Geoscience frontiers最新文献

{"title":"Implications of the newly discovered Triassic suites from the eastern segment in the giant Tongshan porphyry Cu deposit, northeast China","authors":"Chenglin Bai ,&nbsp;Guiqing Xie ,&nbsp;Yang Liu ,&nbsp;Jie Chen ,&nbsp;Qiaoqiao Zhu ,&nbsp;Wei Li","doi":"10.1016/j.gsf.2025.102034","DOIUrl":"10.1016/j.gsf.2025.102034","url":null,"abstract":"<div><div>The Tongshan porphyry Cu deposit is well known as one of the most economically significant porphyry deposits in northeast China. Recently, Tongshan has become the largest porphyry Cu deposit in northeast China with the successful exploration of the concealed ore zone V. Ore zone V has the largest Cu tonnage (562 Mt @ 0.50% Cu) and extends into the eastern segment at Tongshan. Compared with ore zones I–III, which are hosted within granitic rocks in the western segment, the ore zone V mainly occurs in Duobaoshan volcanic rocks and the roof pendants of newly discovered intrusions. Here, we conducted a study of the understudied eastern ore zone and found that copper mineralization is associated with the newly discovered suites in the eastern segment at Tongshan. Two periods of ore-bearing quartz veins with different widths have been recognized, including quartz-chalcopyrite-pyrite veinlets (0.1–0.2 cm) and quartz-chalcopyrite-polymetallic sulfide wide veins (&gt;0.5 cm). The latter veins can be divided into four stages (I–IV) of mineralization and alteration, which are closely related to the newly discovered granodiorite and dacite porphyry. Our new zircon U–Pb ages show that the granodiorite and dacite porphyry were developed between 228–223 Ma, suggesting that the overprinting porphyry copper mineralization occurred in the Triassic. The Triassic suites have adakite-like character with high Sr/Y, and show no or minimal negative Eu anomalies, indicating early dominant amphibole with limited plagioclase fractionation. For the Triassic intrusions, the high zircon Eu/Eu* (0.67–0.89), Δ_FMQ (1.04 ± 0.53; where Δ_FMQ is the log <em>f</em>O₂ difference between the sample value and the fayalite-magnetite-quartz mineral buffer), hygrometer values (∼7.19 wt.% H₂O) and high whole-rock Fe₂O₃/FeO, Sr/Y, V/Sc and 10,000×(Eu/Eu*)/Y ratios together indicate the Triassic magmas were oxidized and hydrous. These contents and ratios of the Triassic suites are significantly higher than those of the Ordovician suites (Δ_FMQ = 0.74 ± 0.26, ∼5.90 wt.% H₂O), suggesting that the newly discovered Triassic magmas are more oxidized and hydrous, with high potential for porphyry copper mineralization. Based on the investigation of mineralization and the above results, we proposed that multiple superimposed mineralizations can help form a large-scale deposit and the southeastern segment is a favorable exploration area at Tongshan.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102034"},"PeriodicalIF":8.5,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cobalt enrichment in Paleoproterozoic African and Brazilian manganese deposits","authors":"Evilarde Carvalho Uchôa Filho ,&nbsp;Felipe Holanda dos Santos ,&nbsp;Douglas Teixeira Martins ,&nbsp;Wagner da Silva Amaral ,&nbsp;José Alberto Rodrigues do Vale","doi":"10.1016/j.gsf.2025.102035","DOIUrl":"10.1016/j.gsf.2025.102035","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study highlights a new by-product source for cobalt by recycling Paleoproterozoic Mn deposits. We present a geochemical modeling approach utilizing Principal Component Analysis (PCA) for available geochemical data of Paleoproterozoic manganese deposits found in Africa and Brazil, which exhibit anomalous cobalt contents (up to 1200 ppm) along with other metals such as copper, nickel, and vanadium. The PCA results for the correlation coefficient matrix of the Enrichment Factor (EF) values of major and trace elements from samples of eight Mn deposits found in Africa and Brazil (Kisenge-Kamata, Moanda, Nsuta in Africa, and Azul, Buritirama, Lagoa do Riacho, Morro da Mina, and Serra do Navio in Brazil) yielded a cumulative variance of 53.3% for PC1 (34%) and PC2 (19.3%). In PC1, the highest positive loadings correspond to the variables Mn&lt;sub&gt;EF&lt;/sub&gt;, Ni&lt;sub&gt;EF&lt;/sub&gt;, and Co&lt;sub&gt;EF&lt;/sub&gt;, while the highest negative loadings correspond to the variables Si&lt;sub&gt;EF&lt;/sub&gt;, Fe&lt;sub&gt;EF&lt;/sub&gt;, K&lt;sub&gt;EF&lt;/sub&gt;, Ti&lt;sub&gt;EF&lt;/sub&gt;, Cr&lt;sub&gt;EF&lt;/sub&gt;, and Zr&lt;sub&gt;EF&lt;/sub&gt;. PC2 exhibits the highest positive loadings for the variables Ca&lt;sub&gt;EF&lt;/sub&gt;, Mg&lt;sub&gt;EF&lt;/sub&gt;, and P&lt;sub&gt;EF&lt;/sub&gt;, while the highest negative loadings are for Cu&lt;sub&gt;EF&lt;/sub&gt; and V&lt;sub&gt;EF&lt;/sub&gt;. The biplot diagram representation showed that clusters of vectors Mn&lt;sub&gt;EF&lt;/sub&gt;, Ni&lt;sub&gt;EF&lt;/sub&gt;, Co&lt;sub&gt;EF&lt;/sub&gt;, V&lt;sub&gt;EF&lt;/sub&gt;, and Cu&lt;sub&gt;EF&lt;/sub&gt; influence samples of Mn-carbonate rock, Mn-carbonate–silicate rock, Mn-silicate rock, and Mn-carbonate-siliciclastic rock, all with high Co&lt;sub&gt;EF&lt;/sub&gt; values (up to 414). The cluster of vectors Ca&lt;sub&gt;EF&lt;/sub&gt;, Mg&lt;sub&gt;EF&lt;/sub&gt;, and P&lt;sub&gt;EF&lt;/sub&gt; significantly influence carbonate rock and dolomite marble, which have low Co&lt;sub&gt;EF&lt;/sub&gt; values (close to 0). The cluster of vectors Si&lt;sub&gt;EF&lt;/sub&gt;, Fe&lt;sub&gt;EF&lt;/sub&gt;, K&lt;sub&gt;EF&lt;/sub&gt;, Ti&lt;sub&gt;EF&lt;/sub&gt;, Cr&lt;sub&gt;EF&lt;/sub&gt;, and Zr&lt;sub&gt;EF&lt;/sub&gt; strongly influences siliciclastic rock, which exhibits low Co&lt;sub&gt;EF&lt;/sub&gt; values. On the other hand, the cluster of vectors Cu&lt;sub&gt;EF&lt;/sub&gt; and V&lt;sub&gt;EF&lt;/sub&gt; influences oxidized Mn ore, which exhibits Co&lt;sub&gt;EF&lt;/sub&gt; values of up to 108. The results reveal a dichotomy regarding the origin of cobalt and other metal enrichments in these deposits linked to the Mn redox cycle. This process involves the formation of Mn-oxyhydroxides with the adsorption of Co and other metals under oxic conditions, followed by the burial of these Mn oxides in an anoxic diagenetic environment, where microbial sulfate reduction leads to the nucleation of Mn-carbonates and the formation of metal-rich sulfides (Fe, Co, Ni, V). Additionally, detrital input and sulfide phases (e.g., framboidal pyrite) for the formation of Mn-rich siliciclastic rocks associated with Mn-carbonate rocks are evidenced by proxies Si&lt;sub&gt;EF&lt;/sub&gt;, Fe&lt;sub&gt;EF&lt;/sub&gt;, K&lt;sub&gt;EF&lt;/sub&gt;, Ti&lt;sub&gt;EF&lt;/sub&gt;, Cr&lt;sub&gt;EF&lt;/sub&gt;, and Zr&lt;sub&gt;EF&lt;/sub&gt;. This new exploration approach, supported by geochemical modeling through PCA, enha","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102035"},"PeriodicalIF":8.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to “Cretaceous magmatic arc in Hainan and the peri-South China Sea as evidenced by geochemical fingerprinting of granitoids in the region” [Geosci. Front. 15(5) (2024) 101866]","authors":"Xiao-Yan Jiang ,&nbsp;Yildirim Dilek ,&nbsp;Xian-Hua Li","doi":"10.1016/j.gsf.2024.101963","DOIUrl":"10.1016/j.gsf.2024.101963","url":null,"abstract":"","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 2","pages":"Article 101963"},"PeriodicalIF":8.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical cycling, tectonic drivers and environmental impacts of CH4-rich mud extrusions in subduction zones","authors":"Umair Khan ,&nbsp;Shiguo Wu ,&nbsp;Majid Khan ,&nbsp;Jinwei Gao ,&nbsp;Junjin Chen","doi":"10.1016/j.gsf.2025.102029","DOIUrl":"10.1016/j.gsf.2025.102029","url":null,"abstract":"<div><div>Subduction zones are critical interfaces for lithospheric volatile fluxes, where complex tectonic and geochemical interactions facilitate the release of gases and fluids from deep-seated reservoirs within the Earth’s crust. Mud volcanism, as a dynamic manifestation of these processes, contributes CH₄ emissions that influence the global methane budget and impact marine ecosystems. Although ∼2000 CH₄-rich mud extrusions have been documented in subduction zones globally, the geological origins and subduction-related geochemical and tectonic mechanisms driving these emissions remain poorly understood. This research examines the Makran subduction zone which hosts one of the world’s largest accretionary wedge and extensive CH₄-rich mud extrusions, as a model system. Integrated geochemical, geophysical, and geological observations reveal that thermogenic CH₄ and clay-rich fluidized muds originate from deeply buried Himalayan turbidites (underthrusted sediments), driven by organic-rich sediment maturation and high fluid overpressure. Key tectonic features, including thrust faults, overburden pressure of wedge-top sediments, normal faults, brittle fractures, and seismicity, facilitate CH₄-rich mud extrusions into the hydrosphere and atmosphere. The extruded gases are predominantly CH₄, with minor C₂H₆, C₃H₈, i-C₄H₁₀, and <em>n</em>-C₄H₁₀ while the mud breccia exhibits a chemical composition dominated by SiO₂, Al₂O₃, and Fe₂O₃, enriched with trace elements (Rb, Zr, and V) and clay minerals, quartz, and carbonates. Geochemical indicators suggest intense chemical weathering and mature sediments classifying the mud breccia as litharenite and sub-litharenite, indicative of deep burial and compaction. These findings model the evolution of CH₄-rich mud extrusions through three geological stages: (i) Eocene to Early Miocene pre-thermogenic formation of the CH₄-rich source, (ii) Middle Miocene to Pliocene syn-thermogenic CH₄ and fluidized mud generation, and (iii) Pleistocene to Recent post-thermogenic CH₄-rich fluidized mud migration. These findings underscore the critical yet often overlooked role of subduction-related geochemical and tectonic processes in CH₄ generation and emission, with significant implications for the global CH₄ budget and marine ecosystems.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102029"},"PeriodicalIF":8.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CAUM: A software for calculating and assessing chemical ages of uranium minerals","authors":"Hao Song ,&nbsp;Tao Xiao ,&nbsp;Guoxiang Chi ,&nbsp;Zexin Wang ,&nbsp;Zhengqi Xu ,&nbsp;Mingcai Hou","doi":"10.1016/j.gsf.2025.102031","DOIUrl":"10.1016/j.gsf.2025.102031","url":null,"abstract":"<div><div>It has been shown that the age of minerals in which U ± Th are a major (e.g., uraninite, pitchblende and thorite) or minor (e.g., monazite, xenotime) component can be calculated from the concentrations of U ± Th and Pb rather than their isotopes, and such ages are referred to as chemical ages. Although equations for calculating the chemical ages have been well established and various computation programs have been reported, there is a lack of software that can not only calculate the chemical ages of individual analytical points but also provide an evaluation of the errors of individual ages as well as the whole dataset. In this paper, we develop a software for calculating and assessing the chemical ages of uranium minerals (CAUM), an open-source Python-based program with a friendly Graphical User Interface (GUI). Electron probe microanalysis (EPMA) data of uranium minerals are first imported from Excel files and used to calculate the chemical ages and associated errors of individual analytical points. The age data are then visualized to aid evaluating if the dataset comprises one or multiple populations and whether or not there are meaningful correlations between the chemical ages and impurities. Actions can then be taken to evaluate the errors within individual populations and the significance of the correlations. The use of the software is demonstrated with examples from published data.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102031"},"PeriodicalIF":8.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detailed in-depth mapping of the world largest anorthositic complex: Magnetic anomalies, 2.5-3D modelling and emplacement constraints of the Kunene Complex (KC), SW Angola","authors":"T. Mochales ,&nbsp;E. Merino-Martínez ,&nbsp;C. Rey-Moral ,&nbsp;A. Machadinho ,&nbsp;J. Carvalho ,&nbsp;P. Represas ,&nbsp;J.L. García-Lobón ,&nbsp;M.C. Feria ,&nbsp;R. Martín-Banda ,&nbsp;M.T. López-Bahut ,&nbsp;D. Alves ,&nbsp;E. Ramalho ,&nbsp;J. Manuel ,&nbsp;D. Cordeiro","doi":"10.1016/j.gsf.2025.102030","DOIUrl":"10.1016/j.gsf.2025.102030","url":null,"abstract":"<div><div>The Kunene Complex (KC) represents a very large Mesoproterozoic igneous body, mainly composed of anorthosites and gabbroic rocks that extends from SW Angola to NW Namibia (outcropping 18,000 km², NE-SW trend, and ca. 350 km long and up to 50 km wide). Little is known about its structure at depth. Here, we use recently acquired aerogeophysical data to accurately determine its hidden extent and to unravel its morphology at depth. These data have been interpreted and modelled to investigate the unexposed KC boundaries, reconstructing the upper crustal structure (between 0 and 15 km depth) overlain by the thin sedimentary cover of the Kalahari Basin. The modelling reveals that the KC was emplaced in the upper crust and extends in depth up to ca. 5 km, showing a lobular geometry and following a large NE-SW to NNE-SSW linear trend, presumably inherited from older Paleoproterozoic structures. The lateral continuation of the KC to the east (between 50 and 125 km) beneath the Kalahari Cenozoic sediments suggests an overall size three times the outcropping dimension (about 53,500 km²). This affirmation clearly reinforces the economic potential of this massif, related to the prospecting of raw materials and certain types of economic mineralization (Fe-Ti oxides, metallic sulphides or platinum group minerals). Up to 11 lobes have been isolated with dimensions ranging from 135.5 to 37.3 km in length and 81.9 to 20.7 km in width according to remanent bodies revealed by TMI mapping. A total volume of 65,184 km³ was calculated only for the magnetically remanent bodies of the KC. A long-lasting complex contractional regime, where large strike-slip fault systems were involved, occurred in three kinematic pulses potentially related to a change of velocity or convergence angle acting on previous Paleoproterozoic inherited sutures. The coalescent magmatic pulses can be recognized by means of magnetic anomalies, age of the bodies as well as the lineations inferred in this work: (i) Emplacement of the eastern mafic bodies and granites in a stage of significant lateral extension in a transtensional context between 1500 Ma and 1420 Ma; (ii) Migration of the mantle derived magmas westwards with deformation in a complex contractional setting with shearing structures involving western KC bodies and basement from 1415 Ma to 1340 Ma; (iii) NNW-SSE extensional structures are relocated westwards, involving mantle magmas, negative flower structures and depression that led to the formation of late Mesoproterozoic basins from 1325 Ma to 1170 Ma. Additionally, we detect several first and second order structures to place the structuring of the KC in a craton-scale context in relation to the crustal structures detected in NW Namibia.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102030"},"PeriodicalIF":8.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial heterogeneity of groundwater depths in coastal cities and their responses to multiple factors interactions by interpretable machine learning models","authors":"Yuming Mo ,&nbsp;Jing Xu ,&nbsp;Senlin Zhu ,&nbsp;Beibei Xu ,&nbsp;Jinran Wu ,&nbsp;Guangqiu Jin ,&nbsp;You-Gan Wang ,&nbsp;Ling Li","doi":"10.1016/j.gsf.2025.102033","DOIUrl":"10.1016/j.gsf.2025.102033","url":null,"abstract":"<div><div>Understanding spatial heterogeneity in groundwater responses to multiple factors is critical for water resource management in coastal cities. Daily groundwater depth (GWD) data from 43 wells (2018–2022) were collected in three coastal cities in Jiangsu Province, China. Seasonal and Trend decomposition using Loess (STL) together with wavelet analysis and empirical mode decomposition were applied to identify tide-influenced wells while remaining wells were grouped by hierarchical clustering analysis (HCA). Machine learning models were developed to predict GWD, then their response to natural conditions and human activities was assessed by the Shapley Additive exPlanations (SHAP) method. Results showed that eXtreme Gradient Boosting (XGB) was superior to other models in terms of prediction performance and computational efficiency (<em>R</em>² &gt; 0.95). GWD in Yancheng and southern Lianyungang were greater than those in Nantong, exhibiting larger fluctuations. Groundwater within 5 km of the coastline was affected by tides, with more pronounced effects in agricultural areas compared to urban areas. Shallow groundwater (3–7 m depth) responded immediately (0–1 day) to rainfall, primarily influenced by farmland and topography (slope and distance from rivers). Rainfall recharge to groundwater peaked at 50% farmland coverage, but this effect was suppressed by high temperatures (&gt;30 °C) which intensified as distance from rivers increased, especially in forest and grassland. Deep groundwater (&gt;10 m) showed delayed responses to rainfall (1–4 days) and temperature (10–15 days), with GDP as the primary influence, followed by agricultural irrigation and population density. Farmland helped to maintain stable GWD in low population density regions, while excessive farmland coverage (&gt;90%) led to overexploitation. In the early stages of GDP development, increased industrial and agricultural water demand led to GWD decline, but as GDP levels significantly improved, groundwater consumption pressure gradually eased. This methodological framework is applicable not only to coastal cities in China but also could be extended to coastal regions worldwide.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102033"},"PeriodicalIF":8.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Mesoproterozoic missing link between eastern Australia and China during the transition from Nuna to Rodinia?","authors":"Alexander Edgar ,&nbsp;Ioan Sanislav ,&nbsp;Paul Dirks","doi":"10.1016/j.gsf.2025.102017","DOIUrl":"10.1016/j.gsf.2025.102017","url":null,"abstract":"<div><div>We document, for the first time, Mesoproterozoic-aged, continental arc magmatism in the Tasmanides. Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant ∼ 1200 Ma igneous zircons, with early-Paleozoic metamorphic rim overgrowths. Analytical mixing between the igneous and metamorphic zircons produces cryptic discordant analyses, but the origin of said discordance is resolved with zircon Th/U ratios. Samples of the Fat Hen Creek Complex are peraluminous, calc-alkaline, S-type granitoids, that record high-grade metamorphism and trace element mobilization. The P3 and P42 intrusions are metaluminous, calc-alkaline, I-type granodiorite, which intruded the Cape River Metamorphics, and contain trace element signatures consistent with a continental-arc setting. We propose that a Mesoproterozoic continental terrane, herein referred to as the Oakvale Province, exists as basement to the Thomson Orogen. We propose several models for the formation of the Oakvale Province, with potential links to the Tarim Block, and the Yangtze Craton, during the late-Mesoproterozoic. We propose that the Oakvale Province supplied the Tasmanides with late-Mesoproterozoic detritus, and that such detritus was not solely sourced from the Musgrave Province as previously interpreted. Finally, we interpret the oroclinal bending of Paleozoic deformation and plutonic fabrics to reflect the buried extent of the Oakvale Province, and to potentially map out the Neoproterozoic rift margin associated with Rodinia break-up.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102017"},"PeriodicalIF":8.5,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ocean singularity analysis and global heat flow prediction reveal anomalous bathymetry and heat flow","authors":"Yang Zhang ,&nbsp;Qiuming Cheng ,&nbsp;Tao Hong ,&nbsp;Junjie Ji","doi":"10.1016/j.gsf.2025.102013","DOIUrl":"10.1016/j.gsf.2025.102013","url":null,"abstract":"<div><div>The investigations of physical attributes of oceans, including parameters such as heat flow and bathymetry, have garnered substantial attention and are particularly valuable for examining Earth’s thermal structures and dynamic processes. Nevertheless, classical plate cooling models exhibit disparities when predicting observed heat flow and seafloor depth for extremely young and old lithospheres. Furthermore, a comprehensive analysis of global heat flow predictions and regional ocean heat flow or bathymetry data with physical models has been lacking. In this study, we employed power-law models derived from the singularity theory of fractal density to meticulously fit the latest ocean heat flow and bathymetry. Notably, power-law models offer distinct advantages over traditional plate cooling models, showcasing robust self-similarity, scale invariance, or scaling properties, and providing a better fit to observed data. The outcomes of our singularity analysis concerning heat flow and bathymetry across diverse oceanic regions exhibit a degree of consistency with the global ocean spreading rate model. In addition, we applied the similarity method to predict a higher resolution (0.1° × 0.1°) global heat flow map based on the most recent heat flow data and geological/geophysical observables refined through linear correlation analysis. Regions displaying significant disparities between predicted and observed heat flow are closely linked to hydrothermal vent fields and active structures. Finally, combining the actual bathymetry and predicted heat flow with the power-law models allows for the quantitative and comprehensive detection of anomalous regions of ocean subsidence and heat flow, which deviate from traditional plate cooling models. The anomalous regions of subsidence and heat flow show different degrees of anisotropy, providing new ideas and clues for further analysis of ocean topography or hydrothermal circulation of mid-ocean ridges.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102013"},"PeriodicalIF":8.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forecasting strong subsequent earthquakes in Japan using an improved version of NESTORE machine learning algorithm","authors":"S. Gentili ,&nbsp;G.D. Chiappetta ,&nbsp;G. Petrillo ,&nbsp;P. Brondi ,&nbsp;J. Zhuang","doi":"10.1016/j.gsf.2025.102016","DOIUrl":"10.1016/j.gsf.2025.102016","url":null,"abstract":"<div><div>In this study, the advanced machine learning algorithm NESTORE (Next STrOng Related Earthquake) was applied to the Japan Meteorological Agency catalog (1973–2024). It calculates the probability that the aftershocks will reach or exceed a magnitude equal to the magnitude of the mainshock minus one and classifies the clusters as type A or type B, depending on whether this condition is met or not. It has been shown useful in the tests in Italy, western Slovenia, Greece, and California. Due to Japan’s high and complex seismic activity, new algorithms were developed to complement NESTORE: a hybrid cluster identification method, which uses both ETAS-based stochastic declustering and deterministic graph-based selection, and REPENESE (RElevant features, class imbalance PErcentage, NEighbour detection, SElection), an algorithm for detecting outliers in skewed class distributions, which takes in account if one class has a larger number of samples with respect to the other (class imbalance).</div><div>Trained with data from 1973 to 2004 (7 type A and 43 type B clusters) and tested from 2005 to 2023 (4 type A and 27 type B clusters), the method correctly forecasted 75% of A clusters and 96% of B clusters, achieving a precision of 0.75 and an accuracy of 0.94 six hours after the mainshock. It accurately classified the 2011 Tōhoku event cluster. Near-real-time forecasting was applied to the sequence after the April 17, 2024 M6.6 earthquake in Shikoku, correctly classifying it as a “Type B cluster”. These results highlight the potential for the forecasting of strong aftershocks in regions with high seismicity and class imbalance, as evidenced by the high recall, precision and accuracy values achieved in the test phase.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102016"},"PeriodicalIF":8.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}