Geosciences doi: 10.3390/geosciences16060239

Authors: Elena A. Kasatkina Oleg I. Shumilov Dmitry V. Makarov

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.

Geosciences doi: 10.3390/geosciences16060238

Authors: Athena Coustenis

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.

Geosciences doi: 10.3390/geosciences16060237

Authors: Alessio Rubino Barbara Frigo Bernardino M. Chiaia

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.

Geosciences doi: 10.3390/geosciences16060236

Authors: Karl-Erich Lindenschmidt Joyce Lutterodt Derrick Amoah Yeboah Michael Lynch Arash Rafat Sergio Gomez Robert Briggs

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.

Geosciences doi: 10.3390/geosciences16060235

Authors: Andrey Melnikov Ze Zhang Tatiana Romanis Leonid Gagarin Viktor Rochev

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.

Geosciences doi: 10.3390/geosciences16060234

Authors: Jia Wang Xiaoqin Liu Pengfei Zhang Jichang Yang Fengjie Li

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.

Geosciences doi: 10.3390/geosciences16060233

Authors: Kekun Li Ruidong Yang Yazhou Fan Jianhan Huang Pengyuan Chen

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% FeOt. 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.

Geosciences doi: 10.3390/geosciences16060232

Authors: Saskia Köhler Daniel Koehn

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.

Geosciences doi: 10.3390/geosciences16060231

Authors: Tianhao Bai Guan Qin Mohamed Y. Soliman

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.

Geosciences doi: 10.3390/geosciences16060230

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

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 εHf(t) values of synmagmatic zircons from Mesozoic igneous rocks and corresponding whole-rock εNd(t) datasets to generate coupled Hf–Nd isotopic mappings. The results show that εHf(t) values range from −19.3 to +11.6 (TDM2: 464–2419 Ma) and εNd(t) values are from −12.2 to +5.0 (TDM2: 580–2008 Ma) in the southern part of South China Block. High εHf(t) (−4~+11.6) and εNd(t) (−4~+5.0) zones are concentrated along the Honghe Fault and Chenzhou–Linwu Fault systems, while low-value Hf–Nd isotopic (εHf(t) = −10.6 to −4; εNd (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 εHf(t)-εNd(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 εHf(t)-εNd(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).

Geosciences doi: 10.3390/geosciences16060229

Authors: Spencer G. Lucas

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.

Geosciences doi: 10.3390/geosciences16060228

Authors: Lisheng Gao Guanghui Wang Guangshu Yang

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.

Geosciences doi: 10.3390/geosciences16060227

Authors: Shayne Klisura Francis J. Sousa Paul O’Sullivan

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.

Geosciences doi: 10.3390/geosciences16060226

Authors: Julien Gargani

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.

Geosciences doi: 10.3390/geosciences16060225

Authors: Sofia De Gregorio Marco Camarda Giorgio Capasso Roberto M. R. Di Martino Antonino Pisciotta Vincenzo Prano Giuseppe M. Riolo

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.

Geosciences doi: 10.3390/geosciences16060224

Authors: Peng Su Shouzhi Hu Honghan Chen Simeng Cui Yangfan Guo

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/PUCC, 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.

Geosciences doi: 10.3390/geosciences16060223

Authors: Peng Li Zichuan Wang Yuqi Liu Jiaxin Yang Xiao Zhang Zemin Xue Dongtun Hao Pengju Qin

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 Cc and secondary compression index Cα rose as vertical stress increased, and Cα 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.

Geosciences doi: 10.3390/geosciences16060222

Authors: Abdillah Mirzam Abdurrachman Yan Rizal Nia Kurniasih Firman Sauqi Nur Sabila

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.

Geosciences doi: 10.3390/geosciences16060221

Authors: Anthony Romilio

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.

Geosciences doi: 10.3390/geosciences16060220

Authors: Giulio Giovannetti Sonia La Felice Claudia Principe

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.

Geosciences doi: 10.3390/geosciences16060219

Authors: Gal-Erdene Battsengel Noune Melkoumian David Harvey Rini Akmeliawati

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.

Geosciences doi: 10.3390/geosciences16060218

Authors: Xinhao Zhu Bingrui Chen

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.

Geosciences doi: 10.3390/geosciences16060217

Authors: Hafid Chafiki Brahim NaitOuacha Badya Lage Paulo Pereira Fatima El Bchari Abdellatif Souhel

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.

Geosciences doi: 10.3390/geosciences16060216

Authors: Antonella Megna Stefano Mazzoli Stefano Santini

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.

Geosciences doi: 10.3390/geosciences16060215

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

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.

Geosciences doi: 10.3390/geosciences16060214

Authors: Rafid al Khoury Cor Kasbergen

Analytical solutions for contaminant transport in porous media are important for understanding subsurface processes and validating numerical models. However, conventional Laplace-transform-based approaches often face difficulties in handling realistic transient boundary conditions and typically result in challenging inverse formulations that require computationally intensive convolved integration. To address these limitations, this paper presents a Fourier-FFT analytical framework for solving the well-established one-dimensional advection–dispersion–reaction (ADR) equation in homogeneous and heterogeneous porous domains. The proposed Fourier-FFT approach enables straightforward mathematical formulation, rapid computation, and incorporation of realistic transient boundary conditions beyond idealized step or impulse inputs. Verification against a Laplace-based analytical solution for a homogeneous domain and a finite element solution for a dual-permeability domain show good agreement, confirming the accuracy of the method. Parametric analyses further demonstrate that the framework captures the expected physical behaviour of contaminant transport under varying hydrogeological and reaction conditions.

Geosciences doi: 10.3390/geosciences16060213

Authors: Jhaber Dahsan Yacoub Breno Padovezi Rocha José Augusto di Lollo Mauro Mitsuuchi Tashima

The rapid advance of urbanization and social development has intensified the complexity of engineering projects, especially where geotechnical constraints play a decisive role. Expanding cities increasingly occupy areas with challenging soil conditions, such as collapsible soils, which demand careful investigation and innovative design solutions. These geotechnical factors directly influence the safety, durability, and cost-effectiveness of infrastructure, making integrated analysis essential from the earliest stages of project planning. An experimental study with lateritic sandy soil was performed to investigate the effect of rice husk ash (RHA) on collapsible soil behavior. Collapsible soils occur worldwide in diverse geological and geotechnical conditions and can result in costly structural damage. Due to intense leaching during tropical weathering, lateritic soil structures and textures show high collapse potential, with substantial volume reduction under constant stress when wetted. The investigated soil was collected in a tropical area of the Paraná Basin (Brazil) and is considered representative of large regions with similar geological conditions. Soil samples and mixtures (2, 4, 6, 8, 10, 12, and 14 wt.% RHA) were tested using standard geotechnical procedures such as grain size distribution and compaction tests. Collapsibility behavior (i.e., collapse potential, CP) was measured using oedometer tests. Tests were conducted with realistic compaction degrees (~80%), representing conditions found in nature and in civil works involving collapsible soils. The results show that RHA can considerably reduce the collapse potential of lateritic fine sandy soils, mainly due to its packing effect, which reduces volumetric changes with increased moisture. The CP was significantly reduced from 9.83% to 1.93% in the mixture containing 14% RHA.

Geosciences doi: 10.3390/geosciences16060212

Authors: Zengan Deng Ruiyao Li

The transport and distribution of Scomber japonicus larvae significantly affect their habitat and population dynamics. Understanding these processes is crucial for developing effective fishing and conservation strategies. However, the interannual variability of the Kuroshio path introduces both complexity and uncertainty. This study implemented a coupled ocean–biophysical model to simulate and analyze the transport of S. japonicus larvae in the Pacific Ocean south of Japan across three Kuroshio path modes, including the offshore non-large-meander (ONLM), nearshore non-large-meander (NNLM), and typical large-meander (TLM) paths. Two transport scenarios, passive drift (PD) and active swimming (AS), were considered in the simulations. The simulated results presented a comprehensive analysis of the distribution, connectivity, and transport distances of S. japonicus larvae. These findings highlighted the significant influence of biological behavior on larval transport, notably reducing transport distances and shifting the distributions northward. This allowed larvae to actively migrate to areas with higher zooplankton aggregation. Larvae released from the western and nearshore spawning grounds around Southern Kyushu–Shikoku were mainly transported to the central nursery region between 132.5° E and 140° E, whereas larvae released from the eastern spawning grounds were mainly distributed in the eastern nursery region east of 140° E near the Kuroshio Extension. These patterns suggest that nursery areas 2 and 3 may warrant further attention in future spatial management assessments, particularly when considering larval transport under different Kuroshio path modes. This study provides valuable insights into the transport and distribution mechanisms of S. japonicus larvae, offering critical guidance for the conservation of fishery resources and the promotion of sustainable fishery management.

Geosciences doi: 10.3390/geosciences16060211

Authors: Richard Henry Worden Auwalu Yola Lawan

Handheld X-ray fluorescence (HHXRF) scanners generate rapid, low-cost geochemical datasets from core and cuttings, yet their potential for quantitative reservoir characterisation remains largely unrealised, partly because standard multivariate methods are inappropriate for the compositional nature of geochemical data. Here we test, for the first time within a compositional data analysis framework, whether centred log-ratio-transformed HHXRF element compositions can simultaneously predict plug-scale porosity, directional permeability and facies in a siliciclastic reservoir in a continuously cored Brent Group well from the Northern North Sea. The cored interval was logged for facies, sampled for routine core analysis, and analysed by HHXRF at plug sample positions. Sixteen consistently detectable elements were transformed using centred log-ratios to respect the compositional nature of the data, and four Random Forest models were trained: regression models for porosity, horizontal permeability and vertical permeability and a seven-category facies classifier. Models were evaluated using out-of-bag predictions, residual analyses, class-wise reliability metrics and permutation-based variable importance. The models reproduce porosity and permeability with high coefficients of determination (R2 > 0.95) and low errors relative to observed ranges and achieve facies classification with substantial agreement (κ = 0.705), with best performance in clean sandstone facies. Predictive skill is dominated by a consistent subset of elements (notably Ca, Ti, Si, V, Zn and Rb), linking bulk composition to mineralogy, depositional texture and diagenetic modification. These results demonstrate that compositional data from HHXRF alone can quantitatively recover key reservoir attributes and facies architecture at plug scale, establishing bulk geochemistry as a robust proxy for reservoir quality in quartz-rich, moderately buried siliciclastic reservoirs. The workflow provides a methodological template for integrating compositional geochemistry with machine learning in subsurface characterisation and, pending multi-well validation, offers a route to cost-effective prediction of porosity, permeability anisotropy and facies from cuttings or high-resolution core scanning. The workflow has direct application to geocellular model population in carbon and hydrogen storage sites, geothermal reservoirs and conventional hydrocarbon fields.

Geosciences doi: 10.3390/geosciences16060210

Authors: Anna D. Kwablah Emmanuel Salifu Aritra Banerjee

Drying in granular porous media is governed by coupled thermal and hydraulic processes that can be substantially modified by biological activity. This proof-of-concept study investigated how surface heating and fungal colonization influence the evolution of thermal conductivity (λ) and matric suction (ψ) as functions of volumetric water content θv in Ottawa 20/30 sand. Four treatments were examined: sterile sand at 22 °C (T1), sterile sand at 28 °C (T2), fungal-amended sand with 10% biomass and 9-day incubation (T3), and fungal-amended sand with 15% biomass and 30-day incubation (T4). Samples were instrumented to monitor θv, λ, and ψ during controlled evaporation using synchronized HYPROP and VARIOS measurements on the same specimen. Across all treatments, λ increased with θv (that is, λ declined as drying progressed), and ψ reflected the transition from hydraulically connected to disconnected pore water. Heating shortened the drying time but did not materially change the form of the λ–θv relationship or generate strong matric gradients in sterile sand. Low biomass (T3) produced thermal and hydraulic responses comparable to the heated sterile control (T2), indicating limited pore-scale modification at early colonization. In contrast, high biomass (T4) widened the effective saturation range, maintained low and nearly uniform ψ across depth, and exhibited the steepest mid-range λ–θv slope with a higher peak λ (~4 Wm−1K−1), consistent with hyphae and extracellular polymers stabilizing thin water films. A soil water retention curve (SWRC) analysis using the van Genuchten model further indicated increased water retention and delayed air entry with an increasing fungal biomass, with approximate air-entry values increasing from ~1.8 kPa (T3) to ~3.0 kPa (T4). Tests were terminated upon tensiometer cavitation rather than complete gravimetric dryness, constraining observations at very low θv. These results indicate that heating primarily affects the rate of drying, whereas fungal networks alter the pathway by preserving hydraulic and thermal continuity at relatively high θv. This behavior suggests a potential role of bio-mediated structuring in influencing near-surface thermo-hydraulic processes relevant to energy foundations, soil covers, and desiccation management in biologically active or bio-engineered soils.

Geosciences doi: 10.3390/geosciences16060208

Authors: Hang Li Zhongkai Xue Jianxiang Luo Cheng Ma Kang Yan Li Chen Haiyang Wang Xutao Yang Haomin Guo

The lamprophyre dikes and multi-generational pyrite and arsenopyrite developed in the Jinshan gold deposit in the West Qinling metallogenic belt provide critical evidence for understanding the role of mantle-derived magmatism in gold mineralization processes. In this study, we conducted zircon U-Pb dating of lamprophyre to constrain the timing of magmatic activity and the mineralization age, and performed EMPA and LA-ICP-MS analyses on sulfides from the main metallogenic stage (Py II–III, Apy II–III) and lamprophyre-hosted pyrite (Py L) to constrain the formation conditions and metal sources of the Jinshan deposit. The results show that the mantle-derived magmatism represented by lamprophyre yields an age of 206 ± 2 Ma, which provides a lower-limit constraint on the timing of gold mineralization, corresponding to the subduction-to-extension transition period in the region. Stage II mineralization occurred at 270–320 °C with logƒS2 of −9 to −5, dominantly as Au-HS complexes, indicating medium-temperature hydrothermal conditions with low sulfur fugacity, consistent with microscopic mineral assemblages and thermodynamic simulations. Systematic δ34S variations reveal: stage II values (9.24–5‰) indicate granitic/Devonian sedimentary sources; Py L values (2.19–3.6‰) reflect mantle contributions; stage III signatures (−2.3–1.93‰) record late meteoric water mixing. Complementary δ56Fe data show that Py II (0.2–0.3‰) and Py L (0.58–0.68‰) preserve magmatic fingerprints, while negative values of Py III (−2.29 to −0.71‰) document increasing sedimentary Fe incorporation. Combined with geochronology, S-Fe isotopes, and physicochemical constraints, we propose that the Jinshan gold deposit formed in a tectonic setting transitioning from compression to extension during the Late Indosinian (ca. 237–201 Ma). Mineralization was initiated by the partial melting of the metasomatized mantle, where hydrous magmas efficiently extracted Au and volatiles. These components ascended through transcrustal faults, with Au partitioning into exsolved fluids that precipitated gold through immiscibility and boiling in secondary structures.

Geosciences doi: 10.3390/geosciences16060209

Authors: Ximena Michelle Trejo-Martínez Omar Delgado-Rodríguez José Alfredo Ramos-Leal Héctor José Peinado-Guevara Simón Eduardo Carranco-Lozada

In central Mexico, ground failure and subsidence have accelerated, as evidenced by the Villa de Reyes graben, particularly at the El Hundido Dam, with the primary cause attributed to groundwater overexploitation. This study integrates electromagnetic profiling (EMP), electrical resistivity tomography (ERT), and transient electromagnetic (TEM) surveys to determine the origin of the fractures at the El Hundido Dam. Based on the TEM survey, a geoelectric section was obtained that models the depth and morphology of the igneous bedrock. At the El Hundido Dam, the igneous basement exhibits convex deformation due to transpressional stresses, which favours the formation of a positive flower-type fault structure. Deformations caused by the basement topography and the fault system are evident in the 100 m-thick Quaternary sequence, as revealed by ERT studies. ERT and EMP surveys showed the presence of a clayey layer that acted as a barrier to surface water infiltration, allowing it to be stored in the past, and which is now destroyed by fractures. Although the drop in the water table has contributed to polygonal cracking, hydro-compaction, and ground subsidence, local tectonics is the primary factor controlling subsoil faulting at the El Hundido Dam.

Geosciences doi: 10.3390/geosciences16060207

Authors: Zongheng Tao Wei Tang Chuan Li Wengang Dang

Understanding the movement behavior of upper blocks along rock joints or weak planes is crucial for the geological hazard forecast and prediction. This paper presents experimental and numerical investigations of a saw-tooth joint under shear and normal load conditions. Multi-stage direct shear tests under different normal load conditions were conducted using a direct shear box apparatus. The reverse dilation behavior of the upper specimen was observed by measuring the normal displacement at the four corners of the upper block. Laboratory test results show that, under lower normal loads, the normal displacement of the upper specimen on the applied shear force side initially decreases (settlement), while the settlement reverses to heave (dilation) when the shear displacement reaches a certain value. However, the settlement reverse behavior does not occur under large normal loads. Corresponding numerical simulation confirms that this settlement reversal is controlled by the specimen fracturing. The saw-tooth asperities are sheared off under a large normal load, while the upper specimen climbs along the slope of the bottom specimen under lower normal loads. Consequently, the changes in contact area, interface normal stress, interface shear stress, and normal displacement of the joint differ significantly between large and low normal load conditions. This research deepens our understanding of the shear-induced dilation and fracture behavior of saw-tooth joints, and the results can provide guidelines for evaluating the stability of geological rock mass.

Geosciences doi: 10.3390/geosciences16050206

Authors: Xianxiang Wang Zefan Hu Shanmei Li Qing Sun

Vertical electric sources serve as an effective method for identifying deep hydrocarbon reservoirs. This involves the ability to generate transverse magnetic fields, concentrate currents at reservoir interfaces, and effectively emphasize resistivity anomalies in late-time domains. Marine geological conditions are often complex, marked by rugged topography and intricate structures. This complexity results in highly complicated electromagnetic response features, presenting significant challenges for data interpretation. This research employs the Time-Domain Finite Element Method (TDFEM) using unstructured meshes to accurately discretize complex geological models. Through the formulation of TDFEM equations, we successfully performed three-dimensional forward modeling of VED transient electromagnetic (VSTEM) responses in intricate geological environments. An analysis was conducted on the diffusion mechanisms and spatial distribution characteristics of VSTEM fields located beneath the seabed. A comparative analysis was conducted on the resolution capabilities of different fields stimulated by horizontal and VED sources. The findings show that the Ex provides enhanced boundary identification for the lateral extent of targets, whereas the Ez displays the greatest anomaly contrast, highlighting its exceptional results in anomaly detection. We investigated how complex seabed topography and geological structures affect the resolution of hydrocarbon targets. The research indicates that complex topography significantly influences electromagnetic fields; however, the proposed method can still effectively identify resistive hydrocarbon reservoirs, even in intricate model scenarios, thus confirming its reliability in challenging marine environments.

Geosciences doi: 10.3390/geosciences16050205

Authors: Qian Liu Mingxin Yue Lianghao Guan

Landslides cause significant casualties and economic losses worldwide each year, creating an urgent demand for rapid and reliable volume estimation during emergency response. Conventional approaches often involve trade-offs among accuracy, efficiency, and data availability, particularly when pre-event topographic data are unavailable. This study proposes a novel GIS-based method for rapid landslide volume estimation through sliding surface reconstruction. By integrating open-source geospatial data (post-landslide Digital Elevation Model and landslide boundary KML) with spline interpolation and spatial analysis, the method reconstructs the subsurface sliding surface and calculates volume by comparing this surface with the post-landslide DEM. Applied to the 2019 Shuicheng landslide (Guizhou Province, China), the method yielded a volume estimate of 1.58 × 106 m3, which deviates by only ~5% from official survey data. The entire workflow can be completed within approximately one hour, demonstrating high efficiency, low operational cost, and acceptable accuracy for rapid post-disaster assessment during the critical “golden 72 h”.

Geosciences doi: 10.3390/geosciences16050204

Authors: Akbar Kurniawan Nurrohmat Widjajanti Harintaka

Land subsidence around the gas exploitation area in Sidoarjo Regency, East Java Province, Indonesia, located in the northeastern part of Java Island, has been detected since 2006. This subsidence occurs not only in the vicinity of the Sidoarjo mud eruption but also extends to the Wunut and Tanggulangin areas, where several gas production wells are located. This study identifies land subsidence using integrated geodetic methods, including InSAR (PS-InSAR and SBAS), GNSS, and levelling observations. InSAR provides spatially continuous measurements from satellite radar imagery, while GNSS and levelling observations at control points are used to evaluate and interpret the detected deformation. GNSS provides point-based three-dimensional displacement, whereas levelling offers high-accuracy vertical displacement information. The results show notable differences between the InSAR approaches. PS-InSAR indicates a maximum subsidence of −249.4 mm, with a velocity of −41.01 mm/year, whereas SBAS yields a maximum subsidence of −510.43 mm and a velocity of −86.08 mm/year. GNSS observations indicate an average subsidence rate of −52.2 mm/year during 2020–2022, while levelling results show an average subsidence rate of −205.4 mm/year during 2022–2023. These differences are primarily attributed to variations in spatial sampling, temporal coverage, and the measurement characteristics of each method, particularly under rural and wetland conditions with limited persistent scatterers. Overall, the integration of InSAR, GNSS, and levelling data provides a more comprehensive interpretation of land subsidence and highlights the importance of considering method-dependent uncertainties when comparing deformation results from different geodetic techniques.

Geosciences doi: 10.3390/geosciences16050203

Authors: Hare Ram Timalsina Krishna Kanta Panthi

This study presents a probabilistic seismic fragility assessment of a jointed rock slope by integrating field characterization, incremental dynamic analysis (IDA), and numerical modeling. Dominant joint sets are identified through field mapping, and key discontinuity parameters are estimated for the Barton–Bandis non-linear shear strength criterion. Dynamic simulations are performed using the distinct element method with the continuously yielding (C-Y) joint model to capture progressive shear degradation. Twenty real earthquake ground-motion records are scaled incrementally to perform IDA, with critical block displacement and cumulative joint slip adopted as engineering demand parameters (EDPs). A probabilistic seismic demand model (PSDM) is developed to correlate peak ground acceleration (PGA) with EDPs. Kinematic analysis indicates that planar failure along joint set 1 is the most likely failure mechanism (90% probability), followed by wedge failure along the intersection of joint sets 1 and 2 (52%). Fragility curves are derived for three displacement-based damage states: minor (1 cm), moderate (5 cm), and severe (15 cm). The results demonstrate that seismic deformation is strongly controlled by discontinuity geometry and progressive joint slip, with the slope exceeding the severe damage state at PGA levels as low as 0.4 g, indicating high seismic vulnerability. This highlights the importance of integrating field characterization with dynamic numerical modeling for reliable seismic stability assessment of such discontinuous rock mass. Future work should incorporate larger datasets, in situ testing, and 3D modeling to enhance assessment reliability.

Geosciences doi: 10.3390/geosciences16050202

Authors: Saowapak Buphu Passakorn Pananont Kevin P. Furlong Patinya Pornsopin

The ML4.9 Wang Nua earthquake on 20 February 2019 is the largest earthquake to occur in Lampang Province in the past four decades and identifies the potential seismic hazard of previously unmapped faults in northern Thailand. We reanalyzed this earthquake sequence using waveform-based matched-filter detection and double-difference relocation techniques. The enhanced catalog increases the number of small earthquakes by 2.5 times compared with the official record. It also reveals microearthquakes down to ML–0.3, including a previously unreported foreshock sequence beginning approximately four hours before the mainshock. Relocated hypocenters define an 8 km long, near-vertical N-S striking rupture zone at depths of 0.7–10.6 km. The focal mechanism of the mainshock indicates right-lateral strike-slip motion (strike ~189°, dip ~77°, rake ~–150°), aligned with the kinematics of other extensions of the Phayao Fault Zone. These results indicate that the sequence occurred on a previously unrecognized fault segment. This highlights the importance of high-resolution seismic analysis for improving hazard assessment in regions with concealed fault systems.

Geosciences doi: 10.3390/geosciences16050201

Authors: Denghui Chen Hao Wu Wei Wang Yujie Zhao Huajun Wen Dongming Jiang Xiaotong Sun Fuhao Xiong

The Cretaceous represents a key period in the geodynamic evolution of the Tibetan Plateau and the initial development of its paleotopography. While widespread orogenesis and magmatism associated with the Lhasa–Qiangtang collision are well documented in southern Tibet, coeval magmatic records in northern Tibet are extremely limited, hindering constraints on the deep processes responsible for surface uplift. Zircon U–Pb ages, whole-rock geochemistry, and Sr–Nd–Hf isotopes are presented for two mafic dyke swarms from the East Kunlun Orogen, northern Tibet. The two dyke swarms were emplaced at 91.8 ± 2.0 Ma and 84.8 ± 0.6 Ma, indicating a previously underrecognized episode of Late Cretaceous mafic magmatism in northern Tibet. They are subalkaline tholeiites enriched in LILEs and LREEs, depleted in HFSEs, and characterized by negative Nb–Ta anomalies. Their decoupled Nd-Hf isotopes (εNd(t) = −4.96 to +0.94; εHf(t) = +3.75 to +5.76) indicate derivation from an enriched lithospheric mantle metasomatized by slab-related fluids during Permian-Triassic Paleo-Tethyan subduction. Partial melting modeling indicates that the magmas were generated by low-degree (1–5%) decompression melting of lherzolite within the spinel–garnet transition zone. We propose that these mafic dyke swarms formed in an intraplate extensional setting triggered by far-field stresses associated with the Lhasa–Qiangtang collision, which reactivated lithosphere-scale faults and induced localized mantle melting. These results provide new petrological constraints on Late Cretaceous intracontinental extension in northern Tibet and highlight mafic dyke swarms as key probes for linking lithospheric reactivation to early surface uplift of the Tibetan Plateau.

Geosciences doi: 10.3390/geosciences16050200

Authors: Sebastiano Ettore Spoto

Radon (222Rn) and thoron (220Rn) are widely used to investigate diffuse degassing, fault-zone permeability, hydrothermal circulation, and subsurface unrest, but their signals are not direct proxies for a single process. This manuscript is a critical synthesis and methodological article that develops a reduced inference framework for interpreting radon–thoron observations in volcanic, tectonic, and hydrothermal settings. The framework separates accessible support of the immediate radium parents 226Ra and 224Ra, recoil-scale release into the mobile phase, multiphase transport, geological carrier-gas throughput, and observational closure. It also distinguishes total activity flux from activity concentration and chamber throughput from natural carrier-gas dilution. Synthetic illustrative experiments test the internal behavior of the reduced operator; a concise re-reading of the public Upper Rhine Graben dataset illustrates the limits of concentration-only inference; and published volcanic and hydrothermal examples are used as literature-grounded vignettes. The purpose is not to validate a universal inversion model but to define what can be inferred from different observation packages. The paper, therefore, emphasizes three operational levels: anomaly reporting, mechanism discrimination, and local inversion.

Geosciences doi: 10.3390/geosciences16050199

Authors: Ricardo Morais Lanes Carolina Coelho de Magalhães Grossi Marcelo Greco

This paper presents a practical numerical procedure for the study of structures on foundations subjected to soil consolidation settlements, using the Finite Element Method (FEM) coupled with the Boundary Element Method (BEM). A theoretical application is presented for a structure built on saturated soft soil, employing the Kelvin–Voigt and Boltzmann viscoelastic models. The Kelvin–Voigt model is suitable for situations where uniform or negligible initial settlements are assumed before the onset of soil consolidation, whereas the Boltzmann model allows for the consideration of differential movements, including both immediate and time-dependent displacements. This study shows that, although the same viscoelastic parameters are adopted for both models, the differences in internal forces and resulting displacements can be significant due to the distinct relative stiffnesses. The choice of viscoelastic model directly impacts the prediction of structural behavior. The analyses were conducted considering an iterative coupling between the FEM and BEM systems, using an MATLAB R2024a routine developed by the authors. Despite the differences between the models, the results obtained were consistent with the technical literature, reinforcing the applicability of the proposed procedure.

Geosciences doi: 10.3390/geosciences16050198

Authors: Junmeng Zhao Junzhe Teng Tsaiba Yangzin Hongbing Liu Sen Hu Jihang Li Taijin Su Kangcheng Zhu Tashi Jizong

The Tibetan Plateau, formed by the Indian-Eurasian collision, is dissected by the north-south trending South Tibet Rift system, but the formation mechanism of these rifts within a continuing compressional setting remains debated. Using P-wave receiver functions and joint inversion with surface wave dispersion along a ~230 km broadband seismic profile crossing the Nyima-Tingri Rift (NTR) and Xianza-Dingjie Rift (XDR), we investigated the detailed crustal structure beneath the Himalayan and Lhasa terranes. Our results reveal three key findings: (1) The crustal thickness ranges from 60 to 80 km, with the XDR exhibiting a pronounced Moho uplift (~10 km) beneath the rift axis, whereas the Moho beneath the NTR remains flat and continuous, indicating contrasting evolutionary stages. (2) A mid-crustal low-velocity layer at ~30 km depth is consistently observed west of 87.2° E, suggesting the presence of partial melt or fluids that decouple upper crustal deformation from mantle flow. (3) A prominent intracrustal discontinuity at 50–70 km depth produces a “Moho doublet” pattern; we interpreted this as the subducted Indian lower crust in the Himalayan terrane but as the relict Tibetan Moho in the Lhasa terrane, reflecting progressive northward modification. Collectively, these observations demonstrate that the north-south structures in southern Tibet lack the deep structural characteristics of mature rifts and instead represent an “infant stage” of extension. Their formation is best explained by east-west crustal stretching driven by an ongoing north-south convergence and eastward flow of lower crustal and upper mantle materials rather than by classical lithosphere-scale rifting.

Geosciences doi: 10.3390/geosciences16050197

Authors: Yongxu Mei Jinning Zhang Yuan Neng Wenjie Wang Ke Xu Honghan Xiang Yanna Wu Peiye Liu

Salt-bearing foreland fold–thrust belts represent a critical tectonic system for ultra-deep hydrocarbon exploration. In the Kalasu structural belt of the Kuqa Depression—characterized by the “four extremes” of ultra-high temperature, pressure, salinity, and stress—conventional single-detachment models fail to adequately resolve the complex subsalt structures. To address this challenge, this study integrates high-resolution 3D seismic data, field outcrop observations, well logs, balanced cross-sections, and particle image velocimetry (PIV)-monitored physical modeling to propose a ramp–flat multi-detachment model. Our results demonstrate that deformation is governed by four regional detachment horizons: gypsum-salt layers, thick mudstones, coal-bearing strata, and the basement, which vertically partition the basin into six tectonic units: supra-salt, salt, subsalt, supra-coal, coal, and sub-coal basement. The structural architecture is controlled by five key factors: (1) paleo-uplift geometry, (2) distance from the South Tianshan orogenic front, (3) orientation of basin-bounding faults, (4) regional stress regime (pure compression versus transpression), and (5) rheological contrasts among detachment layers. The kinematic evolution follows a progressive sequence: basement-involved thrusting → multi-level ramp–flat detachment folding → cover detachment. Three primary trap levels are identified—subsalt, supra-coal, and sub-coal—hosting six distinct trap styles: pop-up anticlines, imbricate faulted anticlines, structural triangle zones, fault-bend fold anticlines, supra-coal anticlines, and inter-coal/sub-coal anticlines. Notably, under transpressional stress, oblique paleo-uplifts control the formation of enigmatic “fish-scale” arcuate trap belts composed of fault-bend fold anticlines.

Geosciences doi: 10.3390/geosciences16050196

Authors: May Samir Saleh Sherien Fadhel Taghreed Khaleefa Mohammed Ali

Sediment accumulates behind dams, thereby reducing their operational efficiency. In response to this issue, hydraulic flushing is considered an effective solution for its removal. A numerical model is used to provide a deep understanding of this process and its dynamics. It acts as a low-cost virtual laboratory that eliminates the need for costly field experiments and provides a precise understanding of sedimentation and flushing behavior. This study used numerical modeling to examine sediment deposition in the Tigris River upstream of the Samarra Barrage. Within the iRIC framework, two models were used: NaysCUBE and Nays2DH. NaysCUBE is a three-dimensional solver that provides detailed simulations of partial gate openings and vertical flow distribution. This capability is crucial for a realistic analysis of the flushing process. Nays2DH is a two-dimensional solver that simulates full gate openings and captures general flow patterns. Results showed that sediment deposits were mostly concentrated within the first kilometer upstream of the dam, particularly when backwater effects caused the outflow to be lower than the inflow. Different gate operation schemes produced varied results: some configurations improved the balance between sediment movement and water flow, whereas others caused local erosion and uneven scouring. Results showed that lowering the water level at the barrage by 1 m increases shear stress on the riverbed by up to 25%, thereby improving the river’s ability to carry sediment without the need for additional discharge. High-discharge flushing operations are no longer feasible because of the reduced flow in the Tigris River since the operation of the Ilisu Dam in Turkey. This study recommends maintaining low water levels at the barrage with frequent and reasonable maintenance operations by partially opening the gates (40–60%). This strategy maintains a balance between the required water storage and sediment control, thereby ensuring the long-term sustainability of the hydraulic structure and the river ecosystem.

Geosciences doi: 10.3390/geosciences16050195

Authors: Danlami Ibrahim Tatsuya Nemoto Venkatesh Raghavan

In many African nations, including Nigeria, groundwater remains the most readily available source of clean water. However, finding and developing these resources in heterogeneous terrain, such as the Federal Capital Territory (FCT), Abuja, is challenging due to the uneven distribution of the aquifers and complex geological settings. Using a GIS-based machine learning approach that incorporates surface and subsurface hydrogeological parameters, this study defines groundwater potential zones (GWPZ). Nine conditioning factors were derived from remote sensing, geophysical and climatic datasets. Aquifer thickness, depth to bedrock, geology, rainfall, slope, LULC, lineament density, drainage density and distance from river were among these variables. Three machine learning models: Extreme Gradient Boosting (XGBoost), Support Vector Machine (SVM) and Random Forest (RF) were trained and validated using 2410 borehole records (productive and abortive). Hold-out validation (80:20), 10-fold cross-validation, ROC-AUC, and confusion matrix were used to assess each model’s performance. The ensemble models outperformed the SVM, achieving higher predictive accuracy and better generalisation (XGBoost: 0.89, RF: 0.88 and SVM: 0.87). The generated maps categorised the study area into five GWPZs: very high, high, moderate, low and very low. These findings provide a scientific foundation for groundwater exploration and sustainable water resource management in the study area.

Geosciences doi: 10.3390/geosciences16050194

Authors: Hong Zhuo Si Li Shaohua Li Zhangying Han Xiuling He Guishan Li Jianwei Ren

In response to the challenges in monitoring the production profile during the development of the Qingcheng shale oil field in the Changqing Oilfield, this study systematically investigates the application mechanism and practical effectiveness of Distributed Temperature Sensing (DTS) technology for dynamic monitoring in horizontal wells. By establishing a coupled model of fracture–matrix dual-porosity media flow and wellbore thermodynamics, which integrates mass, momentum, and energy conservation equations solved via the finite difference method, an interpretation method for the production profile based on the Joule–Thomson effect is proposed. The model was calibrated using shut-in temperature data and validated by comparing simulated temperature profiles with DTS measurements under constant-rate production. Field tests conducted in six horizontal wells in the Qingcheng oil field enabled the quantitative analysis of cluster-level production contributions along the horizontal section, with a water-producing zone localization accuracy of ±3.5 m. The results indicate that shale oil wells exhibit a non-uniform production characteristic of “high at the front and low at the rear” during the early production stage, where the production contribution from fully fractured segments can be up to 2.8 times that of adjacent segments. Inversion of the fiber-optic monitoring data reveals that differences in the conductivity of hydraulic fractures are the primary cause of flow heterogeneity. This research provides a theoretical foundation and technical support for the efficient development of shale oil, contributing to the transition of China’s continental shale oil development from “experience-driven” to “data-driven.”

Geosciences doi: 10.3390/geosciences16050193

Authors: Bo Zheng Jianwei Kang Guilai Yang Yongjie Qiu Zhan Zhao

The upper late Triassic Xujiahe Formation (T3x) is the most important terrigenous stratum gas province, with accumulated gas production over 3TCF, technical recoverable resources at 18TCF (500BCM) and geological reserve close to 50TCF (1TCM), in the Sichuan Basin (SCB). In the Southern Plateaus of SCB (SP-SCB), Upper Yangtze Region also has the matching T3x, i.e., Baiguowan/T3b, often located in the folded smaller basins, i.e., Xichang Basin in this paper, which has not been explored as much. Past study of source rocks in T3x already found extracts to have non-terrestrial-humic biomarker values, and this work further adds the gas composition and isotope data from the T3x formations already producing and the T3b formation in two exploratory wells in the SPSCB, i.e., the Xichang basin/Zhaojue sub-basin, where oil stains and bubbled oil and bitumen are found in cores. Based on the geochemical analysis results of gas isotopes and biomarkers T3x/T3b (in SP-SCB) formations, this paper discusses the sedimentary environment and thermal evolution of source rocks of T3x & T3b, and possible transformation of the oil and gas generated, and the potential to find oil and gas in the T3x and T3b formations. We use latest isotope-maturity–wetness–Gas to Oil Ratio (GOR) templates for gas isotope data interpretation, and show the difference between T3x and T3b, and discuss the possibility of finding liquid in T3x and T3b. The conclusion is that T3b in Xichang basin should have oil and gas, and estimated Gas to Oil ratio is about 3~5:1 on a barrel of equivalent (BOE) basis.

Geosciences doi: 10.3390/geosciences16050192

Authors: Kirill Danilovskiy Anastasia Glinskikh Aleksey Petrov

Spontaneous potential (SP) logging remains a widely used method in well geophysics. However, its interpretation is often limited by simplified physical models and correction charts that do not fully account for the processes governing SP generation, particularly in shaly and heterogeneous formations. In this study, we develop a finite element-based algorithm for modeling SP responses in complex near-wellbore environments, with the aim of providing a more physically consistent framework for interpretation. The proposed algorithm is based on the numerical solution of the Poisson equation with electrochemical source terms, incorporating the cation transport number to describe diffusion–adsorption processes and allowing for smooth variations in formation resistivity, fluid properties, and shale content. The numerical implementation is validated against published analytical solutions, correction charts, and previous numerical studies, showing good agreement in both the shape and amplitude of modeled SP responses across a range of geological scenarios, including thin beds and invasion zones. Application to real data from a Southeast Asia gas field demonstrates that the approach provides reliable estimates of formation water salinity and the cation transport number, with results consistent with independent estimates. The proposed method offers a flexible tool for SP response modeling and may complement existing interpretation techniques, particularly when working with heterogeneous formations and limited legacy datasets.

Geosciences doi: 10.3390/geosciences16050191

Authors: Ying’ai Zhou Yiping Chen Lujun Peng Dezhen Zou Jinlun Cai Hao Lei Jingya Cao

The Guposh an orefield within the western segment of the Nanling Range hosts a globally significant tungsten and tin metallogenic province whose formation is tied to the intense Middle Jurassic granitic magmatism. Nonetheless, critical ambiguities remain regarding the metallogenetic ages and origin of ore-related hydrothermal fluids for W-Sn polymetallic deposits in this orefield. Here, we integrate in situ U-Pb geochronology of monazite and cassiterite and sulfur isotope analyses of pyrite from the Helukou W-Sn polymetallic deposit to resolve this outstanding question. In situ monazite U-Pb geochronology yielded lower intercept ages of 164.4 ± 1.1 Ma and 162.0 ± 2.0 Ma for the fine-grained and medium- to coarse-grained biotite monzogranite phases of the Guposhan pluton, respectively, bracketing its formation during the Middle Jurassic era. The initial 207Pb/206Pb ratio of 0.85 for the monazite grains is within the range of crustal and mantle materials, likely indicating a mantle–crust mixing source for the magma. Cassiterite from skarn-type ores yields a lower intercept U-Pb age of 165.9 ± 3.2 Ma, confirming a genetic relationship between the Guposhan magmatism and Helukou W-Sn mineralization. In situ pyrite δ34SV-CDT values show a uniform range from −0.66‰ to +0.79‰, indicating a uniform magmatic-derived sulfur source for the ore-forming fluids. We further demonstrate that fluid-rock interaction, rather than fluid mixing, acts as a crucial factor in the ore precipitation of W-Sn metals of the Helukou deposit.

Geosciences doi: 10.3390/geosciences16050190

Authors: Christopher P. McKay

Our concept of where life can thrive on Earth has advanced over the past 70 years to include extreme ionizing radiation, high temperatures, the deep subsurface, hydrothermal vents on the deep ocean floor, extreme arid deserts, and the ice-covered lakes and high mountain valleys of Antarctica. This expanding understanding of the biosphere has coincided with the development of space exploration programs, and it has informed those programs with regard to the search for life on other water worlds in our Solar System—especially Mars, Europa, and Enceladus. Titan presents a reverse of this approach. The interesting organic solids and fluids on that world have no analog in Earth habitability but have inspired suggestions of possible biological systems unlike any on Earth. If realized, the discovery of life on Titan would stretch the concept of habitability just as it stretches the concept of life as we know it. Habitability studies on exoplanets may follow both of these paths: we will look for habitability on exoplanets based on observed habitats on Earth, and we will also use observations of exoplanets as grist for contemplation of lifestyles different from anything we know on Earth.

Geosciences doi: 10.3390/geosciences16050189

Authors: Thi Thuy Dung Nguyen Xiao Hua Wang

A wave-resource characterization along the coast of Vietnam was performed based on the 12-year period from 2007 to 2018, using the structured-grid Simulating WAves Nearshore (SWAN) model with a ~2.3 km spatial resolution. Extensive model validations were performed using an observed nearshore dataset and ERA5 offshore datasets. The wave parameters, significant wave height, wave period, total wave energy and omnidirectional wave power varied both spatially and temporally, with a strong seasonal pattern influenced by the northeast and southwest monsoons, with the impact of the northeast monsoon being stronger. Wave energy resources were highest in winter and lowest in summer, making the southcentral coast of Vietnam a prime location for wave energy harvesting. However, further feasibility and design studies are needed before wave farms can be established. The Gulf of Tonkin and the Gulf of Thailand had lower wave energy due to wind distribution, shadowing effects and changes in water depth. This study also noted the impact of ENSO phases on wave conditions. Year-round, El Niño generally weakened winds, leading to smaller waves and reduced wave energy, while La Niña had the opposite effect. Additionally, tropical cyclones can further amplify significant wave height, especially during both ENSO phases in July, thereby increasing wave energy.

Geosciences doi: 10.3390/geosciences16050188

Authors: Zhao Zhan Shanxiong Chen Min Zhang Wenzhong Shi Yangjie Sun Hongbo Luo

Landslide susceptibility assessment (LSA) is crucial for regional landslide risk evaluation and mitigation strategy formulation. Previous studies mostly adopted single-scale features, while landslide formation is influenced by multi-scale factors, making multi-scale information extraction more appropriate for assessment. This study proposes a deep learning framework integrating multi-scale and attention modules for object-based LSA. A multi-scale network extracts geo-environmental features at different scales, which are input into attention networks using multi-head attention and Squeeze-and-Excitation, termed MSMHA and MSSE, respectively, to enhance relevant features and suppress irrelevant ones. Finally, features are fused for classification and prediction. In a case study in Hong Kong, CNN-based and ML-based methods were compared using 9814 landslides and 11 influencing factors. Results show the proposed MSMHA (area under the curve, AUC 0.91) and MSSE (AUC 0.90) outperform conventional methods (e.g., random forest with AUC 0.86; multi-layer perceptron and support vector machine with AUC 0.85; DenseNet with AUC 0.86; CNN with AUC 0.88; VGG with AUC 0.87; GoogLeNet and ResNet with AUC 0.81). CNN-based methods outperformed ML-based ones, indicating that incorporating neighborhood information improves model performance. The rationality of the susceptibility map generated by MSMHA was verified via comparative analysis. Results confirm that the proposed multi-scale and attention-integrated framework outperforms traditional single-scale methods consistently. Equally importantly, the case study provides advanced CNN-based landslide susceptibility maps for Hong Kong, which can serve as a critical reference for regional landslide risk management and the formulation of targeted mitigation strategies.

Geosciences doi: 10.3390/geosciences16050187

Authors: Xiao-Xia Li Shan-Shan Li Murat Tamer Zhuo-Er Teng Qun-Feng Miao Jia-Hui Zhou Cheng-Xun Li Ze-Hai Peng Hao-Chong Huang Zhi-Yuan Zheng Kun-Feng Qiu

Porphyry-type deposits are characterized by well-developed alteration zoning, among which potassic alteration is closely associated with mineralization and represents a key target for prospecting and exploration. The Dengshang molybdenum deposit is a porphyry-type deposit within the Yanliao molybdenum metallogenic belt. Characterized by deep burial and unclear alteration zoning, it presents challenges for prospecting and exploration. This study integrates field surveys, petrographic analysis, and terahertz time-domain spectroscopy (THz-TDS) to characterize the altered wall rocks and molybdenite ores, aiming to support deep prospecting. The main findings reveal a clear spatial gradient from potassic to propylitic alteration zones within and around the rhyolite porphyry intrusion. THz-TDS reveals that the THz spectral characteristics of potassic-altered wall rocks are closely related to the structure of minerals and the intensity of hydrothermal alteration. Propylitically altered wall rocks exhibit distinctive spectral signatures in the terahertz band. For molybdenite ores, the molybdenite content shows a negative correlation with THz amplitude and a positive correlation with both the absorption coefficient and refractive index. This study proposes that the lower refractive index and absorption coefficient of potassic wall rocks, coupled with the higher values in ores, reflect the spatial position of the ore body. Additionally, the characteristic THz spectral curve of propylitically altered rocks can aid in delineating ore body boundaries. These findings hold practical guiding significance for prospecting and exploration.

Geosciences doi: 10.3390/geosciences16050186

Authors: José Carlos Román-Herrera Martín Jesús Rodríguez-Peces Julio Garzón-Roca

Earthquake-induced landslides are a major secondary seismic hazard in mountainous regions and can cause significant human and economic losses. This study presents COSISA (Co-Seismic Slope Instabilities Susceptibility Assessment), a software tool developed in Python and GIS to automate the generation of co-seismic landslide susceptibility maps based on the Newmark displacement method combined with a logic-tree approach. The software integrates geomorphological, geotechnical, and seismic data to compute Newmark displacement using several available empirical equations. The logic-tree framework incorporates the variability and uncertainty of geotechnical parameters, failure depth, degree of saturation, and empirical models through weighted combinations of input variables. As a result, COSISA produces numerous susceptibility maps corresponding to different parameter combinations and generates a weighted susceptibility map. The tool was applied to a case study in the Granada Basin (southeastern Spain), an area affected by the 2021 Santa Fe seismic sequence. Results show that COSISA efficiently generates multiple susceptibility scenarios and identifies best- and worst-case conditions, significantly reducing the time and effort required compared with conventional step-by-step procedures. This approach supports seismic hazard assessment and can contribute to territorial planning and risk management strategies aimed at reducing damage from future co-seismic landslides.

Geosciences doi: 10.3390/geosciences16050185

Authors: Jade Moreira João Luiz Nicolodi Miguel da Guia Albuquerque Breno Mello Pereira Raíssa Magnan Scorsatto

This study assesses the comparative performance of two geotechnologies for shoreline monitoring—Unmanned Aerial Vehicle (UAV) surveys and CoastSnap citizen-science imagery—at Guarita Beach, southern Brazil. The analysis was based on twelve paired monitoring dates distributed over a two-year interval. Shorelines were extracted from the wet–dry line, manually digitized from UAV orthomosaics, and automatically detected from CoastSnap images with subsequent quality control. Shoreline change was quantified in the Digital Shoreline Analysis System (DSAS) using the Shoreline Change Envelope (SCE) and the Linear Regression Rate (LRR). The SCE showed the highest equivalence between methods, with a mean difference close to zero (−0.14 m) and no evidence of systematic bias. For LRR, values derived from CoastSnap tended to be lower than those derived from UAVs (mean difference = −2.14 m year−1), although without statistically significant divergence at the adopted significance level. The results demonstrate that the agreement between CoastSnap and UAV data depends directly on the metric analyzed: SCE was more robust for inter-method comparison, whereas LRR was useful for medium-term trend interpretation but more sensitive to uncertainty propagation. Overall, CoastSnap did not replace UAV surveys, but it proved to be a valuable complementary tool for expanding temporal coverage in coastal monitoring programs.

Geosciences doi: 10.3390/geosciences16050184

Authors: Ali Al Janabi Camelia Knapp Ziyad Albesher Mohammad A. Abdelwahhab Mahmoud Leila Ahmed A. Radwan

In the northern Norwegian North Sea, the Lower Paleogene post-rift succession constitutes an underexplored interval with considerable potential for stratigraphic petroleum plays. Nevertheless, predicting its subsurface prospectivity remains hindered by persistent uncertainties in facies architecture, depositional heterogeneity, and reservoir quality. To address these uncertainties, the present study integrates relative geologic time (RGT)-based seismic stratigraphic interpretation, spectral decomposition, sedimentary facies analysis, and litho-saturation assessment, primarily constrained by seismic and well-log datasets, to evaluate the Paleocene post-rift Lista Formation in the northern Norwegian North Sea. The results reveal the presence of Paleocene mass-transport deposit (MTD) complexes associated with axial lobe sandstones of submarine fan systems. These MTD complexes exhibit pronounced vertical and lateral facies transitions into low-density turbidites, debrites, and hemipelagic drapes, together forming an effective stratigraphic framework for hydrocarbon entrapment. Although the Lista submarine-fan sandstones are relatively thin, typically ranging from a few centimeters to decimeters in thickness, they display favorable reservoir characteristics. Litho-saturation analysis indicates preserved porosity and low water saturation (<20%), supporting their potential as effective hydrocarbon storage intervals. Distal fan-lobe sandstones, despite their limited thickness, show encouraging reservoir quality, whereas thicker low stand systems tract (LST) accumulations and time-equivalent carbonate mound complexes appear to have developed within more proximal structural domains. This proximal-to-distal facies organization reflects the dynamic interaction between tectonically inherited accommodation space and sediment-routing pathways during the early Paleocene. Overall, the findings highlight the significant petroleum prospectivity of the Paleocene post-rift succession in the northern Norwegian North Sea. The stratigraphic juxtaposition of sand-prone submarine-fan lobes against hemipelagic sealing intervals, combined with heterogeneity imposed by syn-rift structural inheritance, generates a highly favorable architecture for stratigraphic trapping. More broadly, the integrated workflow presented here enhances the predictive mapping of subtle stratigraphic traps within post-rift successions and provides a robust framework for reducing exploration uncertainty in analogous basins.

Geosciences doi: 10.3390/geosciences16050183

Authors: Alexander Radulov Yordanka Donkova Nikolay Nikolov Marlena Yaneva Konstantin Kostov Ivan Alexiev

The Devene fault system, a major strike–slip structure at the boundary between the Balkan Range and the Moesian Platform in NW Bulgaria, remains a subject of debate regarding its Quaternary activity. This study investigates the shallow expression of the fault at two representative sites, Tri Kladentsi and Beli Breg, using high-resolution electrical resistivity profiling to differentiate tectonic deformation from climatically driven landscape evolution. At Tri Kladentsi, resistivity profiles confirm a steeply dipping structural boundary within the Miocene bedrock, juxtaposing limestone against sands. The overlying 25 m thick loess cover, however, remains sub-horizontal and undisturbed. Likewise, at Beli Breg, the complex architecture of stacked channel sequences and tributary deposits at the Ogosta River confluence reveals no identifiable fault displacement. Our results suggest a high degree of morphological mimicry, where asymmetric river valleys produced by selective erosion and differential loess accumulation superficially converge with tectonic signatures. The long-term left-lateral slip rate is estimated at 0.14–0.19 mm/yr based on a 20 km Miocene offset. Nevertheless, the lack of modern surface rupture indicates a deceleration of the fault slip rate and a transition to a buried fault top during the Quaternary. These findings necessitate a re-evaluation of regional seismic hazard assessments, because the absence of continuous surface traces physically constrains the maximum earthquake potential.

Geosciences doi: 10.3390/geosciences16050182

Authors: Yao Qu Caide Lin Hai Liu Xiangtai Liu Xu Meng Shangyang Zhang Zixin Yin Hesong Hu

The imaging quality of electrical resistivity tomography (ERT) crucially depends on the electrode array configuration. Although the symmetrical optimized ‘Compare R’ (CR) method improves computational efficiency, restricting the search to the symmetrical data set inherently limits the imaging accuracy. To address this limitation, this paper proposes a multi-step optimized CR method that progressively explores both symmetrical and asymmetrical arrays to extend the search space and further enhance imaging accuracy. Numerical experiments demonstrate that the multi-step optimized array yields the highest average relative model resolution (0.646) and structural similarity index measure (0.668), surpassing the symmetrical optimized array (0.615 and 0.630, respectively). Field experiments on pipeline detection confirm that the proposed array accurately identifies the location and geometry of underground anomalies and achieves superior imaging accuracy. Applications in karst cavity exploration further confirm that the proposed array effectively detects the deep karst caves and the bedrock interfaces, as validated by borehole drilling. Additionally, the detection performance of both optimized arrays is evaluated at different depths. The results indicate that the multi-step optimized array preserves anomaly geometry and resistivity more reliably at greater depths, attributed to the accumulation of asymmetrical data points in deep regions, which results in a significantly higher data density.

Geosciences doi: 10.3390/geosciences16050181

Authors: Haiquan Li Huanhuan Wu He Huang Guoqing Wang Zhanlin Ge Ming Liu Di Hao

Permian A-type granites and associated rare-metal mineralization are widespread in the Halajun area, southwestern Tianshan; however, petrogenetic controls on rare-metal enrichment and mineralization remain under-constrained. Here, we integrate zircon and monazite geochronology, whole-rock geochemistry, and zircon Hf-O isotopes from Halajun I and II plutons to constrain the origin of these granites and their metallogenic significance. Zircon U–Pb and monazite ages indicate emplacement at 274–273 Ma, coeval with regional magmatism associated with the Tarim large igneous province. Geochemical signatures—high SiO2, alkali, and rare-earth element (REE) contents, enrichment of HFSE (e.g., Nb, Zr, and Hf), coupled with LILE (e.g., Ba and Sr) depletion—classify these granites as highly differentiated alkaline A-type rocks. Positive εHf(t) values and intermediate δ18O compositions of zircons suggest derivation from partial melting of Neoproterozoic lower crust with input from mantle-derived melts, reflecting significant crust–mantle mixing. Magmatic differentiation, in concert with regional crustal reworking driven by mantle plume activity, produced granites enriched in Nb, Ta, Zr, and REEs, which host the rare-metal mineralization in the region. These results indicate that Permian crustal reworking in the southwestern Tianshan was a driver of high-differentiation magmatism and rare-metal enrichment, highlighting the potential of similar A-type granitic systems in Central Asia for rare-metal exploration.

Geosciences doi: 10.3390/geosciences16050180

Authors: Zhibo Chen Jinduo Gao Wei Huang Ping Hu Xuefeng Tang Zhigang Zhao Banglai Lü

Completely weathered granite residual soil is a weathering-derived, soil-like geomaterial whose shear strength is difficult to characterize using only conventional small-scale laboratory tests. This study evaluated the effects of specimen size and material structure by comparing in situ direct shear tests, conventional laboratory direct shear tests on undisturbed and remolded specimens, and large-scale laboratory direct shear tests on remolded specimens with box sizes of 150, 200, and 250 mm. The results show that undisturbed specimens exhibited higher shear strength than remolded specimens, indicating a clear structural contribution. With increasing specimen size, cohesion decreased from 41.2 to 31.4 kPa, whereas the friction angle increased from 35.3° to 40.6°. Compared with the conventional undisturbed test, the in situ tests yielded lower cohesion but higher friction angles. These results indicate that both size effect and structural disturbance significantly influence the interpretation of shear strength parameters in completely weathered granite residual soil. For engineering design in weathered-granite terrains, strength parameters derived from larger specimens or in situ tests are likely to be more representative than those obtained from conventional small-scale laboratory tests.

Geosciences doi: 10.3390/geosciences16050179

Authors: Jozef Bódi Peter Vajda Pavol Zahorec René Putiška Juraj Papčo Roman Pašteka José Fernández

Underground water flow in karst areas and changing water levels due to extreme rain can lead to the creation of caverns and sinkhole hazards. Such is the historical experience of the Valaská village in central Slovakia. To better understand the current sinkhole threat in the village, we aim to detect shallow caverns using microgravimetry. Our broader objective is to examine the capabilities of the Growth inversion methodology to detect and characterize shallow cave space. In our study, we focus on the benefits and weak points of the Growth inversion approach, which is a free-geometry inversion method based on model exploration and growing source bodies. Since a sole gravimetric inversion produces ambiguous results, we pay attention to the role and setup of the several free user-adjustable inversion parameters of Growth. We examine tuning these parameters for the specific needs of shallow cavity detection. Valaská experienced sinkholes in 1964, 1968 and 2019. That of 1964 is known for a curious loss of a horse sunk into a karst chimney. Our gravimetric work shows that the sinkhole hazard at the exposed lot in Valaská is ongoing despite the mitigation construction measures. The Growth approach proved to be applicable and useful in microgravimetric identification of sinkhole threat and detection of shallow caverns in karst.

Geosciences doi: 10.3390/geosciences16050178

Authors: Vikas C. Baranwal Martin C. Sinha Lucy M. MacGregor Anna C. Maxey Yang Su

Marine controlled source electromagnetic (CSEM) surveys have been proven to be an effective tool in hydrocarbon exploration, principally due to the method’s ability (in the right circumstances) to identify electrical resistivity contrasts between hydrocarbon-saturated and brine-saturated sedimentary units. However, the sensitivity of such surveys decreases in shallow water, for deeper targets, and for targets with limited horizontal extent. In principle, the resolution and sensitivity of a survey can be improved by moving either the transmitting or the receiving dipoles into the sub-surface. We have therefore investigated the sensitivity of Seafloor to Borehole CSEM (sbCSEM) survey geometries, specifically for the case of simplified targets with small lateral dimensions in shallow water areas—including targets whose depth of burial substantially exceeds their lateral extent. The results are encouraging. Neither small target size nor shallow water presents obstacles in principle to the use of this approach. Our models reveal distinct lobes in the patterns of electric field and current density amplitudes around a sub-seafloor transmitting dipole. The shape, positions and amplitudes of these lobes are all strongly modified by the presence of one or more small resistive targets, and they are strongly influenced by the positions of target edges. These effects significantly modify the pattern of electric fields at the seafloor and hence result in good sensitivity for realistic survey geometries. Small targets can be detected by seafloor receivers when the sub-seafloor transmitting dipole is located at some distance laterally outside the targets—leading to potential applications in ‘step-out’ prospecting. The asymmetry of responses at the seafloor from targets that are offset with respect to transmitter location has potential applications in field appraisal, while monitoring of reservoirs during production provides another possible application. Varying the depth of the transmitter down the borehole generates a Vertical EM Profiling (VEMP) survey—analogous to Vertical Seismic Profiling (VSP)—and we demonstrate that this too can have useful applications. Modelling for deeper (3 km sub-seafloor) targets continues to yield encouraging results and suggests that step-out sbCSEM may be effective at depths beyond the detection limit of conventional seafloor–seafloor CSEM.

Geosciences doi: 10.3390/geosciences16050177

Authors: Demin Zhang Fayou Li Zhongmin Zhang Chaonian Si

Recently, a substantial quantity of oil and gas has been discovered in the pre-salt Lower Cretaceous microbialite successions of Brazil’s Santos Basin, thereby prompting a global surge in research related to microbialites. It has been demonstrated that microbial shoal reservoirs yield the highest hydrocarbon production, with optimal reservoir properties, as evidenced by experience in the field of oilfield production. However, as research progresses, it has become increasingly evident that significant heterogeneity exists in both the lithology and physical properties within microbial shoal bodies. In order to address the identified knowledge gap, the present study employs systematic petrological and petrophysical datasets. These include 30-m continuous core samples, thin-section analyses, routine petrophysical tests and mercury injection capillary pressure (MICP) measurements. The aim is to characterize the internal microfacies architecture and reservoir heterogeneity of microbial shoals. It is imperative to ascertain the principal factors that govern the heterogeneity observed in these reservoirs. This critical step is essential for a comprehensive understanding of the subject matter. The results of the study demonstrate that: the Barra Velha Formation microbial shoals in the Santos Basin can be subdivided into three microfacies, which are delineated from base to top. The foundation of the shoal is the shoal base. The rock composition is dominated by the presence of spherulites, with intracrystalline pores functioning as the primary reservoir spaces. The compositional rocks of the shoal flank are poorly sorted microbial debris, with intergranular and intragranular pores formed by penecontemporaneous dissolution. The sedimentary succession of the shoal core is characterized by well-sorted microbial debris rocks displaying multiple shallowing-upward sequences, with reverse-graded textures. The primary storage space is constituted by fabric-selective pores from penecontemporaneous dissolution, though these are subject to local disruption by destructive silicification. Meanwhile, the microbial shoals demonstrate wide porosity (8.8–26.4%, mean 16.8%) and permeability (0.13–839 mD, mean 169 mD) ranges, thus classifying them as medium-porosity, high-permeability reservoirs. The superimposition of microfacies and diagenetic processes gives rise to considerable reservoir heterogeneity. It is evident that the shoal core microfacies exhibits robust energy and substantial grain size, characteristics that facilitate its exposure above lake level during periods of high-frequency lake-level oscillation. This exposure is further compounded by the influence of atmospheric water dissolution, which remodels the microfacies during the quasi-contemporaneous period. The reservoir quality is optimal, exhibiting the highest proportion of large pores. The reservoir properties of the shoal flank are closely followed by medium and large pores, and those of the shoal base are the worst, with micro and medium pores.

Geosciences doi: 10.3390/geosciences16050176

Authors: Jian Xu Haiping Fan Danial Jahed Armaghani

Accurate prediction of blasting-induced peak particle velocity (PPV) is critical for assessing structural damage risk and ensuring safe tunnel construction. This study proposes an AI agent-based Evaluator-Optimizer workflow that automates the model-development pipeline from prepared dataset input through model training, performance evaluation, hyperparameter optimization, and ensemble construction, with limited manual intervention after dataset definition. The framework employs a multi-agent architecture comprising three collaborative agents—an Orchestrator, an Evaluator, and an Optimizer—supported by a large language model (LLM) reasoning layer. The Evaluator agent analyzes model performance across multiple metrics and generates diagnostic insights; the Optimizer agent translates these insights into structured optimization plans; and the Orchestrator coordinates the evaluate-optimize loop and stopping logic. The workflow was applied to a dataset of 102 tunnel blasting events. Nine candidate regression models spanning tree-based, kernel-based, neural network, and regularized linear families were trained and evaluated. The results show that the workflow enables three substantive observations: (i) across five tree-based models the powder factor is the dominant predictor (28.7–50.5% relative importance); (ii) under 50 Monte-Carlo repeated 80/20 splits, KNN and the Voting ensemble are statistically indistinguishable and form the most stable performance cluster, while Gradient Boosting lies within the same cluster with larger variance; and (iii) under nested 5 × 5 cross-validation, the un-leaked R2 for the top models is about 0.84–0.86, which quantifies the small-sample over-optimism that any future PPV study on single 80/20 splits should expect. The study therefore contributes both a portable agent architecture for tabular geotechnical regression and a concrete cautionary result about single-split benchmarking.

Geosciences doi: 10.3390/geosciences16050175

Authors: Aashish Pokhrel Laureano R. Hoyos Xinbao Yu

Soil thermal conductivity is a key parameter in modeling heat transfer, temperature-driven moisture migration, artificial ground freezing, and geothermal systems. However, most existing thermal-conductivity models do not account for temperature effects. This study aims to determine the temperature-dependent thermal conductivity of silty and fine sandy soils at elevated temperatures using a steady-state heat cell method, addressing the limitations of transient probe techniques, which are affected by air voids and heat loss at the needle–soil interface. The experiment employs a heat cell under one-dimensional steady-state heat-transfer conditions, with sufficiently small temperature gradients to prevent temperature-induced moisture migration, and measures the soil’s thermal properties at steady state by indirect temperature and heat-flux measurements using various sensors. The test observations showed well-correlated thermal conductivity readings from steady state and transient probe methods at room temperature. Furthermore, the measured thermal conductivity of the sandy soil demonstrated a near-linear increase with temperature, with the highest dependence at 15.1% and 22.5% saturation for Benbrook (SM) and fine-grained Ottawa (SP) sands, respectively. Several commonly used existing thermal conductivity models were used to fit the measured thermal conductivity. A new thermal conductivity model was developed, incorporating a temperature-dependent correction based on the best-fit model. The proposed model could more accurately capture the increased thermal conductivity of soils with temperature. The findings will significantly improve the modeling of soil-temperature-dependent multi-physics behavior.

Geosciences doi: 10.3390/geosciences16050174

Authors: Joseph Moll David Malone Tiffany Rivera Robert Biek David Hacker Ashley Griffith Michael Braunagel

The late Paleogene White River Group is a post-Laramide sedimentary succession that occurs within Laramide intermontane basins and atop some basement-cored uplifts. Detrital zircon U-Pb dates of tuffaceous sandstones from the uppermost White River Group in eastern Wyoming and western Nebraska yield a maximum depositional age of 23.07 ± 0.46 Ma, which overlaps the emplacement of the Markagunt Gravity Slide in Utah’s Marysvale Volcanic Field at 23.05 + 0.22/− 0.20 Ma. The Marysvale Volcanic Field (~31–18 Ma) lies at the east margin of the Nevadaplano, a longstanding highland in the Sevier Hinterland later dismembered by basin and range extension. Strata both proximal and distal to the Marysvale Volcanic Field show an increase in Marysvale provenance up to the emplacement of the Markagunt Gravity Slide. After emplacement, distal sediment sourcing of Miocene strata in the Great Plains shifted back to older Paleogene volcanic fields farther west in Nevada. This temporal relationship suggests that the collapse of the Marysvale Volcanic Field associated with the emplacement of the Markagunt Gravity Slide forced drainage reorganization and sediment sourcing during the transition from White River to Arikaree Group sedimentation.

Geosciences doi: 10.3390/geosciences16050173

Authors: Hernán Patiño Fausto Molina-Gómez Rubén Ángel Galindo-Aires

Tailings are unconventional geomaterials that require dynamic characterisation due to seismic hazards at several storage facilities. Due to the anthropic origin of these materials, their dynamic properties differ from those reported for natural soils. In particular, the damping ratio is a relevant parameter that controls the dynamic response of tailings storage facilities. It can be estimated using different experimental methods. The objective of this research is to disclose the results obtained through laboratory tests in which the damping ratio was evaluated independently by Half-Power Bandwidth or the free-vibration decay methods. A comprehensive testing plan comprising resonant column tests and free-vibration decay tests was carried out on three types of tailings from the Riotinto mines (Huelva, Spain): Cerro Salomón Sand (CSS), High-Density Sludge (HDS), and Copper Lamas (CL). These tests were carried out under different effective consolidation pressures and torsional excitations. The results allowed the establishment of a series of relationships between the testing conditions and the identification of differences between the methods for tailings.

Geosciences doi: 10.3390/geosciences16050172

Authors: Rui Gao Chenxi Zhang Weichen Gao Guorui Feng Xiao Huang Xueming Zhang Hong Guan

Rock fracture mechanics and the associated energy-release behavior play a key role in ensuring safe extraction in underground coal mining. Hydraulic fracturing generates prefabricated fracture networks in competent rock strata, thereby modifying fracture propagation patterns and reducing the failure resistance of the strata. In this study, standardized three-point bending tests were conducted to investigate the fracture behavior of pre-cracked sandstone specimens with different crack morphologies, quantities, and spacings. New crack initiation occurred mainly at the midspan in specimens containing horizontal prefabricated cracks, whereas inclined prefabricated cracks promoted crack initiation from the crack tips. Although horizontal crack length did not exhibit a clear monotonic effect on load-bearing capacity, the overall capacity decreased with increasing crack density or decreasing crack spacing. Vertical cracks further reduced load-bearing performance, particularly at relatively small crack spacings. The strain response exhibited a non-monotonic relationship with horizontal crack parameters, increasing first and then decreasing with increasing crack length and spacing, while showing a positive correlation with vertical crack spacing. Dissipated energy was negatively correlated with prefabricated crack angle, accounting for 92.65%, 89.10%, and 94.03% of the total input energy. With increasing crack length, the proportion of dissipated energy first increased and then decreased, with values of 92.65%, 90.77%, 92.52%, and 96.13%. Energy dissipation decreased with increasing horizontal crack spacing but increased with vertical crack spacing. Numerical simulations further showed that both horizontal and vertical fractures generated by ground fracturing promoted timely strata failure, while vertical fractures were more effective in facilitating overburden fracture propagation and reducing the bearing capacity of the rock strata and advance coal body by more than 13%. These findings provide a mechanistic basis for the control of thick and competent hard-roof strata.

Geosciences doi: 10.3390/geosciences16050171

Authors: Leila Abbasian Pushpinder S. Rana Alison Leitch Stephen D. Butt

Non-destructive characterization of electromagnetic (EM) wave propagation properties in drill cores is gaining prominence as a foundation for reliable geophysical inversion, improved rock-physics modeling, and increasingly data-driven mineral exploration workflows. Lab-based rock characterization requires benchmarks that link the density, elastic, electrical, magnetic, and EM properties of studied cores to lithology and mineralization, enabling more accurate interpretation of geophysical data. This study develops a robust high-frequency EM (HFEM) wave velocity measurement technique and incorporates it within a standardized non-destructive framework validated across multiple mineral systems in Newfoundland and Labrador, Canada. The developed method derives EM velocities from two-way travel time through drill cores positioned above a metallic reflector, supported by finite-difference time-domain simulations to optimize antenna frequency and test geometry. A repeatable signal-processing workflow was implemented to enhance reflection picking. Results reveal systematic EM velocity contrasts among host rocks and oxide or sulfide-bearing systems, with oxide-rich and massive sulfide intervals exhibiting higher density, elevated conductivity and susceptibility with strong EM attenuation. The integrated dataset shows that conductivity and magnetic susceptibility significantly influence EM velocity response and detectability limits. The proposed multi-parameter benchmark enables enhanced discrimination of lithological and mineralization controls in mineral exploration workflows and supports more accurate time–depth conversion in HFEM geophysical and ground-penetrating radar (GPR) methods.

Geosciences doi: 10.3390/geosciences16050170

Authors: Béla Raucsik Andrea Varga Olga Piros Andrea Szuromi Korecz Elemér Pál-Molnár

The Middle Triassic Bulz Dolomite Formation in the Apuseni Mountains (Romania) lacks detailed microfacies documentation and paleoenvironmental reconstruction, leaving its regional correlation unresolved. This study aims to describe the microfacies and fossil assemblages of the Bulz Dolomite to reconstruct the Anisian depositional environment and establish regional stratigraphic links. More than twenty outcrop samples were analyzed using conventional microfacies analysis, UV/VIS-fluorescence, and cathodoluminescence microscopy. Results reveal that early, fabric-retentive dolomitization preserved microbial boundstones, dasycladalean algae (Teutloporella peniculiformis, Physoporella pauciforata), and benthic foraminifers (Hoyenella sinensis), indicating shallow-marine, peritidal, and restricted lagoonal environments. The multiphase diagenetic history involves early reflux dolomitization from hypersaline brines, burial recrystallization forming nonplanar and saddle dolomites, and late-stage meteoric calcite cementation. The diagnostic fossil assemblage firmly constrains the formation to the Anisian age. Consequently, the Bulz Dolomite shares compelling lithological, diagenetic, and biostratigraphic affinities with the Szeged Dolomite Formation in the basement of the southeastern Pannonian Basin, demonstrating the presence of a unified, expansive evaporitic carbonate shelf extending across the Tisza Megaunit along the Neotethyan passive margin.

Geosciences doi: 10.3390/geosciences16050169

Authors: Jiawen Chen Changbao Yang Liguo Han Shiqin Yang

This study investigates how solar and geomagnetic driver selection affects 24 h-ahead global ionospheric vertical total electron content (VTEC) prediction under different geomagnetic conditions. A four-step feature selection strategy involving importance evaluation, redundancy elimination, physical interpretability prioritization, and performance validation was developed to identify five key drivers from candidate solar and geomagnetic factors. Using global ionospheric maps provided by the Center for Orbit Determination in Europe (CODE) from 2014 to 2018, a non-overlapping 90-day temporal block scheme was adopted to reduce the risk of temporal information leakage. Six ablation experiments were conducted to compare the predictive performance of different driver combinations. The results show that the full-factor configuration selected by the proposed strategy achieved the most favorable overall performance among the tested combinations, although the global-average improvement relative to the baseline remained modest. The optimal driver combination varied with geomagnetic disturbance level, and the contribution of external drivers showed clear latitudinal dependence. In addition, the full-factor configuration yielded a more balanced global error distribution and was associated with slower error accumulation over the 24 h horizon. These findings suggest that physically guided driver selection is useful for constructing more physically meaningful driver combinations and for improving long-horizon prediction stability within a unified ConvLSTM-based framework.

Geosciences doi: 10.3390/geosciences16050168

Authors: Nada Bouferdous Eric Guilbert Sylvie Daniel

The introduction of multibeam echosounders has marked a turning point in bathymetric data acquisition, providing precise and detailed digital bathymetric models. These instruments not only enhance our understanding of underwater terrain dynamics but also reveal the presence of complex sedimentary structures, such as submarine dunes. Dunes play an important role in the preservation of the environment but can also be obstacles to safe navigation, requiring dragging operations. Hence, it is important to detect them from bathymetric models. Although information about these dunes has numerous applications, their identification methods remain poorly automated. This paper aims to leverage deep learning to develop a segmentation method for submarine dunes. Several challenges must be overcome. Dunes are complex objects with irregular, highly variable shapes, while bathymetric data are noisy and lack detailed information. Furthermore, in the fluvio-marine context, no labeled datasets exist for training purposes. Starting from a small pre-labeled dataset, this paper proposes a systematic approach to train a Mask R-CNN network. First, data augmentation techniques are applied to expand the dataset significantly and introduce meaningful variations. By relying on transfer learning with a carefully selected pre-trained backbone, feature extraction is optimized, reducing training time while enhancing model performance. The adaptation of the Mask R-CNN model to our submarine dune segmentation task has led to a significant improvement in detection performance, with a pixel-level F1-score reaching 89%. Additionally, the mean Average Precision has exceeded 50%, demonstrating the model’s effectiveness in identifying and delineating dunes despite their varied shapes and blurred contours. These results confirm the relevance of our approach for achieving more reliable dune segmentation in a complex fluvio-marine environment.

Geosciences doi: 10.3390/geosciences16050167

Authors: Shuang Geng Zhanyu Wei Xi Xi Yating Deng Da Zhang Chenyu Ma Honglin He

The Daliangshan Fault Zone (DLSFZ) constitutes a key segment of the Xianshuihe–Xiaojiang Fault System (XXFS) and exerts fundamental control on the eastward extrusion of the Sichuan–Yunnan Block (SYB). In this work, we present new slip rate determinations at three key sites (Tekoujiagu, Yeer, Damulo) along its middle-southern segments using UAV-based high-resolution topography and OSL dating. Results yield late Quaternary slip rates of 4.5 ± 1.4, 3.7 ± 1.1, and 5.5 ± 1.0 mm/a, respectively. Combined with previous data, the slip rate is 1.5–3.1 mm/a in the northern segment, 1.36–4.3 mm/a in the middle and 2.5–4.5 mm/a in the southern segment, which exhibits a spatial pattern of “higher in the south, lower in the north, with transition in the middle”. Temporal evolution suggests increased slip rates from the Late Pleistocene to Holocene. These characteristics indicate that the DLSFZ is a heterogeneous deformation system, where strain focusing on the southern segment reflects the block’s eastward escape constrained by the rigid Sichuan Basin (SB). Thus, the DLSFZ, especially its southern segment, serves as a key structure regulating crustal extrusion at the southeastern margin of the Tibetan Plateau (TP).

Geosciences doi: 10.3390/geosciences16050166

Authors: Félix Díaz Nhell Cerna Rafael Liza Bryan Motta

Radon has long been investigated as a potential earthquake precursor, yet its interpretation remains challenged by meteorological, hydrological, and instrumental variability that can generate apparent departures unrelated to tectonic processes. This review synthesises how artificial intelligence is being applied in radon-based earthquake precursor research, with particular emphasis on anomaly detection and the evaluation of radon seismicity associations. Following a PRISMA-guided workflow, Scopus and the Web of Science Core Collection are searched and screened for eligibility, yielding 26 journal articles, most of which are concentrated in a limited number of tectonically active regions. Across the reviewed literature, a consistent pattern emerges: AI is used primarily to model the expected radon background, while candidate precursors are identified mainly through threshold-based indices derived from residuals or concentration ratios rather than through explicit earthquake-probability outputs. Although pre-seismic departures are reported repeatedly, this review shows that the evidence base remains constrained by heterogeneous operational definitions of anomaly, strong methodological variation across studies, a predominant emphasis on background goodness-of-fit instead of alarm-level performance, and limited use of time-ordered validation. These findings highlight both the promise and the current limitations of AI-enabled radon analysis. The main contribution of the field so far is not direct earthquake prediction but a more structured framework for separating potential tectonic signals from non-seismic variability. In this sense, the review provides an important methodological synthesis for future research and shows that more reproducible and operationally useful radon monitoring will depend on clearer anomaly definitions, stronger confounder control, more rigorous temporal validation, and more standardised performance reporting.

Geosciences doi: 10.3390/geosciences16040165

Authors: Yue Cai Shiwu Liu Liangliang He Xiang Guo Guijuan Li Lei Yang Shaoni Wei

Sandstone of the Lower Cretaceous Luohe Formation is the main water inrush source in the Binchang Mining Area in the southwestern Ordos Basin. Its sedimentary environment and provenance features are critical for local coal development and safe mining. The Luohe Formation at Xiaozhuang Coal Mine comprises three vertical members: the lower member dominated by coarse- to medium-grained sandstones, the middle member mainly composed of fine-grained sandstones, and the upper member characterized by interbedded fine- to medium-grained sandstones and sandy conglomerates. This subdivision newly identifies a complete hydrodynamic evolutionary cycle of depositional environments from high-energy to low-energy and back to high-energy conditions. Integrated petrographic observations and analyses of major and rare earth elements first confirm that the tectonic affinity of the Luohe Formation progressively shifted from a passive continental margin to an active continental margin, accompanied by a corresponding transition in sediment provenance from the North China Craton to a magmatic arc source region. Trace element compositions precisely indicate that the Luohe Formation was deposited in a fluvial freshwater environment under hot, arid, and oxidizing conditions, thus providing new constraints on the paleoenvironmental evolution of the region.

Geosciences doi: 10.3390/geosciences16040164

Authors: Noura Lkebir Xiongwei Zeng Long Cheng Zhijun Niu

This study fills a knowledge gap in the distribution of the Upper Cretaceous dinosaur tracks in central China by examining two newly discovered tracksites near Xiakou village (Nanzhang County) and Jiuxian town (Yuan’an County), Hubei Province. Eleven Isolated tracks were analyzed to identify the ichnofauna assemblage. Morphometric analysis indicates the presence of tridactyl and rounded morphologies. The tridactyl tracks are consistent with a small-sized theropod and ornithischian ichnofauna, whereas the rounded shape remains ichnotaxonomically indeterminate. These tracks are the first reported dinosaur ichnite from central China at this age. Despite limited preservation, this research highlights how extromorphological factors influence track morphology, a key issue in ichnological studies. Overall, it contributes new data on the presence of dinosaur ichnofauna in China during the late Mesozoic.

Geosciences doi: 10.3390/geosciences16040163

Authors: Xingping Yin Yuqiang Jiang Yifan Gu Yuegang Li Zhanlei Wang Xiugen Fu

The marine shale of the Longmaxi Formation is the main layer for shale gas exploration and development in the Sichuan Basin. That said, the pore structure in the Longmaxi shale is strongly heterogeneous, and how these pores form and are preserved remains unclear—which limits our understanding of what makes a good reservoir and holds back efficient shale gas development. To investigate the coupling relationship between hydrocarbon generation and pore evolution in marine shale, medium-maturity shale from the Longmaxi Formation in NE Sichuan was collected for thermal maturation experiments. Shale samples and pyrolysis products from different evolutionary stages were obtained for a series of analyses, including gas composition and pore structure. The influence of organic hydrocarbon generation and inorganic diagenesis on the development of shale nanopores was revealed, and a pore evolution model for marine shale was established. The results show the following: (1) The hydrocarbon generation process of medium-maturity marine shale consists of three stages. The maximum methane yield is 362.58 mL/g. (2) As the thermal maturity increases, the quartz content shows a gradual increase, while the content of clay minerals, feldspar, and carbonate minerals decreases. (3) As the thermal maturity increases, pore evolution is observed in four stages: “slow decrease,” “rapid increase,” “relatively stable,” and “slow decrease.” The first stage is characterized by pore reduction dominated by intense compaction. The second stage is dominated by pore expansion driven by mineral transformation and dissolution. The third stage is the pore preservation stage, during which continuous natural gas generation occurs. The fourth stage is characterized by pore reduction, mainly driven by weak compaction. This study has enriched the theoretical understanding of the dynamic evolution of shale pores, providing a theoretical basis for the research on the formation and enrichment mechanism of shale gas and the exploration practice of shale gas reservoirs.

Geosciences doi: 10.3390/geosciences16040162

Authors: Wei Yu Li Gong Jiao Wang Feng Wang Jingchun Tian Jie Chen

Diagenetic anomalies within the Upper Paleozoic coal-bearing strata of the Longdong area, Ordos Basin, represent a complex interplay between thermal maturation and fluid evolution, yet their governing mechanisms remain poorly understood. This study integrates petrographic analysis, X-ray diffraction, vitrinite reflectance (Ro) measurements, and fluid inclusion microthermometry to evaluate the discrepancy between organic thermal maturity and mineralogical diagenetic records. The results indicate that the mudstones achieved high thermal maturity, with mean Ro and Tmax values of 2.3% and 555.1 °C, respectively. However, the associated sandstones exhibit anomalous mineral assemblages, characterized by persistent high levels of illite/smectite (I/S) mixed-layer minerals and authigenic kaolinite, which are inconsistent with the anticipated advanced diagenetic stage. Furthermore, homogenization temperatures (Th) of fluid inclusions are significantly lower than expected, implying a localized suppression of illitization. We propose that this atypical diagenetic trajectory is governed by sluggish fluid–rock interactions in a confined diagenetic environment. Specifically, the dissolution of feldspars during acidic diagenesis provided a localized Al3+ supply, favoring kaolinite precipitation, while the limited availability of reactive feldspar precursors and pore-fluid retention effectively stalled the progression of illitization. These findings demonstrate that reactant availability and reaction kinetics can decouple mineralogical evolution from organic thermal maturation in coal-bearing sequences. This study provides a novel mechanistic framework for interpreting anomalous diagenetic signatures in heterogeneous sedimentary basins, offering significant implications for reservoir quality prediction in deep-seated, thermally mature strata.

Geosciences doi: 10.3390/geosciences16040161

Authors: Qianlong Zhang Wei Deng Ming Su Jinqiang Liang Lei Lu

Natural gas hydrate is a clean energy resource critical for global energy security and low-carbon transition. Understanding its geological accumulation mechanisms is essential for exploration and development. However, the current research on NGH geological accumulation lacks a systematic and quantitative analysis of its global research evolution, hotspots, and frontiers. To fill this gap, this study conducts a bibliometric analysis of 5891 articles (1999–2025) from the Web of Science Core Collection using CiteSpace and VOSviewer to map research trends, contributions, and frontiers. The results show that annual publications followed a three-stage trajectory: slow initiation, rapid growth, and stable development, with key boosts from production tests in Japan (2013) and China (2017). Marine and Petroleum Geology emerged as the most cited journal. China, the United States, and Germany lead research output, with the Chinese Academy of Sciences serving as the central hub (centrality: 0.46). Core researchers such as Jinqiang Liang have established foundational knowledge through highly cited studies on accumulation theory and resource–environment interactions. Research focus has shifted from early resource assessment to controlling factors, and recently toward production technologies and parameter optimization, highlighting a transition from basic to applied research with strong interdisciplinary integration. While bibliometrics reveals structural evolution and hotspots, limitations in data sources and analytical scope remain. Future efforts should integrate multi-source data and deepen content analysis to address unresolved challenges in NGH geological accumulation.

Geosciences doi: 10.3390/geosciences16040160

Authors: Vincenzo Amato Sabatino Ciarcia Cristiano B. De Vita Laura De Girolamo Daniela Musmeci Lorenzo Radaelli Alfonso Santoriello

The viae romanae (Roman roads) were constructed according to precise designs and exceptional engineering techniques, ensuring their strength and durability. They represent an immeasurably important factor in human history. Their impact has been universal, facilitating the movement of people, goods, ideas, beliefs and religions over the centuries. The Via Appia Regina Viarum, built between the end of 4th and 1st centuries BCE, connected Rome to Brundisium, spanning the region of Latium and Apulia. The road initially crossed the coastal plains of the Tyrrhenian Sea (in Latium) before cutting through the reliefs and river valleys of the southern Apennines (in Campania) and finally crossing the regio Apulia et Calabria via Tarentum, to the harbor of Brundisium, along the Adriatic coast. In 2024, the Italian Ministry of Culture proposed the ‘Via Appia Regina Viarum’ for inscription on the Unesco World Heritage List, recognizing its unique and exceptional testimony to Roman civilization. Later that same year, the nomination was accepted, and today, the Via Appia is part of the UNESCO World Heritage List. A significant contribution to this nomination came from the multidisciplinary studies and research conducted along the Via Appia between the ancient cities of Beneventum and Aeclanum in the Campanian Apennine, including: (1) geoarcheological investigation aimed at identifying the ancient path of the road, which was not well documented in the area between Beneventum and Aeclanum; (2) studies focused on cultural and geological heritage along the road and its surrounding landscapes, enhancing the value of the nomination; and (3) the organization of social and cultural events designed to disseminate scientific findings and raise awareness among scientists, students, local and national administrators, local food and wine producers, and the general public. This paper highlights the pivotal role of geoscience at all stages of the project: from preliminary field surveys and mapping of landforms and lithofacies, to targeted field and geophysical surveys, to archaeological excavation and geoarchaeological consideration, and to the dissemination of new data through cultural events.

Geosciences doi: 10.3390/geosciences16040159

Authors: Floriana Angelone Francesca Martucci Edoardo G. D’Onofrio Filippo Russo Paolo Magliulo

The assessment of the hydromorphological state of a river is fundamental for both correctly evaluating its ecological conditions and planning its restoration. Despite this, there is a critical gap in studies on this topic in Southern Italy, although they are recommended by several EU Framework Directives. This research provides a contribution to filling this gap by assessing the hydromorphological quality of the Middle and Lower Sabato River (Southern Italy), by using the method officially adopted by the Italian Institute for Environmental Protection and Research (ISPRA), named IDRAIM. The method presents the advantage of considering the specific Italian context in terms of channel adjustments and anthropogenic impacts. However, it also considers pre-existing geomorphological approaches developed in other countries that make the method applicable at least in the entire Mediterranean area. To apply the method, in this study, we used data obtained by GIS analysis, remotely sensed data, and field-surveyed data. The study has highlighted that, in the Middle and Lower Sabato R., eight river reaches out-of-fifteen have displayed a “moderate or sufficient” morphological quality, five reaches a “good” morphological quality, while the remaining two reaches have been characterized by a “poor” morphological quality. Functional alterations have seemed to prevail over artificiality and intensity of short-term channel adjustments in conditioning hydromorphological quality. These results will be a key starting point for already planned studies dealing with both the restoration of the Sabato R. and flood hazard and risk assessment.

Geosciences doi: 10.3390/geosciences16040158

Authors: Eli K. Moore Shaunna M. Morrison Amber Hatter

Continental remobilization is a crucial driver of metallogenesis and the formation of ore deposits. Some of the world’s largest mineral deposits of the economically valuable elements tin (Sn), tungsten (W), gold (Au), copper (Cu), lead (Pb), and zinc (Zn) formed during the Mesozoic Era. Additionally, the chemistry and distribution of the elements Sn and W have been investigated in previous studies to understand planetary formation and differentiation processes. These two elements are largely co-located during certain South China Mesozoic metallogenic events but are not co-located during other time periods in the same regions. Here, we investigated the mineral chemistry network similarities and dissimilarities of Sn and W to understand their mineral formation and distribution during the Mesozoic Era and throughout Earth history. Mineral chemistry network community detection analysis and electronegativity associations among mineral constituent elements of Sn minerals and W minerals indicate that the elements have similar chemistry among their oxide minerals. However, Sn forms a much wider range of minerals that also contain S compared to W, which occurs in a limited number of S-containing minerals. The divergent constituent element interactions among S-containing Sn minerals and W minerals reflect the redox sensitivity and importance of oxygen (O) fugacity in Sn mineral formation. Conversely, extensive W mineral deposits are known to form at both high and low O fugacities. The similarities and differences between the mineral chemistry networks of Sn and W reflect the mineral distribution of the two elements in the Sn-W mineralization event from 160 to 139 Ma vs. the Sn–uranium (U) mineralization event from 125 to 98 million years ago (Ma). The mineral chemistry and distribution of Mesozoic Sn and W deposits illustrate the contrasting importance of redox and O fugacity on the mineral formation of different elements, and the dynamic crustal evolution that took place during this period of Earth history.

Geosciences doi: 10.3390/geosciences16040157

Authors: Fanfan Dou Yan Zou Huaixue Xing Hongjie Ma Chaojie Zhen Shiying Yang Yong Hu Haijie Yang

Geological environment evaluation for urban underground space (UGEE) is a critical foundation for optimizing the utilization of urban underground space (UUS) and mitigating exploitation risks. With recent advancements in 3D geological modeling technology, 3D UGEE has emerged as a transformative approach, offering innovative perspectives and technical solutions for rational 3D spatial development and geological risk reduction in subsurface engineering. A core component of the 3D UGEE workflow is the integration of diverse 3D spatial analysis methods, which enable comprehensive extraction of evaluation indices from multidimensional datasets—forming the essential basis for scientifically informed development planning. Focusing on quantitative 3D UGEE, this study systematically investigates the implementation of 3D spatial analysis methods across four key stages: (1) geological condition analysis, (2) evaluation information extraction, (3) 3D comprehensive evaluation, and (4) result analysis. Specifically, five core methodologies are highlighted: (1) 3D spatial statistical analysis, (2) 3D mathematical morphological analysis, (3) 3D surface morphology analysis, (4) 3D spatial distance field analysis, and (5) 3D spatial interpolation analysis. To improve the reliability and objectivity of 3D comprehensive evaluation results, we integrate game theory-based combination weighting with an improved TOPSIS model, which balances the subjectivity of expert judgment and the objectivity of data characteristics while adapting to the 3D block unit data structure, effectively avoiding the bias of single weighting or evaluation models. To validate these techniques, a case study in Hangzhou, Zhejiang Province, is conducted, demonstrating their practical effectiveness in evaluating UUS resources. The findings underscore that advanced 3D spatial analysis methods significantly enhance decision-making precision in UUS planning and risk management, providing a replicable framework for sustainable subsurface development.

Geosciences doi: 10.3390/geosciences16040156

Authors: Alfio Di Giovanni Simone Saltarin Andrea Carigi Carmine Todaro

The management of waste bentonite slurry (WBS) produced during slurry shield TBM excavation involves environmental and operational challenges from the perspective of developing a more sustainable tunnelling construction process. In this study, the potential reuse of WBS as a complete replacement for bentonite in two-component grout formulations used for TBM backfilling is explored. A comprehensive laboratory testing program is conducted, in which the effects of WBS on the properties of two-component grout (unit weight, viscosity, bleeding, gel time, and mechanical strength) are assessed after various curing times, and the outcomes are compared with standard values commonly given in technical specifications. WBS produced from two different commercial bentonites is investigated. The results show that while the first formulation exhibits rapid setting and irregular gelation, the mix derived from the second bentonite demonstrates superior mechanical performance, increasing compressive strength by up to 40%. This enhancement is primarily governed by a physical filler effect, where fine soil particles optimize packing density and refine the microstructure. Consequently, the incorporation of selected types of WBS into a two-component grout could be a practicable approach, since it offers benefits in terms of mechanical performance, although careful mix design would be required to manage workability. This study shows how tunnelling can become more sustainable by reusing excavation waste and transforming it into a useful by-product.

Geosciences doi: 10.3390/geosciences16040155

Authors: Katherine E. Broad Benjamin O. Sadler Peter B. James Skylar L. Hoover Nicholas L. Wagner Don R. Hood

We conducted a paired gravity and seismic survey at Kentland Crater with the goal of investigating its subsurface density structure. Our results show that the complex crater hosts a ~4.5 mGal Bouguer gravity high corresponding to the central uplift. The southeastern portion of the crater structure exhibits a low-gravity annulus at 3.5–4.5 km radius, with an adjacent high that we define as the rim at ~5.0 km radius, implying a 10 km apparent diameter. Passive seismic data is used to characterize the low-density glacial till layer, which blankets the bedrock throughout the study area. The central gravity anomaly persists after removing the gravitational influence of the till layer. Kentland’s large, positive central gravity anomaly is likely due to the removal of the low-density material beneath the original crater floor by extensive erosion via glacial scouring. We therefore suggest that the impact-induced porosity at Kentland Crater was likely confined to the original near-surface (<900 m), which aligns with recent numerical modeling. Due to the wide range of diameter estimates, we conclude that the current geometry of Kentland Crater remains ill-defined. Compiled datasets are provided here for use in future investigations.

Geosciences doi: 10.3390/geosciences16040154

Authors: Amed Bonilla Pérez Nathan Cogné Carlos Alfonso Zafra Mejía

The northwestern Amazonian Craton exposed in eastern Colombia preserves a complex Proterozoic tectonothermal history. In this study, we present new zircon and apatite U–Pb geochronological data from orthogneisses of the Guaviare Complex (Termales Gneiss unit) to constrain the timing of crust formation, metamorphism, and subsequent thermal events. Zircon U–Pb data define a dominant concordant population at ca. 1.30 Ga, interpreted as the crystallization age of an igneous protolith. This age is consistent with Mesoproterozoic A-type magmatism previously recognized in the region and consistent with emplacement under intracratonic extensional conditions, as suggested by previous studies. A limited number of discordant zircon analyses indicate Pb loss and/or partial isotopic resetting between ~1.0 and 0.6 Ga, although no well-defined metamorphic zircon population is identified. Meanwhile, apatite U–Pb analyses from key samples yield consistent lower intercept ages between 633 ± 16 Ma and 543 ± 8 Ma, indicating a widespread Ediacaran thermal disturbance that may have affected the Guaviare Complex, temporally overlapping with alkaline magmatism in the northwestern Amazonian Craton, including the San José del Guaviare Nepheline Syenite. However, alternative mechanisms such as fluid-assisted Pb mobility, regional reheating, or prolonged cooling cannot be excluded. Finally, the combined zircon–apatite dataset highlights the value of multi-chronometer approaches for resolving complex thermal histories in cratonic domains.

Geosciences doi: 10.3390/geosciences16040153

Authors: Elias E. Chikalamo Olga C. Mavrouli Piernicola Lollino

Research on landslides around reservoirs is necessitated to strengthen risk prevention and mitigation, as their occurrence has catastrophic consequences. For reservoir safety assessments, landslide susceptibility analysis is commonly concentrated on single reservoir bank slopes or individual landslides. However, focusing solely on bank slopes and individual landslides gives an incomplete picture of how safe the reservoir is from possible landslide related risks, since landslides from distant slopes can also adversely affect the reservoir in different ways. In this paper, landslide susceptibility assessment was conducted using machine learning models (Gradient Boosting Machine, XGBoost, Random Forest and Ensemble Stacking) in the area around the San Pietro Dam, an earth dam located in Southern Italy, in a region highly prone to landslide hazards. The landslide inventory for the area was used to generate landslide and non-landslide points for model training and testing. The area under curve (AUC) of a receiver operating characteristic (ROC) curve approach was used to evaluate, validate, and compare the performance of the four models. Results indicated that the ROC AUC values of the models ranged from 0.76 to 0.77, with the Random Forest, Gradient Boosting and Ensemble stacking models having AUC values of 0.77. All the models classified about 15–20% of the reservoir basin as highly susceptible to landslides. The generated basin-scale landslide susceptibility maps can be used to prioritize monitoring and maintenance in areas around the dam that have been identified as highly susceptible.

Geosciences doi: 10.3390/geosciences16040152

Authors: Joana Alexandra Ferreira Helena C. B. Martins Maria dos Anjos Ribeiro José Francisco dos Santos

Isotopic disequilibrium during the formation of high-temperature (HT) metamorphic complexes by anatexis during continental collision is a process that deserves intense discussion since it is fundamental to understand the evolution of continental crust. The axial sector of the Iberian Variscan Belt (IVB) is known by the profusion of synorogenic granites that are sometimes clearly associated with the migmatites composing the HT metamorphic complexes. The Pedregal Migmatitic Complex is located in the autochthonous domain of the IVB and is composed of metatexites and diatexites associated to syntectonic two-mica granites. The anatectic process occurred by dehydration melting of muscovite and biotite with the growth of peritectic minerals such as garnet, K-feldspar, and sillimanite in metatexites; and K-feldspar, sillimanite, and hercynite in diatexites reaching the metamorphic peak at 313.3 ± 0.5 Ma. A process of residuum-melt separation during crustal melting is attested by the Pedregal migmatites, giving origin to metatexites and residual diatexites as indicated by field evidence and their geochemical signature. Zircon oxygen isotopes and inherited zircon ages point to the Douro-Beiras Supergroup metasedimentary sequence (Beiras group) as a possible protolith of the Pedregal diatexites. Conversely, the isotopic composition of the diatexites suggests isotopic disequilibrium caused by residual mineral phases (biotite, monazite and garnet).

Geosciences doi: 10.3390/geosciences16040151

Authors: Juan Luis Ccamapaza Aguilar Hebert Hernán Soto Gonzales Sheda Méndez-Ancca Mario Ruiz Choque Luis Enrique Sosa Anahua Renzo Pepe-Victoriano Alex Tejada Cáceres Danny Efrain Baldarrago Centeno Olegario Marín-Machuca Jorge González Aguilera

The geomorphological characterization of coastal–marine environments is essential for environmental management and biodiversity conservation. The objective of this study was to model the geomorphological diversity of the Punta de Coles National Reserve, located in Puerto de Ilo, Moquegua, Peru, using GNSS geodetic receivers, integrating topographic and bathymetric data to continuously represent both the emerged and submerged relief. The methodology involved establishing two “C”-order geodetic control points, implementing a closed polygon with 13 vertices, conducting a topographic survey, and recording bathymetric data along coastal transects extending 1 km offshore using an echo sounder and GNSS positioning. The data were processed in a GIS environment to generate a Coastal–Marine Digital Terrain Model (CM-DTM) with metric resolution. The results showed a total area of 171.451 ha, with elevation variations ranging from sea level to 71.617 m above sea level. Distinct geomorphological units were identified, such as coastal plains (0–5% slope), hills (15–35%), and cliffs (>45%), in addition to 16 rocky islets covering 1.537 ha. In the underwater environment, the model made it possible to identify submerged terraces, slopes, and local depressions down to a depth of −115 m, revealing a continuous transition between the land and sea topography; additionally, areas with a higher susceptibility to erosion and areas of high ecological importance were identified. This study’s contribution lies in the integration of GNSS geodetic data with topobathymetric surveys, which enabled the generation of a high-precision continuous model in an area with limited prior information, establishing a scientific baseline for coastal and marine management and conservation.

Geosciences doi: 10.3390/geosciences16040150

Authors: Suresh Neupane Netra Prakash Bhandary Dericks Praise Shukla

Rain-induced shallow landslides persistently disrupt Nepal’s mountain roads, frequently leading to fatalities, transport disruptions, and economic losses. This study develops physically validated, site-specific rainfall thresholds for the landslide-prone Kanti National Roadway (H37) by integrating empirical intensity–duration (I-D) analysis, antecedent rainfall metrics, and satellite-derived soil moisture data. Using 35 years of rainfall records (1990–2024) and 59 field-verified landslides (2017–2024), we derived a localized I-D threshold: I = 19.37 × D−0.6215 (I: rainfall intensity in mm/h; D: duration in hours), effective for durations of 48–308 h, encompassing short intense storms and prolonged moderate rainfall. The Cumulative Antecedent Rainfall (CAR) method associated most failures with 3-day totals, while the Antecedent Precipitation Index (API) showed superior performance, with a 10-day threshold of 77 mm capturing all events. For physical validation, NASA’s SMAP Level-4 root-zone (0–100 cm) soil moisture data revealed a 1-day lag in response to rainfall; after adjustment, trends matched API saturation predictions and identified an inverse rainfall–moisture pattern before the 11 August 2019 landslide, indicating a potential instability precursor. This integration enhances predictive accuracy, bolsters mechanistic understanding of landslide hazards, and offers a scalable, cost-effective early-warning framework for data-scarce mountain regions, aiding climate-resilient infrastructure in regions with intensifying rainfall extremes.

Geosciences doi: 10.3390/geosciences16040149

Authors: Emmanouil A. Varouchakis Evangelos Machairas Ioulia Koroptsenko Stylianos Tampouris Christos Stenos Michail Galetakis

The growing demand for Critical Raw Materials (CRMs) requires mining practices that align with sustainability and environmental, social, and governance (ESG) principles, while mining training increasingly benefits from advanced digital tools. Virtual Reality (VR) can provide high-resolution site representations that support both interactive learning and data-oriented analysis without operational risk. This study presents a VR-based framework for the quantitative assessment of pit lake rehabilitation using Virtual Excursions (VEs) developed from panoramic imagery and supported by machine-learning correction. High-resolution 360° panoramic images were used to extract geometric characteristics of a rehabilitated pit lake at the LARCO GMMSA Euboea mine site, Greece, including surface area, shoreline length, mean diameter, and maximum diameter. These image-derived estimates were validated against ground-truth data from field surveys and mine-closure documentation. To reduce systematic deviations associated with panoramic image measurements, a supervised multiple linear regression model was applied as a correction step. Validation based on Root Mean Square Error (RMSE) and the coefficient of determination (R2) showed substantial improvement of the corrected estimates relative to the uncorrected image-based measurements. The results demonstrate that panoramic VR imagery can support site-specific quantitative environmental assessment in addition to its educational value. Although the present findings are limited to a single pit lake case study, the proposed workflow provides a structured basis for integrating immersive visualization, image-based measurement, and regression-based correction in post-mining rehabilitation assessment.

Geosciences doi: 10.3390/geosciences16040148

Authors: Spyridon Mavroulis Efthymios Lekkas

This research provides an extensive evaluation of liquefaction induced by earthquakes in the Ionian Islands, specifically Lefkada, Cephalonia, Ithaki, and Zakynthos, through the compilation of a liquefaction inventory and GIS-based liquefaction susceptibility index (LiSI) maps. A total of 49 liquefaction sites from 20 causative earthquakes confirm that liquefaction is a recurrent geohazard in the area, primarily affecting coastal and low-lying areas with unconsolidated post-alpine deposits. The relationship between earthquake magnitude and maximum epicentral distance of observed liquefaction is consistent with global empirical datasets, indicating that moderate to strong earthquakes (Mw = 5.9–7.4) can induce liquefaction at considerable distances. The susceptibility model integrates eleven conditioning variables, classified as geological and geomorphological variables, hydrological indices and optical satellite imagery-derived data, within an analytic hierarchy process (AHP) framework. Lithology, age, and geomorphological unit emerged as the dominant conditioning variables. The LiSI maps confirm the zones previously identified in the inventory. Model validation and sensitivity analysis including confusion matrix components, key performance metrics and ROC analysis in coarser grid sizes demonstrate performance ranging from excellent (Zakynthos) to moderate (Lefkada and Cephalonia), while remaining inconclusive for Ithaki due to data limitations. The model exhibits generally conservative behavior, characterized by high precision and specificity but variable sensitivity, while it is largely stable across spatial resolutions in most cases.

Geosciences doi: 10.3390/geosciences16040147

Authors: Alexandra Mota Joana Alexandra Ferreira Fernando Noronha Helena Sant’Ovaia

Variscan two-mica granites are widespread in the Trás-os-Montes region (NE Portugal), yet their emplacement ages, petrogenesis, and relationship with Variscan deformation phases remain poorly constrained. This study integrates U–Pb zircon geochronology, whole-rock geochemistry, and oxygen isotope data to characterise four peraluminous two-mica granites in the Trás-os-Montes area (Fornos, Carviçais, Fonte Santa, and Bruçó) and to refine their tectonomagmatic context within the Central Iberian Zone. All granites are S-type, ilmenite-series, and derived from reduced magmas, as indicated by their strongly peraluminous compositions, mineral assemblages (muscovite ± biotite), absence of magnetite and presence of ilmenite, and high δ18O values (>11‰), consistent with partial melting of metasedimentary crust. U–Pb ages reveal two distinct magmatic pulses: an older event at ~340 Ma (Fornos and Fonte Santa granites), predating the onset of C3 deformation and likely associated with late C1 crustal thickening to early C2 tectonics, and a younger pulse at ~320–318 Ma (Carviçais and Bruçó granites). These magmatic pulses are linked to contrasting structural controls, with the older granites emplaced within regional-scale antiforms and the younger intrusions localised along structures related to C3 deformation. Together, these results document two discrete crustal melting events separated by ~20 Ma and record a progressive shift from fold-controlled to strike-slip-dominated granite emplacement during Variscan orogenic evolution. Moreover, the study highlights that tungsten mineralisation is preferentially associated with reduced, crust-derived granites emplaced during specific tectonic regimes, providing new constraints for metallogenic models in NW Iberia.

Geosciences doi: 10.3390/geosciences16040146

Authors: Bikash Chaudhary Krishna Kanta Panthi

Unlined pressure tunnels and shafts are widely employed in hydropower projects where the surrounding rock mass is required to sustain the internal water pressure. Their hydraulic stability is governed by complex interactions among the three-dimensional in situ stress state, discontinuity geometry, rock mass properties, and operational water pressure. Conventional deterministic design approaches address these factors implicitly and provide limited information on the likelihood of hydraulic failure mechanisms, such as hydraulic jacking, hydraulic fracturing, and shear slip of discontinuities. This paper presents a probabilistic framework for assessing the hydraulic stability of unlined pressure tunnels and shafts, in which the governing failure mechanisms are explicitly formulated as limit states and key sources of uncertainty are systematically represented. The full three-dimensional stress tensor is rotated onto potential discontinuity planes to evaluate effective normal and shear stresses, and reliability-based methods are employed to quantify probabilities of failure. The methodology is demonstrated through a representative case study of a failed unlined pressure tunnel reflecting typical geological and stress conditions encountered in hydropower projects. The results show that variability in stress orientation and discontinuity characteristics has a strong influence on hydraulic stability and that commonly used deterministic criteria may not fully capture the associated failure risk.

Geosciences doi: 10.3390/geosciences16040145

Authors: Xijiang Wu Hengli Zhou Wenlong Xu Fasheng Miao Lixia Chen Chuncan He Yiqing Sun

As one of the most catastrophic geological hazards globally, landslides exhibit heightened risks due to their increasing frequency, destructive potential, and extensive spatial distribution. The primary objective of this study is to develop an integrated analytical framework to quantitatively evaluate the stability of variably shaped slopes under rainfall infiltration. The core hypothesis is that slope curvature significantly alters infiltration behavior and stress distribution, leading to morphology-dependent failure mechanisms. Employing Green-Ampt infiltration theory coupled with limit equilibrium analysis, we establish stability prediction models for three fundamental slope geometries (linear, concave, convex) under contrasting rainfall regimes (high-intensity vs. low-intensity precipitation). The derived analytical solutions reveal two critical phenomena: (1) progressive downward migration of the saturation front maintaining parallelism with slope surfaces during infiltration and (2) time-dependent stability deterioration following hyperbolic decay patterns. The proposed models are rigorously validated through numerical simulations employing finite element methods, which demonstrate remarkable congruence with theoretical predictions, showing safety factor discrepancies below 5% (ΔFs < 0.05). Particularly, concave slopes exhibit 18–22% faster destabilization rates compared to convex counterparts under equivalent rainfall conditions. The validated models elucidate the spatiotemporal evolution of matric suction and pore pressure distributions, providing quantitative insights into morphology-dependent failure thresholds. These findings advance predictive capabilities for rainfall-induced landslides through physics-based stability criteria, offering critical guidance for terrain-specific early warning systems and mitigation strategies in geohazard-prone regions.

Geosciences doi: 10.3390/geosciences16040144

Authors: Paxton Tomko Cesar Ivan Ovando-Ovando Pierre Boussagol Michel Geovanni Santiago-Martínez Pieter T. Visscher

Methanogens, or methanogenic archaea (MA), are among the most ancient and widely distributed microorganisms, characterized by a unique metabolism that generates methane (CH4) as the terminal product of anaerobic respiration. Their ability to grow and/or survive across a wide range of environmental conditions has made methanogens key contributors to biogeochemical cycles throughout most of Earth’s history. Most importantly, these oxygen-sensitive microorganisms have regulated the climate since the early Archean and impacted biogeochemical cycles throughout Earth’s history by producing the potent greenhouse gas, CH4, while consuming H2, CO2, and small organic molecules. Hence, methanogens are attributed a key role in the start and end of several Proterozoic glaciations and mass extinction events. Their specific roles in the long-term carbon cycle that focus on CH4 production are well-established, but, in contrast, only very few studies report on interactions with CaCO3 and long-term carbon storage. Methanogens evolved early during Earth’s history, likely during the Archaean Eon, in layered benthic microbial communities called microbial mats. When lithified, these mats form microbialites that represent some of the earliest evidence of life in the fossil record, dating back >3.5 Gy. Methanogens are an integral part of contemporary microbial mats and have been identified both in the anoxic and oxic zones of these sedimentary ecosystems; however, their adaptations to apparently unfavorable oxic conditions and their role in the precipitation of carbonate in mats are unclear. In addition to an important role in the evolution of our planet by producing CH4, methanogens may also produce a biosignature that could be relevant for astrobiology research. This review will discuss the diversity, physiology, and ecology of methanogens in detail to clarify their role in some of the major biogeochemical processes and ecological climatic events through the fluctuating environmental conditions on Earth through geologic time.

Geosciences doi: 10.3390/geosciences16040143

Authors: Tao Lin Weiwei Tao Yakang Xu Wenjing Niu

Aiming at the problems of microseismic signals from rock mass fracture in deep-buried tunnels with low signal-to-noise ratio (SNR) suffering from coupled interference of multi-source noise, and traditional filtering methods having fixed parameters and poor processing effects on spectral aliasing, this study proposes a ternary coupled adaptive filtering method integrating the Sparrow Search Algorithm, Variational Mode Decomposition and Wavelet Threshold Denoising (SSA-VMD-DWT). First, the noise intrusion characteristics of low-SNR microseismic signals in deep-buried tunnels were analyzed, and the filtering difficulties of white noise, low-frequency noise, high-frequency noise and non-stationary noise were clarified. Subsequently, a parameter optimization framework with the Sparrow Search Algorithm (SSA) as the core was constructed to optimize the key parameters, including the penalty factor α and modal number K of Variational Mode Decomposition (VMD), as well as the wavelet basis and decomposition layers of Wavelet Threshold Denoising (DWT), respectively. A dual-index threshold decision function based on kurtosis and correlation coefficient, and a wavelet packet entropy weighted reconstruction algorithm were designed to realize the collaborative adaptive adjustment of decomposition depth and threshold rules. Finally, the performance of the algorithm was verified through simulation signal experiments and an engineering case of a deep-buried tunnel in Southwest China. The results show that for the simulated signal with a low SNR of 2 dB, the SNR is increased to 12.43 dB, and the root mean square error is reduced to 2.36 × 10−7 after denoising by this algorithm, which is significantly superior to the Empirical Mode Decomposition (EMD) and traditional DWT methods. In the engineering case, the information entropy of the filtered signal is the lowest among all methods, which can effectively suppress multi-band noise and retain the core characteristics of microseismic signals from rock mass fracture, solving the problems of spectral aliasing, detail loss and empirical parameter setting of traditional methods. This method provides a new technical paradigm for the processing of low-quality microseismic signals in deep tunnel engineering and can improve the accuracy of monitoring and early warning for rock mass dynamic disasters.

Geosciences doi: 10.3390/geosciences16040142

Authors: Xianxiang Wang Shanmei Li Zefan Hu Qing Sun

Marine electric-source time domain electromagnetic (TDEM) surveys typically involve the simultaneous movement of transmitters and receivers, which generates a large number of transmitter–receiver pairs. This acquisition geometry creates notable challenges for 3D inversion, mainly because of the large data volume and high computational cost. However, the electromagnetic “sensitive region” for each transmitter–receiver pair is much smaller than the full survey area. Based on this feature, we propose an efficient 3D inversion approach using the footprint technique. By clearly defining the sensitivity region, referred to as the footprint domain, for each pair, the method builds the sensitivity matrix only within localized subsurface regions that significantly affect the observed response. This approach greatly reduces both forward modeling cost and memory requirements. The forward modeling adopts an integral equation method combined with cosine transforms for fast 3D field computation, while the inversion framework uses a regularized conjugate-gradient algorithm, further accelerated by parallel computing under footprint domain constraints. Numerical simulations also examine the effects of offset, time channel, seawater thickness, and resistivity on the footprint domain, helping clarify the spatiotemporal diffusion behavior of TDEM fields in shallow marine environments. Tests on representative models show that the proposed method remains stable and accurate under complex geological conditions while significantly improving computational efficiency. In particular, the footprint domain technique improves inversion speed by about 55% compared with full domain inversion. These results indicate that the proposed approach provides a reliable and scalable option for large-scale 3D inversion of marine TDEM data.

Geosciences doi: 10.3390/geosciences16040141

Authors: Agostino Meo Bruno Massa Sabatino Ciarcia Maria Rosaria Senatore

The Gulf of Taranto (Ionian Sea) is a key transitional sector between the Southern Apennines collisional belt and the Calabrian Arc system, where the expression of Pleistocene–Holocene deformation in the shallow stratigraphic record remains debated. This study focuses on the Taranto Canyon area, the main morphologic feature of the northeastern Gulf of Taranto slope. We integrate high-resolution multibeam bathymetry (10 m grid) with Sparker seismic profiles to (i) define the shallow seismo-stratigraphic framework and (ii) document spatial relationships between shallow discontinuities, morphostructural lineaments, and submarine channel network organization. A simplified tie to the Livia 001 well constrains the subdivision of the shallow succession into four seismic units: the late Pleistocene–Holocene unit (PtH), the Santerno Formation (SNT), the Calcarenite di Gravina (GRA), and the Cupello Limestones (CPL). The PtH interval shows the strongest lateral variability and includes widespread acoustically disturbed bodies and recurrent sub-vertical fluid escape acoustic anomalies. Steep discontinuities producing reflector terminations, minor vertical separation, and localized bending affect PtH and, locally, SNT, with normal fault geometries prevailing where resolvable. Bathymetric mapping reveals multiple lineament families and preferred channel orientations that persist across higher Strahler orders, supporting a structurally conditioned template that guides seafloor morphology, sediment routing, and canyon–slope evolution in the northeastern Gulf of Taranto.

Geosciences doi: 10.3390/geosciences16040140

Authors: Nikolay Bonev

The Circum-Rhodope Belt fringes the Rhodope and Serbo-Macedonian zones in the Alpine orogen of the northern Aegean region. This belt contains Late Paleozoic and Mesozoic metasedimentary successions that record depositional history along the continental margin of Eurasia. Critical successions of the eastern Circum-Rhodope Belt, such as those exposed in the Fanari and Petrota areas, are studied here, integrating their structure, whole-rock geochemistry and U-Pb LA-ICP-MS zircon geochronological context. The Fanari turbiditic succession contains quartz arenite, while the Petrota succession consists of Fe-rich shale and sandstone, and both successions are distinguished by REE-depleted and REE-enriched characteristics and acidic and intermediate arc-related sedimentary sources, respectively. Detrital U-Pb zircon geochronology reveals a Late Carboniferous–Early Permian maximum depositional age of 301.2 ± 8.4 Ma for Fanari quartz arenite and a Late Jurassic maximum depositional age of 147.0 ± 2.0 Ma for Petrota Fe-shale. The results are interpreted in terms of Late Paleozoic continental slope deposition of the Fanari succession along the Eurasian margin and trench-arc sedimentation of the Petrota succession linked to the development of a Jurassic island arc system pertinent to the eastern Circum-Rhodope Belt. These tectonic settings and depositional environments can be used to restore an overall picture of a Late Paleozoic to Mid-Mesozoic sedimentation at the Rhodope–Serbo-Macedonian continental margin of Eurasia. Structures that developed in greenschist facies conditions and N-directed kinematics of the studied successions unequivocally relate them to other units of the eastern Circum-Rhodope Belt and its Late Jurassic tectonic evolution.