Geosciences

24 pages, 4581 KB

Open AccessArticle

Geology-Guided Fixed-Group Fusion ResUNet for Predicting Calcrete-Type Uranium Prospectivity: A Case Study from the Yilgarn Craton, Western Australia

by Dawei Fan, Jianfeng He, Guoyun Zhong, Fei Xia, Fengjun Nie, Fan Diao, Weidong Li and Xin Zhang

Geosciences 2026, 16(6), 244; https://doi.org/10.3390/geosciences16060244 - 22 Jun 2026

Viewed by 174

Abstract

Calcrete-type uranium prospectivity prediction is challenged by the strong heterogeneity of multi-source geoscientific raster datasets, weak anomaly responses, and the lack of explicit heterogeneous information organization in conventional deep learning models. In this study, the Yilgarn Craton of Western Australia was selected as [...] Read more.

Calcrete-type uranium prospectivity prediction is challenged by the strong heterogeneity of multi-source geoscientific raster datasets, weak anomaly responses, and the lack of explicit heterogeneous information organization in conventional deep learning models. In this study, the Yilgarn Craton of Western Australia was selected as the study area, and a geology-guided fixed-group fusion ResUNet model (GGF-ResUNet) was developed based on 12-channel multi-source geoscientific raster datasets. At the input stage, the evidence layers were divided into four fixed geoscientific proxy groups according to their data modality and geological interpretation, namely gravity, aeromagnetic, radiometric, and geochemical groups, and intra-group channel weighting together with inter-group gating was introduced to enhance the hierarchical representation and adaptive fusion of heterogeneous information. Ablation results showed that GGF-ResUNet achieved better performance than the baseline ResUNet, with AUC increasing from 0.9340 to 0.9740 and F1-score improving from 0.7264 to 0.8356. Further comparative experiments with Attention U-Net, U-Net, SegNet, and FCN showed that GGF-ResUNet achieved comparatively better quantitative performance and more spatially coherent prediction results under the current experimental setting. Without substantially increasing model complexity, the proposed method improves the representation and integration of heterogeneous geoscientific information and provides a feasible technical pathway for calcrete-type uranium prospectivity prediction under weak-anomaly conditions. Full article

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26 pages, 6913 KB

Open AccessArticle

Prediction of Shear-Wave Velocity from SPT and Soil Index Properties: Comparison Between NSPT and (N₁)₆₀ Using Classical Baselines and Machine Learning Under Grouped Validation

by Arturo Zevallos, Julio Torres, Cristian Segura, Javier Carrasco, Dante Cieza and Pedro Carrasco

Geosciences 2026, 16(6), 243; https://doi.org/10.3390/geosciences16060243 - 22 Jun 2026

Viewed by 188

Abstract

Shear-wave velocity (V_s) estimation from the Standard Penetration Test (SPT) can support preliminary site characterization when direct geophysical data are limited, but empirical correlations require validation schemes that reflect transferability between sites. This study evaluates V_s prediction using an interval-paired [...] Read more.

Shear-wave velocity (V_s) estimation from the Standard Penetration Test (SPT) can support preliminary site characterization when direct geophysical data are limited, but empirical correlations require validation schemes that reflect transferability between sites. This study evaluates V_s prediction using an interval-paired dataset derived from geotechnical investigations of school foundations in Piura, Peru. Its novelty lies in comparing the raw SPT blow count (NSPT) and the overburden- and energy-corrected SPT blow count ((N₁)₆₀) on the same strict common sample, using grouped cross-validation by school, thereby emphasizing transferability across sites rather than only internal fit. Five predictive scenarios were tested, from penetration-only formulations to geotechnically enriched specifications. The lowest grouped out-of-fold error among the evaluated models was obtained by a generalized power baseline using (N₁)₆₀ and the integral geotechnical predictor set, yielding root mean square error (RMSE) = 80.48 m/s, mean absolute error (MAE) = 60.15 m/s, and coefficient of determination (R²) = 0.338. This moderate R² indicates limited standalone predictive capacity under transfer to unseen schools; therefore, the model is interpreted as a preliminary transfer-oriented correlation rather than as a substitute for direct V_s measurements or as an independent design equation. In the complementary full-data analysis, the strongest descriptive fit was obtained with Hist Gradient Boosting, whereas the strongest explicit equation corresponded to the log-semi baseline. Overall, the findings show that externally validated transferability, descriptive full-data fit, and equation-based interpretability represent different analytical roles in V_s-SPT modeling. Full article

(This article belongs to the Special Issue Advances in Instrumentation and Experimental Methods for Geosciences)

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16 pages, 5778 KB

Open AccessArticle

Influence of Dry Density and Salt Content on Hydraulic Conductivity and Drying Shrinkage

by Xuejun Liu, Lifeng Zeng, Zejun Song, Bo Yao, Wuping Ran, Yanjun Li and Tiande Wen

Geosciences 2026, 16(6), 242; https://doi.org/10.3390/geosciences16060242 - 22 Jun 2026

Viewed by 205

Abstract

Soil is prone to structural degradation under water infiltration, and the combined effects of dry density and salinity further complicate its hydraulic conductivity and drying shrinkage behavior. However, previous studies have primarily focused on single factors, and the interactive mechanisms between compaction state [...] Read more.

Soil is prone to structural degradation under water infiltration, and the combined effects of dry density and salinity further complicate its hydraulic conductivity and drying shrinkage behavior. However, previous studies have primarily focused on single factors, and the interactive mechanisms between compaction state and salinity remain poorly understood. To investigate the hydraulic conductivity and drying shrinkage behavior of soil under different dry densities and salinity levels, this study examined three dry densities (1.30, 1.35, 1.45 g/cm³) and four NaCl contents (0, 0.5%, 2%, 6%). Saturated hydraulic conductivity (ks) and drying shrinkage were systematically measured. The results indicate that dry density is the primary factor controlling pore structure evolution, ks and drying shrinkage behavior. Increasing dry density markedly reduced porosity (up to 15.95%), ks (by 57.14–92.91%), and drying shrinkage. In contrast, salinity exhibited non-monotonic, density-dependent effects. Salts increased porosity through electrochemical interactions and crystallization-induced pore support, but their effects on ks and drying shrinkage displayed threshold and reversal behavior. These coupled effects demonstrate strong nonlinearity and density dependence, providing a mechanistic basis for compaction optimization and the stability assessment of soil under saline conditions. Full article

(This article belongs to the Section Geomechanics)

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21 pages, 28444 KB

Open AccessArticle

Conceptual Model for Development of Karst–Erosion Processes in Large Dam Reservoir Coastal Geosystem: Bratsk Reservoir, Baikal-Angara Hydroengineering System, Russia

by Oksana Mazaeva, Viktoria Babicheva and Artem Rybchenko

Geosciences 2026, 16(6), 241; https://doi.org/10.3390/geosciences16060241 - 22 Jun 2026

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Abstract

The sulphate–carbonate karst in the southern part of the Bratsk Reservoir has been active throughout the reservoir’s operation. Long-term monitoring of the coastal zone, interpretation of multi-temporal images, and field studies at the Khadakhan key site resulted in the creation of a conceptual [...] Read more.

The sulphate–carbonate karst in the southern part of the Bratsk Reservoir has been active throughout the reservoir’s operation. Long-term monitoring of the coastal zone, interpretation of multi-temporal images, and field studies at the Khadakhan key site resulted in the creation of a conceptual model of coastal geosystem functioning in areas of sulphate–carbonate rock development under conditions of long-term and seasonal fluctuations in the reservoir water level. The structure of interactions within the coastal geosystem is organized at three hierarchical levels: (1) the intra-rock level, (2) the level of interacting factors, and (3) the level of interacting exogenous geological processes, whose activation is driven by an external factor—changes in the reservoir’s water level. We identified five stages of gully formation and the cyclic nature of the karst–erosion process in the coastal geosystem under conditions of seasonal and long-term reservoir water-level fluctuations. Our findings indicate that, when regulating reservoir water levels, dramatic drawdowns should be avoided. This conceptual model aims to improve the understanding of the impact of large reservoir operation on the dynamics of a complex of interacting coastal processes, as well as on the peculiarities of karst development in a boreal climate. Full article

(This article belongs to the Section Natural Hazards)

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20 pages, 9373 KB

Open AccessArticle

Machine Learning-Based Delineation of Anomalous Gold Zones from Drillhole Geochemistry in a Sulphide-Hosted Orogenic Gold System

by Gilbert Yaw Bimpong, Justina Senam Lotsu and Kwaku Boakye

Geosciences 2026, 16(6), 240; https://doi.org/10.3390/geosciences16060240 - 22 Jun 2026

Viewed by 374

Abstract

Early stage mineral exploration requires the reliable identification of anomalous gold zones from drillhole geochemistry in data-limited environments. This study applies a machine learning (ML) classification framework to detect anomalous gold zones (Au ≥ 0.68 ppm; 90th percentile) from bulk XRF multielement drillhole [...] Read more.

Early stage mineral exploration requires the reliable identification of anomalous gold zones from drillhole geochemistry in data-limited environments. This study applies a machine learning (ML) classification framework to detect anomalous gold zones (Au ≥ 0.68 ppm; 90th percentile) from bulk XRF multielement drillhole geochemistry in a Paleoproterozoic Birimian greenstone belt sulphide-hosted orogenic gold system, West African Craton. A total of 53,126 one-metre diamond core samples from 301 drillholes were preprocessed within a compositional data analysis (CoDA) framework, with Au being explicitly excluded from the centred log-ratio (CLR) transformation to eliminate target–predictor circularity. After Minimum Covariance Determinant (MCD) outlier filtering, 40,385 samples were retained to construct a 19-feature matrix of 10 CLR-transformed elements, 1 rock-type feature, and 8 sulphide–lithology interaction features. Drillhole-based block cross-validation (DH-block CV), validated by an experimental along-hole variogram (practical autocorrelation range ≈ 20 m), ensured spatially honest performance estimates. Four nonlinear classifiers—Random Forest (RF), XGBoost, LightGBM, and Multi-Layer Perceptron (MLP)—were benchmarked against a Logistic Regression (LR) linear baseline. All nonlinear classifiers achieved validation AUC of 0.936–0.938, outperforming LR (AUC = 0.931) with F1-score improvements of +0.09 to +0.11 and precision gains of up to +35 percentage points—directly reducing wasted drill holes in applied exploration. MLP recorded the highest F1-score (0.666) and precision (0.765), and XGBoost the highest recall (0.787). Permutation importance identified S-Ti (ΔAUC = 0.028), S-Fe (0.021), and S-Al (0.013) as the top-ranked features, confirming that sulphide enrichment relative to lithological background is the primary discriminating signal. Partial dependence analysis revealed a threshold-driven non-monotonic Fe dependence at CLR(Fe) ≈ 3, marking the transition from lithological dilutant to sulphide co-indicator—a nonlinear pattern inaccessible to linear classifiers. Full article

(This article belongs to the Topic Big Data and AI for Geoscience)

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15 pages, 3322 KB

Open AccessArticle

Recent Trends and Regime Shifts in Arctic Coastal Temperatures: Evidence of AMOC Slowing?

by Elena A. Kasatkina, Oleg I. Shumilov and Dmitry V. Makarov

Geosciences 2026, 16(6), 239; https://doi.org/10.3390/geosciences16060239 - 19 Jun 2026

Viewed by 272

Abstract

This study analyzes surface air temperature (SAT) trends at 158 stations located on or above the Arctic Circle over the 2000–2024 period, aiming to assess whether recent temperature shifts could serve as indirect indicators of a slowing Atlantic Meridional Overturning Circulation (AMOC). Regression [...] Read more.

This study analyzes surface air temperature (SAT) trends at 158 stations located on or above the Arctic Circle over the 2000–2024 period, aiming to assess whether recent temperature shifts could serve as indirect indicators of a slowing Atlantic Meridional Overturning Circulation (AMOC). Regression analysis reveals that only 40% of stations show statistically significant warming trends (p < 0.05), while 33% exhibit no significant trend. Applying the Pettitt and Buishand tests, we detect abrupt regime shifts at 38 stations, with breakpoints concentrated between 2009 and 2014. Notably, 36 of these stations display a weakening of the warming trend after the breakpoint: at 13 stations (including key Arctic archipelagos and the White Sea coast), an initial increase shifts to a decrease; at 17 stations, warming continues but at a slower rate; and at 6 stations (near the Bering Strait), a decrease intensifies. These spatial patterns suggest a potential fingerprint of AMOC slowdown, consistent with recent modeling studies that predict cooling in northwestern Europe and possible Little Ice Age-type environmental conditions. Our findings have implications for assessing future Arctic navigation, coastal infrastructure, and resource extraction under changing climate regimes. Full article

(This article belongs to the Special Issue Climate Risks and Impacts)

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35 pages, 3370 KB

Open AccessReview

Searching for Habitable Conditions in the Solar System: Issues and Challenges from the Planetary Protection Perspective

by Athena Coustenis

Geosciences 2026, 16(6), 238; https://doi.org/10.3390/geosciences16060238 - 19 Jun 2026

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Abstract

Numerous space missions are advancing our understanding of the origin and evolution of planetary bodies and the potential for the emergence of life throughout the Solar System and beyond. Investigations across the inner Solar System have revealed contrasting planetary environments: Venus offers insights [...] Read more.

Numerous space missions are advancing our understanding of the origin and evolution of planetary bodies and the potential for the emergence of life throughout the Solar System and beyond. Investigations across the inner Solar System have revealed contrasting planetary environments: Venus offers insights into runaway greenhouse processes, while Mars remains a primary target for studying climate evolution, atmospheric loss, past water activity, and extinct life, with sample return missions planned in the next decade. Beyond the traditional habitable zone, attention has shifted to the icy moons of Jupiter and Saturn. Data from space missions have identified subsurface oceans and possibly active geology on moons such as Europa, Ganymede, Titan, and Enceladus, highlighting their astrobiological potential. Among others, Europa’s ocean, possibly interacting with a silicate mantle and sustained by tidal heating, Enceladus plumes and Titan’s complex organic chemistry make these worlds compelling targets. Current and upcoming missions will further explore these environments and refine our understanding of habitability. This work also emphasizes the importance of planetary protection to prevent biological contamination, particularly for sample return missions. Continued exploration, supported by international collaboration and technological innovation, will be essential to address engineering challenges and to expand our knowledge of potentially habitable environments across the Solar System. Full article

(This article belongs to the Special Issue Worlds of the Solar System: Geological Evolution and Habitability of Planets and Moons)

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25 pages, 3524 KB

Open AccessArticle

A Simple Multi-Criteria Risk Assessment of Buildings and Infrastructures Under Snow Avalanche Hazard

by Alessio Rubino, Barbara Frigo and Bernardino M. Chiaia

Geosciences 2026, 16(6), 237; https://doi.org/10.3390/geosciences16060237 - 18 Jun 2026

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Abstract

The increasing number of extreme events affecting buildings and strategic infrastructures in mountain areas requires reliable approaches for territorial risk assessment with respect to snow avalanches. Considering risk as the combination of hazard, vulnerability, and exposure factors, a simplified framework—recently adopted in Italian [...] Read more.

The increasing number of extreme events affecting buildings and strategic infrastructures in mountain areas requires reliable approaches for territorial risk assessment with respect to snow avalanches. Considering risk as the combination of hazard, vulnerability, and exposure factors, a simplified framework—recently adopted in Italian national guidelines—is proposed. Avalanche hazard is defined by considering the intrinsic avalanche susceptibility of the territory under investigation, typically described by means of hazard intensity maps. On the other hand, the vulnerability of the construction is determined by considering both the physical, or structural, vulnerability of the building and the functional vulnerability of network systems. Finally, the exposure level accounts for the direct and indirect losses resulting from the hazardous event, based on the typology, use, and potential occupancy of the building or infrastructure. A weighted classification system combining these three factors is adopted to derive risk matrices, in which the risk class of each exposed construction is defined across five levels (high, medium–high, medium, medium–low, low), thus enabling a hierarchical risk classification at the territory scale. The methodology is intended to bridge technical risk assessment and territorial governance, offering an operational decision-support tool for policymakers, emergency planners, and infrastructure operators to support resource allocation and mitigation strategies. Full article

(This article belongs to the Section Natural Hazards)

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24 pages, 31785 KB

Open AccessArticle

Investigating the Occurrence of Cracks in the Ice Cover of a Regulated River

by Karl-Erich Lindenschmidt, Joyce Lutterodt, Derrick Amoah Yeboah, Michael Lynch, Arash Rafat, Sergio Gomez and Robert Briggs

Geosciences 2026, 16(6), 236; https://doi.org/10.3390/geosciences16060236 - 17 Jun 2026

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Abstract

This study examines why ice covers on the Churchill River in Labrador crack during winter and how weather, river flow, freezing conditions, and riverbed features contribute to these events. Using data from 2010 to 2025 and satellite imagery, the study shows that cracks [...] Read more.

This study examines why ice covers on the Churchill River in Labrador crack during winter and how weather, river flow, freezing conditions, and riverbed features contribute to these events. Using data from 2010 to 2025 and satellite imagery, the study shows that cracks most often occur in December to February when heavy snow, rapid flow changes, or long cold periods place stress on the ice. Cracking also frequently starts near sandbars where the ice is weaker. The results highlight that no single factor causes cracking. Instead, a combination of snow load, temperature, flow variability, and local river conditions determines when and where cracks form. There is also a disconnect from flow regulation since cracks also formed in 2012 before the construction of the dam began in 2015. A field survey was also carried out employing a combination of borehole jack (BHJ) testing and ground-penetrating radar (GPR) surveys to quantify spatial variations in ice strength and thickness across a portion of the lower Churchill River across two sandbars. In situ BHJ measurements were conducted at multiple sites to determine confined compressive ice strength under both floating and grounded conditions, revealing substantial local variability linked to differences in ice support and the presence of white versus black ice. Complementary GPR transects using 500 MHz and 1000 MHz systems provided high-resolution profiles of ice thickness and internal structure, enabling identification of transitions between grounded and floating ice. The integrated BHJ–GPR approach allowed direct comparison between point-scale strength measurements and spatially continuous thickness and grounding patterns, demonstrating that grounded ice and ice containing higher proportions of white ice exhibited more complex stress states and greater variability in mechanical response. Together, these measurements highlight the importance of combining geophysical surveying with in situ mechanical testing to better understand how environmental conditions control ice integrity and potentially influence ice-jam lodgement propensity along regulated subarctic rivers. Full article

(This article belongs to the Special Issue In Situ Data on Snow and Sea Ice in Polar Regions)

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13 pages, 5622 KB

Open AccessArticle

Snowpatch Influence on Rock Weathering in the Goltsy Altitudinal Belt of South Yakutia, Russia

by Andrey Melnikov, Ze Zhang, Tatiana Romanis, Leonid Gagarin and Viktor Rochev

Geosciences 2026, 16(6), 235; https://doi.org/10.3390/geosciences16060235 - 15 Jun 2026

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Abstract

This research was conducted on mountain summits in South Yakutia, Russia. The findings indicate that within the goltsy altitudinal belt (comparable to the alpine zone), the weathering intensity of rocks above 1400 m depends on the development of snow-ice formations, particularly snowpatches. Snowpatches [...] Read more.

This research was conducted on mountain summits in South Yakutia, Russia. The findings indicate that within the goltsy altitudinal belt (comparable to the alpine zone), the weathering intensity of rocks above 1400 m depends on the development of snow-ice formations, particularly snowpatches. Snowpatches promote physical rock weathering along their edges by up to 1.5–4 times more intensely compared to baseline levels. The ground temperature at the edges was examined in relation to air temperatures. The conditions that facilitate rock weathering at the snowpatch edge during the summer months are characterized by diurnal air temperatures below 10–15 °C, with minimum temperatures below 5 °C. Nivation processes in the goltsy altitudinal belt of South Yakutia are considered as one of the dominant geomorphic agents. However, future changes are expected in the existing nival-glacial belts, as snowpatches respond rapidly to climate change, with the mean annual air temperature in South Yakutia exhibiting a rising trend. Full article

(This article belongs to the Section Cryosphere)

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17 pages, 9934 KB

Open AccessArticle

Genesis and Geological Significance of Tuff in the Wujiaping Formation, Upper Permian, Northern Sichuan Basin, China

by Jia Wang, Xiaoqin Liu, Pengfei Zhang, Jichang Yang and Fengjie Li

Geosciences 2026, 16(6), 234; https://doi.org/10.3390/geosciences16060234 - 13 Jun 2026

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Abstract

In the northern Sichuan Basin, distant from the main body of the Emeishan Large Igneous Province (ELIP), marine deposits of the Wujiaping Formation from the Permian period contain widely distributed tuffs of varying thicknesses. To clarify the genesis of these tuffs and their [...] Read more.

In the northern Sichuan Basin, distant from the main body of the Emeishan Large Igneous Province (ELIP), marine deposits of the Wujiaping Formation from the Permian period contain widely distributed tuffs of varying thicknesses. To clarify the genesis of these tuffs and their relationship with the ELIP, this study conducted field measurements and sample collection at the Daliang Section, Wangcang County, and the Qiaoting Section, Nanjiang County, of the northern Sichuan Basin and compared them with basalts and tuffs from Well DY1 in a minor basaltic eruption zone in the northern Sichuan Basin. The results indicate that tuffs from the Daliang and Qiaoting Sections of the northern Sichuan Basin exhibit high Al₂O₃/TiO₂ ratios (23.65–39.55) and significant depletion of Eu, Ba, and Sr elements. These characteristics suggest that their origin is linked to multiphase felsic volcanic activity within the ELIP and formation in an intraplate extensional setting. The basalts and tuffs developed at Well DY1 share the same low Al₂O₃/TiO₂ ratios (4.02–4.97), similar to the Emeishan basalts. In the Zr-Ti, Zr/Sc-Th/Sc, Nb/Y-Zr/TiO₂, and Zr/TiO₂-SiO₂ diagram plots, they fall within the basalt range, indicating that the tuffs at Well DY1 originated from the mid-ELIP eruption of basic basalt. In contrast to the felsic nature of the tuffs at Well DY1, the northern Sichuan Basin lacks records of such basic–alkaline igneous eruptions, suggesting that the influence of basalt eruptions in the northeastern Sichuan Basin is limited and does not affect the Wujiaping Formation in the northern Sichuan Basin. There is a positive correlation between volcanic activity and the total organic carbon (TOC) content of black siliceous rocks and siliceous shales in the Wujiaping Formation of northern Sichuan. The acid volcanic eruptions from Emeishan likely also played a key role in the formation of high-quality hydrocarbon source rocks in the deep-water continental shelf areas of the Wujiaping Formation in the northern Sichuan Basin. Full article

(This article belongs to the Special Issue Sedimentary Basins and Energy Resources)

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24 pages, 8182 KB

Open AccessArticle

Geochronology, Geochemistry, and Tectonic Implications of the Early Devonian Mafic Intrusions in the Southern Margin of the North China Craton

by Kekun Li, Ruidong Yang, Yazhou Fan, Jianhan Huang and Pengyuan Chen

Geosciences 2026, 16(6), 233; https://doi.org/10.3390/geosciences16060233 - 12 Jun 2026

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Abstract

The Heilongtai–Maogudui (HM) mafic intrusions are exposed in the southern margin of the North China Craton (SNCC), which are contemporaneous with a variety of strategic metal/non-metal minerals (niobium, uranium, and high-purity quartz) and magmatic hydrothermal REE deposits. New geochronology and geochemistry of these [...] Read more.

The Heilongtai–Maogudui (HM) mafic intrusions are exposed in the southern margin of the North China Craton (SNCC), which are contemporaneous with a variety of strategic metal/non-metal minerals (niobium, uranium, and high-purity quartz) and magmatic hydrothermal REE deposits. New geochronology and geochemistry of these intrusions are examined and interpreted to decipher their petrogenesis and tectonic settings. Zircon LA–ICP–MS data formed a concordant cluster, yielding a mean ²⁰⁶Pb/²³⁸U age of 397.5 ± 3.5 Ma, which is interpreted as an Early Devonian crystallization age. The HM mafic intrusions have similar whole-rock geochemical compositions, containing 48.94–51.51 wt% SiO₂, 1.26–1.61 wt% TiO₂, 5.96–7.13 wt% MgO, and 11.00–12.48 wt% FeO_t. The total alkali contents range from 1.61 wt% to 3.53 wt%, with Mg^# values of 47.23–52.30. The petrographic and geochemical results suggest the fractional crystallization of mainly olivine, clinopyroxene, and minor Fe–Ti oxide in the mafic intrusions. Being of tholeiitic composition, these mafic rocks display relatively flat rare earth element (REE) and trace element patterns, which are similar to those of the normal mid-ocean ridge basalt (N–MORB) and the enriched mid-ocean ridge basalt (E–MORB). The HM mafic intrusions are proposed to originate in the continental extensional environment through 5–10% partial melting of the depleted spinel asthenosphere mantle source. This is attributed to the gravitational delamination of the lithospheric mantle and the upwelling of the hot asthenosphere, marking the end of the Paleozoic Proto–Tethyan orogenic cycle. The Paleozoic strategic mineral deposits are proposed to have formed under this specific tectonic regime. Full article

(This article belongs to the Section Geochemistry)

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24 pages, 8450 KB

Open AccessArticle

Tectonic Stylolite Stress Inversion, Angle Correction, Validation Across Scales and Variability Within Outcrops

by Saskia Köhler and Daniel Koehn

Geosciences 2026, 16(6), 232; https://doi.org/10.3390/geosciences16060232 - 11 Jun 2026

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Abstract

Quantitative stylolite roughness inversion technique (SRIT) is a powerful tool that is increasingly used to determine burial depth and tectonic stress of rocks that contain stylolites. Despite the increasing use of SRIT, there is still a need to validate the accuracy of the [...] Read more.

Quantitative stylolite roughness inversion technique (SRIT) is a powerful tool that is increasingly used to determine burial depth and tectonic stress of rocks that contain stylolites. Despite the increasing use of SRIT, there is still a need to validate the accuracy of the method. The presented work aims to evaluate three fundamental questions: (i) Do we need to correct the calculated stress magnitude if the stress field is tilted? (ii) What is the variability of results as a function of sample length, and (iii) how representative are samples for one outcrop? In order to answer these questions, we derive a corrected formula for tectonic stylolite stress inversion that includes tilted principal stresses, we apply the inversion method across multiple scales on single and variable stylolite samples and we evaluate the stress for multiple samples from one outcrop. Our results show that angle correction is needed for strongly tilted samples (to reduce a potential error of up to 50%), that one single stylolite inversion is not representative no matter what the scale, that the inversion accuracy decreases with scale but can be optimized with mean values (down to a length of 20× crossover length) and that at least the orientation of stresses is very consistent within an outcrop. Full article

(This article belongs to the Special Issue Innovative Experimental Methods, Advanced Field/in-Situ Testing, and Their Engineering Applications in Geomechanics)

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30 pages, 4885 KB

Open AccessReview

Review of Hydraulic Fracture Diagnostics: Technologies, Interpretation Challenges, and Emerging Advances

by Tianhao Bai, Guan Qin and Mohamed Y. Soliman

Geosciences 2026, 16(6), 231; https://doi.org/10.3390/geosciences16060231 - 9 Jun 2026

Viewed by 574

Abstract

Hydraulic fracture diagnostics are essential for characterizing fracture geometry, connectivity, and effectiveness in unconventional reservoirs. However, the diversity of available techniques and fragmented understanding of their physical mechanisms hinder multidisciplinary communication and lead to inconsistent field decisions. This review provides a systematic assessment [...] Read more.

Hydraulic fracture diagnostics are essential for characterizing fracture geometry, connectivity, and effectiveness in unconventional reservoirs. However, the diversity of available techniques and fragmented understanding of their physical mechanisms hinder multidisciplinary communication and lead to inconsistent field decisions. This review provides a systematic assessment of diagnostic methods, focusing on their physical foundations, applicability, and limitations, and proposes a unified reference framework. Direct diagnostics, including microseismic monitoring, fiber-optic sensing (DTS and DAS), and tiltmeter measurements, are evaluated in terms of data characteristics, interpretation challenges, and field applicability. Indirect methods based on pressure, production, and tracer data—such as DFITs, pressure interference tests, and tracer analysis—are examined for their roles in fracture closure evaluation and interwell connectivity. The review further distinguishes between single-well and multi-well applications, providing a structured classification framework. It highlights that individual methods are constrained by non-uniqueness, modeling assumptions, and non-ideal field conditions, especially in complex fracture networks. Therefore, reliable characterization requires integrating multiple diagnostics with physics-based modeling and uncertainty-aware interpretation. Recent advances in AI and machine learning are also briefly discussed as tools to enhance automated analysis and support real-time, predictive diagnostics. Full article

(This article belongs to the Section Geophysics)

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23 pages, 8254 KB

Open AccessArticle

Deep-Seated Processes Controlling Mesozoic Differential Metallogeny in the Southern Region of South China: Insights from Hf-Nd Isotope Mapping

by Yuqing Yin, Bo Xu, Maowen Yuan, Zhuang Miao, Jin Wang, Zihao Wen, Tianli Jin, Peidong Chai, Wenqi Song, Shiying Fu and Masroor Alam

Geosciences 2026, 16(6), 230; https://doi.org/10.3390/geosciences16060230 - 8 Jun 2026

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Abstract

The southern region of the South China Block hosts a super-large metallogenic province. However, the Mesozoic differential metallogeny between the southern Cathaysia Block (W-Sn) and the southern Yangtze Block (Au-Sb) remains enigmatic. To characterize the crustal architecture beneath different metallogeny belts, we integrate [...] Read more.

The southern region of the South China Block hosts a super-large metallogenic province. However, the Mesozoic differential metallogeny between the southern Cathaysia Block (W-Sn) and the southern Yangtze Block (Au-Sb) remains enigmatic. To characterize the crustal architecture beneath different metallogeny belts, we integrate 3239 published ε_Hf(t) values of synmagmatic zircons from Mesozoic igneous rocks and corresponding whole-rock ε_Nd(t) datasets to generate coupled Hf–Nd isotopic mappings. The results show that ε_Hf(t) values range from −19.3 to +11.6 (T_DM2: 464–2419 Ma) and ε_Nd(t) values are from −12.2 to +5.0 (T_DM2: 580–2008 Ma) in the southern part of South China Block. High ε_Hf(t) (−4~+11.6) and ε_Nd(t) (−4~+5.0) zones are concentrated along the Honghe Fault and Chenzhou–Linwu Fault systems, while low-value Hf–Nd isotopic (ε_Hf(t) = −10.6 to −4; ε_Nd (t) = −12.2 to −4) zones are mainly distributed in the interior of the southern Yangtze Block. The W-Sn deposits in the southern Cathaysia Block are genetically linked to the heterogeneous ε_Hf(t)-ε_Nd(t) isotopic domains. The ore-forming materials of these high-temperature W-Sn polymetallic deposits may primarily derive from crust hybrid magmas that have undergone multistage crustal reworking. In contrast, low-temperature Au-Sb deposits in the northern Youjiang basin are distributed in areas characterized by elevated ε_Hf(t)-ε_Nd(t) isotopic signatures, which are primarily derived from reworked crust with significant mantle contributions. Most magmatic rock-associated Au deposits tend to cluster at the boundaries of Hf-Nd isotopic anomalies, which indicates the contribution of crust-mantle interaction to Au mineralization. Our Hf-Nd isotopic mappings reveal that mantle-crust deep-seated process controls the Mesozoic differential metallogeny between the southern Cathaysia Block (W-Sn) and the southern Yangtze Block (Au-Sb). Full article

(This article belongs to the Special Issue Isotope Geochemistry: New Techniques and Applications)

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23 pages, 5041 KB

Open AccessArticle

The Trouble with Ichnofacies

by Spencer G. Lucas

Geosciences 2026, 16(6), 229; https://doi.org/10.3390/geosciences16060229 - 6 Jun 2026

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Abstract

For about 60 years, the ichnofacies model has been used to identify trace fossil assemblages associated with sedimentary environments. However, the ichnofacies model faces many problems, including: (1) how ichnofacies are defined; (2) non-environmental controls of trace fossil distribution; (3) trace fossil homeomorphy; [...] Read more.

For about 60 years, the ichnofacies model has been used to identify trace fossil assemblages associated with sedimentary environments. However, the ichnofacies model faces many problems, including: (1) how ichnofacies are defined; (2) non-environmental controls of trace fossil distribution; (3) trace fossil homeomorphy; (4) lack of autecology; (5) facies-crossing ichnotaxa; (6) non-uniformitarian aspects of trace fossil history; (7) monotaxial and other low-diversity ichnoassemblages; (8) ichnoassemblages that do not fit into established ichnofacies; and (9) taphonomic biases. Because of these problems, ichnofacies have become an over-generalized, assumption-ridden, exception-laden model that relies on diverse ad hocisms to explain away many of its shortfalls. Ichnofacies should be abandoned, and the relationship of trace fossils to sedimentary environments should be analyzed in a more granular and precise manner, focused on individual trace fossils or ichnoassemblages in conjunction with analysis of lithofacies and other biofacies data. Fossilized behavior is the conceptual paradigm of ichnology, not ichnofacies. Full article

(This article belongs to the Special Issue Perspectives on Palaeogeography, Palaeoclimate, Palaeobiology and Sedimentary Records)

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19 pages, 3509 KB

Open AccessArticle

Metal Sources of Zn–Pb and Bauxite Deposits in the Sichuan–Yunnan–Guizhou Region: Constraints from Pb Isotopes and Zn/Cd Ratios of Basement and Cover Strata

by Lisheng Gao, Guanghui Wang and Guangshu Yang

Geosciences 2026, 16(6), 228; https://doi.org/10.3390/geosciences16060228 - 5 Jun 2026

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Abstract

Critical metals such as gallium and germanium are strategic mineral resources widely used in advanced technology, including semiconductors and solar cells. These metals are recovered as by-products from the processing of Zn–Pb and bauxite ores. In China, the Sichuan–Yunnan–Guizhou (SYG) region is abundant [...] Read more.

Critical metals such as gallium and germanium are strategic mineral resources widely used in advanced technology, including semiconductors and solar cells. These metals are recovered as by-products from the processing of Zn–Pb and bauxite ores. In China, the Sichuan–Yunnan–Guizhou (SYG) region is abundant in Zn–Pb and bauxite ore deposits, such as the Huize Zn–Pb–Ge deposit and the Wuchuan–Zheng’an–Daozhen (WZD) area Al–Ga deposit. Although previous studies have proposed models to explain the enrichment mechanisms of critical metals in this area, the metal sources of these deposits remain controversial. In this study, samples were collected from the Paleoproterozoic Kunyang Group to the Permian Emeishan basalts, and the metal sources of these deposits were traced by comparing the Pb isotopic ratios and Zn/Cd ratios of potential source rocks and deposits. The findings indicate: (1) The Pb isotopic compositions of most samples are relatively homogeneous, but certain differences exist among strata from different geological periods. (2) The metal sources of the Yunnan and Guizhou bauxite may both have been controlled by the underlying carbonate rocks, but the specific source horizons differ significantly between the two regions. (3) Based on the Pb isotopic compositions of regional strata and Zn–Pb deposits, it appears that the regional basement and sedimentary cover likely contributed significantly to the ore-forming metals, whereas the Emeishan basalts may have played a relatively minor role. However, due to the complex lithology and substantial thickness of the basement and cover strata in the SYG region, there may be issues of sampling inadequacy. Nonetheless, this study provides important foundational data and insights for tracing the metal sources of deposits in this region using Pb isotopes and Zn/Cd ratios. Full article

(This article belongs to the Special Issue Critical Metals from Magmatic–Hydrothermal and Supergene Systems: From Genesis to Comprehensive Utilization)

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15 pages, 6030 KB

Open AccessArticle

Fission Track Thermochronology from the Siletzia–Klamath Mountains Boundary

by Shayne Klisura, Francis J. Sousa and Paul O’Sullivan

Geosciences 2026, 16(6), 227; https://doi.org/10.3390/geosciences16060227 - 5 Jun 2026

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Abstract

We report the first low-temperature thermochronologic data from the Oregon Coast Range. This includes apatite and zircon fission-track data from fifteen samples of the Umpqua Group and Dothan Formation collected across the Wildlife Safari Fault near Roseburg, Oregon. This structure marks the boundary [...] Read more.

We report the first low-temperature thermochronologic data from the Oregon Coast Range. This includes apatite and zircon fission-track data from fifteen samples of the Umpqua Group and Dothan Formation collected across the Wildlife Safari Fault near Roseburg, Oregon. This structure marks the boundary between the Siletzia terrane and the Klamath Mountains Province, where collision and accretion at 51–49 Ma produced a fold-and-thrust belt. Our sampling was designed to test whether fission track thermochronometry records structurally controlled exhumation across this fault during Siletzia accretion. The data fail to support this hypothesis. Instead, apatite fission track ages define a single thermally reset population at 45.3 ± 1.1 Ma that is uniform across all sampled stratigraphic and structural positions. Unimodal, moderately shortened track lengths (12.5–14.1 μm) record protracted cooling through the apatite partial annealing zone. Zircon fission track data show a time-continuous partial annealing pattern with youngest grain ages of 49–43 Ma, indicating temperatures reached at least the lower zircon partial annealing zone. These data record a regionally pervasive mid-Eocene thermal event that we interpret as syn-collisional heating followed by protracted cooling. Full article

(This article belongs to the Section Structural Geology and Tectonics)

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22 pages, 4052 KB

Open AccessArticle

When Relief Becomes Unstable: Analyzing the Role of Tensile and Hybrid Fractures in Maximum Escarpment Heights

by Julien Gargani

Geosciences 2026, 16(6), 226; https://doi.org/10.3390/geosciences16060226 - 5 Jun 2026

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Abstract

Slope stability description through mechanical laws has important implications for Earth morphology understanding and risk assessment. Previous research studies have shown that shear, tensile, and hybrid fractures can be observed experimentally and in the field, but their description by a single equation is [...] Read more.

Slope stability description through mechanical laws has important implications for Earth morphology understanding and risk assessment. Previous research studies have shown that shear, tensile, and hybrid fractures can be observed experimentally and in the field, but their description by a single equation is still an open debate. Fracture envelopes able to contemporaneously describe these three fracture modes differ significantly from the Mohr–Coulomb law. Despite the need to apply such a law at all scales, from the laboratory to the mountain range, the fracture criterion that characterizes all types of fractures is rarely used in geotechnical engineering and geological investigations. In order to analyze the stability thresholds of large-scale relief, the current work examines the effects of considering the Griffith criterion with variable rock traction instead of the Mohr–Coulomb law using a modeling approach. The difference estimated for the maximum relief using these two different rupture criteria could be of the same order as those caused by geological phenomena, such as with or without seismic activity, or those caused by destabilization processes (tilting vs. landslide). When compared to the modified Griffith criterion, the Mohr–Coulomb law tends to overestimate the maximum escarpment height. The results are examined in relation to Carrara marble, which serves as a case study for the theoretical framework. Full article

(This article belongs to the Section Geomechanics)

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18 pages, 5661 KB

Open AccessArticle

Tectonic Control on Soil CO₂ Emissions in an Active Volcanic System: Insights from Vulcano Island

by Sofia De Gregorio, Marco Camarda, Giorgio Capasso, Roberto M. R. Di Martino, Antonino Pisciotta, Vincenzo Prano and Giuseppe M. Riolo

Geosciences 2026, 16(6), 225; https://doi.org/10.3390/geosciences16060225 - 4 Jun 2026

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Abstract

Soil CO₂ emissions are widely used to trace fluid circulation in the crust, as faults and fracture networks act as preferential pathways for fluid ascent from depth. Their spatial distribution may reveal tectonic lineaments controlling fluid migration, while temporal variations may reflect [...] Read more.

Soil CO₂ emissions are widely used to trace fluid circulation in the crust, as faults and fracture networks act as preferential pathways for fluid ascent from depth. Their spatial distribution may reveal tectonic lineaments controlling fluid migration, while temporal variations may reflect stress changes associated with seismogenic processes. In active volcanic systems, however, identifying tectonic influences is challenging because volcanic and hydrothermal activity can mask tectonically controlled signals. Vulcano Island is particularly suitable for investigating these interactions, as it is characterized by both persistent volcanic–hydrothermal activity and a tectonic setting shaped by major regional fault systems. In this study, we analyze continuous soil CO₂ flux records and periodic surveys conducted over a fixed measurement grid during the last 20 years. Continuous records show that a clear tectonic signal is recognizable only at the Faraglione site, where the most pronounced increase in soil CO₂ flux occurred after the 16 August 2010 M 4.8 earthquake. Spatial analysis reveals two anomalous phases following this event, in September 2010 and January 2011, both showing a NNW-SSE alignment consistent with the regional structural framework. Analysis of data collected during the 2021 unrest confirms that the tectonic framework exerts strong control on fluid release both during quiescence and during phases of enhanced volcanic activity. Full article

(This article belongs to the Section Geochemistry)

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19 pages, 6344 KB

Open AccessArticle

Effects of Carnian Pluvial Episode on the Yanchang Formation Depositional Environment and Hydrocarbon Accumulation, Ordos Basin, China

by Peng Su, Shouzhi Hu, Honghan Chen, Simeng Cui and Yangfan Guo

Geosciences 2026, 16(6), 224; https://doi.org/10.3390/geosciences16060224 - 4 Jun 2026

Viewed by 439

Abstract

The Carnian Pluvial Episode (CPE) was a major Late Triassic climatic event, but its recognition in the North China Block remains limited due to challenges in correlating continental strata with global marine records. This study integrates sedimentological, pyrolytic, and elemental geochemical data from [...] Read more.

The Carnian Pluvial Episode (CPE) was a major Late Triassic climatic event, but its recognition in the North China Block remains limited due to challenges in correlating continental strata with global marine records. This study integrates sedimentological, pyrolytic, and elemental geochemical data from the Yanchang Formation in the Ordos Basin to characterize the stratigraphic response to the CPE and evaluate its implications for hydrocarbon exploration. Results show high total organic carbon content and a negative δ¹³C excursion during the CPE, along with significant shifts in sedimentary microfacies. Palynological assemblages and recent geochronology identify the Chang 7₃ black shales as products of this event. Enrichments in Fe, P, Cu, and U indicate strong reducing conditions and high paleo-productivity. Elemental ratios (CIA, Sr/Cu, Fe/Mn) reveal a shift from arid to humid conditions between the Chang 8 and Chang 7 units. Redox (V/Cr, V/(V + Ni), U/Th) and productivity (TOC/P, P/P_UCC, Cu/Ti) proxies reflect enhanced reducing conditions and elevated productivity, consistent with the CPE. Correlation analyses link lithological transitions and organic matter characteristics to this event, highlighting the CPE as a key control on high-quality source rock development in the Ordos Basin. Full article

(This article belongs to the Topic Hydrocarbon Generation, Storage, and Accumulation Within Shale Reservoirs)

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20 pages, 3921 KB

Open AccessArticle

Deformation and Resistivity Characteristics of Compacted Loess Under Dry–Wet Cycles

by Peng Li, Zichuan Wang, Yuqi Liu, Jiaxin Yang, Xiao Zhang, Zemin Xue, Dongtun Hao and Pengju Qin

Geosciences 2026, 16(6), 223; https://doi.org/10.3390/geosciences16060223 - 3 Jun 2026

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Abstract

Compacted loess is widely used as road subgrade filling in northwestern China, but its stability is threatened by traffic loads and repeated dry–wet cycles, leading to subgrade settlement or collapse. This study investigated the compression and resistivity characteristics of Q₃ Malan loess [...] Read more.

Compacted loess is widely used as road subgrade filling in northwestern China, but its stability is threatened by traffic loads and repeated dry–wet cycles, leading to subgrade settlement or collapse. This study investigated the compression and resistivity characteristics of Q₃ Malan loess under 0–3 dry–wet cycles by incremental loading (IL) and constant rate of strain (CRS) tests. A self-developed consolidation chamber was used for the IL and CRS tests with the simultaneous monitoring of deformation and resistivity, with the moisture content controlled within the range of 1% to 29% to 15%. The results showed that loess compressibility increased rapidly after the first dry–wet cycle and became slow after other dry–wet cycles; The primary compression index C_c and secondary compression index C_α rose as vertical stress increased, and C_α stabilized at a vertical stress larger than 200 kPa. Resistivity decreased with stress and cycles, and sharply decreased after the first cycle (enhanced pore connectivity) and stabilized after two to three cycles, matching the compression stages. The compression and resistivity characteristics obtained by IL and CRS tests had consistent variation rules, confirming the reliability of the tests. This study provides a preliminary laboratory theoretical basis for exploring the feasibility of using resistivity in subgrade deformation monitoring. Full article

(This article belongs to the Special Issue Advanced Studies in Rainfall-Induced Soil Degradation, Failure and Landslide Hazards)

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23 pages, 25568 KB

Open AccessArticle

Integrating Geological Evolution and Spatial Connectivity in Geotrail Design: A Framework from the Ijen UNESCO Global Geopark, East Java, Indonesia

by Abdillah, Mirzam Abdurrachman, Yan Rizal, Nia Kurniasih and Firman Sauqi Nur Sabila

Geosciences 2026, 16(6), 222; https://doi.org/10.3390/geosciences16060222 - 3 Jun 2026

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Abstract

The Ijen UNESCO Global Geopark exhibits high geological diversity, recording a transition from Tertiary volcanism to active Quaternary volcanic systems and associated carbonate–karst development; however, geotourism remains predominantly site-based, limiting spatial integration and thematic continuity. This study aims to identify and structure geotrail [...] Read more.

The Ijen UNESCO Global Geopark exhibits high geological diversity, recording a transition from Tertiary volcanism to active Quaternary volcanic systems and associated carbonate–karst development; however, geotourism remains predominantly site-based, limiting spatial integration and thematic continuity. This study aims to identify and structure geotrail routes by integrating geological setting, site diversity, and spatial relationships. The methodology applies a sequential framework comprising geological review, site inventory (geosites, biosites, and cultural sites), site characterization, accessibility and clustering analysis, route delineation, and SWOT-based evaluation. The results define five geotrail routes reflecting the geological evolution of the region, with spatial distribution characterized by older volcanic systems in the southern sector, Quaternary volcanism in the northern sector, and carbonate units in the eastern sector. Despite coherent geological relationships among sites, connectivity remains limited due to accessibility constraints and lack of integrated management. SWOT analysis indicates near-balanced internal factors (−0.0047) and externally constrained conditions (−0.5584), placing development in a defensive position. These findings indicate that the main limitation is the lack of spatial and interpretative integration rather than geological diversity. The study provides a systematic framework linking geological evolution to geotrail design to support integrated geotourism development. Full article

(This article belongs to the Special Issue Earth System–Society Nexus: Geoheritage and Geopark Practices)

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16 pages, 2242 KB

Open AccessArticle

‘Typical’ No More: Digital Re-Evaluation of Yanguoxia Caririchnium Trackways Reveals Behavioural Complexity

by Anthony Romilio

Geosciences 2026, 16(6), 221; https://doi.org/10.3390/geosciences16060221 - 2 Jun 2026

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Abstract

Ornithopod dinosaur trackways (OA and OB) from the Lower Cretaceous Hekou Group at Yanguoxia (Gansu Province, China) have previously been described as “typical”—a term applied to contrast them with swim traces from the same surface rather than as a comprehensive behavioural assessment. Building [...] Read more.

Ornithopod dinosaur trackways (OA and OB) from the Lower Cretaceous Hekou Group at Yanguoxia (Gansu Province, China) have previously been described as “typical”—a term applied to contrast them with swim traces from the same surface rather than as a comprehensive behavioural assessment. Building on published trackway maps, this study uses an expanded suite of quantitative digital analytical tools to reassess ichnotaxonomic affinity, manus–pes relationships, and locomotor behaviour. Pes morphology in both trackways is consistent with the ornithopod ichnogenus Caririchnium, with closest affinity to Caririchnium lotus. However, quantitative analysis reveals crossover events, extreme pes-dominated heteropody, and unusual manus placement that depart substantially from expectations for typical quadrupedal ornithopod locomotion. These features are most parsimoniously explained by trackmaker locomotion under shallow subaqueous conditions, in which partial buoyancy reduced effective forelimb loading rather than reflecting anatomically reduced palmar surfaces. Exploratory statistical analysis indicates left–right asymmetry in pace and step parameters within the OA trackway, raising the possibility of lateralised locomotor behaviour. Together, these findings demonstrate that trackways previously regarded as typical may preserve unrecognised behavioural complexity, and that digital re-evaluation of legacy ichnological datasets can substantially refine interpretations of dinosaur locomotion. Full article

(This article belongs to the Special Issue Perspectives on Palaeogeography, Palaeoclimate, Palaeobiology and Sedimentary Records)

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15 pages, 2021 KB

Open AccessArticle

Simulations of Different Helmholtz Coil Configurations for Induction Magnetometers in Archaeomagnetic Applications

by Giulio Giovannetti, Sonia La Felice and Claudia Principe

Geosciences 2026, 16(6), 220; https://doi.org/10.3390/geosciences16060220 - 2 Jun 2026

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Abstract

Archaeomagnetic studies provide crucial information on the spatial and temporal evolution of the geomagnetic field as recorded in rocks and archeological artifacts, offering insights into both Earth’s magnetic evolution and past geological and human activities. Measurements of the direction, intensity, and relative variations [...] Read more.

Archaeomagnetic studies provide crucial information on the spatial and temporal evolution of the geomagnetic field as recorded in rocks and archeological artifacts, offering insights into both Earth’s magnetic evolution and past geological and human activities. Measurements of the direction, intensity, and relative variations in the Earth’s Magnetic Field (EMF) are performed using sensitive magnetometers. Among these, induction magnetometers exploit Faraday’s law of electromagnetic induction to measure magnetic fields with high precision. In this work, we present a comparison between two different configurations of Helmholtz-based induction magnetometers carried out through the analysis of the magnetic field distribution obtained through analytical simulations. The study examines both the uniformity and intensity of the magnetic fields produced by each configuration, highlighting the influence of coil geometry on field homogeneity and sensitivity. The results reveal differences between the two configurations, providing important insights for optimizing magnetometer design, improving measurement accuracy, and facilitating analytical procedures in archaeomagnetic research. Full article

(This article belongs to the Section Geophysics)

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19 pages, 4153 KB

Open AccessArticle

Strength Evolution of Lunar Highland Regolith Simulant LHS-1E with Moisture Content: Insights from Compressive, Shear, and Indirect Tensile Tests

by Gal-Erdene Battsengel, Noune Melkoumian, David Harvey and Rini Akmeliawati

Geosciences 2026, 16(6), 219; https://doi.org/10.3390/geosciences16060219 - 1 Jun 2026

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Abstract

The Artemis program led by NASA aims to establish a sustained human presence at the lunar south pole, increasing the need to characterise the mechanical behaviour of polar regolith, particularly within the highland terrains that dominate the lunar crust. This study investigates the [...] Read more.

The Artemis program led by NASA aims to establish a sustained human presence at the lunar south pole, increasing the need to characterise the mechanical behaviour of polar regolith, particularly within the highland terrains that dominate the lunar crust. This study investigates the compressive, shear and tensile strengths of the frozen lunar highland simulant LHS-1E under controlled moisture contents of 5–13 wt%, representing ice-bearing conditions reported in permanently shadowed regions. Freezing serves as a controlled terrestrial proxy for assessing ice-cemented behaviour, although full lunar vacuum and cryogenic conditions are not replicated. Results show systematic strengthening with increasing moisture content. Namely, the unconfined compressive strength increased from 1.09 MPa to 6.31 MPa, the Young’s modulus from 66 MPa to 238 MPa, the friction angle from 35° to 45°, and the tensile strength from 286 kPa to 463 kPa, while the cohesion remained between 6 and 8 kPa and the Poisson’s ratio decreased from 0.19 to 0.09. These findings capture and quantify the mechanical transition from friction-dominated to ice-bonded granular behaviour and provide strength bounds relevant to infrastructure development and excavation in ice-bearing lunar polar regolith. Full article

(This article belongs to the Topic Advances in Mining and Geotechnical Engineering)

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19 pages, 3974 KB

Open AccessArticle

Robust Attenuation Estimation of Microseismic Waves in Geotechnical Engineering

by Xinhao Zhu and Bingrui Chen

Geosciences 2026, 16(6), 218; https://doi.org/10.3390/geosciences16060218 - 31 May 2026

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Abstract

Accurate calculation of microseismic wave attenuation in engineering remains challenging because of the high noise levels and short durations of microseismic signals. The conventional methods applied to the calculation of microseismic wave attenuation are often very ineffective and do not yield good attenuation [...] Read more.

Accurate calculation of microseismic wave attenuation in engineering remains challenging because of the high noise levels and short durations of microseismic signals. The conventional methods applied to the calculation of microseismic wave attenuation are often very ineffective and do not yield good attenuation patterns. Hence, this study improves conventional algorithms and uses body wave data to calculate the quality factor Q value, including both regression analysis and spectral ratio methods. A fixed-length S-window is adopted, and a multitaper spectral algorithm is employed to optimize spectral estimation. The improved method is applied to process microseismic data obtained from two projects. The results demonstrate that the magnitude of the Q values is consistent with the geological conditions on site. Compared to the results before improvement, the optimized results exhibit high stability and significantly improved resolution of the Q values. The results also show a pronounced minimum in Q over the analyzed frequency range, indicating strong frequency-dependent behavior. The improved method provides more stable Q estimates for short-duration records affected by noise and limited spectral resolution. Full article

(This article belongs to the Topic Control Mechanisms and Technological Applications for Surrounding Rock in Deep Mine Roadways)

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21 pages, 13523 KB

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The Paleogeographic Mapping of the Middle Liassic in the Western Edge of the Central High Atlas (Morocco): A Contextualized Educational Approach Within the M’Goun Geopark

by Hafid Chafiki, Brahim NaitOuacha, Badya Lage, Paulo Pereira, Fatima El Bchari and Abdellatif Souhel

Geosciences 2026, 16(6), 217; https://doi.org/10.3390/geosciences16060217 - 31 May 2026

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Abstract

This study analyzes the educational and scientific potential of paleogeographic reconstruction as a contextualized geoscience teaching tool within the UNESCO Global Geopark of M’Goun (Central High Atlas, Morocco). It addresses a major limitation of Moroccan geology curricula, which mainly rely on generalized paleogeographic [...] Read more.

This study analyzes the educational and scientific potential of paleogeographic reconstruction as a contextualized geoscience teaching tool within the UNESCO Global Geopark of M’Goun (Central High Atlas, Morocco). It addresses a major limitation of Moroccan geology curricula, which mainly rely on generalized paleogeographic models disconnected from local geological realities and field evidence. The Ouaouizaght sector, characterized by a continuous Jurassic–Cretaceous sedimentary succession and well-preserved Middle Liassic facies, was selected as a representative case study for developing an integrated field-based educational framework. The methodological approach combines cartographic analysis, geological field observations, structural interpretation, and GIS-based spatial synthesis. Field investigations conducted along a northwest–southeast transect enabled the characterization of carbonate platform, slope, and distal hemipelagic environments. Meanwhile, they identified tectonic controls influencing facies organization and basin geometry. The integration of lithostratigraphic, paleoenvironmental, and structural data led to the reconstruction of a coherent paleogeographic model for the western edge of the Central High Atlas during the Middle Liassic. The main target audience of this research is Life and Earth Sciences (LES) teachers, both in initial training and continuing professional development, and indirectly secondary school students. This study highlighted the pedagogical value of combining fieldwork, spatial reasoning, and geological interpretation to support inquiry-based and contextualized geoscience education. Full article

(This article belongs to the Special Issue Earth System–Society Nexus: Geoheritage and Geopark Practices)

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22 pages, 9337 KB

Open AccessArticle

Subducting Slab—Upper Plate Configuration, and Three-Dimensional Thermal Structure of Central-Southern Peru

by Antonella Megna, Stefano Mazzoli and Stefano Santini

Geosciences 2026, 16(6), 216; https://doi.org/10.3390/geosciences16060216 - 30 May 2026

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Abstract

The study investigates the three-dimensional architecture and thermal structure of the Central Andes in centralsouthern Peru, highlighting the interplay between basement structure, Moho geometry, slab configuration, and thermal properties. Basement structural highs and lows acted as zones of weakness that localized deformation during [...] Read more.

The study investigates the three-dimensional architecture and thermal structure of the Central Andes in centralsouthern Peru, highlighting the interplay between basement structure, Moho geometry, slab configuration, and thermal properties. Basement structural highs and lows acted as zones of weakness that localized deformation during Andean shortening. The Moho exhibits significant lateral heterogeneity, reflecting the combined effects of subduction processes, crustal shortening, magmatic underplating, and lower crustal flow or delamination. Its geometry provides key constraints on crustal thickness, seismic structure, and lithospheric dynamics. The subducting Nazca Plate shows strong along-strike variations in dip and continuity, influenced by plate kinematics and features such as the Nazca Ridge. These variations control mantle wedge development, arc magmatism, and deformation patterns in the overriding plate, contributing to the segmentation of the Andes. Steepslab segments promote mantle melting and volcanic activity, whereas flat-slab regions suppress magmatism. Consistent with these tectonic controls, Qs values increase from northwest to southeast, reflecting a transition from flat-slab conditions with low heat flow and limited geothermal activity to steep subduction zones characterized by active magmatism, elevated heat flow, and significant geothermal potential. This spatial variation underscores the strong coupling between slab geometry, thermal structure, and surface geothermal expression. Full article

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26 pages, 14233 KB

Open AccessArticle

Petrographic and Geochemical Evidence from the Jatunyacu River Outcrop, Central Abitagua Batholith, Ecuadorian Amazon: Preliminary Constraints on Magmatic Evolution and Arc Affinity

by Cindy Vera-Jaramillo, Oswaldo Guzmán, Dayana Vera, Carlos Correa-Jaramillo, Christian Coral, Renato Gonzalez, Corina Campos and John E. Soto Luzuriaga

Geosciences 2026, 16(6), 215; https://doi.org/10.3390/geosciences16060215 - 29 May 2026

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Abstract

The Abitagua batholith is a 120 km long plutonic body located in the northern sub-Andean zone of Ecuador. Despite its size, previous studies have focused on its northern and southern sectors, leaving the central sector uncharacterized. This study presents the first petrographic and [...] Read more.

The Abitagua batholith is a 120 km long plutonic body located in the northern sub-Andean zone of Ecuador. Despite its size, previous studies have focused on its northern and southern sectors, leaving the central sector uncharacterized. This study presents the first petrographic and geochemical evidence from a single outcrop exposed along the Jatunyacu River, in the central part of the Abitagua Batholith, in order to understand its magmatic evolution and tectonic affinity. Petrographically, the dominant lithology is an equigranular monzogranite. The fractured zones show localized hydrothermal alteration, including epidote, sericitization of plagioclase, and chloritization of biotite. Subordinate bodies include tonalitic enclaves, felsic dikes, and an andesitic dike. Geochemically, the studied sector shows a calc-alkaline affinity, peraluminous character, and a volcanic arc granite (VAG) signature broadly consistent with I-type granitoids formed in a continental arc related to subduction. Samples from fractured zones show small shifts toward the S-type field in the K₂O vs. Na₂O diagram, attributed to hydrothermal alkali mobility rather than primary magmatic variation, as supported by petrographic evidence. Multi-element normalized diagrams reveal distinct signatures among subordinate bodies: tonalitic enclaves show strong enrichment in mafic components and Nb, suggesting a primitive mafic source; felsic dikes display enrichment in incompatible elements (Nb, Rb) consistent with evolved residual melts; and the andesitic dike exhibits the most primitive composition with apparent minimal interaction with the felsic host. These are interpreted as evidence of a complex magmatic evolution involving mafic recharge, magma mixing, late injection of residual melts, and localized hydrothermal alteration. Comparison with previous studies suggest that the studied outcrop records an arc signature similar to that reported for the northern and southern sectors, although further work is needed to confirm the extent of this affinity across the central sector. Full article

(This article belongs to the Section Geochemistry)

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