Geoscience frontiers最新文献

{"title":"Aquifer characterization and salinization origin using unsupervised machine learning and 3D gravity inversion modeling, Siwa Oasis, Egypt","authors":"Mohamed Hamdy Eid ,&nbsp;Khouloud Jlaiel ,&nbsp;Mohamed Ayed Elbalawy ,&nbsp;Yetzabbel G. Flores ,&nbsp;Ali A. Mohieldain ,&nbsp;Tamer Nassar ,&nbsp;Mostafa R. Abukhadra ,&nbsp;Haifa A. Alqhtani ,&nbsp;Attila Kovács ,&nbsp;Péter Szűcs","doi":"10.1016/j.gsf.2026.102258","DOIUrl":"10.1016/j.gsf.2026.102258","url":null,"abstract":"<div><div>Groundwater salinization in arid oasis environments poses significant challenges for sustainable water resource management. In Siwa Oasis, Egypt, the deep Nubian Sandstone Aquifer System (NSSA) and the shallow Tertiary Carbonate Aquifer (TCA) interact through fault systems. At the same time, the potential leakage from hypersaline surface lakes creates complex hydrogeological conditions that require comprehensive characterization. Despite the critical importance of understanding aquifer connectivity and salinization processes, there remains a significant knowledge gap in the quantitative integration of multiple geophysical datasets for objective aquifer characterization and structural control identification. Traditional methods lack the spatial resolution and objective framework necessary to map lithofacies distributions and identify structural pathways controlling groundwater flow in complex multi-aquifer systems.</div><div>This study presents an integrated approach, combining machine learning clustering with gravity data analysis, to characterize the region’s aquifer systems. K-means and Self-Organizing Maps (SOM) were applied to well log data, including Gamma Ray (GR), Spontaneous Potential (SP), and resistivity (R), to delineate lithofacies. Three distinct units were identified: clean sand, shaly sand, and clay-rich facies. The SOM algorithm outperformed the clustering of K-means in accurately estimating layer thickness and resolving lithological transitions. A 3D lithofacies model revealed spatial heterogeneity within the NSSA, highlighting clean sand layers as primary groundwater extraction zones.</div><div>Gravity data analysis using upward continuation and edge-filtering techniques identified dominant NE-SW, NW-SE, and E-W lineaments controlling groundwater flow dynamics. The 3D gravity inversion model revealed density contrasts associated with structural features, providing insights into potential groundwater flow between aquifers. Spatial analysis reveals lower groundwater salinity in the southern part of the Oasis, coinciding with areas of reduced structural complexity. Higher salinity zones in central and northeastern regions show spatial correlation with gravity-derived structural systems, though causal relationships require additional validation through hydrochemical studies. This integrated approach provides critical insights for sustainable groundwater management in structurally complex arid environments.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102258"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized inversion of Chang’e-2 gamma-ray spectrum data into heat production rate for thermal evolution study: Imbrium Basin as an example","authors":"Zhenghe Li,&nbsp;Yuyan Zhao,&nbsp;Xiaodan Tang,&nbsp;Zhiguo Meng","doi":"10.1016/j.gsf.2026.102254","DOIUrl":"10.1016/j.gsf.2026.102254","url":null,"abstract":"<div><div>The lunar surface element distribution obtained from Chang’e-2 gamma-ray spectrometer has provided new insights into the thermal activity and element migration of the Moon. To further investigate lunar thermal evolution and geological activities, the heat production rate (HPR) distribution was selected as a breakthrough. An optimized inversion method for Chang’e-2 gamma-ray spectrum data, based on multivariate statistical analysis, was developed to effectively reduce the influence of time-varying factors by improving the background estimation and subtraction process. The results validated the utility of HPR for lunar research. The global HPR distribution maps not only provide a reference for assessing the thermal state of the lunar surface, demonstrating that radiogenic heat production can be reliably studied at a global scale, but also enable detailed investigations of regional geological processes. In the Imbrium Basin, HPR clearly reflects the effects of large-scale impact events and subsequent mare volcanic activity. High-HPR materials associated with impact ejecta can be distinguished from the lower-HPR mare basalts. Furthermore, by integrating HPR data with additional geological information, it is possible to assess and partially subdivide the structure of the Imbrium Basin, providing new quantitative insights into its evolution and compositional heterogeneity.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102254"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fine characterization of micro-nano fractures and analysis of network connectivity: Mechanistic controls on hydrocarbon enrichment in shale reservoirs","authors":"Boyang Wang ,&nbsp;Dengfu Yuan ,&nbsp;Jingjing Li ,&nbsp;Shichao Li ,&nbsp;Fei Xiao ,&nbsp;Shansi Tian ,&nbsp;Mengjing Yin ,&nbsp;Jianguo Yang","doi":"10.1016/j.gsf.2025.102233","DOIUrl":"10.1016/j.gsf.2025.102233","url":null,"abstract":"<div><div>Micro-nano fractures serve as the bridge connecting nanopores and macro-fractures. The unclear understanding of their developmental characteristics and controlling factors significantly hinders the large-scale, efficient development of continental shale oil. To address this, this study employs the entropy weight method to establish an evaluation model for fracture development strength that comprehensively considers fracture number, average width, areal density, and areal porosity. Additionally, topology is introduced to evaluate fracture connectivity. The research clarifies the differences in micro-nano fracture developmental characteristics and primary controlling factors among different lithofacies and elucidates the impact of micro-nano fracture development on pore structure and hydrocarbon accumulation in Gulong shale. The results indicate that the HQS (high-organic laminated felsic shale) lithofacies exhibits high micro-nano fracture development strength and connectivity, yielding the highest comprehensive evaluation index. The HCS (high-organic laminated mixed shale) shows high development strength but low connectivity, resulting in a secondary comprehensive evaluation index. Higher organic matter content correlates with greater fracture development strength; clay mineral content controls the characteristics of nano-fracture development; felsic mineral content positively influences fracture connectivity. The development of micro-nano fractures not only enhances macropore content and average pore size but also effectively connects pores of various scales, increasing the effectiveness of the pore-fracture system. Lithofacies with low fracture connectivity (primarily HCS) exhibit more complex pore structures. Shale oil in such lithofacies mainly accumulates via a self-sealing model, making it difficult to form complex fracture networks during hydraulic fracturing and hindering efficient development. Conversely, the HQS lithofacies demonstrates optimal pore-fracture connectivity, favorable oil content, and represents the most favorable lithofacies for Gulong shale oil development. These findings contribute to the optimization of sweet-spot intervals for shale oil exploration in the study area.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102233"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First observation of coexisting crystalline and amorphous mineral phases in the Bhawad LL6 chondrite: Evidence from Micro-Raman spectroscopic studies","authors":"Bhaskar J. Saikia ,&nbsp;G. Parthasarathy ,&nbsp;Binoy K. Saikia ,&nbsp;Puja Bordoloi ,&nbsp;Rashmi R. Borah","doi":"10.1016/j.gsf.2025.102236","DOIUrl":"10.1016/j.gsf.2025.102236","url":null,"abstract":"<div><div>We report here for the first time the detailed spectroscopic investigations on Bhawad meteorite using micro-Raman spectroscopic and high-resolution transmission electron microscopy (HR-TEM) investigation of the Bhawad LL6 ordinary chondrite, focusing on its mineralogical composition and carbonaceous phases. Raman spectroscopy reveals crystalline silicates including olivine, pyroxene, and plagioclase, along with accessory chromite containing ≤20% of Al. Carbonaceous material exhibits broad <em>I</em>_D (∼1336 cm⁻¹) and <em>I</em>_G (∼1587 cm⁻¹) bands with an <em>I</em>_D/<em>I</em>_G ratio of ∼1.04, indicative of disordered graphite and nanocrystalline carbon, reflecting shock-induced metamorphism. High-pressure TiO₂ polymorphs are identified by characteristic Raman modes at 146, 394, 446, and 610 cm⁻¹. HR-TEM imaging confirms the presence of nanocrystalline TiO₂ particles embedded within amorphous carbonaceous matrices, demonstrating the coexistence of crystalline and amorphous phases. The Raman spectra of the Bhawad meteorite reveal the presence of high-temperature plagioclase phases, characterized by these distinct vibrational features. This observation indicates possible quenching of the melts having feldspar components, representing the complex thermal and shock metamorphic history of the meteorite. This coexistence of crystalline and amorphous phases highlights the complex thermal and shock history of the Bhawad meteorite, revealing insights into phase transitions and structural order–disorder phase transition induced by impact processes.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102236"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predictive modeling of pore pressure build-up in vibratory pile driving through machine learning","authors":"Sepideh Fadaei ,&nbsp;Amir Hamidi ,&nbsp;Enrico Soranzo","doi":"10.1016/j.gsf.2025.102209","DOIUrl":"10.1016/j.gsf.2025.102209","url":null,"abstract":"<div><div>In the context of large-scale infrastructure projects, such as major bridges and docks on shorelines, understanding the behavior of deep piles in saturated sandy soils is crucial. This study employs three-dimensional numerical modeling of vibratory pile driving using Midas GTS NX finite element software and the UBCSAND constitutive model, challenging several common simplifying assumptions found in prior research. The efficacy of the numerical model in predicting pile driving processes and potential liquefaction was rigorously evaluated and validated against experimental data from previous studies. Sensitivity analyses were performed to investigate how pore pressure and liquefaction potential are influenced by various factors, including vibratory pulse counts, pile length-to-diameter ratios, and soil properties. The results from these analyses were utilized to train artificial neural networks and symbolic regression models. The performance of these models was assessed using a range of performance metrics and ROC curves. To enhance interpretability, symbolic regression provided a clear mathematical expression capturing the relationship between key features and soil liquefaction. Furthermore, SHapley Additive exPlanations were employed to offer detailed insights into feature importance and the model’s decision-making process. Design charts were developed based on these models to offer practical guidance for practitioners. Overall, this study underscores the effectiveness of integrating advanced numerical simulations with machine learning techniques, demonstrating significant improvements in understanding and predicting pile driving behavior and liquefaction potential in saturated sandy soils.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102209"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Collision-related tin metallogeny: Insight from a new discovery of the volcanic-subvolcanic-hosted Sn deposit in the western Gangdese, Xizang","authors":"Hao Chen ,&nbsp;Xin Chen ,&nbsp;Youye Zheng ,&nbsp;Xian Che ,&nbsp;Yuanping Lai ,&nbsp;Xingkai Huang ,&nbsp;Shunbao Gao ,&nbsp;Bei Pang","doi":"10.1016/j.gsf.2025.102216","DOIUrl":"10.1016/j.gsf.2025.102216","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Gangdese metallogenic belt in Xizang, a world-class copper polymetallic province, has a poorly understood western segment due to extensive volcanic cover and limited historical exploration. The recent discovery of the Sangmoladong (SMLD) deposit, the first undocumented volcanic- to subvolcanic-hosted, tin-dominant polymetallic system in western Gangdese, provides a unique opportunity to investigate collisional metallogeny. Through integrated LA-ICP-MS U-Pb geochronology of zircon and cassiterite, comprehensive whole-rock geochemistry, and Nd-Hf isotopes, this research establishes a genetic link between Paleocene magmatism and Sn-polymetallic mineralization. The mineralization is hosted within granite porphyry stocks and associated rhyolitic tuff breccias of a volcanic dome complex. It comprises two main stages: an early, disseminated cassiterite-sulfide stage with chloritic alteration, followed by later fluorite-cassiterite-tourmaline veins and veinlets. New LA-ICP-MS U-Pb dating constrains the timing of granite porphyry emplacement to 61.3 ± 0.2 Ma and rhyolitic tuff deposition to 61.8 ± 0.5 Ma. Cassiterite mineralization occurred between 61.0 ± 2.2 Ma and 59.3 ± 3.5 Ma, confirming that Sn metallogenesis was coeval with this Paleocene magmatic pulse during the Indo-Asian collision. The ore-forming granitic porphyries are highly evolved, A-type granites, characterized by high SiO&lt;sub&gt;2&lt;/sub&gt; (77.50 – 80.40 wt.%), elevated zircon saturation temperatures (831 – 870 °C), and high Ga/Al ratios (10,000 × Ga/Al = 5.75 – 6.51). Their Nd-Hf isotopic signatures (&lt;em&gt;ε&lt;/em&gt;&lt;sub&gt;Nd&lt;/sub&gt;(&lt;em&gt;t&lt;/em&gt;) =  −6.5 to −6.3; zircon &lt;em&gt;ε&lt;/em&gt;&lt;sub&gt;Hf&lt;/sub&gt;(&lt;em&gt;t&lt;/em&gt;) =  −5.2 to +2.1) indicate an origin from anatexis of ancient Lhasa terrane metapelites, likely triggered by lithospheric extension during Neo-Tethyan slab rollback. This generated a reduced, fluorine- and boron-rich magmatic-hydrothermal system highly efficient at mobilizing and concentrating tin. On a regional scale, a metallogenic framework is proposed where Fe-Cu mineralization is sourced from hybridized mantle-crust magmas, whereas Pb-Zn and Sn systems derive from similar crustal-dominated sources. This metallogenic divergence of Pb-Zn and Sn reflects contrasting thermal regimes and magma crystallization pathways during a transtensional setting with local extension in pull-apart and uplift structures. The formation of the SMLD tin deposit is attributed to prolonged fractional crystallization of a high-temperature, low &lt;em&gt;f&lt;/em&gt;O&lt;sub&gt;2&lt;/sub&gt; magma within a subvolcanic dome complex. These conditions suppressed early cassiterite saturation and promoted extreme tin enrichment in the residual melt. This study makes two key contributions: (1) it identifies the first volcanic-hosted tin system in the western Gangdese, challenging traditional exploration models focused on porphyry skarn Cu-Pb-Zn deposits; and (2) it establishes a new tectono-metallogenic model that elucidates the spatiotempor","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102216"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast production of large lithologic maps using lithologic sample generation strategies based on 3D spatial positioning","authors":"Tao Zhang ,&nbsp;Zhifang Zhao ,&nbsp;Min Zeng ,&nbsp;Haiying Yang","doi":"10.1016/j.gsf.2025.102217","DOIUrl":"10.1016/j.gsf.2025.102217","url":null,"abstract":"<div><div>The acquisition of spatiotemporal information for lithological mapping with timeliness, accuracy, and high precision is crucial for mineral resource exploration and geological hazard prevention. However, large-scale lithological mapping remains severely constrained by the limitations of visual interpretation in obtaining representative samples from remote sensing data and error propagation during sample collection based on existing geological maps. To address this, we propose a three-dimensional spatial dual-positioning sample generation methodology (SG-3DSD) using Sentinel-2 (S2) and Landsat 8 (L8) data on the Google Earth Engine (GEE) platform, enabling automated generation of 11 lithological class samples across the Beishan region of Gansu Province, China (covering approximately 6,000 km²). First, boundary association rules were established to reconstruct 1:200,000-scale geological maps, mitigating data acquisition biases and cartographic compilation errors. Second, principal component analysis (PCA) was performed on seven S2 spectral bands, with the first three principal components (capturing &gt; 98% information variance) constituting a 3D feature space for localized clustering. Concurrently, four L8 bands were selected through lithological spectral curve analysis to implement band ratio (BR) transformations for secondary positioning. Finally, a two-step refinement strategy was implemented to filter high-confidence samples across 11 lithological classes, balancing intraclass feature consistency and sample purity. Applying SG-3DSD-derived samples to multiple machine learning models revealed that (1) the Stacking ensemble model demonstrated superior lithological discrimination capability compared to conventional algorithms, achieving peak accuracy of 94.15% and mean F1-score of 93.87%; (2) integrating topographic data (especially Elevation) enhanced lithological positioning accuracy by 4.43% ± 1.13%; (3) PCA and BR transformations effectively enhanced lithological separability, particularly at lithological boundary zones; (4) while SG-3DSD enables efficient large-scale sample generation, it is advisable to avoid using excessively large training samples for regional-scale mapping. This methodology mitigates the weighting dependence on geological maps during sample selection and dilutes inherent cartographic error propagation, providing a novel paradigm for large-scale lithological mapping with broad application potential.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102217"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harnessing LoRa for real-time landslide monitoring and early alerts in Kerala’s terrain","authors":"R. Amirthavarshini ,&nbsp;A.I. Mohamed Shamil ,&nbsp;P.S. Aswin Raaj ,&nbsp;G. Kanimozhi","doi":"10.1016/j.gsf.2025.102242","DOIUrl":"10.1016/j.gsf.2025.102242","url":null,"abstract":"<div><div>Landslides trigger high loss of life, damage to property and infrastructure, particularly in sensitive terrains like Kerala, India. Real-time monitoring and forecasting remain difficult due to rugged topography and low connectivity in remote terrain. The current work depicts a low-power, long-range IoT framework for monitoring applications utilizing LoRaWAN for data transmission and machine learning for forecasting. Soil moisture, accelerometer–gyroscope (MPU6050), humidity (DHT22), and simulated piezometer sensor nodes periodically store important slope-stability parameters. The sensed data are transmitted across LoRa to a base hub where the site-specific machine learning program analyzes the data in real time. Experimental results reveal soil moisture increasing from 2% to 10%, humidity from 89.8% to 91.5%, pore water pressure from 0.2 kPa to 0.5 kPa, and fluctuating accelerometer during simulated slope failure—variables closely related to landslide initiating factors. Machine learning outcomes reveal the ExtraTrees Classifier obtained 87.0% accuracy and gave the best results relative to different algorithms. The system provides automatic SOS messages to the Geological Survey of India (GSI) and executes site-based alarms for communities at risk. In comparison with the current GSM or satellite-based systems, the presented method provides longer-range communications and reduced energy consumption, along with quicker responses. The work presents a field-applicable and scalable solution for landslide risk management and disaster preparedness applications.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102242"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-deep tight sandstone reservoirs quality evaluation with a new perspective on petrofacies and differential diagenesis: Insights from the Tarim Basin","authors":"Zhida Liu ,&nbsp;Xiaorong Luo ,&nbsp;Xiaofei Fu ,&nbsp;Xianqiang Song ,&nbsp;Haijun Yang ,&nbsp;Haixue Wang","doi":"10.1016/j.gsf.2026.102252","DOIUrl":"10.1016/j.gsf.2026.102252","url":null,"abstract":"<div><div>Ultra-deep sandstone reservoirs are characterized by poor petrophysical properties. Identifying effective reservoir rocks and evaluating reservoir quality are key but challenging aspects in the exploration and development of ultra-deep hydrocarbon reservoirs. Adopting the Cretaceous Bashijiqike Formation of the Keshen gas field in the Tarim Basin with burial depths exceeding 8000 m as an example, we evaluated the quality of this ultra-deep tight sandstone reservoir by classifying petrofacies and analyzing the diagenetic evolution of different petrofacies. We revealed that although the petrophysical properties of ultra-deep reservoirs are poor, effective reservoir rocks with relatively high porosities and permeabilities can still develop locally. According to the detrital mineralogy and texture, diagenesis, and pore system, we classified sandstone into effective petrofacies (ductile lithic-lean sandstone) and tight petrofacies (ductile lithic-rich sandstone and tightly carbonate-cemented sandstone), which underwent differential diagenetic evolution processes. Such processes significantly influence the quality of ultra-deep tight sandstone reservoirs. High contents of ductile grains and carbonate cement explained the low reservoir quality. The ductile lithic-rich sandstone was relatively fine-grained and contained a high content of ductile grains, which, owing to mechanical compaction during early burial, were compacted and largely occupied the pore space, yielding a low reservoir quality. The carbonate-cemented sandstone pores were filled with large amounts of carbonate cements during early diagenesis, resulting in a low reservoir quality. The ductile lithic-lean sandstone was relatively coarse-grained, contained a high content of rigid grains, and exhibited moderate compaction, with relatively well-developed primary pores and secondary dissolution pores. This sandstone exhibited the highest reservoir quality and represents an effective reservoir rock type in ultra-deep tight sandstone reservoirs. This study provides new insights for the evaluation of the effective properties of ultra-deep tight sandstone reservoirs.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102252"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genesis of shallow-water manganese nodules with uniquely high Mn/Fe ratios","authors":"Hyo Jin Koo ,&nbsp;Hyen Goo Cho ,&nbsp;Young Keun Jin ,&nbsp;Dong-Hun Lee ,&nbsp;Ji-Hoon Kim ,&nbsp;Tae Siek Rhee ,&nbsp;Jong Kuk Hong ,&nbsp;Sung Keun Lee","doi":"10.1016/j.gsf.2025.102219","DOIUrl":"10.1016/j.gsf.2025.102219","url":null,"abstract":"<div><div>While manganese (Mn) nodules are authigenic metal concretions that form predominantly on deep-sea seafloor, they have also been found along shallow seafloors. The formation environments of these nodules — deep sea <em>vs.</em> shallow water — often result in distinct chemical and morphological characteristics. As Mn is one of the essential components of energy-storing technologies, assessing the proper estimation of Mn and metal contents in both deep- and shallow-water Mn nodules is critical. It has been found that the Mn content of shallow-water nodules is often lower than that from deep-sea environments. Here, we report the discovery of shallow-water Mn nodules with exceptionally high Mn/Fe ratios on the continental slope of the East Siberian Sea, Arctic Ocean. Despite their shallow-water origin, Mn nodules show morphological and chemical characteristics that are typically unique to deep-sea nodules. These distinctive features, including exceptionally high Mn/Fe ratios, may reflect suboxic diagenesis and the preferential remobilization and re-precipitation of Mn from the adjacent continental shelf. The formation of high Mn/Fe nodules may reflect unique ocean circulation patterns that provided oxygenated bottom waters to the study area. Particularly, Pacific Water entering through the Bering Strait, which overlaps with the nodule formation depth (160 – 240 m) and is enriched in dissolved oxygen, could facilitate Mn-rich nodule growth under suboxic diagenetic conditions since the Holocene. Shallow-water Mn nodules with uniquely high Mn/Fe ratios may offer a novel paleo-environmental proxy for reconstructing paleohydrology and bio-geochemical evolutions in shallow marine environments.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"17 2","pages":"Article 102219"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}