16030100

Authors: Qianyun Wang Dingjian Wang Pengju An Qiong Nie Jianlin Lu Zhiyuan Cheng

Model tests are effective for studying the entire deformation and evolution process of reservoir landslides. The sensitivity of similar materials to seepage effects is crucial to the accuracy of landslide model testing. Based on a fuzzy evaluation of in situ sliding zone soil, this study compared three similar materials, using shear tests and microscopic SEM to assess the similarity. The optimal similar material (sliding zone soil: bentonite: standard sand = 50%: 20%: 30%) with a water content of 13.5% and a permeability coefficient of 3.8 × 10−6 cm/s was identified, simultaneously matching physical–mechanical properties and seepage effects. When the proportion of in situ sliding zone soil exceeds that of bentonite, the in situ sliding zone soil dominates the strength. Cohesion depends on interparticle cementation force and water film viscosity. Bentonite modifies these forces in stages, leading to a trend where cohesion (c′) first increases and then decreases with rising water content, while the internal friction angle (φ’) decreases continuously. Model test results indicate the failure mode of reservoir landslides is a three-stage traction-braking failure, evolving from initial shallow deformation to deep progressive failure and finally to overall large-scale instability. The proposed similar material exhibits reliable physical–mechanical and seepage similarity and can be directly applied in physical model tests of reservoir-induced landslides to reproduce the hydro-mechanical coupling behavior of sliding zones.

Geosciences doi: 10.3390/geosciences16030103

Authors: Aichuan Bai Xiangyu Fan Muming Xia Xiao Zou Changchun Zou Panpan Fan

Real-time lithology identification while drilling is widely applied in oil and gas exploration, development drilling, geo-steering, unconventional resource extraction, well logging, and environmental monitoring, enhancing efficiency and accuracy in subsurface operations. This study investigates the frequency characteristics of rock-drilling sounds generated during drilling operations and explores their potential for real-time lithology identification. Experiments were conducted using 8 mm and 14 mm drill bits at both high and low rotational speeds on four types of rock samples: sandstone, limestone, granite, and shaly sandstone. Sound signals were recorded both within the rock and in air using high-fidelity sensors. The results reveal distinct frequency patterns for each rock type, with sandstone exhibiting dominant low-frequency energy, limestone and granite showing broader frequency bands with strong high-frequency components, and shaly sandstone displaying a mix of low- and high-frequency energy. Quadratic polynomial regression models between the Vp or Vs and the peak frequencies of the four distinct rock samples are built, and the corresponding coefficients of determination are 0.9878 and 0.9799. The study also demonstrates that drilling parameters, such as drill bit diameter and revolutions per minute (RPM), significantly influence the frequency distribution of rock-drilling sounds, with larger drill bits and higher RPMs producing broader frequency bands and stronger high-frequency energy. Comparisons between in-rock and in-air recordings show that the latter captures richer high-frequency information, though the overall trends remain consistent. These findings provide an experimental foundation for using rock-breaking sounds as a potential tool for lithology identification during drilling operations. The study highlights the importance of considering rock heterogeneity and drilling conditions when interpreting acoustic data and suggests future work to validate the method in field conditions and integrate advanced data processing techniques.

Geosciences doi: 10.3390/geosciences16030102

Authors: Ethan W. Conley Eric W. Peterson Toby J. Dogwiler John C. Kostelnick

While dissolution dominates the genesis of karst systems, physical erosion processes also play a significant role in their development. Lowering of the water table exposes caves to vadose conditions, reducing roof-supporting buoyancy and potentially leading to catastrophic conduit ceiling failure and cave collapse. The locations and extents of collapse areas are not always identifiable at the landscape surface. High-resolution topographic data derived from LiDAR were used to develop a digital elevation model (DEM) that isolates areas that may have sustained episodes of cave collapse and improves our understanding of past hydrogeological and geomorphological conditions of the system. Cave level delineation from LiDAR data was used to assign elevations to cave entrances. Spatial susceptibility to past collapse was evaluated using a weighted multi-criteria analysis that integrated terrain slope, proximity to mapped cave entrances, and distance to surface streams. Areas identified as having a high likelihood of collapse spatially coincide with cave level contacts and known karst windows and terraces, indicating that this replicated methodology is effective as an initial survey tool for identifying collapse-prone areas in karst landscapes.

Geosciences doi: 10.3390/geosciences16030101

Authors: Fang Liu Dongjun Sun Ting Yang Yuhang Dai

We present a high-resolution 3-D shear-wave velocity model of the Indonesian lithosphere and upper mantle, constructed through a weighted joint inversion of complementary surface wave datasets. Our model integrates teleseismic Rayleigh waves from 387 earthquakes recorded at 31 stations, analyzed using a modified two-plane-wave tomography method, with two years of ambient noise data from 30 stations processed via image transformation techniques. Our results provide new structural constraints on the four principal subduction systems in Indonesia. Along the Sunda–Java Trench, the slab exhibits a systematic along-strike transition from a continuous and well-defined geometry in the west to increasingly disrupted and thickened structures toward the east. This evolution correlates with the subduction of progressively older lithosphere. Beneath the Banda Arc, we image a continuous slab whose dramatic 180° curvature and deep coalescence of distinct segments provide direct evidence for a single-slab rollback and folding origin. In the Molucca Sea region, tomography reveals a shallow low-velocity zone and resolves the complex geometry of an active double-sided subduction system associated with arc–arc collision. Collectively, these findings provide unprecedented constraints on slab segmentation and deformation, highlighting the dominant control of lithospheric age and complex plate interactions on the geodynamic evolution of this exceptional convergent boundary.

Geosciences doi: 10.3390/geosciences16030099

Authors: Hao Li Yanqing Wu Liang Du

When examining ground-penetrating radar (GPR)-based advanced detection ahead of the tunnel face for tunnel constructions, existing numerical forward simulations have not effectively accounted for the actual orientation of the strata and the conditions, limiting their theoretical guidance. In this study, we classify tunnel boring through strata attitudes into horizontal, vertical, positively inclined, reverse inclined, and other anomalous structures. We also consider tunnel faces with different planarity (perfectly smooth or irregular). Using the finite-difference time-domain method with a generalized perfectly matched layer, we simulated 21 forward models for GPR-based advanced detection ahead of the tunnel face. The comparative simulation results indicate that the superposition of reflections from different directions at irregular tunnel faces, lithological interfaces, complicated numerical forward models of typical target geological bodies, making it difficult to distinguish the reflection signals of target geological bodies, and the signal strength in numerical forward modeling profiles with antenna touch with tunnel face is significantly stronger than those without such touch. The flatness of the tunnel face and the close proximity between the antenna and tunnel face are the keys to obtain high-quality original data. These research findings will contribute to improving instruments, data processing, and geologic interpretation in future.

Geosciences doi: 10.3390/geosciences16030098

Authors: Wei Wang Jihong Li Xiuqin Deng Shutong Li Junlin Chen Junli Qiu Xiaoyan Li Youwei Duan

The Chang 8 Member in the Longdong area of the Ordos Basin hosts significant petroleum resources, demonstrating substantial potential for tight oil exploration and development. Astronomical forcing exerts a discernible influence on the evolution of its petroleum system. To elucidate the impact of Milankovitch orbital cycles on organic enrichment and the development of source rocks, reservoirs and cap rocks, we conducted a high-resolution cyclostratigraphic analysis of the Chang 8 Member stratigraphy. This study utilized gamma-ray (GR) well log series as the primary dataset. This lacustrine succession preserves distinct Milankovitch cycles, including ~405 ka long eccentricity, ~125 ka short eccentricity, obliquity, and precession periods, with eccentricity cycles showing particularly strong expression. These diagnostic eccentricity signals provided the framework for delineating high-frequency sequences. Subsequent astronomical tuning and base-level reconstruction constrain the depositional age of the Chang 8 Member to 242.22–241.23 ± 1.4 Ma. During this interval, the lacustrine system exhibited a pronounced trend of base-level fall followed by rise, punctuated by higher-frequency fluctuations. Milankovitch cycles govern the development of high-quality reservoirs and cap rocks and organic enrichment by modulating climate and lake-level fluctuations. These orbital forcings drive weathering processes, control fluvial sediment supply and lacustrine accommodation space, and influence biological productivity. Our results demonstrate a pronounced association between the long eccentricity cycle (~405 ka) and enhanced reservoir quality development, while the short eccentricity cycle (~125 ka) exhibits a stronger correlation with organic matter enrichment, cap rocks, and source rock formation. Ultimately, the interplay of eccentricity cycles jointly governs the formation of the hydrocarbon system within the continental Chang 8 Member.

Geosciences doi: 10.3390/geosciences16030097

Authors: Jianrong Wang Zhipeng Xie Chuandong Xue Wenchang Li Lei Dou Wei Wang Xingwang Song

The Indosinian granitoids of Guangdong Province, South China, record a complex history of crust–mantle interactions during the Triassic assembly of the South China Block (SCB) and Indochina Block (ICB). Integrated zircon U–Pb geochronology, geochemistry, and Sr–Nd–Hf isotopes from these plutons reveal two magmatic episodes: an Early Indosinian phase (253–230 Ma) of large, west-to-east younging batholiths, and a later scattered phase (230–200 Ma). While most granitoids are peraluminous S-types formed by the melting of the Paleoproterozoic crust with limited mantle input (0–30%), the Taibao pluton and its enclaves are anomalous. They are more mafic and record a substantial mantle contribution (40–65%), pointing to focused, high-heat flux magmatism. This spatial and petrogenetic heterogeneity, coupled with the granitoids’ NE–SW trend orthogonal to the collisional zone, cannot be explained by simple crustal thickening. We propose that these features are the direct result of the slab tearing of the subducting Paleo-Tethys oceanic plate, triggered by an oblique collision between the SCB and ICB. This tearing induced asthenospheric upwelling, providing the thermal engine for widespread crustal anatexis and localized mantle melting. Our findings establish slab tearing as a key catalyst for syn-collisional, high-temperature magmatism, offering a unified framework for interpreting lithospheric processes during continental collisions.

Geosciences doi: 10.3390/geosciences16030096

Authors: Lingling Liao Yifei Zhang Yan Li Yinhua Pan

The Yanchang Formation in the Ordos Basin is a key target for continental shale oil exploration in China. Due to its complex geological background and diversified organic inputs, the hydrocarbon generation and accumulation in the lacustrine basin remain to be fully understood. Unlike marine shales rich in Type I kerogen, this lacustrine system is dominated by Type II and III kerogens. In this study, Rock-Eval pyrolysis was performed on lacustrine shales with Type IIa, IIb, and III kerogens to investigate the effect of kerogen type on their hydrocarbon generation and expulsion characteristics. The results reveal that the hydrocarbon generation potential of the Yangchang Formation shale generally follows the order of Type IIa > Type IIb > Type III. Pyrolysis kinetic calculations of the kerogens demonstrate a clear hierarchy of hydrocarbon generation and expulsion among the kerogen types, of which Type II kerogen has better hydrocarbon generation potential, earlier generation timing, and narrower generation window than Type III kerogen. The discrepancy in hydrocarbon generation potential and pyrolysis kinetic behavior is largely attributed to the kerogen components and types, which manifests as a kerogen-type constraint on the hydrocarbon generation and expulsion of shale. Based on the geological mapping of the lacustrine shales in the study area, we propose a “kerogen type-specific” exploration strategy that prioritizes Type IIa-rich intervals in moderate-maturity areas for shale oil exploration, Type IIb as secondary prospects, and Type III in high-maturity areas for shale gas exploration. This study provides a systematic investigation of pyrolysis simulation and hydrocarbon generation and expulsion kinetics on the Yanchang Formation shale, as well as a practical framework for optimizing exploration in analogous lacustrine basins.

Geosciences doi: 10.3390/geosciences16030095

Authors: Vega Perez-Gracia Oriol Caselles Jose Ramón Gonzalez Drigo Viviana Sossa Jaume Clapes

Preventive conservation of historic buildings is crucial to avoid extensive damage, yet assessments are often reactive. Following mortar detachment at the Basilica of Santa María del Pi, this paper presents a diagnosis using Non-Destructive Testing (NDT). The study employed Horizontal-to-Vertical Spectral Ratio (HVSR) for subsoil analysis and Ground Penetrating Radar (GPR) for superstructure inspection. HVSR analysis differentiated fill material from compacted ground, revealing that most of the basilica rests on infilled soil, except the northern corner, suggesting differential settlement risks. Concurrently, GPR survey of vaults and roofs identified internal structures, specifically zones lightened with hollow ceramics, and mapped high-moisture anomalies via wave amplitude and velocity analysis. The study concludes that these methods are complementary, addressing distinct spatial domains. Integrating subsoil characterization with superstructure analysis provided a comprehensive diagnosis essential for long-term maintenance and preservation.

Geosciences doi: 10.3390/geosciences16030094

Authors: Pedro Miguel Callapez Fernando Barroso-Barcenilla Melani Berrocal-Casero José Manuel Brandão Maria José Comas-Rengifo Rúben Domingos Elsa Gomes Fernando Carlos Lopes Mário Miguel Mendes Senay Ozkaya de Juanas Hélder José Pereira Jordi Perez-Cano Ricardo Jorge Pimentel Vanda Faria dos Santos Manuel Segura

A new species of pectinid bivalve, Syncyclonema goyi sp. nov., is described in honour of Professor Antonio Goy, one of the leading stratigraphers who shaped Mesozoic studies in Iberia over the past half century. It represents one of the smaller fossil scallops currently known from the Upper Cretaceous of Europe, alongside a few boreal species previously assigned to the family Entoliidae. The type specimens have orbicular valves, almost smooth, with unequal auricles. The right valve is more convex and bears a well-marked paleal sinus. The sculpture of the shell is weak, exhibiting concentric growth lines and lamellae. However, nearly 90 very small, uniform radial striae are discernible beneath the outer shell layer. This species is frequent in open marine, fine-grained, inner shelf facies of the Tethyan West Portuguese Carbonate Platform, near the main localities of Coimbra, Tentúgal, and Condeixa-a-Nova, in the Baixo Mondego region of West Portugal. It mostly occurs in the upper Cenomanian beds of the Trouxemil Formation, with Euomphaloceras septemseriatum and Vascoceratidae ammonites.

Geosciences doi: 10.3390/geosciences16030093

Authors: Xiang Cheng Shengqian Liu Jinxiong Luo Yan Zhong Dazhi Zhang Shan Sun

The Sinian (Ediacaran) Dengying Formation in the northeastern Sichuan Basin exhibits a significant exploration potential. Nevertheless, the great burial depth of carbonates in the Dengying Formation and the scarcity of drilling data have imposed constraints on in-depth investigations into the evolution of lithofacies paleogeography as well as the primary controlling mechanisms. Through integrated analysis of field outcrops, core and well logging data, the evolution of the lithofacies and paleogeography of the Dengying Formation in the northeastern Sichuan Basin was reconstructed by using 3D stratigraphic forward modeling. The study area is predominantly characterized by platform margin facies and restricted platform facies, comprising four subfacies including microbial (algal) mound, grain shoal, intershoal sea, and intraplatform depression. The microbial (algal) mound and grain shoal subfacies are primarily developed along the western and eastern platform margins, exhibiting a near north–south trend. Scattered mound–shoal complexes and intershoal sea occur within the platform, with localized intraplatform depression zone. During the depositional stage of the Dengying Formation, three primary paleogeomorphic units were developed including the platform margin topographic high zone, intraplatform gentle slope zone, and intraplatform depression zone. During the Deng-1 and Deng-3 periods, sea level rise increased accommodation space, leading to a gradual decline in carbonate productivity and limited development of the mound–shoal complexes. In contrast, during the Deng-2 and Deng-4 periods, sea level decreased, water depth decreased, and carbonate productivity was enhanced, resulting in extensive development of the mound–shoal complexes. The simulation results indicate that carbonate-producing ecosystems thrive when wind blows from 270° W (80% frequency) or 15° N (60% frequency); with an effective water depth of 10–20 m, the elevated carbonate productivity is conducive to the growth of biogenic calcification. Comprehensive analysis suggests that paleogeomorphology, eustatic fluctuations, and paleowind fields collectively control the distribution and evolution of the lithofacies in the Dengying Formation in the northeastern Sichuan Basin. Paleogeomorphology governs the types and distribution of sedimentary facies belts as well as the spatial arrangement of lithofacies. Eustasy determines the magnitude of mound–shoals and their lateral migration. Three-dimensional stratigraphic forward modeling offers a novel approach for reconstructing paleogeographic evolution of carbonate platforms and analyzing key controlling factors, while also enhancing our ability to predict the distribution patterns of mound–shoal complexes.

Geosciences doi: 10.3390/geosciences16030092

Authors: Olga Druzhinina Kseniya Filippova Lyudmila Lazukova Alexandra Golyeva

In this paper, we present the results of a paleoanthracological analysis of the Lateglacial Kulikovo section (eastern Baltic, Kaliningrad region). This is proposed as a new methodological approach to studying the presence of woody taxa in Lateglacial vegetation. Woody vegetation is an important marker of environmental dynamics in post-glacial areas and one of the most important indicators of climate amelioration. Therefore, establishing the time of the appearance of woody vegetation during the Lateglacial period is essential. Paleoanthracological analysis revealed 22 macrocharcoal morphotypes, among which were the following indicators of woody (coniferous and deciduous) vegetation: wood, punky wood, needles, leaf stems, etc. The results indicate an almost continuous local presence of woody species in the study area since the Older Dryas, 14.0 ka. This conclusion is in good agreement with the available data on the presence of phytoliths of conifers and palynological data, indicating that from the end of the Older Dryas up to approximately 12.5 ka, the percentage of arboreal vegetation did not fall below 50% of terrestrial pollen, and over a significant part of the studied time interval it reached 70–80%. Paleoanthracological analysis can serve as both an independent method of studying the emergence of woody vegetation in a certain area and an important addition to the reconstruction of Lateglacial vegetation based on pollen data.

Geosciences doi: 10.3390/geosciences16030091

Authors: Zisong Zhao Shengwei Wu Fucheng Yu Shanping Li Zhiyi Zhao

Mafic microgranular enclaves (MMEs) are widespread in granitic plutons and provide valuable insights into mush–magma mixing processes in crustal magma reservoirs. In this study, we characterize chemical zoning and Sr isotopic compositions of plagioclase in the MMEs, gabbro and host monzogranite from the Late Triassic Xiuyan pluton in East China, to constrain the origin of MMEs and the role of crystal mushes in magma mixing. The MMEs in the Xiuyan pluton are angular and range from centimeters to several meters in size. They exhibit sharp contacts with the host monzogranite and show diverse disequilibrium textures. Plagioclase in MMEs occurs as fine-grained antecryst with normal zoning (An46–66 in the core and An17–29 in the rim). The cores are commonly characterized by coarse sieve textures, patchy zoning, and resorption surfaces at core–rim boundaries. In situ Sr isotopic compositions show subtle but systematic core–rim variations, with (87Sr/86Sr)i increasing slightly from cores (~0.70639) to rims (~0.70664), and rim values overlapping the whole-rock (87Sr/86Sr)i of MMEs. These features suggest that the rim was crystallized from locally hybridized melts produced by interaction between interstitial melts in a basaltic mush and granitic magma. Plagioclase in the gabbro occurs as medium-grained phenocryst with normal zoning (An46–65 in the core and An18–27 in the rim) but shows nearly homogeneous (87Sr/86Sr)i across individual grains (0.70612–0.70637), comparable to whole-rock gabbro values of 0.70623. The plagioclase cores in gabbro also show coarse sieve texture and patchy zoning with the resorption surface in the margin of the core and rim. We interpret the sieve textures in plagioclase cores from both MMEs and gabbro to record partial dissolution during rapid ascent and decompression of an initially H2O-undersaturated, crystal-bearing basaltic magma, during which increased effective water activity reduced plagioclase stability prior to the growth of the rim. Plagioclase in the host monzogranite is medium- to coarse-grained, compositionally homogeneous, and characterized by low An contents (An12–24) and elevated (87Sr/86Sr)i of ~0.70828. We propose that MMEs in the Xiuyan pluton formed when semi-consolidated mafic mush was mechanically disaggregated into angular fragments and subsequently entrained into coexisting granitic melt. This study reveals that MMEs formed by mechanical disaggregation of a semi-consolidated mafic mush into angular fragments, followed by their entrainment into the granitic melts.

Geosciences doi: 10.3390/geosciences16020090

Authors: Hsien-Wang Ou

We develop a minimal thermodynamic model to predict Titan’s surface temperature based on radiative–convective equilibrium and the principle of maximum entropy production (MEP). The model retains only the essential atmospheric constituents: gaseous methane, which absorbs both longwave and near-infrared radiation, and stratospheric haze, which scatters and absorbs solar flux. Subject to Clausius–Clapeyron scaling of methane vapor pressure together with energy balances at the surface, tropopause, and stratopause, the model links the convective flux to the surface temperature, which exhibits a pronounced maximum due to competing radiative effects of tropospheric methane. As the surface warms, enhanced greenhouse effect would strengthen the convection, whereas the rising anti-greenhouse effect would suppress convection. The resulting convective peak corresponds to MEP, which thus selects a surface temperature slightly above methane’s triple point. To assess its long-term evolution, we consider a 20% dimmer early Sun and a hypothetical 20% enrichment of the oceanic methane. Even in combination, they only cool the surface by ~2 K, in sharp contrast to the ~20 K cooling inferred in studies that prescribe haze abundance. This study suggests a critical role of self-adjusting haze in providing the internal degree of freedom necessary for MEP closure, thereby stabilizing Titan’s temperature.

Geosciences doi: 10.3390/geosciences16020089

Authors: Massimo Zecchin Mauro Caffau Octavian Catuneanu

The integration of sedimentological and micropaleontological data in the Zanclean and Gelasian shallow-marine deposits of the Crotone Basin (southern Italy) has allowed documentation of meter-to-decameter-scale high-frequency sequences bounded by wave-ravinement surfaces (WRSs), which in turn are composed of meter-scale sedimentological cycles, referred to as bedsets. In contrast to high-frequency sequences, bedsets have a more subtle appearance, and their boundaries exhibit limited lateral extent compared to WRSs. Moreover, the micropaleontological analyses have allowed the definition of three parameters: distal/proximal (D/P: ratio between distal and proximal benthic foraminifera); fragmentation (Fr: percentage of fragmentation of benthic foraminifera); and P/B (ratio between planktonic and benthic foraminifera). In particular, the D/P and Fr allow to recognize uncertainty intervals containing the maximum flooding surface (MFS) of high-frequency sequences, whereas the P/B documents water-depth changes. Unlike in high-frequency sequences, the D/P, Fr and P/B parameters usually do not show appreciable variations associated with bedsets, confirming that the latter are unrelated to shoreline shifts and water-depth variations, but are rather controlled by minor sediment supply and/or wave regime changes. However, in rare cases, the micropaleontological parameters seem to indicate that subtle transgressive-regressive trends and water-depth variations can also be associated with bedset deposition, alluding to a ‘grey area’ of transition between high-frequency sequences of very small scale and bedsets. Further research is, therefore, needed to constrain the boundary between sedimentology and stratigraphy.

Geosciences doi: 10.3390/geosciences16020088

Authors: Sobhan Emtehani Victor Jetten Cees van Westen Bastian van den Bout

Extreme rainfall events often trigger landslides, debris flows, and sediment-laden floods that cause severe damage in built-up areas, yet sediment deposition is rarely quantified in hazard assessments. This study evaluates the capability of the physically based catchment model LISEMHazard to reconstruct sediment generation, transport, and deposition during Hurricane Maria (2017) in two catchments in Dominica (Coulibistrie and Grand Bay). Simulations were performed at 10 m resolution using rainfall, topography, soil, and land-use data. Model calibration and validation used mapped landslides and debris flows, field measurements of deposition height, and DEMs of Difference (DoDs). LISEMHazard reproduced the general magnitude of sediment volumes and the frequency–area distribution of medium and large landslides but showed poor ability to predict their exact locations and overestimated landslide depth and deposition height. Agreement between modeled and observed debris-flow patterns was good in major channels but weak in minor ones. Sensitivity analysis indicated that soil depth and cohesion dominate uncertainties, whereas saturated hydraulic conductivity and surface roughness exert minimal influence. Despite substantial data and model limitations, physically based modeling remains a practical approach for spatial estimation of sediment deposition needed for risk assessment, structural damage evaluation, and cleanup cost estimation.

Geosciences doi: 10.3390/geosciences16020086

Authors: Wael R. Abdellah Hassan A. M. Abdelkader Atef M. Abu Khatita Mahrous A. M. Ali

This study evaluates the stability and failure probability of rock slopes at Mount Uhud, Madinah, Saudi Arabia, with particular attention to a representative slope in the densely populated southern part. A combined deterministic–probabilistic approach was adopted using a two-dimensional, nonlinear elastoplastic finite element model to capture realistic slope behavior. Uncertainty in key geomechanical parameters—slope angle, cohesion, and internal friction angle—was quantified through Li’s Point Estimate Method, resulting in n3 probabilistic simulations. Slope performance was assessed in terms of both factor of safety (FoS) and probability of failure (Pf). Deterministic analysis yielded a factor of safety of 0.813, while probabilistic simulations produced a factor of safety range between 0.468 and 1.052, with a mean value of approximately 0.73. The corresponding probability of failure was estimated at about 5.16%. Sensitivity analysis indicates that cohesion and internal friction angle exert the strongest influence on stability outcomes. Although the slope shows noticeable sensitivity to reductions in these parameters, the overall probability of failure remains relatively low under current conditions. The results demonstrate that integrating deterministic and probabilistic analyses provides a robust basis for evaluating rock slope reliability in complex geological environments, particularly in rapidly urbanizing mountainous areas such as Mount Uhud.

Geosciences doi: 10.3390/geosciences16020087

Authors: Mihnea Cristian Popa Daniel Constantin Diaconu Adrian Gabriel Simion Ioan Florin Voicu Costache Romulus

The paper addresses the limitations of fragmented and delayed hydrological information systems in supporting timely disaster risk mitigation. The paper introduces the RoWaterAPI, a framework that integrates near real-time hydrological measurements with geospatial analytics to improve awareness during flood-related events. The methodology utilizes open-source technologies, including Django, Kafka, and PostGIS, to support scalable data ingestion and hazard mapping. Initial baseline evaluation under a simulated bursty workload indicates an end-to-end latency of ≈1–3 s and a peak throughput of ≈6000–8500 messages/s. This performance supports real-time alerts for data variations, bridging advanced geoprocessing with user-centered design for public and institutional stakeholders. Ultimately, RoWaterAPI provides a transferable implementation model that can be adapted to any national context facing similar constraints in data fragmentation and operational accessibility.

Geosciences doi: 10.3390/geosciences16020085

Authors: Sydney Adelaide Richards John McBride Scott M. Ritter Kathryn J. Smith Kaleb Markert Keili M. M. Kwong Kevin A. Rey

The Bahamas is an ideal location for studying the calcium carbonate sedimentation of Holocene strandplains in relation to seaward progradation. We use ground-penetrating radar (GPR) to image and interpret the fine-scale stratigraphy of three carbonate strandplains on Crooked Island, The Bahamas. GPR has been extensively used to analyse the interiors of clastic strandplain deposits worldwide, while tropical carbonate settings have received less attention. Due to the lack of outcrops in our study area on Crooked Island, we validate the interpretation of the 2D profiles by comparing them with a 3D GPR data volume collected adjacent to and over a Pleistocene aeolianite outcrop on San Salvador Island, where porosity layering can be directly observed. Data processing employed state-of-the-art techniques adapted from the petroleum industry to enhance the visualisation of reflection amplitude on the GPR images. Our data support a model in which the progradation of carbonate sediment preserved in strandplains was deposited through a combination of storm processes and gradual sediment progradation.

Geosciences doi: 10.3390/geosciences16020084

Authors: Luca Pasqualone Francesco Brozzetti Francesco Mirabella Lucina Luchetti Anna Chiara Tangari Simonetta Cirilli Massimiliano Rinaldo Barchi

The Marnoso-arenacea basin (MaB) of the Northern Apennines represents one of the most significant lower–middle Miocene foredeep turbidite systems in the Mediterranean region. While the northern part of the basin (Emilia-Romagna Region) has been extensively investigated, the Umbrian portion remains less understood, particularly concerning high-resolution stratigraphic and structural frameworks. This study integrates detailed field mapping, physical stratigraphy, biostratigraphic data from calcareous nannofossils, and petrographic analyses of arenites and calcarenites to reconstruct the tectono-stratigraphic evolution of the MaB in the Umbrian portion of the basin. The basin is divided into three main tectono-stratigraphic units: Afra-Mt. Verde, Pietralunga–Gubbio–Valtopina and Mt. Vicino. The middle unit is detailed by means of stratigraphic architecture and sedimentary characteristics, which allow us to identify two distinct sub-units. Several carbonate and hybrid turbidite beds, including the Contessa megabed, serve as regional key markers, enabling robust stratigraphic correlations. Two mass-transport complexes (MTDs) have been identified and dated, revealing close relationships between sedimentation patterns and thrust propagation. Modal petrographic data indicate a mixed provenance, from the Alpine and Apennine regions, changing over time in response to tectonic segmentation. These findings enhance our understanding of the internal organization of the MaB and provide new insights into the foredeep’s paleogeography and tectono-sedimentary evolution during the Langhian–Serravallian stages.

Geosciences doi: 10.3390/geosciences16020083

Authors: Milan Đorđević Mrđan Đokić Miloš Manić Jelena Vesković Ranko Dragović Ivana Smičiklas Snežana Dragović Antonije Onjia

Among the most serious types of land degradation, soil erosion poses a major threat to agricultural productivity, water quality, and ecosystem stability. Using a multidisciplinary approach, this study aimed to identify the spatial patterns of soil erosion and dominant drivers influencing soil loss in the Toplica River Basin in southern Serbia. Soil properties, including texture and organic matter content, were analyzed in samples collected throughout the study area, accounting for variations in altitude, soil type, and land use, to determine the erodibility factor (K). The rainfall erosivity factor (R), topographic factor (LS), and cover management factor (C) were determined using available inputs on rainfall erosivity, topography, land use, and vegetation cover. The Revised Universal Soil Loss Equation (RUSLE) was used to estimate annual soil erosion rates, and GIS tools and cartographic techniques were used to create spatial layers for each RUSLE factor and to generate a detailed erosion risk map. The results showed a mean annual soil loss of 5.45 t ha−1 year−1, with values ranging from 0 to 397.09 t ha−1 year−1, indicating considerable spatial variability. The regression modeling revealed the dominant roles of factors LS (β = 0.828), C (β = 0.731), and their interaction (LS × C, β = 0.561), followed by rainfall-related interactions (R × C, β = 0.268 and R × LS, β = 0.261). Two dominant erosion regimes were distinguished: topography-controlled erosion in mountainous regions and land-use-controlled erosion in low- to moderately sloping agricultural areas. The maps and analyses presented in this study provide a process-based framework for interpreting spatial erosion patterns, identifying critical hotspots and areas with higher erosion risk, and supporting more focused and context-aware conservation strategies.

Geosciences doi: 10.3390/geosciences16020082

Authors: Berat Sinani Blazo Boev Arianit A. Reka Bahri Sinani Ivan Boev

This study investigates the presence of Technology-Critical Elements in the Trepça mine (Stan Tërg, Mitrovicë), representing the first assessment of their distribution within this mining district. Samples were collected in all ore bodies (three samples per ore body) in horizons VIII-XI. Mineralogical, geochemical and microstructural characterization was performed using X-ray diffraction (XRD), Inductively Coupled Plasma Mass-Spectrometry (ICP-MS), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The analyses confirmed the presence of several Technology-Critical Elements, especially Bi, Co, Ge, W, Ga, In, Te and Sb, whose distribution, correlation with mineral phases and structure were also identified. XRD enabled the identification of mineral phases while SEM-EDX provided structural and morphological characteristics of these mineral phases. The ICP-MS results indicate significant variability in the distribution of these elements. Bi reached extremely high concentrations (up to 2570.68 ppm in ore body 136), well above the method detection limit (MDL = 0.01 ppm), whereas Co exhibited elevated yet moderate concentrations that increased with depth, indicating a depth-dependent rise in concentration. V, W, Sb and Sn also exhibited elevated concentrations. Peak enrichment levels were observed for Bi (up to 2750 ppm) in Horizon IX, Sb (up to 504 ppm) in Horizon XI, W (up to 308 ppm) in Horizon VIII, and In (up to 34,730 ppm) within selected ore bodies, indicating pronounced vertical geochemical zonation. The results demonstrate that selected ore bodies represent significant potential sources of Technology-Critical Elements, supporting future resources and strategic raw material assessment within the Trepça mining district.

Geosciences doi: 10.3390/geosciences16020081

Authors: Mahmood Salem Dhabaa Ahmed Gaber Adel Kamel Mohammed

This study addresses a critical knowledge gap in quantifying strategic mineral resources within hyper-arid, tectonically complex terrains by establishing a recursive framework that reconciles deterministic resource estimation with the nonlinear dynamics of tectonically mediated metamorphic systems. Using Libya’s Wadi El Shati as a case study, legacy lithological misclassifications are rectified through the fusion of Sentinel-1 Synthetic Aperture Radar, Sentinel-2 multispectral imagery, and Digital Elevation Model analytics within a unified geospatial workflow. The methodology synergizes atmospherically corrected optical data, processed via supervised Maximum Likelihood Classification, with calibrated radar-derived structural lineaments. Classified marble-bearing zones within the Al Mahruqah Formation are integrated with DEM data and field-validated thickness measurements using Triangulated Irregular Network models to resolve surface–subsurface dependencies and compute volumes. The results demonstrate a 91% lithological classification accuracy, rectifying a 22% error in legacy maps. Structural analysis of 1213 lineaments confirms a dominant NE–SW extensional regime (σ3) that facilitated fluid conduits. The quantified marble-bearing horizon spans ~334 km2 with a volume of 6.0 km3 (±9%). Spatial analysis reveals a causal link between high-grade marble clusters, basaltic intrusions, and NE–SW fault systems, refining models of contact metamorphism in rift-related settings.

Geosciences doi: 10.3390/geosciences16020080

Authors: Fei Teng Jiangwei Zhang Wendi Guo Leon Bagas Kang Yan Yuxiang Teng Ying Wei Ningchao Zhou Yongbao Gao Liyong Wei

Recent exploration has demonstrated significant prospecting potential at the Huayagou Au deposit in Longnan mineral Field, Gansu Province, West Qinling Orogen, Central China. However, the nature and evolution of the auriferous fluids responsible for gold enrichment remain poorly constrained, hindering effective exploration targeting of high-grade ores. In this study, apatite and tourmaline closely associated with gold mineralization are investigated as mineralogical recorders of fluid composition and evolution. Integrated petrographic observations, TIMA phase mapping, cathodoluminescence imaging, electron probe microanalysis, and in situ trace element analyses were used to distinguish magmatic, metamorphic, and syn-ore hydrothermal generations of apatite and tourmaline, together with in situ Nd isotopic analyses of apatite and B isotopic analyses of tourmaline. Syn-ore hydrothermal apatite is characterized by homogeneous blue cathodoluminescence, fluorapatite compositions, strong LREE depletion, and εNd(t) values overlapping those of Triassic magmatic apatite, whereas Early-Devonian magmatic and metamorphic apatites display more distinct signatures. Tourmaline records a systematic evolution from early dravite to late schorl, accompanied by trace element enrichment and a shift toward heavier δ11B values. These mineralogical and isotopic features, together with published sulfur isotope constraints, indicate that gold mineralization at Huayagou was dominantly controlled by structurally focused metamorphic fluids, with localized Triassic magmatic–hydrothermal overprinting enhancing gold enrichment in high-grade ores. The Huayagou Au deposit is, therefore, best interpreted as an atypical orogenic gold system, highlighting enhanced exploration potential in structurally favorable zones at depth, particularly in the western part of the district where Triassic magmatism is inferred.

Geosciences doi: 10.3390/geosciences16020079

Authors: Taoran Liu Guangxia Yu Shuanghua Ye Jin Qi Xingru Huang Zhiwen Zheng Jin Liu Stefan Poslad Xiaoshuai Zhang Guangyuan Zhang

Conventional wisdom posits that smog suppresses outdoor activity while shifting peoples’ activities indoors. Using anonymized Mobile Phone Data Provider Records fused with Point-of-Interest (POI) data sourced from the Gaode (Amap) open database for Beijing (2–22 February 2015), we test this substitution hypothesis at an hourly resolution across 12 POI-defined activity categories. We estimate the adjusted population density (APD) from mobile phone data via usage-bias calibration, interpolate city-wide AQI (Air Quality Index) and PM2.5 fields, and identify associations with a two-way fixed-effects design (Voronoi polygon (VP), day × hour model. We also handle time-invariant POI activities, while factoring in weather and day types. We find a dual suppression of both outdoor and indoor physical activities: worsening air quality is associated with lower participation in most outdoor and indoor activities. Effects are heterogeneous across categories and hours; shopping shows all-day negative marginal effects, whereas a few categories (e.g., sightseeing) display positive correlations in select afternoon hours consistent with congestion-avoidance rather than health-driven indoor substitution. Quantitatively, a 100-point AQI increase is associated with an order of 1–5 persons/km2 decline at peak hours for most activities. A Comprehensive Impact Index (CII) summarizes the spatial heterogeneity across the city. POI venue operators should anticipate city-wide activity reduction both indoors and outdoors under heavy pollution, rather than plan solely for outdoor-to-indoor activity shifts.

Geosciences doi: 10.3390/geosciences16020078

Authors: Jelmir Craveiro de Andrade Vinicius Kartnaller Mário Miguel Mendes Pedro Miguel Callapez Darlly Erika Silva dos Reis Tereza Cristina Souza de Oliveira Celeste Yara dos Santos Siqueira

Coari Lake is a critical area in the Amazon due to the oil exploration that began in the 1980s. The present study evaluates the impact on Coari Lake and the Solimões River in order to identify the origin of the sedimentary organic matter. This research is of great importance as it constitutes a crucial follow-up assessment, conducted 13 years after the initial survey by the same research group. Aliphatic hydrocarbons found in the new collected samples ranged from n-C14 to n-C34, with Cmax at C29–C31 and CPI values between 2.5 and 5.1, suggesting predominantly terrestrial biogenic inputs. Although the total n-alkane concentrations increased from 2012 to 2025, values remained within natural background ranges and as well as those ones associated with contaminated sediments. Aromatic hydrocarbons were strongly dominated by perylene, further supporting a biogenic origin. Monoaromatic and polyaromatic triterpenoids derived from α-amyrin, β-amyrin and lupeol were consistently detected, reflecting contributions from higher-plant material. No petrogenic indicators such as hopanes, steranes or unresolved complex mixtures were identified in any sample. Principal Component Analysis confirmed a temporal increase in hydrocarbon abundance while maintaining stable source signatures. Overall, the results demonstrate that Coari Lake sediments are still dominated by natural organic matter.

Geosciences doi: 10.3390/geosciences16020077

Authors: Ekaterina V. Kovalenko (Levashova) Nikolai M. Kudryashov Sergey G. Skublov Vladislav G. Kurichev Xian-Hua Li

A comprehensive investigation was conducted on high-hafnium zircons from the LCT (Li-Cs-Ta) pegmatites of the Vasin-Mylk rare-metal deposit within the Fennoscandian Shield. In situ analysis of trace element composition and oxygen isotope ratios were performed using secondary ion mass spectrometry (SIMS), complemented by internal structural examination via scanning electron microscopy (SEM). The research focuses on deciphering compositional zoning within zircon crystals and characterizing their geochemical signatures to constrain crystallization conditions. The study revealed anomalously high concentrations of Hf (up to 381,000 ppm) and Li (up to 152 ppm), paired with extremely low abundances of U (~10 ppm) and total rare earth elements (~35 ppm). Marked geochemical contrasts were identified between the central and rim domains of the zircons. Central zones display well-fractionated rare earth element (REE) patterns featuring positive Ce and negative Eu anomalies, while the high-Hf rims exhibit weakly differentiated spectra with variable Ce anomalies. The identified W-type tetrad effect suggests crystallization from a melt strongly influenced by coexisting fluids. The obtained δ18O values are consistent with a mantle source and suggest crystallization within a system closed to external fluids. The zircons from the Vasin-Mylk deposit crystallized during the transitional period between the late magmatic and early hydrothermal stages of a highly differentiated pegmatite system. These results contribute to a better understanding of ore genesis in LCT pegmatite systems.

Geosciences doi: 10.3390/geosciences16020076

Authors: Mustapha El Hamidy Károly Németh

The 2023 Al Haouz earthquake (Mw 6.7–6.9) is the strongest quake ever recorded in modern Morocco and ranks among North Africa’s most significant seismic events of the century. It struck the High Atlas region, causing widespread land changes, thousands of landslides, destruction in remote mountain villages, and heavy losses of life and cultural heritage. The earthquake not only had immediate humanitarian and economic effects but also dramatically transformed the landscape, uncovered new geological features, and reshaped the region—providing a unique opportunity to study seismic activity as geoheritage. Researchers have begun systematically documenting how this earthquake affected perceptions of seismic hazards in the High Atlas area. Although often considered a dark geoheritage, the event holds valuable lessons that can inform programs to strengthen resilience to geohazards. This research places the 2023 Al Haouz earthquake in a geoheritage context, underscoring its scientific, educational, and cultural importance. By analyzing how the earthquake altered the terrain, exposed tectonic activity, and left lasting geological marks, this work aims to bridge the gap between the high scientific interest in seismic events and their limited roles in geoheritage, conservation, tourism, and education.

Geosciences doi: 10.3390/geosciences16020075

Authors: David Santiago Avellaneda-Jiménez Gaspar Monsalve

The Eastern Cordillera of the Colombian Andes is a high-elevation asymmetric plateau subjected to NW–SE shortening. An interesting aspect of this plateau is the presence of high geothermal gradients (up to 52 °C/km), constrained by wells drilled in sedimentary basins. Radial and transverse receiver functions were computed at key sites in the plateau and the adjacent low-elevation foreland region to better understand the controlling factors of these anomalous gradients. Results indicate the presence of tilted anisotropic layers in the uppermost crust of the Cordillera, and nonexistent to weak anisotropy in the foreland region. The estimated SE fast-axis trend of the anisotropy is related to NNE-striking faults and top-to-the-east tectonic transport during deformation. We interpret the SE fast axis as being associated with shearing of NW-dipping faults in the plateau. Compiled thermochronological data point to high deformation and exhumation rates since the middle Miocene, which we use to propose that the rapid rise of deep and hot blocks along major regional faults is perturbing the background geothermal gradient. Regions near major thrust faults in the Eastern Cordillera are potential areas for geothermal energy exploration due to the perturbed geothermal gradient and enhanced fluid infiltration related to deep fault systems.

Geosciences doi: 10.3390/geosciences16020074

Authors: Emiliya Raeva Lora Bidzhova Gatien Morin Svetoslav Georgiev

Knowledge of the trace element contents of petroleum can improve crude oil exploration and refining and aid environmental studies. Analytical challenges prompt experimentation with various digestion methods and analytical techniques, but the assessment of the efficiency of applied methodologies is hindered by the scarcity of multi-element standard reference materials. In this study, NIST SRM 1634c residual fuel oil and NIST RM 8505 crude oil were subjected to (i) hotplate acid digestion and (ii) one, two or three cycles of microwave acid digestion, and analyzed by ICP-MS. Comparison with the few available certificate values shows optimum recoveries for both reference materials with two and three cycles of microwave digestion. Hotplate digestion can also efficiently decompose petroleum, although this procedure requires more time and reagents than the microwave digestion. To better characterize the trace element composition of the two reference materials for future use in the community, we integrate our new results with a comprehensive compilation of published trace element data for both petroleum samples. Finally, we show that the V/Ni and V/(V + Ni) ratios commonly used for oil–oil and oil–source rock correlations remain sufficiently close to the expected ratios even in cases of incomplete digestion with lower recoveries for both elements.

Geosciences doi: 10.3390/geosciences16020073

Authors: Davide Elmo Samantha Kenzie Adams

It is important for the rock engineering practice to acknowledge the difference between uncertainty, which diminishes with adequate data access, and radical uncertainty, which persists because critical features and failure mechanisms may remain undetected, not because of inadequate sampling but because they represent conditions that cannot be expected. Radical uncertainty represents an ontological feature of complex geological systems rather than a limitation of our current state of knowledge. The paper’s central thesis is that current rock engineering practice has developed what we term the “epistemological three-body problem”: the interaction between (i) inherent geological uncertainty that includes radical uncertainty (unknown unknowns), (ii) empirical methods that lack field-scale validation yet have gained professional acceptance through historical precedent, and (iii) regulatory frameworks that demand apparent certainty. We demonstrate this thesis through three interconnected arguments. First, we expose the epistemological and validation challenges inherent in widely adopted design methods. Second, we analyze how operational definitions, validation processes, and numerical modelling approaches may generate misleading precision rather than meaningful understanding of rock engineering problems, and third, we propose a framework for acknowledging and working within the boundaries of radical uncertainty. On this basis, we must acknowledge that rock engineering practice necessarily operates under a standard of a “balance of probabilities”. Given the nature of radical uncertainty, professional practice should evaluate methods not by whether they eliminate uncertainty, but by whether they represent reasonable approaches to managing it.

Geosciences doi: 10.3390/geosciences16020072

Authors: Dániel Rezes Ildikó Gyollai Sándor Biri Krisztián Fintor Zoltán Juhász Richárd Rácz Béla Sulik Máté Szabó Bernadett D. Pál Ákos Kereszturi

This study reveals the effects of artificial space-like proton irradiation on three meteorite samples that are Northwest Africa (NWA) 4560 LL3.2 and NWA 5838 H6 chondrite meteorites, as well as the Dhofar (Dho) 007 eucrite. We used low-vacuum scanning electron microscopy (LV-SEM) and Raman Spectroscopy to examine the structure and composition of olivine and pyroxene grains in the meteorites before and after the irradiation events. This article focuses on the strongest and most intense irradiation, which was performed by protons up to 12 keV with a fluence value of 1019 ions/cm2 that lasted ~30 h. According to the Raman spectra, significant lattice disruption in all analyzed silicates occurred, and a more extensive amorphous, glassy layer developed under the strongest irradiation conditions. Relative to the second irradiation, peak 1 (820.0 cm−1) shifts slightly negatively (–0.46 cm−1) with a small FWHM increase (+0.88 cm−1), while peak 2 (850.3 cm−1) shifts positively in both parameters (+0.40 and +4.04 cm−1) in NWA 4560 olivines. In NWA 5838 olivines, both olivine peaks (820.5 and 850.8 cm−1) shift positively (+7.40 and +7.90 cm−1) and broaden (+2.75 and +4.29 cm−1). In Dho 007 pyroxenes, peak 1 (997.1 cm−1) shifts positively (+3.01 cm−1) with an FWHM decrease (−0.46 cm−1), peak 2 (669.7 cm−1) shifts slightly negatively (−0.75 cm−1) while broadening strongly (+29.23 cm−1), and peak 3 (327.7 cm−1) shifts positively (+0.86 cm−1) with reduced FWHM (−4.55 cm−1). Three characteristic amorphous bands appear in all examined meteorite silicates, located at ~550–1000 cm−1, ~1100–1700 cm−1, and ~1700–1850 cm−1. Olivines in NWA 4560 and NWA 5838 exhibited similar responses across all irradiation events. In contrast, Dho 007 pyroxenes showed variable compositional changes without a consistent or well-defined pattern in our SEM dataset. The Fo decrease in our experiments likely results from preferential Mg sputtering in the olivine lattice, leading to relative Fe enrichment, similar to but more pronounced than after the first irradiation. Pyroxenes exhibit a comparable response, with Fs and En increasing and Wo sharply decreasing, reflecting preferential Ca loss relative to Mg alongside Fe enrichment. Investigating these processes improves the interpretation of planetary remote sensing data and advances our understanding of planetary surface evolution, while also clarifying how surface materials respond to space environmental conditions.

Geosciences doi: 10.3390/geosciences16020071

Authors: Yoshihiro Shishikura Wataru Hotta Muneo Hori

We have proposed the reduction in triple integral to double integral that is used in multiple shear mechanism model for faster 3D nonlinear ground motion analysis. In this study, we propose reformulation of the mechanism which results in the expression of an elasto-plastic tensor as the product of strain and 4th-, 6th- and higher-order tensors. Storing these high-order tensors in a database, we can eliminate numerical computation required for the triple or double integration. Because the database is stored in the memory of a computational node, it is necessary to design the database considering the trade-off relation between the database size and the accuracy of computing the elasto-plasticity tensor. We carried out numerical experiments to verify the reformulation that uses the database for high-order tensors and to examine the performance of using the database. It is shown that the computational time is reduced to approximately 2% by using the reformulation and the database.

Geosciences doi: 10.3390/geosciences16020070

Authors: Nicola Angelo Famiglietti Alessandro Angelo Visconti Gaetano Memmolo Antonino Memmolo Lorenzo Radaelli Daniela Musmeci Bruno Massa Vincenzo Amato Annamaria Vicari Alfonso Santoriello

This study presents an integrated geophysical–geomatic approach for the investigation of archaeological sites, combining low-frequency Ground-Penetrating Radar (GPR) and close-range photogrammetry at the Archaeological Park of Abellinum (southern Italy). Unlike conventional applications using high-frequency antennas, the low-frequency GPR system employed in this study enabled deep subsurface imaging, allowing reconstruction of buried stratigraphic and architectural features to depths of several metres. This enhanced penetration capacity facilitated a more comprehensive understanding of the investigated environments, by complementing rather than replacing high-frequency surveys and expanding the interpretable volume in complex urban and peri-urban contexts. GPR reflection data were integrated with high-resolution photogrammetric surface models, enabling direct comparison between visible structures and subsurface geometries. The combined dataset provided precise correlations between surface features and subsurface anomalies, demonstrating the potential of this integrated methodology for detailed archaeological interpretation. Overall, this approach offers a scalable, non-invasive framework applicable to other complex archaeological landscapes, supporting both research objectives and long-term heritage management. By systematically combining low-frequency GPR with high-resolution photogrammetry, the study introduces a methodological contribution that extends interpretative depth well beyond the limits of conventional surveys.

Geosciences doi: 10.3390/geosciences16020069

Authors: Mohamed M. Ghoneim Mohamed Mitwalli Hanaa A. El-Dokouny Mai A. El-Lithy Maher Dawoud Yue-Yue Liu Tariq Al-Abdullah Abdelhalim S. Mahmoud

This study is carried out to investigate the radiological characteristics and mineralogical controls of natural radioisotopes (238U, 226Ra, 232Th, and 40K) in granitic pegmatites from Abu Zawal Area (AZA) in the Eastern Desert of Egypt. The analyzed pegmatites, containing thorite, zircon, monazite, ferrocolumbite, and fergusonite, exhibit exceptionally high radioactivity concentrations of 238U ≤ 568; 232Th ≤ 674; 226Ra ≤ 170 (Bq kg−1), significantly exceeding the world average permissible limits (35, 30, 30, and 400 Bq kg−1 for 238U, 226Ra, 232Th, and 40K, respectively). Comprehensive radiological assessment reveals severely elevated radiological impact associated with Raeq ≤ 1243 (Bq kg−1) and hazard indices (Hex≤ 3.36; ELCR ≤ 12.2 × 10−3) surpassing international safety thresholds (Hex ≤ 1; ELCR ≤ 1 × 10−3). The observed disequilibrium between 238U and 226Ra (with 226Ra activities approximately half those of 238U) is attributed to the geochemical mobility of radium and potential selective leaching during late-stage hydrothermal alteration, while the overall enrichment of the uranium series over the thorium series is linked to the predominance of uranium-bearing minerals like zircon and fergusonite in these pegmatites. Mineralogical analysis demonstrates distinct radiation patterns: thorite and monazite dominate Th-derived gamma radiation and radon/thoron exhalation, while zircon and fergusonite control U enrichment and decay chain disequilibrium. Notably, nominally low-activity minerals like ferrocolumbite contribute to localized radiation hotspots through U/Th co-concentrations. The calculated absorbed dose rates ranged from 182 to 978 (nGy h−1) and annual effective doses show extreme spatial variability correlated with Th-rich mineral assemblages.

Geosciences doi: 10.3390/geosciences16020068

Authors: Yuriy Pak Saule Sagintayeva Pyotr Kropachev Aleksey Veselov Dmitriy Pak Diana Ibragimova Anar Tebayeva

This review deals with the issue of operational coal quality control using instrumental nuclear–physical methods. The existing traditional method of coal testing, characterized by high labor intensity and low representativeness, cannot serve as a basis for operational management of mining and processing processes. Instrumental nuclear–physical methods are free from these drawbacks; they are based on various processes of interaction of gamma and neutron radiation with substances. The main modifications of instrumental methods using gamma radiation are discussed: backscattering, forward gamma scattering, gamma absorption, gamma annihilation, and natural gamma activity. Various modifications of gamma methods are related to the energy of the primary and recorded radiation, the prevalence of a particular interaction process, the depth of the method, characteristics of the test object, the measurement geometry, and the other factors. The features of gamma methods are described in the context of the tasks being solved, interfering factors (variations in the bulk density, the moisture content, and the elemental composition), and methodological approaches for increasing the sensitivity and accuracy of the coal quality assessment. The variety of modifications of neutron methods is associated with irradiation of the analyzed coal with neutrons of different energies and detection of secondary gamma radiation arising from neutron activation of elements, inelastic scattering of fast neutrons, and radiative capture of thermal neutrons by the elements composing the coal. The methodological features of neutron activation, the neutron–gamma method of inelastic scattering and radiative capture are considered in the context of elemental analysis for Al, Si, S, Ca, Fe, H, C, and O and determining the ash content of coal in general. The main trends of the instrumental quality control are highlighted and recommendations are given for their use depending on the metrological characteristics and physical and chemical properties of the control object. The gamma-albedo method with registration of X-ray fluorescence of heavy gold-forming elements is the most promising for express analysis of powder samples. To test coarse coal in large amounts, multiparameter neutron methods are needed that comprehensively utilize high-precision equipment and instrumental signals from carbon, oxygen, and major ash-forming elements.

Geosciences doi: 10.3390/geosciences16020067

Authors: Fenglai Yang Chenhui Wang Furong Wang Li Dai Haifa Tang Chen Zhang Xingnan Ren Jian Li

The efficient extraction of natural gas from water-drive reservoirs is often hindered by premature water breakthrough and the consequent trapping of significant residual gas, which collectively result in suboptimal recovery and economic returns. Traditional production methods have proven inadequate in mitigating water influx and mobilizing this trapped gas, underscoring the need for advanced enhanced gas recovery (EGR) strategies. This research specifically examines the potential of nitrogen injection as a tertiary recovery technique in such reservoirs, with a focus on its mechanistic role and displacement efficiency. Utilizing high-pressure core flooding experiments and complementary numerical simulations, the process of nitrogen injection following water flooding was systematically investigated. Experimental findings at 30 MPa indicate that while water flooding left a substantial residual gas saturation of 28.1%, subsequent nitrogen injection reduced this to 20.8% at breakthrough and ultimately to 7.99%, achieving a final recovery of 88.9%. Simulation results further elucidate that in fractured systems, water preferentially channels through high-permeability fractures, while capillary imbibition leads to gas entrapment within the matrix. Nitrogen injection effectively targets and reduces this trapped gas saturation by 30–50%, demonstrating its efficacy as a viable EGR method. The study thus provides critical theoretical and practical insights for improving recovery in challenging water-drive gas reservoirs.

Geosciences doi: 10.3390/geosciences16020066

Authors: Liliang Han Yu Cong Xiaoshan Wang Wenyang Du Lixia Zhang Jian Gao Yuming Wang Zhanchao Zhang

Based on true triaxial loading experiments and particle flow numerical simulations (PFC3D), this study systematically analyzes the mechanical behavior and failure mechanisms of granite under the influence of stress difference (deviatoric stress). The experimental results indicate that increasing deviatoric stress reduces peak strength, axial strain, and lateral strain, promoting rock failure with less deformation and dilatancy. An energy analysis reveals that higher deviatoric stress suppresses peak energy accumulation, with a greater proportion of energy being dissipated through crack initiation and propagation. Macroscopic observations show that failure surfaces develop combined tensile-shear cracks, evolving into distinct “V” shapes as deviatoric stresses increase. Numerical simulations demonstrate that intermediate principal stress plays a dual role, initially facilitating, then inhibiting, and finally promoting rock failure with its continuous increase. Microscopically, tensile cracks dominate during pre-peak stages, while rapid crack coalescence in the post-peak stage leads to the formation of throughgoing V-shaped failure zones. Particle displacement analysis reveals that deformation concentrates along the minimum principal stress direction, with the displacement vectors ultimately forming a V-shaped boundary that delineates the failure zone. The research provides comprehensive insights into the macro-meso failure characteristics of hard rock under true triaxial conditions, offering valuable guidance for stability prediction and control in underground rock engineering projects such as water-sealed storage caverns.

Geosciences doi: 10.3390/geosciences16020065

Authors: Chao Li Yangkang Chen

Full waveform inversion (FWI) iteratively improves the accuracy of the model by minimizing the discrepancies between the predicted and the observed data. However, FWI commonly suffers from cycle skipping when the initial model is poor, leading to an erroneous result. To mitigate this problem, we propose deep-learning-backed adaptive waveform inversion (DL-AWI), which introduces a deep twin neural network to precondition the waveforms and compare the ratio of two signals with a zero-lag spike, thereby enhancing the stability of the inversion process. DL-AWI can project the synthetic and observed signals into an extended latent space via several convolutional neural networks (CNNs) with shared weights, which can accelerate the data matching. Compared with classic FWI methods, the proposed DL-AWI provides a wider space for model updates, significantly decreasing the risk of being trapped in local minima. We use synthetic and field examples to validate its efficiency in subsurface model inversion, and the results show that DL-AWI is robust even when a poor initial model is provided.

Geosciences doi: 10.3390/geosciences16020064

Authors: Muhammad Rafique Awais Rasheed Muhammad Osama Adil Aslam Mir Dimitrios Nikolopoulos Kyriaki Kiskira Aftab Alam Georgios Prezerakos Aqib Javed Panayiotis Yannakopoulos Christos Drosos Georgios Priniotakis Nikitas Gerolimos Michail Papoutsidakis Kimberlee Jane Kearfott Saeed Ur Rahman

Long-term monitoring of radon (222Rn) and thoron (220Rn) radioactive gases has been used in earthquake forecasting. Seismic activity before earthquakes raises the levels of these gases, causing abnormalities in the baseline values of radon and thoron time series (RTTS) data. This study reports applications of kernel density estimation (KDE) and wavelet-based density estimation (WBDE) to detect anomalies in radon, thoron, and meteorological time-series data. Anomalies appearing in the RTTS data have been assessed for their potential correlation with seismic events. Using KDE and WBDE, radon anomalies were observed on 12 March, 15 August, 17 September, in the year 2017, and 19 January 2018. Thoron anomalies were recorded on 12 March, 15 August, 17 September 2017, and 28 February 2018. Irregularities in RTTS were observed several days before seismic events. Anomalies in RTTS, detected using KDE, successfully correlated five out of nine seismic events while WBDE identified four anomalies in RTTS which were successfully correlated with the corresponding seismic events. The wavelet transform has been used to reduce noise at higher decomposition levels in radon and thoron time series. Findings of the study reveal the potential of radon and thoron time series that can be used as precursors for earthquake forecasting.

Geosciences doi: 10.3390/geosciences16020063

Authors: Valentina Volpi Cinzia Bellezza Dario Civile Flavio Accaino Erika Barison Piero Corubolo Biancamaria Farina Edy Forlin Massimo Giorgi Michela Giustiniani Fabio Meneghini Alberto Pettinau Alberto Plaisant Andrea Schleifer Flavio Poletto

In February 2024, the European Union published its Industrial Carbon Management Strategy, setting ambitious goals for carbon capture and storage (CCS), carbon capture and utilisation (CCU), and related technologies. Industrial decarbonisation will require a mix of solutions, CCUS, electrification, hydrogen and hydrogen-derived fuels, and energy efficiency, which are all dependent on affordable clean energy. Although carbon management technologies could contribute substantially to climate targets, their deployment has been slowed by technical barriers and public concerns. Sotacarbo has created a research centre dedicated to developing and testing carbon capture, utilisation, and storage technologies. Within this framework, the new Sotacarbo Fault Laboratory (SFL) was designed to investigate gas migration in faults and to test monitoring systems capable of detecting potential short- and long-term CO2 leakages. This paper presents a preliminary study, including seismic full-waveform simulations for time-lapse surveys before and after CO2 injection, and a suite of geophysical methods used to characterise the Matzaccara Fault within the Eocene Sulcis Basin. The results of the application of integrated geophysical methods support the selection of a safe and suitable injection-well location and demonstrate the value of these methods for detailed fault characterisation in CCUS applications.

Geosciences doi: 10.3390/geosciences16020062

Authors: Hongming Zhan Xizhe Li Weikang He Longyi Wang Yuchuan Chen Zhiming Hu Jizhen Zhang Yuhang Zhou Shan Huang Xiangyang Pei Jing Xiang

Characterization of shale pore architecture forms the scientific basis for effective shale gas exploitation. Deep LMX FM shale from the Luzhou area was analyzed using SANS, LTPA, XRD, and SEM. This study quantitatively characterized the pore structure, focusing on closed-pore development and connectivity, and explored lithological controls. Pore-size distribution shows that micropores and small mesopores dominate the pore volume, with an average median pore diameter of 5.17 nm. Closed pores are abundant, indicated by a high average closed-pore ratio of 28.98%, reflecting generally poor connectivity. Pores smaller than 5 nm contribute 88.12% of the total SSA. Both pore volume and SSA correlate positively with TOC. In organic-rich and moderately organic-rich siliceous shales, these parameters also correlate positively with quartz content. In contrast, for organic-rich mixed shales, they correlate positively with clay mineral content. Among the lithofacies, organic-rich siliceous shale possesses relatively larger pore volume and SSA, along with better pore connectivity, making it the most favorable reservoir facies. Based on pore-structure characteristics and the regional structural setting, we recommend adopting close-spacing hydraulic fracturing with reduced cluster spacing in structurally stable areas to enhance stimulation. In structurally complex areas, engineering designs should prioritize risk mitigation to ensure operational success.

Geosciences doi: 10.3390/geosciences16020061

Authors: Anna Chiaradonna

The prediction of earthquake-induced excess pore water pressure is becoming a crucial step for liquefaction-related problems, such as the prediction of settlements, assessment of bearing capacity of shallow foundations, and efficiency of liquefaction mitigation measurements. The goal of this review is to provide a state of the art of the available methods for estimating excess pore water pressure from the most simplified approaches, based on simple hand-made calculations, to the most simplified models for pore pressure prediction, and finally to the most advanced models implemented in computer codes for seismic site response analysis. The hierarchy of the methods is enriched with exemplificative applications from real cases to help understand the classification provided and the usability of each method according to the needs of the professional practice.

Geosciences doi: 10.3390/geosciences16020060

Authors: Natalya Mikhailova Vitaliy Morozov Aidyn Mukambayev Assem Issagali Ulan Igibayev

In 2023–2025, a research study named “Application of nuclear, seismic and infrasound methods for assessing climate change and mitigating the effects of climate change” was conducted in Kazakhstan under the Targeted Funding Program. The main task of the study was to create an observation network for processes occurring in the glaciers of the high Tien Shan. Seismic and infrasound methods were used for signal recording, and meteorological data was additionally used for the analysis. A network of seismic, infrasound and meteorological stations has been installed near the large glaciers of Tien Shan in Kazakhstan. This paper presents the results of the recorded data in terms of seismic and infrasound noise levels, daily variations, and the relationship between noise and changes in temperature and wind speed. The threshold of the expected minimal magnitude and energy classes of glacial earthquakes for day and night was assessed. Seismic and infrasound monitoring has proven to be a reliable all-season and all-weather tool for monitoring the dynamics of glacial processes. Among the large number of recorded glacial events, more than 4000 have been located, and a seismic bulletin that includes information on the location, magnitude, and energy class of each has been compiled.

Geosciences doi: 10.3390/geosciences16020059

Authors: Baohang Wang Guangrong Li Chaoying Zhao Liye Yang Shuangcheng Zhang Bojie Yan Wenhong Li

Potential tropospheric noise is a critical factor that undermines the effectiveness of deformation monitoring in Synthetic Aperture Radar Interferometry (InSAR) technologies. In most scenarios, many point targets within the InSAR deformation monitoring area either do not undergo deformation or exhibit only minimal deformation trends. The phases of densely distributed stable points can effectively respond to spatial tropospheric delays, particularly turbulent atmospheric phases. This study proposes a data-driven InSAR atmospheric correction method by exploring how to use these densely stable InSAR time series to model atmospheric phase delays. Our focus is on selecting stable InSAR time series point targets and evaluating the impact of different densities of stable points on atmospheric correction performance. Analysis of 645 interferograms derived from 217 Sentinel-1A SAR images, spanning from 13 June 2017 to 15 November 2024, demonstrates that the proposed method reduces the Root Mean Square Error (RMSE) by 70%, 59%, and 69% compared to the terrain-related linear approach, the General Atmospheric Correction Online Service, and common scene stacking methods, respectively. In addition, simulation data and leveling data were used to validate the proposed method. This article does not develop an independent InSAR atmospheric correction method. Instead, the proposed approach starts with the InSAR deformation time series, allowing for easy integration into existing InSAR workflows and widely used atmospheric correction strategies. It can serve as a post-processing tool to improve InSAR time series analysis.

Geosciences doi: 10.3390/geosciences16020058

Authors: Marwan Marwan Dian Darisma Amir Asyqari Rifa Salma Salsabila Fajrul Hani Tarmizi Hasyem Rifqan Rifqan Cahyo Aji Hapsoro Fadhli Syamsuddin Dian Budi Dharma

The Jaboi geothermal field, located on Weh Island in western Indonesia, has a potential output of approximately 55 MWe. Previous geophysical surveys have not sufficiently identified the components of the geothermal system. The success of drilling in identifying a geothermal system depends heavily on the accuracy of the conceptual model. Consequently, developing a more precise subsurface model is crucial to minimizing drilling failures. This study aims to map the resistivity structure of the Jaboi geothermal field using the magnetotelluric method. In our research, we used 16 magnetotelluric sites that recorded data for 7 to 8 h. We successfully estimated the cap rock area with resistivity < 10 Ωm distributed across Jaboi Volcano to depths of 500 m and identified an intense resistive anomaly starting at depths of 1–2 km with resistivity > 5000 Ωm. This anomaly is probably due to a block of crystalline basement being uplifted by upwelling magmatic intrusions. The reservoir zone was estimated to be located directly below the cap rock area. The resistivity structure also reveals a fluid pathway zone in the upflow and outflow zone that connects the reservoir to the surface manifestations influenced by the Ceunohot Fault and Jaboi Fault. The resistivity structure confirmed the boundary of the Jaboi geothermal system along the coastline and in the southeastern part. This study successfully identifies key components of geothermal systems, including cap rock, reservoir zones, and fluid migration pathways.

Geosciences doi: 10.3390/geosciences16020057

Authors: Jia Xu Yongqiang Cao Jie Liu Jiayu Hou Wei Yan Changrong Yi Guodong Jia

Land subsidence constitutes a critical hazard to coastal megacities globally, amplifying flood risks and damaging infrastructure. Taking Tianjin—a major port city underlain by compressible sediments and affected by groundwater over-exploitation—as a case study, we address two key research gaps: the absence of a quantitative framework coupling groundwater extraction with construction land expansion, and the inadequate separation of seasonal and long-term subsidence drivers. We developed an integrated remote-sensing-based approach: high-resolution subsidence time series (2016–2023) were derived via Small BAseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) using Sentinel-1 Synthetic Aperture Radar (SAR) imagery, validated against leveling measurements (R > 0.885, error < 20 mm). This subsidence dataset was fused with groundwater level records and annual construction land maps. Seasonal-Trend Decomposition using Loess (STL) isolated trend, seasonal, and residual components, which were input into a Random Forest (RF) model to quantify the relative contributions of subsidence drivers. Dynamic Time Warping (DTW) and Cross-Wavelet Transform (CWT) were further employed to characterize temporal patterns and lag effects between subsidence and its drivers. Our results reveal a distinct shifting subsidence pattern: “areal expansion but intensity weakening.” Groundwater control policies mitigated five historical subsidence funnels, reducing areas with severe subsidence from 72.36% to <5%, while the total subsiding area expanded by 1024.74 km2, with new zones emerging (e.g., northern Dongli District). The RF model identified the long-term groundwater level trend as the dominant driver (59.5% contribution), followed by residual (23.3%) and seasonal (17.2%) components. Cross-spectral analysis confirmed high coherence between subsidence and long-term groundwater trends; the seasonal component exhibited a dominant resonance period of 12 months and a consistent subsidence response lag of 3–4 months. Construction impacts were conceptualized as a “load accumulation-soil compression-time lag” mechanism, with high-intensity engineering projects inducing significant local subsidence. This study provides a robust quantitative framework for disentangling the complex interactions between subsidence, groundwater, and urban expansion, offering critical insights for evidence-based hazard mitigation and sustainable urban planning in vulnerable coastal environments worldwide.

Geosciences doi: 10.3390/geosciences16020056

Authors: Yukai Qi Chao Li Likuan Zhang Hanwen Hu Wenjun He Huixi Lin Zhongpei Zhang Changrong Bian Yida Zhao

The Jurassic reservoirs in the Fukang Sag of the Junggar Basin exhibit heterogeneous overpressure. As the mechanisms underlying overpressure generation remain poorly constrained, this poses challenges for accurate pre-drilling-pressure prediction and hinders a comprehensive understanding of hydrocarbon accumulation processes. Through integrated analysis of measured pressure, mud weight, and well-logging curves, this study delineates distinct overpressure characteristics in sandstones and identifies the well-logging response to overpressure in mudstones. By coupling the loading-unloading response with the analysis of geological conditions conducive to overpressure, we differentiate the overpressure-generating mechanisms between sandstones and mudstones and assess their implications for deep petroleum exploration. The study reveals significant vertical heterogeneity in pressure regimes, with sandstones exhibiting pressure coefficients ranging from 1.2 to 1.8, locally exceeding 2.1. Strong overpressure preferentially develops in isolated sand bodies linked to deep source kitchens via oil-source faults. The logging response of overpressured mudstones shows high acoustic transit time, high neutron, and low resistivity, deviating from the normal compaction trend, yet demonstrates progressive density increases attributable to chemical compaction processes. Overpressure points with pressure coefficients between 1.2 and 1.4 align with the loading curve dominated by disequilibrium compaction. The overpressure with a pressure coefficient exceeding 1.4 correlates with abrupt unloading responses indicative of fault-transferred overpressure in sandstones. Our results highlight that overpressured fluid migration via faults is a critical process in hydrocarbon migration, with large-magnitude overpressured reservoirs being readily formed near oil-source faults. Multi-overpressure mechanisms create a complex pore-pressure distribution in deep layers, challenging conventional pressure-prediction models. These insights advance predictive models for pore pressure and provide a robust framework for optimizing exploration strategies in the Fukang Sag.

Geosciences doi: 10.3390/geosciences16020055

Authors: Mauricio Secchi Antonio Pasculli Massimo Mangifesta Nicola Sciarra

Accurate numerical simulation of debris flows is essential for hazard assessment and early-warning design, yet high-fidelity solvers remain computationally expensive, especially when large ensembles must be explored under epistemic uncertainty in rheology, initial conditions, and topography. At the same time, field observations are typically sparse and heterogeneous, limiting purely data-driven approaches. In this work, we develop a deep-learning Fourier Neural Operator (FNO) as a fast, physics-consistent surrogate for one-dimensional shallow-water debris-flow simulations and demonstrate its application to the Rendinara–Morino system in central Italy. A validated finite-volume solver, equipped with HLLC and Rusanov fluxes, hydrostatic reconstruction, Voellmy-type basal friction, and robust wet–dry treatment, is used to generate a large ensemble of synthetic simulations over longitudinal profiles representative of the study area. The parameter space of bulk density, initial flow thickness, and Voellmy friction coefficients is systematically sampled, and the resulting space–time fields of flow depth and velocity form the training dataset. A two-dimensional FNO in the (x,t) domain is trained to learn the full solution operator, mapping topography, rheological parameters, and initial conditions directly to h(x,t) and u(x,t), thereby acting as a site-specific digital twin of the numerical solver. On a held-out validation set, the surrogate achieves mean relative L2 errors of about 6–7% for flow depth and 10–15% for velocity, and it generalizes to an unseen longitudinal profile with comparable accuracy. We further show that targeted reweighting of the training objective significantly improves the prediction of the velocity field without degrading depth accuracy, reducing the velocity error on the unseen profile by more than a factor of two. Finally, the FNO provides speed-ups of approximately 36× with respect to the reference solver at inference time. These results demonstrate that combining physics-based synthetic data with operator-learning architectures enables the construction of accurate, computationally efficient, and site-adapted surrogates for debris-flow hazard analysis in data-scarce environments.

Geosciences doi: 10.3390/geosciences16020054

Authors: Kathryn Metcalf Jenna Guyer Joana Camargo Ramirez

The age, provenance, and evolution of some terranes in the Klamath Mountains are poorly constrained because of low detrital zircon yields. We present petrography and 947 new detrital and igneous zircon U-Pb ages from the North Fork (NFT), Eastern Hayfork (EHT), and Western Hayfork (WHT) terranes in the central and southern Klamath Mountains. Chert and argillite are abundant in the NFT and EHT, but matrix sandstones with abundant Proterozoic-to-Archean zircon ages indicate that the EHT received more sediment from North America. Detrital zircon ages from the WHT are ~171 Ma with scattered pre-Mesozoic ages, consistent with previous ages and continental input. A younger population of three grains at 145 Ma is interpreted as Pb loss during metamorphism. In the southernmost EHT, a 143 Ma dike correlates with plutons in the northern Sierra Nevada, which were offset from the Klamath Mountains 140–130 Ma. A 158 Ma metavolcanic/metavolcaniclastic rock in the EHT is a possible extrusive equivalent of the Wooley Creek intrusive suite. The metamorphosed EHT matrix has a young population of six ages at 69 Ma, which we tentatively interpret may represent Pb loss during metamorphism. This study documents an exposure of Late Jurassic arc cover sequence and suggests there may be previously unrecognized local metamorphism/magmatism ≤69 Ma.

Geosciences doi: 10.3390/geosciences16020053

Authors: Zheng Mu Xiaoqing Su Kai Chang Yaxin Zhao

Pre-seismic anomalies in solid tidal factors can reveal crustal stress accumulation and predict seismic risk; such disturbance signals associated with earthquake incubation are extremely subtle and easily obscured by environmental noise, instrument errors, and other interference factors, placing heightened demands on the precision of gravity data acquisition and the capability to detect and isolate solid tidal signals effectively. In this paper, we propose a novel method for determining time-varying solid tidal factors based on the normal time–frequency transform (NTFT) theory, an approach allowing us to unbiasedly determine the instantaneous amplitude, frequency, and phase of time-varying signals, while mitigating the influence of edge effects to a certain extent. In the study outlined in this paper, we first design simulation experiments to validate the effectiveness of the new method. Subsequently, utilising high-precision superconducting gravimeter observation data, the proposed method is applied to the detection of pre-seismic disturbances preceding the 2004 Sumatra megathrust earthquake. Our results demonstrate that, compared to traditional harmonic analysis methods, this novel approach more accurately filters out interference signals, effectively captures the faint pre-seismic perturbations of solid tides, and significantly enhances the timeliness of pre-seismic disturbance detection, thus providing more reliable technical support for earthquake precursor monitoring.

Geosciences doi: 10.3390/geosciences16010052

Authors: Juan David Solano-Acosta Jillian Pearse Ana Ibis Despaigne-Diaz

This study utilizes Digital Elevation Models (DEMs) with different spatial resolutions (SRTM 90 m, ASTER DEM 30 m, and ALOS PALSAR 12.5 m), Landsat-8 satellite imagery, and the Bouguer WGM-12 gravity model to analyze morphotectonic features in the Upper Guajira region of Colombia, a desert area in northern South America, area that is composed by low-relief serranías of Cabo de la Vela, Carpintero, Cosinas, Simarua, Jarara, and Macuira. Three DEMs were used to extract and map morphotectonic lineaments, drainage networks, and morphological features. Lineaments were characterised by azimuth frequency, length, density, lithological distributions, and geological timeframes, with support from a digitized geological map from the Colombian Geological Service (SGC). The analysis of the east–west (E-W) Cuisa fault, using the Riedel shear model, suggests a transtensional/transpressional tectonic regime influenced by the Caribbean and South American plates, characterised by NE-SW and E-W fault orientations. Lineaments were grouped into five geochronological categories based on the geological map, revealing a shift from NE-SW to E-W orientations from the Cretaceous period onward, reflecting the ongoing movement of the Caribbean plate. Folds and faults from this tectonic activity were enhanced using Landsat-8 band combinations. The WGM-12 model was separated into regional and residual signals, with the latter highlighting the serranías subregions. Residual gravity analysis revealed significant negative anomalies, suggesting lower-density lithologies surrounded by higher-density blocks. This pattern aligns with the regional geological framework and may reflect a crustal root or terrain dragging linked to the tectonic processes that shaped the serranías. Derivative residual gravity data also revealed lineaments oriented NE–SW, whose distribution extends beyond the morphometric boundaries of the subregions. The study found a strong correlation between structural and drainage patterns, demonstrating structural control over geomorphology. This study establishes a solid morphotectonic and geophysical framework for the Upper Guajira region, demonstrating how multi-resolution DEM analysis combined with gravity data can resolve regional deformation patterns, crustal architecture, and tectonic development along the Caribbean–South American plate boundary.

Geosciences doi: 10.3390/geosciences16010051

Authors: Lucas Faria De Sousa Alessandro Filippo Ariadne Marra de Souza Armando Dais Tavares Mauro Cesar Geraldes

This study investigates the hydrography and geochemical signature in Ilha Grande Bay (RJ, Brazil), focusing on the seasonal intrusion of South Atlantic Central Water (SACW) and its interaction with lead sources. CTD (Conductivity, Temperature, and Depth) data revealed the presence of SACW during the summer campaigns (Mangaratiba/2011 and Frade/2012), characterized by temperatures below 20 °C and salinity between 34.6 and 36. The intrusion is driven by northeasterly winds that favor coastal upwelling, establishing a classic thermohaline stratification. The winter campaigns did not detect SACW, confirming its seasonal nature. Isotopic analysis of Pb in sediments identified six Pb206/Pb207 intervals, indicating multiple sources, including natural contributions, industrial waste, and urban effluents. The Pb206/Pb207 ranges were defined based on cluster analysis and frequency histograms, which are common methods in isotopic provenance studies. An overlap between the most radiogenic isotopic signatures and the presence of SACW suggests that this water mass acts as a vector for transporting trace elements from the deep oceanic region to the coast. This study provides the first evidence that the South Atlantic Central Water (SACW) acts as a seasonal vector, importing a distinct radiogenic Pb isotopic signature onto the continental shelf of Ilha Grande Bay. By synoptically coupling physical water-mass analysis (CTD) with Pb isotopic tracers, we introduce a novel approach that successfully discriminates oceanic from anthropogenic Pb sources, offering a new framework for understanding contaminant transport in coastal areas influenced by boundary currents. It is concluded that the coastal dynamics in Ilha Grande Bay are governed by the seasonal interaction of coastal, continental, and oceanic waters, and that the integration of physical and geochemical data is crucial for understanding mixing processes and contaminant transport in this complex environment.

Geosciences doi: 10.3390/geosciences16010050

Authors: Yonas Oyda Samuel Dagalo Hatiye Muralitharan Jothimani

Population growth and agricultural expansion are threatening groundwater resources in the Maze Zenti catchment, Southern Ethiopia. This study evaluated groundwater suitability for drinking and irrigation by analyzing 30 samples using an integrated approach. This approach included GIS-based IDW interpolation, hydrochemical characterization, drinking water quality index, entropy weight, pollution index of groundwater, multivariate statistics, Piper, Gibbs, and Wilcox diagrams, ANOVA, and irrigation indices based on WHO standards. The correlation matrix revealed strong associations between Na+-TDS (r = 0.77) and Na+-Ca2+ (r = 0.68), indicating mineral dissolution, ion exchange, and agricultural inputs as key factors. Weak correlations were found for NO3− and F−, reflecting localized anthropogenic and geogenic influences. Component analysis identified four components explaining 78.2% (wet season) and 81.2% (dry season) of the variance, highlighting mineralization and anthropogenic inputs. Hydrochemical facies were mainly Ca-Mg-HCO3 with some localized Na-HCO3, suggesting that rock–water interactions are the primary source of geochemical control. Drinking water quality assessment showed that, during the wet season, 52.8% of the catchment had excellent water quality, 45.8% was good, and 1.4% was poor–very poor. In the dry season, 51.6% was excellent, 47.4% was good, 0.8% was poor, and 0.2% was very poor. The results of the entropy-weighted analysis indicated seasonal improvement, with excellent areas increasing from 13.1% to 31.4% and poor zones decreasing from 7.5% to 3.4%. Irrigation indices (Na%, PI, MAR, SAR) and Wilcox analysis (86.4% C2S1) suggested low sodicity and salinity hazards. This study provides the first integrated seasonal mapping of drinking and irrigation water quality, entropy-weighted water quality, and pollution index for the Maze Zenti catchment, establishing a hydrogeochemical baseline. Overall, groundwater in the area is generally suitable for drinking and irrigation. However, localized monitoring and sustainable land-use practices are recommended to mitigate contamination risks.

Geosciences doi: 10.3390/geosciences16010049

Authors: Grant K. W. Dawson Suzanne D. Golding Dirk Kirste Julie K. Pearce

Detailed geochemical modelling of the potential groundwater impacts of CO2 geo-sequestration requires site-specific knowledge of how mobile elements are hosted within rocks. We present a simple sequential extraction procedure analogous to pH conditions produced by different partial pressures of carbon dioxide (CO2) in contact with water. The procedure consists of three sequential steps: water at pH 7; acetic acid–ammonium acetate at pH 5 and then at pH 3, with the amounts of specific elements extracted by each step considered with respect to the whole rock total element abundance. Our purpose in developing this procedure is three-fold: (1) identify readily mobilized suites of elements for groundwater baseline and monitor bore studies; (2) provide insights regarding the mode/s of occurrence of easily extracted elements within rock samples; and (3) suggest possible mechanisms for the mobilization of rock-sourced elements into groundwater under neutral to moderately acidic pH that can inform the reactive transport modelling of carbon storage sites. In our case study, the second step extracted most of the main mobile elements of interest.

Geosciences doi: 10.3390/geosciences16010048

Authors: Rashed Rahman Tejo V. Bheemasetti Tanvi Govil Rajesh Sani

Freeze-thaw (F-T) cycles in seasonally frozen regions induce progressive volumetric strains leading to degradation of soils’ mechanical properties and performance of earthen infrastructure. Conventional chemical stabilization techniques often are not adaptive to cyclic thermal stresses and do not address the fundamental phase changes of porous media, underscoring the need for sustainable alternatives. This study explores the potential of extracellular polymeric substances (EPS) produced by the psychrophilic bacterium Polaromonas hydrogenivorans as a bio-mediated soil treatment to enhance freeze-thaw durability. Two EPS formulations were examined—EPS 1 (high ice-binding activity) and EPS 2 (low ice-binding activity)—to evaluate their effectiveness in improving volumetric stability and thawing strength of silty soil subjected to ten F-T cycles. Tests were conducted at four moisture contents (12%, 18%, 24%, and 30%) and three EPS concentrations (3, 10, and 20 g/L). Volumetric strain measurements quantified freezing expansion and thawing contraction, while unconfined compressive strength assessed post-thaw mechanical integrity. The untreated soils exhibited maximum net volumetric strains (γNet) of 5.62% and only marginal strength recovery after ten F-T cycles. In contrast, EPS 1 at 20 g/L mitigated volumetric changes across all moisture contents and increased compressive strength to 191.2 kPa. EPS 2 yielded moderate improvements, reducing γNet to 0.98% and enhancing strength to 183.9 kPa at 30% moisture. Lower EPS concentrations (3 and 10 g/L) partially mitigated volumetric strain, with performance strongly dependent on moisture content. These results demonstrate that psychrophilic EPS, particularly EPS 1, effectively suppresses ice formation within soil pores and preserves mechanical structure, offering a sustainable, high-performance solution for stabilizing frost-susceptible soils in cold-regions.

Geosciences doi: 10.3390/geosciences16010047

Authors: Bin Zhu Mengrui Zhao Yuan Sun Chao Li Huaibo Song Weiling Liu

The electrical resistivity and acoustic properties of marine sediments are essential for understanding their physical and mechanical behavior. Over recent decades, significant advancements have been made in both in situ and laboratory measurement techniques, alongside theoretical models, to establish correlations between these geophysical parameters and sediment properties such as porosity, saturation, and consolidation degree. However, a comprehensive comparison of the advantages, limitations, and applicability of different measurement methods remains underexplored, particularly in complex scenarios such as gas hydrate-bearing sediments. This review provides an in-depth synthesis of recent developments in in situ and laboratory testing technologies for assessing the resistivity and acoustic characteristics of marine sediments. Special emphasis is placed on the latest advances in acoustic measurements during gas hydrate formation and decomposition. The review highlights key challenges, including (1) limited vertical resolution in in situ resistivity measurements due to probe geometry; (2) errors arising from electrode polarization and poor soil–electrode contact; and (3) discrepancies in theoretical models linking geophysical parameters to sediment properties. To address these challenges, future research directions are proposed, focusing on optimizing electrode array designs for high-resolution resistivity measurements and developing non-destructive acoustic techniques for deep-sea sediments. This work offers a critical reference for marine geophysics and offshore engineering researchers, aiding the selection and development of testing technologies for effective marine sediment characterization.

Geosciences doi: 10.3390/geosciences16010046

Authors: Kenneth D. Collerson David Wilson

Post-collisional Cu-Au-Ni-Co-Pt-Pd-Sc porphyry [Duck Creek porphyry system (DCPS)] with overlying Au-Te-Bi-W-HRE epithermal mineralisation [Highway epithermal system (HES)] has been discovered in the core of the Mitakoodi anticline, southwest of Cloncurry. Xenotime and monazite geochronology indicate mineralisation occurred between ~1490 and 1530 Ma. Host rock lithologies show widespread potassic and/or propylitic to phyllic alteration. Paragenesis of porphyry sulphides indicates early crystallisation of pyrite, followed by chalcopyrite, with bornite forming by hydrothermal alteration of chalcopyrite. Cu sulphides also show the effect of supergene oxidation alteration with rims of covellite, digenite and chalcocite. Redox conditions deduced from the V/Sc systematics indicate that the DCPS contains both highly oxidised (typical of porphyries) and reduced lithologies, typical of plume-generated tholeiitic and alkaline suites. Ni/Te and Cu/Te systematics plot within the fields defined by epithermal and porphyry deposits. Duck Creek chalcophile and highly siderophile element (Cu, MgO and Pd) systematics resemble data from porphyry mineral systems, at Cadia, Bingham Canyon, Grasberg, Skouries, Kalmakyr, Elaisite, Assarel and Medet. SAM geophysical inversion models suggest the presence of an extensive porphyry system below the HES. A progressive increase in molar Cu/Au ratios with depth from the HES to the DCPS supports this conclusion. Three metal sources contributed to the linked DCPS-HES viz., tholeiitic ferrogabbro, potassic ultramafic to mafic system and an Fe and Ca-rich alkaline system. The latter two imparted non-crustal superchondritic Nb/Ta ratios that are characteristic of many deposits in the eastern Mount Isa Block. The associated tholeiite and alkaline magmatism reflect mantle plume upwelling through a palaeo-slab window that had accreted below the eastern flank of the North Australian craton following west-verging collision by the Numil Terrane. Discovery of this linked mineral system provides a new paradigm for mineral exploration in the region.

Geosciences doi: 10.3390/geosciences16010045

Authors: Paweł Wolniewicz

The global production of dimension stones, that is, natural stones that can be processed into blocks and used as building and decorative materials, has grown steadily since the second half of the twentieth century. The rise of global markets and trade has also contributed to a rapid increase in imports of natural stones from distant locations. The introduction of dimension stones sourced from other continents can contribute significantly to geocultural heritage, defined as geological features that have acquired cultural, historical or symbolic meaning, as well as cultural elements embedded in a geological context. In the present contribution, the use of dimension stones in the city of Poznań (Poland, central Europe) is quantified. The study reveals dramatic changes in natural stone use between 1990 and 2019, with the number of dimension stone types increasing nearly threefold, and the mean distance to the stone source areas rising from 322 to 3885 km. Growing numbers and more diversified lithologies of natural stones can improve the urban landscape and contribute to the development of geotourism. On the other hand, increasing imports of dimension stones negatively affect local producers, threaten future conservation efforts, and have significant geoethical implications.

Geosciences doi: 10.3390/geosciences16010044

Authors: Zexi Zhao Guoyun Zhong Fan Diao Peng Ding Jianfeng He

Total organic carbon (TOC) is a critical parameter for evaluating shale source rock quality and hydrocarbon generation potential. However, accurate TOC estimation from conventional well logs remains challenging, especially in data-limited geological settings. This study proposes an optimized XGBoost model for TOC prediction using conventional logging data from the Shahejie Formation in the Dongying Depression, Bohai Bay Basin, China. We systematically transform four standard logs—resistivity, acoustic transit time, density, and neutron porosity—into 165 candidate features through multi-scale smoothing, statistical derivation, interaction term creation, and spectral transformation. A two-stage feature selection process, combining univariate filtering and recursive feature elimination and further refined by principal component analysis, identifies ten optimal predictors. The model hyperparameters are optimized via Bayesian search within the Optuna framework to minimize cross-validation error. The optimized model achieves an R2 of 0.9395, with a Mean Absolute Error (MAE) of 0.3392, a Root Mean Squared Error (RMSE) of 0.4259, and a Normalized Root Mean Squared Error (NRMSE) of 0.0604 on the test set, demonstrating excellent predictive accuracy and generalization capability. This study provides a reliable and interpretable methodology for TOC characterization, offering a valuable reference for source rock evaluation in analogous shale formations and sedimentary basins.

Geosciences doi: 10.3390/geosciences16010043

Authors: Ghulam Zakir-Hassan Lee Baumgartner Catherine Allan Jehangir F. Punthakey

Water quality assessment is crucial for the sustainable use and management of groundwater resources. This study was carried out in the irrigated plains of Vehari District, Punjab, Pakistan, to evaluate groundwater suitability for a managed aquifer recharge (MAR) project. Twenty groundwater samples were collected in June 2021 from an area of 1522 km2 and analysed for major physicochemical parameters including electrical conductivity (EC), total dissolved solids (TDS), pH, turbidity, calcium (Ca), magnesium (Mg), chloride (Cl), alkalinity (Alk), bicarbonate (HCO3−), hardness, potassium (K), sulphate (SO42−), sodium (Na), and nitrate (NO3−). Water quality was assessed using WHO and PID standards, alongside derived hydrochemical indices such as sodium percentage (%Na), Kelly’s ratio (KR), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), and the water quality index (WQI). The dataset was interpreted using geo-statistical, geospatial, multivariate, and correlation analyses. Cations and anion dominance followed the order Na+ > Ca2+ > Mg2+ > K+ and HCO3− > SO42− > Cl− > NO3−. According to the WQI analysis, 35% of the water samples are classified as “poor,” half (50%) as “very poor,” and the remaining 15% as “unsuitable” for drinking purposes. However, irrigation suitability indices confirmed that groundwater is generally acceptable for agricultural use, though unfit for drinking. The outcomes of this study provide essential insights for groundwater management in the region, where the Punjab Irrigation Department (PID) has initiated a MAR project. Considering that the irrigation sector is the major groundwater consumer in the area, the compatibility of groundwater and surface water quality supports the implementation of MAR to enhance agricultural sustainability.

Geosciences doi: 10.3390/geosciences16010042

Authors: Álvaro-Francisco Morote Jorge Olcina Alberto Alfonso-Torreño

The cut-off low that struck Valencia (Spain) on 29 October 2024, causing 229 deaths, underscored the pressing need to promote awareness and strengthen education on natural hazards, particularly among school-aged students. In this scenario, revising the school curriculum becomes essential to ensure that future generations are prepared to confront the challenges posed by climate change. This study examines how knowledge related to natural hazards is incorporated into the official curricula of Secondary (ages 12 to 16) and Baccalaureate education (ages 16 to 19), based on the Royal Decrees enacted since 2022. The study aims to determine which contents are included, the Specific Competencies addressed, and the pedagogical approaches employed (descriptive, preventive, or critical), while also evaluating the coherence of these elements across subjects and educational levels. Findings reveal a scarce and often fragmented presence of such contents, with a predominance of descriptive approaches and limited emphasis on prevention or critical reflection. The study concludes that risk education should be transversal, contextually grounded, and transformative. Current curricular gaps and that current gaps and overlaps represent an opportunity to reinforce territorial literacy and enhance students’ resilience.

Geosciences doi: 10.3390/geosciences16010041

Authors: Yihan Zhang Gaoneng Lai Shanshan Li Dan Li

This study investigates the spatial patterns and drivers of carbon emissions across China’s three major urban agglomerations—Beijing–Tianjin–Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD)—from 2011 to 2020. A sequential analytical framework was employed to examine emission inequality, spatial dependence, dynamic transitions, and multi-scale drivers. Specifically, the Gini and Theil indices were used to quantify and decompose regional disparities. Spatial clustering patterns and heterogeneity were then identified through global and local Moran’s I analysis. Following this, spatial Markov chains modeled state transitions and neighborhood spillover effects. Finally, the Spatial Durbin Model (SDM) was applied to distinguish between the direct and indirect effects of key socioeconomic drivers. The findings reveal that disparities in emissions are largely driven by factors within each region. In BTH, heavy industrial lock-in accounts for 47.1% of the within-group inequality. By contrast, the YRD and PRD show noticeable convergence, achieved through industrial synergy and technological restructuring, respectively. The mechanisms of spatial spillover also differ across regions. In the YRD, emissions exhibit strong clustering tied to geographic proximity, with Moran’s I consistently above 0.6. In BTH, policy linkages play a more central role in shaping emission patterns. Meanwhile, in the PRD, widespread technological diffusion weakens the conventional distance-decay effect. The influence of key drivers varies notably among the urban agglomerations. Economic growth has the strongest scale effect in the PRD, reflected by a coefficient of 0.556. Industrial transformation significantly lowers emissions in the YRD, with a coefficient of −0.115. Technology investment reduces emissions in BTH (−0.124) and the PRD (−0.076), but is associated with a slight rebound in the YRD (0.037). Overall, these results highlight the persistent path dependence and distinct spatial interdependencies of carbon emissions in each region. This underscores the need for tailored mitigation strategies that are coordinated across administrative boundaries.

Geosciences doi: 10.3390/geosciences16010040

Authors: Pavel Kepezhinskas Nikolai Berdnikov Irina Voinova Nikita Kepezhinskas Nadezhda Potapova Valeria Krutikova

Quaternary lavas (ankaramite, basalt, basaltic andesite, andesite, dacite) from the Kamchatka, Kurile, Ecuador and Cascade volcanic arcs contain Cl-bearing mineral microinclusions in rock-forming minerals and groundmass volcanic glass. They are represented by chlorargyrite (with a variable amount of native Ag), Cu, Ag, Sn, and Zn compounds with Cl and S, Sn- and Pb-Sb oxychlorides compositionally similar to abhurite and nadorite, as well as bismoclite and Cl-F-apatite. The Cl-bearing compounds with chalcophile metals are best approximated by mixtures of chlorargyrite with Cu sulfides, malachite, or azurite. Some Cl-bearing solid microinclusions in magmatic rock-forming minerals could have formed from Cl-rich melts exsolved from arc magmas during differentiation. Alternatively, specific magmatic microinclusions may record the decomposition of primary sulfides in the presence of Cl-bearing magmatic volatiles. Post-magmatic Cl microminerals found in fractures, pores, grain contacts, and groundmass glass are most probably precipitated from hydrothermal fluids accompanying their emplacement at the surface and post-eruption transformations in active fumarole fields. Assemblages of Cl-bearing microminerals with native metal, alloy, sulfide, oxide, and sulfate microinclusions in arc lavas potentially record late-magmatic to post-magmatic stages of formation of the epithermal and possibly porphyry mineralization beneath arc volcanoes.

Geosciences doi: 10.3390/geosciences16010039

Authors: Dunja Perić Arash Olia Jack Fry Chamidu D. B. Acharige Justin Yenne

This study focuses on the scale of wind and rainfall-induced soil erosion that is relevant to transportation infrastructure. To this end, an experimental approach was devised and carried out to assess the effectiveness of lignin, a biodegradable and non-toxic plant-derived biopolymer, in enhancing soil resistance to wind and rainfall-induced erosion. The experimental program included basic soil tests required for soil classification, wind and rainfall-induced erosion tests, pocket penetrometer tests to assess the near-surface soil strength, SEM, EDS scans, and FTIR spectroscopy to evaluate changes in the fabric and chemical composition of the soil treated with lignin. Additionally, the effect of lignin on the re-establishment of the vegetative cover after the construction completion was also investigated. It was found that an increased spraying rate of lignin solution increased both the near-surface strength and wind erosion resistance. Moreover, SEM scans showed that the presence of lignin provided abundant particle coating, which is a source of additional cohesive strength. However, the spraying rate had a minor effect on rainfall erosion resistance, which increased with an increase in lignin solution concentration. Finally, lignin treatment did not significantly affect the size of the vegetative cover and had a minor effect on soil nutrients.

Geosciences doi: 10.3390/geosciences16010038

Authors: Alexey Ostapchuk Ilmir Nugmanov

The heterogeneity of a tectonic fault interface controls both the spatial features of seismicity and the locations of the foci of shallow earthquakes. Strong earthquakes are associated with ruptures of asperities. We present the Seismogenic Patches Detection (SPAD) algorithm to analyze background seismicity to reveal tectonic asperities. In the first stage, the algorithm detects background seismicity based on the nearest-neighbor method. In the second stage, fuzzy clustering of the background mode is performed. Dense clusters of background seismicity, called seismogenic patches, can be interpreted as tectonic asperities. The SPAD algorithm does not use a priori data about the localizations of strong earthquakes. Using SPAD, we analyzed the seismicity of the Kamchatka segment of the Kuril–Kamchatka subduction zone for the period from 1 January 1990 to 23 September 2025. The Kamchatka regional seismic catalog includes 39,104 events, and the magnitude of completeness Mc equals 3.0. We have identified seven seismogenic patches with a size of 170–270 km. Seismogenic patches correlate with the tectonic asperity determined by the maps of the slip distributions for the four largest earthquakes—Mw7.5 (8 June 1993), Mw7.8 (5 December 1997), Mw8.8 (30 July 2025), and Mw7.8 (13 September 2025).

Geosciences doi: 10.3390/geosciences16010037

Authors: Ahmed M. Abdel-Rahman Bassam A. Abuamarah Ali Shebl Jason B. Price Andrey Bekker Mokhles K. Azer

Gabal (G.) Suwayqat El-Arsha contains two distinct phases of granitoids: I-type granodiorite and A-type monzogranite. Both of them experienced intense fractional crystallization that affected plagioclase, alkali feldspar, quartz, and, to a lesser degree, ferromagnesian minerals. EnMAP hyperspectral data were used to discriminate between the different granitoid types through spectral analysis, using various techniques, including the Sequential Maximum Angle Convex Cone (SMACC) method. Granodiorite has high SiO2 (68.21–71.44 wt%), Al2O3 (14.29–14.92 wt%), Fe2O3 (1.99–3.32 wt%), and CaO (2.34–3.87 wt%), whereas monzogranite has even higher SiO2 (73.58–75.87 wt%) and K2O (4.28–4.88 wt%). Both granodiorite and monzogranite exhibit calc-alkaline, peraluminous to metaluminous, and medium- to high-K characteristics, with attendant enrichment of light REE and LILE and depletion of heavy REE and HFSE. A negative Eu anomaly may indicate early plagioclase fractionation, especially in the monzogranite. The I-type granodiorite is likely derived from a high-K, mafic protolith that partially melted during lithospheric delamination, leading to severe fractional crystallization in the upper crust in a post-collisional environment. In contrast, the monzogranite exhibits A-type characteristics and was likely emplaced in an anorogenic setting. Both granites were affected by several episodes of hydrothermal alteration, resulting in silicification, kaolinitization, sericitization, and chloritization. The intrusions studied here exhibit key similarities with those in the Wadi El-Hima area, including tectonic setting, petrogenetic type, Neoproterozoic age (Stage I collisional: ca. 650–620 Ma; Stage II post-collisional: ca. 630–590 Ma), and mineralogical assemblages (notably two-mica granites). These correlations suggest that both suites form part of a regionally extensive batholith composed of I- and A-type granites, stretching from north of the Marsa Alam Road (Umm Salatit–Homrit Waggat) southward to at least Wadi El-Hima.

Geosciences doi: 10.3390/geosciences16010036

Authors: Binghao Zhou Kepeng Hou Huafen Sun Qunzhi Cheng Honglin Wang

Rainfall infiltration is one of the main factors inducing slope instability, while the spatial heterogeneity and uncertainty of soil parameters have profound impacts on slope response characteristics and stability evolution. Traditional deterministic analysis methods struggle to reveal the dynamic risk evolution process of the system under heavy rainfall. Therefore, this paper proposes an uncertainty analysis framework combining Karhunen–Loève Expansion (KLE) random field theory, Polynomial Chaos Kriging (PCK) surrogate modeling, and Monte Carlo simulation to efficiently quantify the probabilistic characteristics and spatial risks of rainfall-induced slope instability. First, for key strength parameters such as cohesion and internal friction angle, a two-dimensional random field with spatial correlation is constructed to realistically depict the regional variability of soil mechanical properties. Second, a PCK surrogate model optimized by the LARS algorithm is developed to achieve high-precision replacement of finite element calculation results. Then, large-scale Monte Carlo simulations are conducted based on the surrogate model to obtain the probability distribution characteristics of slope safety factors and potential instability areas at different times. The research results show that the slope enters the most unstable stage during the middle of rainfall (36–54 h), with severe system response fluctuations and highly concentrated instability risks. Deterministic analysis generally overestimates slope safety and ignores extreme responses in tail samples. The proposed method can effectively identify the multi-source uncertainty effects of slope systems, providing theoretical support and technical pathways for risk early warning, zoning design, and protection optimization of slope engineering during rainfall periods.

Geosciences doi: 10.3390/geosciences16010035

Authors: Pavle Tančić Željko Cvetković Ivana Jovanić Darko Spahić

The chemical compositions and formation temperatures of magnesian calcite and dolomite were estimated by using the combination of chemical analysis, crystallographic parameters, and a plethora of various diagrams and mathematical calculations. This study presents an example of the calculated crystallo-chemical formula (Ca0.960Mg0.039Fe0.001)CO3, obtained from chemical analysis on a representative marble sample from the Bukulja–Venčac area in central Serbia. Substituting CaCO3 with MgCO3 and FeCO3 in dolomite adds approximately 3–5 mol. %, enhancing the classification and indicating that it is more accurately identified as magnesium-excess dolomite. The estimated formation temperature of magnesian calcite (1) is approximately 528 °C, whereas magnesian calcite (2) forms at about 341 °C. The ~187 °C difference corresponds to ~3.28 mol. % MgCO3 (~7.18% dolomite), reflecting the distinction between magnesian calcite (1) and magnesian calcite (2). Considering the presence of the submicroscopic intergrowth and exsolution of dolomite within magnesian calcite (1), which are further subdivided in magnesian calcite (2), the estimated formation temperature of ~341 °C appears to be more realistic. The synthesis of the results suggests that this combined method could be helpful in the geothermometry of marble samples after the treatment with acetic acid. However, despite the promising results, additional experiments are necessary to validate the proposed modified geothermometry approach.

Geosciences doi: 10.3390/geosciences16010034

Authors: Kenneth W. W. Sims Gregory J. Stark Lynne J. Elkins Mark K. Reagan Peter B. Kelemen Janne Blichert-Toft

Understanding how processes of magma genesis and magma differentiation control and modify the chemical composition of erupted lavas from the geochemical measurements of the latter is an under-constrained inverse problem, as there is only one known parameter—the measured composition of the erupted lava—but two unknown parameters—the chemical composition and lithology of the source before melting and how melting, crystallization, and melt–rock interactions act to alter the lava en route to the surface. In this invited contribution, we review nearly seven decades of scientific research that demonstrate the potential of U and Th decay series measurements for unraveling the complexities of oceanic magmatism. We review the underlying nuclear theory, geochemical principles, and application of the 238U, 235U, and 232Th decay series for (i) defining the timescales of magma genesis during decompression mantle melting, (ii) establishing the timescales of magma recharge and magma degassing, and (iii) determining the eruption ages of oceanic Quaternary volcanism.

Geosciences doi: 10.3390/geosciences16010033

Authors: Sreejesh V. Sreedhar Camelia C. Knapp James H. Knapp

Faults and fractures play a critical role in subsurface systems; they may act as hydrocarbon traps, compartmentalize reservoirs, or serve as conduits for fluid migration across stratigraphic intervals. Consequently, fault delineation from seismic data plays a key role in reservoir characterization. This study presents a workflow for generating ant-tracking attribute volumes using multiple structural attributes to enhance fault/fracture delineation. Our results were thereafter validated with formation microimager (FMI) data. The workflow involves a sequential process comprising seismic data conditioning, structural attribute computation, and ant-tracking volume generation. Variance, curvature, and amplitude contrast attributes were calculated on conditioned 3D seismic data and subsequently used as input for the ant-tracking process. Parameter optimization was conducted through an iterative process of varying individual parameters and qualitatively assessing the results against key seismic features in both vertical sections and time slices. The ant-tracking volumes generated from individual attribute volumes were integrated to produce a composite volume, which served as input for automatic fault extraction. The resultant fault patch orientations were consistent with the formation microimager (FMI) log orientations. The integration of multiple structural attributes within the ant-tracking workflow significantly enhanced fault and fracture delineation by leveraging the complementary strengths of each attribute.

Geosciences doi: 10.3390/geosciences16010032

Authors: Asep Hidayatulloh Jarbou Bahrawi Aris Psilovikos Mohamed Elhag

Flooding is a significant natural hazard in arid regions, particularly in Saudi Arabia, where intense rainfall events pose serious risks to both infrastructure and public safety. Bahrah City, situated between Jeddah and Makkah, has experienced recurrent flooding owing to its topography, rapid urbanization, and inadequate drainage systems. This study aims to develop a comprehensive flood hazard mapping approach for Bahrah City by integrating remote sensing data, Geographic Information Systems (GISs), and Multi-Criteria Decision Analysis (MCDA). Key input factors included the Digital Elevation Model (DEM), slope, distance from streams, and land use/land cover (LULC). The Analytical Hierarchy Process (AHP) was applied to assign relative weights to these factors, which were then combined with fuzzy membership values through fuzzy overlay analysis to generate a flood susceptibility map categorized into five levels. According to the AHP analysis, the high-susceptibility zone covers 2.2 km2, indicating areas highly vulnerable to flooding, whereas the moderate-susceptibility zone spans 26.1 km2, representing areas prone to occasional flooding, but with lower severity. The low-susceptibility zone, covering the largest area (44.7 km 2), corresponds to regions with a lower likelihood of significant flooding. Additionally, hydraulic simulations using the rain-on-grid (RoG) method in HEC-RAS were conducted to validate the hazard assessment by identifying inundation depths. Both the AHP analysis and the RoG flood hazard maps consistently identify the western part of Bahrah City as the high-susceptibility zone, reinforcing the reliability and complementarity of both models. These findings provide critical insights for urban planners and policymakers to improve flood hazard mitigation and strengthen resilience to future flood events.

Geosciences doi: 10.3390/geosciences16010031

Authors: XinFei Wang Xin Li RenDong Peng ShuGuang Yang Bin Zhang

The Lower-Middle Jurassic Xishanyao Formation in the Nileke Sag of the Yili Basin contains substantial reserves of coal and coalbed methane (CBM). Elucidating its depositional evolution and the controlling factors of coal accumulation within a sequence-stratigraphic framework is crucial for guiding future exploration. This study integrates regional geological surveys, core observations, well-log analysis, and quantitative lithofacies statistics of the lower member to establish a sequence-stratigraphic framework and reconstruct the sedimentary paleogeography. Eleven minable coal seams are identified, exhibiting a depositionally controlled spatial thickness distribution. The coal is classified as low-rank bituminous (Rank I–II), characterized by high inertinite, low ash, medium-high volatile matter, and ultra-low sulfur content, indicating formation in a freshwater swamp influenced by seasonal droughts and floods. Three third-order sequences (SQ1–SQ3) are recognized. SQ2, deposited during peak transgression as a braided-river delta plain, provided the optimal environment for peat accumulation. In contrast, SQ3 is dominated by progradational deltas with coarser sediments, where coal accumulation weakened. The results demonstrate that coal accumulation was jointly controlled by tectonic subsidence (providing accommodation space), climate (causing peat oxidation and fine-clastic input), and sedimentation (with interdistributary bays on the delta plain being the most favorable sites). Coal accumulation in the Lower Xishanyao Member resulted from the coupling of tectonic, climatic, and sedimentary processes. This genetic model provides a theoretical basis for regional coal and CBM exploration.

Geosciences doi: 10.3390/geosciences16010030

Authors: Diana Urda Kathryn Metcalf Jennifer Diaz

The basement of the Rattlesnake Creek terrane (RCT) in the Klamath Mountains is a mélange of metamorphosed sedimentary and igneous blocks. Recent work shows that the overlying RCT cover sequence has a North American provenance but formed after accretion to the continental margin, so it is unclear if the basement mélange formed exotic or endemic to North America. This study presents petrography and zircon geochronology from RCT metasedimentary blocks and crosscutting intrusions. The southernmost RCT preserves both Early Jurassic and Middle-Late Jurassic cover sequence deposits and records continental clasts and 33% pre-Mesozoic zircons at ~201 Ma, effectively none at ~191 Ma, and 79–90% from 168 to 163 Ma. During active magmatism 207–193 Ma, the RCT was receiving continental sediment, inconsistent with a distant intraoceanic arc. We interpret that the RCT subduction zone formed proximal to North America in the Late Triassic and that there was a sediment pathway to the RCT at ~201 Ma. During Middle to Late Jurassic rifting and subsequent Nevadan compression, the cover sequences were dismembered and incorporated into the mélange by tectonic and sedimentary processes. The age and provenance of metasedimentary deposits in the RCT is inconsistent with west-dipping subduction models in the Klamath Mountains region.

Geosciences doi: 10.3390/geosciences16010029

Authors: Dmitry A. Ruban

The present work reconsiders our current knowledge of the presence of brachiopod genera in the Chattian and Aquitanian stages (late Oligocene and Early Miocene, respectively). Two of the most important sources of paleontological information were used. The uncertain presence of taxa in the particular stages was recorded. The results indicated that the total number of brachiopod genera in the Chattian and the Aquitanian was generally the same, irrespective of the chosen dataset. If so, the short-term paleoenvironmental perturbations did not affect the generic diversity of brachiopods. These findings contribute to a better understanding of the presently available, traditional estimates of the generic diversity of brachiopods. However, further critical consideration and improvement of the data and application of some advanced analytical tools is needed.

Geosciences doi: 10.3390/geosciences16010028

Authors: Andreia Santos Bernardo Marques João Martins Rubén Sobral Carlos Ferreira Fernando Almeida Paulo Dias Beatriz Sousa Santos

Nowadays, despite the advancements in several technological areas, the education process of various subjects shows minimal evolution from the approaches used in prior years. In light of these, some fields struggle to capture the student’s attention and motivation, in particular, when the subject addresses remote locations that students are unable to visit and relate to. Therefore, an opportunity exists to explore novel technologies for such scenarios. This work introduces an educational approach that integrates 3D Reconstruction, Virtual Reality (VR), and a Large Display to enrich Geoscience learning at the university level. In this teacher-centric approach, manipulation of virtual replicas of real-world geological sites can be performed, creating an immersive yet asymmetric collaborative environment for students in the classroom. The teacher’s VR interactions are mirrored on a large display, enabling clear demonstrations of complex concepts. This allows students, who cannot physically visit these locations, to explore and understand the sites more deeply. To evaluate the effectiveness of this approach, a user study was conducted with 20 participants from Geoscience and Computer Science disciplines, comparing the VR-based method with a conventional approach. Analysis of the collected data suggests that, across multiple relevant dimensions, participants generally favored the VR condition, highlighting its potential for enhancing engagement and comprehension.

Geosciences doi: 10.3390/geosciences16010027

Authors: Candela Marco-Peretó Ruth Durán Gonzalo Simarro Jorge Guillén

Morphological variability on Mediterranean embayed sandy beaches is largely driven by wave storms and episodic sediment inputs from local streams during intense rainfall. While storm impacts are well documented, the combined influence of stream discharge, wave forcing and morphological response remains poorly understood. This study examines these interactions at Castell beach, one of the few non-urbanised, stream-fed embayed beaches on the northwestern Mediterranean, during two high-energy storms with heavy rainfall: December 2019 and January 2020 (Storm Gloria). Morphological changes in the subaerial and submerged beach, and stream dynamics were assessed using repeated RTK–GNSS surveys, orthophotos and echo-sounder bathymetry. Results show the stream mouth shifted along the beach (east, central or west) during heavy rainfall episodes depending on wave direction and pre-existing topography, tending toward more wave-sheltered zones. The storms induced contrasting responses: the first caused slight subaerial accretion, whereas Storm Gloria produced subaerial erosion and nearshore sediment deposition from both beach and stream sources. This material was subsequently reworked and reincorporated into the subaerial beach under calmer conditions, with full recovery by February 2022. These findings highlight the role of stream–wave interactions in sediment dynamics and the capacity of highly protected embayed beaches to adapt to extreme events.

Geosciences doi: 10.3390/geosciences16010026

Authors: Cuimei Zhang Gianreto Manatschal Pauline Chenin Nick Kusznir Sanzhong Li Yanhui Suo Zhongxian Zhao

A rifted margin can be regarded, in the first place, as a crustal thinning taper framed by “box-shaped” continental and oceanic crusts whose top basement and Moho are parallel. Attempts to understand the relationship between lithosphere extension, crustal thinning and strain localization have been addressed in part by characterizing and modeling rift modes. However, a weakness of models stems from their using generalized physical parameters and initial conditions, while each system is unique in terms of its geological complexity. In this study, we develop a new approach to investigate the relation between crustal shape, the nature of the top basement and the accommodation space to reveal the link between extension, strain localization and crustal thinning in the northern South China Sea (N-SCS). Our results show the following: (1) box-shaped crusts may indicate no or minor extension, or extension compensated by crustal flow and/or magmatic additions; (2) crustal thinning and strain localization occurred through extensional detachment faults coevally during the rifting of the N-SCS; (3) strain localization was triggered or enhanced by magmatic weakening, and the weak crustal rheology at the onset of the rifting favored the formation of detachment faults; and (4) the inherited composition of the crust (magmatic rocks in the arc and meta-sediments in the forearc) controls the distribution of crustal thinning. We propose that the different initial conditions, changes in extension rates and the presence/absence of subduction dynamics account for the different rift evolutions observed in the SCS and Atlantic-type rift systems.

Geosciences doi: 10.3390/geosciences16010025

Authors: Emerzon Torres Jonathan Dungca

Soil liquefaction remains a critical geotechnical hazard during earthquakes, posing significant risks to infrastructure and urban resilience. Traditional empirical methods, while practical, often fall short in capturing complex parameter interactions and providing interpretable outputs. This study presents an interpretable machine learning (IML) framework for soil liquefaction assessment using Rough Set Theory (RST) to generate a transparent, rule-based predictive model. Leveraging a standardized SPT-based case history database, the model induces IF–THEN rules that relate seismic and geotechnical parameters to liquefaction occurrence. The resulting 25-rule set demonstrated an accuracy of 86.2% and strong alignment (93.8%) with the widely used stress-based semi-empirical model. Beyond predictive performance, the model introduces scenario maps and parameter interaction diagrams that elucidate key thresholds and interdependencies, enhancing its utility for engineers, planners, and policymakers. Notably, the model reveals that soils with high fines content can still be susceptible to liquefaction under strong shaking, and that epicentral distance plays a more direct role than previously emphasized. By balancing interpretability and predictive strength, this rule-based approach advances site-adaptive, explainable, and technically grounded liquefaction assessment—bridging the gap between traditional methods and intelligent decision support in geotechnical engineering.

Geosciences doi: 10.3390/geosciences16010024

Authors: Thairine Lima dos Santos Mário Miguel Mendes Pedro Alexandre Dinis Pedro Miguel Callapez Pedro Proença e Cunha Ilunga Tshibango André Magaly Girão Albuquerque Celeste Yara dos Santos Siqueira

The first comprehensive study about of amber from the Lower Cretaceous of the Lusitanian Basin, in the Estremadura region of western Portugal, is here reported. The amber was recovered as isolated clasts in the Portela da Vila outcrop section, near the small villages of Ramalhal and Ameal, from sedimentary deposits belonging to the Lugar d’Além Formation considered to be of Hauterivian age. The chemical composition of amber clasts was examined in order to infer their botanical source via biomarker analysis. GC–MS and GC×GC–TOFMS showed a strong predominance of abietane-type diterpenoids, including compounds such as amberene, ferruginol (phenolic abietane), kaurane and the derivative of clerodane. The dominance of abietane diterpenoids along with these specific biomarkers is consistent with resin exudation by Araucariaceae/Cheirolepidiaceae conifers, as supported by previous chemotaxonomic studies of Cretaceous amber. Palynological studies of the same sedimentary rock samples highlighted a pollen–spore assemblage characterized by low diversity and number of specimens, and dominated by conifer pollen assigned to the genera Classopollis, Araucariacites and coniferous bisaccate pollen, with relative occurrences of fern spores. The combined geochemical and palynological studies strongly support a source related to conifer plants for the amber here reported.

Geosciences doi: 10.3390/geosciences16010023

Authors: Edgar A. Terekhin Pavel A. Ukrainskiy

Analysis of regional changes in climatic parameters and moistening conditions is a necessary task for obtaining objective data on changes in landscapes. The article analyzes long-term changes in a complex of climatic variables on the south of the Central Russian Upland of the East European Plain in the last decades of the 20th century–the first decades of the 21st century. Opposite trends were identified for heat and moisture supply characteristics. The annual average temperature increased by 2.1 °C between 1980 and 2020. During this same time, the absolute values of the temperature of the warmest and coldest quarters, accumulated temperature over the period with values above 10 °C, increased significantly. The annual average temperature, the average temperature of the warmest and coldest quarters showed a positive, statistically significant trend. Precipitation characteristics, compared with temperatures, showed less pronounced trends during the study period. Annual precipitation and precipitation during the warmest quarter showed a weak negative trend. Precipitation of the coldest quarter showed an increasing trend. Contrasting changes in temperature and precipitation characteristics led to a decrease in moistening indicators during the warm season. The hydrothermal coefficient decreased by more than 18%, and the drought index increased by approximately the same amount. Spatial changes in most climatic parameters are associated with a shift in isolines to the north or northwest. The range of variations in climatic parameters across the region did not undergo significant changes.

Geosciences doi: 10.3390/geosciences16010022

Authors: Shakeel Abid Mohammed Jorge G. Zornberg

The hydraulic performance of woven geotextiles is frequently overlooked in roadway design, despite their extensive use for reinforcement applications. Woven geotextiles are typically manufactured from hydrophobic polymers such as polypropylene or polyester and can act as capillary barriers under unsaturated conditions. This results in moisture accumulation at the soil–geotextile interface, adversely impacting long-term pavement performance. Such problems can be effectively mitigated using geotextiles with enhanced lateral drainage (ELD) capabilities, which are engineered with hydrophilic fibers to facilitate capillary-driven lateral water movement under unsaturated conditions. This functionality facilitates the redistribution of moisture away from the interface, mitigating moisture retention and enhancing drainage performance. The hydraulic performance of geotextiles with enhanced lateral drainage capabilities under unsaturated conditions remains insufficiently understood, particularly in terms of their influence zone and drainage efficiency. For this reason, the present study evaluates the lateral drainage behavior of an ELD geotextile using a soil column test, compared against a control setup without a geotextile and with a non-woven geotextile. Two moisture migration scenarios, namely capillary rise and vertical infiltration, were simulated, with the water table varied at multiple depths. Moisture sensors were embedded along the column depth to monitor real-time water content variations. Results show that the ELD geotextile facilitated efficient lateral drainage, with a consistent influence zone extending up to 2 inches below the fabric. Under infiltration, the ELD geotextile reduced moisture accumulation by 30% around the geotextile, highlighting its superior drainage behavior. These findings encourage practicing engineers to adopt rational, performance-based designs that leverage ELD geotextiles to enhance subgrade drainage and moisture control in pavement and geotechnical applications.