Pub Date : 2025-03-02DOI: 10.1016/j.gsf.2025.102034
Chenglin Bai , Guiqing Xie , Yang Liu , Jie Chen , Qiaoqiao Zhu , Wei Li
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 (>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), ΔFMQ (1.04 ± 0.53; where ΔFMQ is the log fO2 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 (ΔFMQ = 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.
{"title":"Implications of the newly discovered Triassic suites from the eastern segment in the giant Tongshan porphyry Cu deposit, northeast China","authors":"Chenglin Bai , Guiqing Xie , Yang Liu , Jie Chen , Qiaoqiao Zhu , 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 (>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<sub>FMQ</sub> (1.04 ± 0.53; where Δ<sub>FMQ</sub> is the log <em>f</em>O<sub>2</sub> difference between the sample value and the fayalite-magnetite-quartz mineral buffer), hygrometer values (∼7.19 wt.% H<sub>2</sub>O) and high whole-rock Fe<sub>2</sub>O<sub>3</sub>/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<sub>FMQ</sub> = 0.74 ± 0.26, ∼5.90 wt.% H<sub>2</sub>O), 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}
Pub Date : 2025-03-02DOI: 10.1016/j.gsf.2025.102036
Manob Das , Arijit Das , Suman Singha
This study focuses on the assessment of ecosystem health (EH), ecosystem services (ES), and ecosystem risk (ER) in East Kolkata Wetland (EKW). A comprehensive framework on the EH, ES and ER has been developed using remote sesning and geo-spatial techniques for the year 2000, 2005, 2010, 2015, and 2020. The study also assessed ecosystem structure and fragmentation using landscape metrics calculated using fragstats, which showed a significant influence of land use and land cover (LULC) changes on the wetland’s ecological integrity. The study revealed that 6.86% of EKW fallen under a very low EH zone, while 20% was categorized as having very high EH. Spatio-temporal analysis of ES indicated that 30% of the area had very low ES value, with only 8% exhibiting very high ES. ER assessment revealed that 7% of the study area was highly ER, while 12% identified within a high ER zone, reflecting frequent LULC changes. The correlation analysis highlighted strong negative relationships between landscape deviation degree (LDD) and EH (−0.971), and between normalized difference water index (NDWI) and normalized difference vegetation index (NDVI) (−0.991). Additionally, landscape metrics such as the number of patches (NP) and the largest patch index (LPI) exhibited significant correlations, emphasizing the impact of fragmentation on EH and resilience. This comprehensive assessment underscores the importance of integrated approaches to monitor and manage wetland ecosystems, particularly in urban areas facing significant environmental stressors. The findings are crucial for informed decision-making and sustainable management of the wetland ecosystems, particularly in the cities of the global south.
{"title":"Development of a comprehensive framework for wetland ecosystem assessment and management","authors":"Manob Das , Arijit Das , Suman Singha","doi":"10.1016/j.gsf.2025.102036","DOIUrl":"10.1016/j.gsf.2025.102036","url":null,"abstract":"<div><div>This study focuses on the assessment of ecosystem health (EH), ecosystem services (ES), and ecosystem risk (ER) in East Kolkata Wetland (EKW). A comprehensive framework on the EH, ES and ER has been developed using remote sesning and geo-spatial techniques for the year 2000, 2005, 2010, 2015, and 2020. The study also assessed ecosystem structure and fragmentation using landscape metrics calculated using fragstats, which showed a significant influence of land use and land cover (LULC) changes on the wetland’s ecological integrity. The study revealed that 6.86% of EKW fallen under a very low EH zone, while 20% was categorized as having very high EH. Spatio-temporal analysis of ES indicated that 30% of the area had very low ES value, with only 8% exhibiting very high ES. ER assessment revealed that 7% of the study area was highly ER, while 12% identified within a high ER zone, reflecting frequent LULC changes. The correlation analysis highlighted strong negative relationships between landscape deviation degree (LDD) and EH (−0.971), and between normalized difference water index (NDWI) and normalized difference vegetation index (NDVI) (−0.991). Additionally, landscape metrics such as the number of patches (NP) and the largest patch index (LPI) exhibited significant correlations, emphasizing the impact of fragmentation on EH and resilience. This comprehensive assessment underscores the importance of integrated approaches to monitor and manage wetland ecosystems, particularly in urban areas facing significant environmental stressors. The findings are crucial for informed decision-making and sustainable management of the wetland ecosystems, particularly in the cities of the global south.</div></div>","PeriodicalId":12711,"journal":{"name":"Geoscience frontiers","volume":"16 3","pages":"Article 102036"},"PeriodicalIF":8.5,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629264","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}
Pub Date : 2025-03-01DOI: 10.1016/j.gsf.2025.102035
Evilarde Carvalho Uchôa Filho , Felipe Holanda dos Santos , Douglas Teixeira Martins , Wagner da Silva Amaral , José Alberto Rodrigues do Vale
<div><div>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<sub>EF</sub>, Ni<sub>EF</sub>, and Co<sub>EF</sub>, while the highest negative loadings correspond to the variables Si<sub>EF</sub>, Fe<sub>EF</sub>, K<sub>EF</sub>, Ti<sub>EF</sub>, Cr<sub>EF</sub>, and Zr<sub>EF</sub>. PC2 exhibits the highest positive loadings for the variables Ca<sub>EF</sub>, Mg<sub>EF</sub>, and P<sub>EF</sub>, while the highest negative loadings are for Cu<sub>EF</sub> and V<sub>EF</sub>. The biplot diagram representation showed that clusters of vectors Mn<sub>EF</sub>, Ni<sub>EF</sub>, Co<sub>EF</sub>, V<sub>EF</sub>, and Cu<sub>EF</sub> influence samples of Mn-carbonate rock, Mn-carbonate–silicate rock, Mn-silicate rock, and Mn-carbonate-siliciclastic rock, all with high Co<sub>EF</sub> values (up to 414). The cluster of vectors Ca<sub>EF</sub>, Mg<sub>EF</sub>, and P<sub>EF</sub> significantly influence carbonate rock and dolomite marble, which have low Co<sub>EF</sub> values (close to 0). The cluster of vectors Si<sub>EF</sub>, Fe<sub>EF</sub>, K<sub>EF</sub>, Ti<sub>EF</sub>, Cr<sub>EF</sub>, and Zr<sub>EF</sub> strongly influences siliciclastic rock, which exhibits low Co<sub>EF</sub> values. On the other hand, the cluster of vectors Cu<sub>EF</sub> and V<sub>EF</sub> influences oxidized Mn ore, which exhibits Co<sub>EF</sub> 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<sub>EF</sub>, Fe<sub>EF</sub>, K<sub>EF</sub>, Ti<sub>EF</sub>, Cr<sub>EF</sub>, and Zr<sub>EF</sub>. This new exploration approach, supported by geochemical modeling through PCA, enha
{"title":"Cobalt enrichment in Paleoproterozoic African and Brazilian manganese deposits","authors":"Evilarde Carvalho Uchôa Filho , Felipe Holanda dos Santos , Douglas Teixeira Martins , Wagner da Silva Amaral , José Alberto Rodrigues do Vale","doi":"10.1016/j.gsf.2025.102035","DOIUrl":"10.1016/j.gsf.2025.102035","url":null,"abstract":"<div><div>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<sub>EF</sub>, Ni<sub>EF</sub>, and Co<sub>EF</sub>, while the highest negative loadings correspond to the variables Si<sub>EF</sub>, Fe<sub>EF</sub>, K<sub>EF</sub>, Ti<sub>EF</sub>, Cr<sub>EF</sub>, and Zr<sub>EF</sub>. PC2 exhibits the highest positive loadings for the variables Ca<sub>EF</sub>, Mg<sub>EF</sub>, and P<sub>EF</sub>, while the highest negative loadings are for Cu<sub>EF</sub> and V<sub>EF</sub>. The biplot diagram representation showed that clusters of vectors Mn<sub>EF</sub>, Ni<sub>EF</sub>, Co<sub>EF</sub>, V<sub>EF</sub>, and Cu<sub>EF</sub> influence samples of Mn-carbonate rock, Mn-carbonate–silicate rock, Mn-silicate rock, and Mn-carbonate-siliciclastic rock, all with high Co<sub>EF</sub> values (up to 414). The cluster of vectors Ca<sub>EF</sub>, Mg<sub>EF</sub>, and P<sub>EF</sub> significantly influence carbonate rock and dolomite marble, which have low Co<sub>EF</sub> values (close to 0). The cluster of vectors Si<sub>EF</sub>, Fe<sub>EF</sub>, K<sub>EF</sub>, Ti<sub>EF</sub>, Cr<sub>EF</sub>, and Zr<sub>EF</sub> strongly influences siliciclastic rock, which exhibits low Co<sub>EF</sub> values. On the other hand, the cluster of vectors Cu<sub>EF</sub> and V<sub>EF</sub> influences oxidized Mn ore, which exhibits Co<sub>EF</sub> 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<sub>EF</sub>, Fe<sub>EF</sub>, K<sub>EF</sub>, Ti<sub>EF</sub>, Cr<sub>EF</sub>, and Zr<sub>EF</sub>. 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}
Pub Date : 2025-03-01DOI: 10.1016/j.gsf.2024.101963
Xiao-Yan Jiang , Yildirim Dilek , Xian-Hua Li
{"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 , Yildirim Dilek , 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}
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 n-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.
{"title":"Geochemical cycling, tectonic drivers and environmental impacts of CH4-rich mud extrusions in subduction zones","authors":"Umair Khan , Shiguo Wu , Majid Khan , Jinwei Gao , 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 CH<sub>4</sub> emissions that influence the global methane budget and impact marine ecosystems. Although ∼2000 CH<sub>4</sub>-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 CH<sub>4</sub>-rich mud extrusions, as a model system. Integrated geochemical, geophysical, and geological observations reveal that thermogenic CH<sub>4</sub> 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 CH<sub>4</sub>-rich mud extrusions into the hydrosphere and atmosphere. The extruded gases are predominantly CH<sub>4</sub>, with minor C<sub>2</sub>H<sub>6</sub>, C<sub>3</sub>H<sub>8</sub>, i-C<sub>4</sub>H<sub>10</sub>, and <em>n</em>-C<sub>4</sub>H<sub>10</sub> while the mud breccia exhibits a chemical composition dominated by SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, and Fe<sub>2</sub>O<sub>3</sub>, 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 CH<sub>4</sub>-rich mud extrusions through three geological stages: (i) Eocene to Early Miocene pre-thermogenic formation of the CH<sub>4</sub>-rich source, (ii) Middle Miocene to Pliocene syn-thermogenic CH<sub>4</sub> and fluidized mud generation, and (iii) Pleistocene to Recent post-thermogenic CH<sub>4</sub>-rich fluidized mud migration. These findings underscore the critical yet often overlooked role of subduction-related geochemical and tectonic processes in CH<sub>4</sub> generation and emission, with significant implications for the global CH<sub>4</sub> 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}
Pub Date : 2025-02-24DOI: 10.1016/j.gsf.2025.102031
Hao Song , Tao Xiao , Guoxiang Chi , Zexin Wang , Zhengqi Xu , Mingcai Hou
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.
{"title":"CAUM: A software for calculating and assessing chemical ages of uranium minerals","authors":"Hao Song , Tao Xiao , Guoxiang Chi , Zexin Wang , Zhengqi Xu , 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}
Pub Date : 2025-02-24DOI: 10.1016/j.gsf.2025.102033
Yuming Mo , Jing Xu , Senlin Zhu , Beibei Xu , Jinran Wu , Guangqiu Jin , You-Gan Wang , Ling Li
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 (R2 > 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 (>30 °C) which intensified as distance from rivers increased, especially in forest and grassland. Deep groundwater (>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 (>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.
{"title":"Spatial heterogeneity of groundwater depths in coastal cities and their responses to multiple factors interactions by interpretable machine learning models","authors":"Yuming Mo , Jing Xu , Senlin Zhu , Beibei Xu , Jinran Wu , Guangqiu Jin , You-Gan Wang , 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><sup>2</sup> > 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 (>30 °C) which intensified as distance from rivers increased, especially in forest and grassland. Deep groundwater (>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 (>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}
Pub Date : 2025-02-21DOI: 10.1016/j.gsf.2025.102017
Alexander Edgar , Ioan Sanislav , Paul Dirks
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.
{"title":"A Mesoproterozoic missing link between eastern Australia and China during the transition from Nuna to Rodinia?","authors":"Alexander Edgar , Ioan Sanislav , 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}
Pub Date : 2025-02-17DOI: 10.1016/j.gsf.2025.102013
Yang Zhang , Qiuming Cheng , Tao Hong , Junjie Ji
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.
{"title":"Ocean singularity analysis and global heat flow prediction reveal anomalous bathymetry and heat flow","authors":"Yang Zhang , Qiuming Cheng , Tao Hong , 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}
Pub Date : 2025-02-17DOI: 10.1016/j.gsf.2025.102016
S. Gentili , G.D. Chiappetta , G. Petrillo , P. Brondi , J. Zhuang
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).
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.
本研究将先进的机器学习算法 NESTORE（Next STrOng Related Earthquake）应用于日本气象厅的地震目录（1973-2024 年）。该算法计算余震达到或超过等于主震震级减一的概率，并根据是否满足这一条件将震群划分为 A 类或 B 类。在意大利、斯洛文尼亚西部、希腊和加利福尼亚州进行的测试表明，该方法非常有用。由于日本的地震活动频繁而复杂，我们开发了新的算法来补充 NESTORE：一种混合聚类识别方法，同时使用基于 ETAS 的随机去聚类和基于确定性图的选择；以及 REPENESE（RElevant features, class imbalance PErcentage, NEighbour detection, SElection），一种在偏斜类分布中检测异常值的算法，它考虑了一个类相对于另一个类是否有更多的样本（类不平衡）。该方法使用 1973 年至 2004 年的数据（7 个 A 类集群和 43 个 B 类集群）进行了训练，并对 2005 年至 2023 年的数据（4 个 A 类集群和 27 个 B 类集群）进行了测试，结果正确预测了 75% 的 A 类集群和 96% 的 B 类集群，在主震发生六小时后达到了 0.75 的精度和 0.94 的准确度。该方法准确地对 2011 年东北事件群进行了分类。对 2024 年 4 月 17 日四国 M6.6 级地震后的序列进行了近实时预报，并正确地将其归类为 "B 类地震群"。这些结果凸显了在地震频发和等级不平衡地区预报强余震的潜力，测试阶段取得的高召回率、高精确度和高准确度值证明了这一点。
{"title":"Forecasting strong subsequent earthquakes in Japan using an improved version of NESTORE machine learning algorithm","authors":"S. Gentili , G.D. Chiappetta , G. Petrillo , P. Brondi , 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}
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