Pub Date : 2025-11-19DOI: 10.1016/j.gr.2025.10.018
Ricardo Pagung , Carlos Alberto Rosière , Armin Zeh , Tiago Amâncio Novo
This study integrates U–Pb zircon geochronology and Lu–Hf isotope data from metasedimentary rocks of the Southern Guanhães Basement Inlier and surroundings with detailed mapping and structural analysis to propose a refined geodynamic model for the São Francisco paleocontinent during the Statherian period, highlighting the interplay between the Espinhaço Basin sedimentation and the contemporaneous exhumation of the anorogenic Borrachudos Suite. The detrital zircon age spectra of the analyzed samples exhibit distinct clusters at Archean (3500–2500 Ma), Neoarchean–Siderian (2500–2400 Ma), Rhyacian–Orosirian (2300–1915 Ma), and Statherian (1800–1675 Ma), with a well-constrained maximum depositional age (MDA) of 1727 ± 7 Ma. The subchondritic εHf(t) signatures (−18.0 to −13.0) of the Statherian zircon grains unequivocally identify the anorogenic granites of the Borrachudos Suite as the youngest source of detritus for the Lower Espinhaço Sequence within the Southern Guanhães Basement Inlier. The comparison of relative age probability between the Lower Espinhaço Sequence in the Southern Espinhaço Range (its typical location) and the analyzed metasedimentary rocks reveals a significantly higher contribution from Statherian sources within the Guanhães Basement Inlier. The common sedimentary source of these units, combined with the distribution of normal-sense displacement faults and shear zones reactivated and aligned with the regional shear zones, whose present kinematics converge towards and enclose the area of exposure of the Borrachudos Suite, supports the interpretation that the deep plutonic rocks of the Borrachudos Suite were exhumed and eroded together with the Archean basement during the formation of the Espinhaço rift basin. This tectonic scenario resulted in the juxtaposition of sediments of the Lower Espinhaço Sequence, which were deposited between uplifted crustal blocks during the Statherian, here collectively referred to as the Guanhães Crustal Core Complex.
{"title":"Constraints on the Statherian tectonic evolution of the São Francisco paleocontinent: the Espinhaço Basin and the Guanhães Crustal Core Complex","authors":"Ricardo Pagung , Carlos Alberto Rosière , Armin Zeh , Tiago Amâncio Novo","doi":"10.1016/j.gr.2025.10.018","DOIUrl":"10.1016/j.gr.2025.10.018","url":null,"abstract":"<div><div>This study integrates U–Pb zircon geochronology and Lu–Hf isotope data from metasedimentary rocks of the Southern Guanhães Basement Inlier and surroundings with detailed mapping and structural analysis to propose a refined geodynamic model for the São Francisco paleocontinent during the Statherian period, highlighting the interplay between the Espinhaço Basin sedimentation and the contemporaneous exhumation of the anorogenic Borrachudos Suite. The detrital zircon age spectra of the analyzed samples exhibit distinct clusters at Archean (3500–2500 Ma), Neoarchean–Siderian (2500–2400 Ma), Rhyacian–Orosirian (2300–1915 Ma), and Statherian (1800–1675 Ma), with a well-constrained maximum depositional age (MDA) of 1727 ± 7 Ma. The subchondritic εHf(t) signatures (−18.0 to −13.0) of the Statherian zircon grains unequivocally identify the anorogenic granites of the Borrachudos Suite as the youngest source of detritus for the Lower Espinhaço Sequence within the Southern Guanhães Basement Inlier. The comparison of relative age probability between the Lower Espinhaço Sequence in the Southern Espinhaço Range (its typical location) and the analyzed metasedimentary rocks reveals a significantly higher contribution from Statherian sources within the Guanhães Basement Inlier. The common sedimentary source of these units, combined with the distribution of normal-sense displacement faults and shear zones reactivated and aligned with the regional shear zones, whose present kinematics converge towards and enclose the area of exposure of the Borrachudos Suite, supports the interpretation that the deep plutonic rocks of the Borrachudos Suite were exhumed and eroded together with the Archean basement during the formation of the Espinhaço rift basin. This tectonic scenario resulted in the juxtaposition of sediments of the Lower Espinhaço Sequence, which were deposited between uplifted crustal blocks during the Statherian, here collectively referred to as the Guanhães Crustal Core Complex.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 109-130"},"PeriodicalIF":7.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145560224","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}
The Abu Rusheid A-type granite and Abu Ghalaga I-type tonalite in the Southern Eastern Desert (SED) of Egypt are a part of the Arabian-Nubian Shield (ANS), which was generated during the East African Orogeny. This study presents a multidisciplinary approach integrating field observations, petrography, mineral and whole-rock chemistry, and remote sensing data. The main objectives are to delineate the type and distribution of post-magmatic hydrothermal alteration, sources and mechanisms of fluid flow along shear zones, and metasomatic processes controlling mineralization in these particular granitic plutons and the ANS in general. Remote sensing, using Landsat-8 OLI, ASTER, and Sentinel-1A datasets, successfully identified structural controls of fluid flow, which has given rise to four hydrothermal alteration zones, including argillic, propylitic, phyllic and gossan. The Najd Fault System, with an NW-SE trend and its conjugated NE-SW trends, served as primary conduits, which facilitated fluid circulation and subsequent metasomatism and post-magmatic hydrothermal alteration. The studied granitoids have undergone alkali metasomatism in the form of albitization, muscovitization, and argillic overprints. Abu Rusheid granites experienced extensive albitization (Na2O, up to 7 wt%; Na/K, 15) relative to Abu Ghalaga tonalite (Na2O, up to 5.6 wt%; Na/K, 16). Isocon analyses and mass-balance calculations indicate significant mobility of major and trace elements, driven primarily by albitization processes, including Na, Ca, K, Fe, Mg, P, Rb, Sr, and Zn. While the apparent ‘gains’ and losses of immobile elements (e.g., U, Zr, Hf, Nb, Ta, Y, Ti, and REE) between metasomatic fronts of the studied granitoids are probably due to dissolution of their host mineral phases such as biotite, zircon, garnet, columbite and monazite, and cannot be related to albitization processes. The surface-derived fluids serve as albitizing agent in Abu Rusheid and Abu Ghalaga granitoids. However, magmatic-hydrothermal fluid overprint is clearly evidenced in Abu Rusheid granites through muscovitization (K2O, up to 7.0 wt%) associating albitization, alongside the tetrad effect of highly to extremely albitized samples. Conversely, albitization in Abu Ghalaga tonalite is overprinted by argillic and propylitic alteration. Despite overprinting magmatic geochemical signatures by metasomatism, a set of least altered granitic samples, as well as preserved primary garnet and biotite retain primary igneous features, allowing inferences about their parental magma and tectonic setting. Abu Rusheid granites display geochemical signatures of peraluminous to alkaline crustal-derived magma (ASI: ∼1.03–1.05) in a post-collisional extension setting, with high silica (SiO2 up to 77 wt%), elevated HFSE (e.g., Nb, Zr, and Hf), and REE (up to ∼473 µg/g) contents, along with prominent negative Eu anomalies (av. Eu/Eu*= 0.002–0.04). On the other hand, Abu
{"title":"Alkali metasomatism overprinting magmatic signatures of A-type and I-type granitoids in the Eastern Desert of Egypt: Insights from geochemistry and remote sensing","authors":"Mohamed Zaki Khedr , Eiichi Takazawa , Mokhles K. Azer , Mohamed Attia , Sherif Mansour , Tehseen Zafar , Zaheen Ullah , Shaimaa Ali El-Shafei","doi":"10.1016/j.gr.2025.11.002","DOIUrl":"10.1016/j.gr.2025.11.002","url":null,"abstract":"<div><div>The Abu Rusheid A-type granite and Abu Ghalaga I-type tonalite in the Southern Eastern Desert (SED) of Egypt are a part of the Arabian-Nubian Shield (ANS), which was generated during the East African Orogeny. This study presents a multidisciplinary approach integrating field observations, petrography, mineral and whole-rock chemistry, and remote sensing data. The main objectives are to delineate the type and distribution of post-magmatic hydrothermal alteration, sources and mechanisms of fluid flow along shear zones, and metasomatic processes controlling mineralization in these particular granitic plutons and the ANS in general. Remote sensing, using Landsat-8 OLI, ASTER, and Sentinel-1A datasets, successfully identified structural controls of fluid flow, which has given rise to four hydrothermal alteration zones, including argillic, propylitic, phyllic and gossan. The Najd Fault System, with an NW-SE trend and its conjugated NE-SW trends, served as primary conduits, which facilitated fluid circulation and subsequent metasomatism and post-magmatic hydrothermal alteration. The studied granitoids have undergone alkali metasomatism in the form of albitization, muscovitization, and argillic overprints. Abu Rusheid granites experienced extensive albitization (Na<sub>2</sub>O, up to 7 wt%; Na/K, 15) relative to Abu Ghalaga tonalite (Na<sub>2</sub>O, up to 5.6 wt%; Na/K, 16). Isocon analyses and mass-balance calculations indicate significant mobility of major and trace elements, driven primarily by albitization processes, including Na, Ca, K, Fe, Mg, P, Rb, Sr, and Zn. While the apparent ‘gains’ and losses of immobile elements (e.g., U, Zr, Hf, Nb, Ta, Y, Ti, and REE) between metasomatic fronts of the studied granitoids are probably due to dissolution of their host mineral phases such as biotite, zircon, garnet, columbite and monazite, and cannot be related to albitization processes. The surface-derived fluids serve as albitizing agent in Abu Rusheid and Abu Ghalaga granitoids. However, magmatic-hydrothermal fluid overprint is clearly evidenced in Abu Rusheid granites through muscovitization (K<sub>2</sub>O, up to 7.0 wt%) associating albitization, alongside the tetrad effect of highly to extremely albitized samples. Conversely, albitization in Abu Ghalaga tonalite is overprinted by argillic and propylitic alteration. Despite overprinting magmatic geochemical signatures by metasomatism, a set of least altered granitic samples, as well as preserved primary garnet and biotite retain primary igneous features, allowing inferences about their parental magma and tectonic setting. Abu Rusheid granites display geochemical signatures of peraluminous to alkaline crustal-derived magma (ASI: ∼1.03–1.05) in a post-collisional extension setting, with high silica (SiO<sub>2</sub> up to 77 wt%), elevated HFSE (e.g., Nb, Zr, and Hf), and REE (up to ∼473 µg/g) contents, along with prominent negative Eu anomalies (av. Eu/Eu*= 0.002–0.04). On the other hand, Abu ","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 82-108"},"PeriodicalIF":7.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145554299","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}
Pub Date : 2025-11-16DOI: 10.1016/j.gr.2025.10.016
A. Polonia , A. Asioli , L. Ferraro , E. Colizza , F. Corticelli , G.J. de Lange , A. Gallerani , G. Gasparotto , L. Gasperini , G. Giorgetti , V. La Cono , G. La Spada , T. Tesi , M. Yakimov
The Hellenic Arc subduction system hosts unique brine-filled depressions that represent the world’s deepest and most hypersaline basins currently characterized by anoxic sedimentation and gypsum precipitation. Their origin is intimately linked to active tectonics and to the presence of Messinian evaporites in the sub-seafloor, but the formation processes are not fully understood. Understanding how they developed and the triggering mechanism for brine formation can provide valuable information about their evolution and the past history of such extreme environments on Earth and extraterrestrial analogues.
We conducted sediment coring and direct sampling of the brine lake Hephaestus to reconstruct the sedimentary and environmental characteristics of the basin. We found that the basin preserves a stratigraphy spanning at least 200 kyr and contains a combination of pelagic sediment and resedimented deposits. Sediment stratigraphy records the transition from oxic sediment at the core bottom to recent anoxic conditions marked by black viscous sediment. This transition is punctuated by multi-sourced slumped material that was emplaced during a catastrophic event capable of simultaneously triggering deep sea slope failures and turbidity currents from the coastal environment. Radiometric dating and age modeling suggest that sediment anoxia resulted from catastrophic sediment remobilization that occurred sometime in the time interval CE 155-439. This is consistent with the CE 365 M>8 Crete earthquake and related mega-tsunami. We propose that seismic shaking triggered slope failures, turbidity currents and large-amplitude waves of the brine interface in the neighboring anoxic Kryos basin with brine spillover from one basin into deep depression(s).
{"title":"Seismically triggered anoxia and brine spillover during the CE 365 Crete mega-earthquake in the eastern Mediterranean Sea","authors":"A. Polonia , A. Asioli , L. Ferraro , E. Colizza , F. Corticelli , G.J. de Lange , A. Gallerani , G. Gasparotto , L. Gasperini , G. Giorgetti , V. La Cono , G. La Spada , T. Tesi , M. Yakimov","doi":"10.1016/j.gr.2025.10.016","DOIUrl":"10.1016/j.gr.2025.10.016","url":null,"abstract":"<div><div>The Hellenic Arc subduction system hosts unique brine-filled depressions that represent the world’s deepest and most hypersaline basins currently characterized by anoxic sedimentation and gypsum precipitation. Their origin is intimately linked to active tectonics and to the presence of Messinian evaporites in the sub-seafloor, but the formation processes are not fully understood. Understanding how they developed and the triggering mechanism for brine formation can provide valuable information about their evolution and the past history of such extreme environments on Earth and extraterrestrial analogues.</div><div>We conducted sediment coring and direct sampling of the brine lake Hephaestus to reconstruct the sedimentary and environmental characteristics of the basin. We found that the basin preserves a stratigraphy spanning at least 200 kyr and contains a combination of pelagic sediment and resedimented deposits. Sediment stratigraphy records the transition from oxic sediment at the core bottom to recent anoxic conditions marked by black viscous sediment. This transition is punctuated by multi-sourced slumped material that was emplaced during a catastrophic event capable of simultaneously triggering deep sea slope failures and turbidity currents from the coastal environment. Radiometric dating and age modeling suggest that sediment anoxia resulted from catastrophic sediment remobilization that occurred sometime in the time interval CE 155-439. This is consistent with the CE 365 M>8 Crete earthquake and related mega-tsunami. We propose that seismic shaking triggered slope failures, turbidity currents and large-amplitude waves of the brine interface in the neighboring anoxic Kryos basin with brine spillover from one basin into deep depression(s).</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 206-231"},"PeriodicalIF":7.2,"publicationDate":"2025-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145535883","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}
Pub Date : 2025-11-15DOI: 10.1016/j.gr.2025.10.013
Xingchen Yang , Yuanfang Zhao , Maotang Cai , Fengbao Ji , Lingtong Meng , Qiuyu Zhou , Yuanjian Zhou , Yingru Pei , Changjiang Yuan
The Bangong–Nujiang suture zone (BNSZ), separating the Qiangtang and Lhasa blocks, exhibits extensive Early Cretaceous varied magmatism and significant metallogenetic potential. However, geodynamic mechanisms driving this magmatic flare-up remain controversial. To address this issue, we conducted a comprehensive study focusing on the multi-type intrusions within and adjacent to the mélange zone in the Amdo–Nagqu area, middle BNSZ. Zircon U–Pb dating indicates that these intrusions emplaced during the Early Cretaceous (119–109 Ma). They display consistent arc-like whole-rock major and trace element characteristics with highly variable whole-rock initial 87Sr/86Sr (0.706534–0.712838) ratios, negative εNd(t) (−3.7 to − 9.2) values, and negative to weakly positive zircon εHf(t) (–14.7 to + 2.0) values. These geochemical features suggest their petrogenesis involved crust–mantle interactions. Furthermore, the mafic samples are characterized by narrow-ranging 143Nd/144Nd ratios but a wide range of Hf/Nd ratios, and a broader variation of zircon δ18O values (8.9–15.5 ‰) compared with coeval felsic samples (7.8–9.8 ‰), indicating the involvement of subducted sediments in the mantle source. Based on the new and previously published data, we suggest that the mafic intrusions originated from partial melting of the sediment-dominated mélange in the sub-continental lithospheric mantle (SCLM), providing tangible evidence of the southward oceanic subduction. In contrast, the felsic intrusions formed through partial melting of the continental crust within hot zones, accompanied by varying degrees of mantle-derived magma mixing. We propose the following geodynamic model for the widespread, small-volume, compositionally diverse Early Cretaceous magmatism along the BNSZ: Demise of the Bangong–Nujiang Tethys Ocean via low-angle bidirectional subduction during the Early Cretaceous, followed by extensive and contemporaneous partial melting. This process was triggered by the decompression and hot asthenosphere upwelling through corner flow and local sporadic slab windows within the fractured zones, along with sinking of the eclogitized ocean slab.
{"title":"Early Cretaceous magmatic flare-up in the northern-central Tibetan Plateau: Products of low-angle bidirectional subduction and slab sinking of the Bangong–Nujiang Tethys Ocean","authors":"Xingchen Yang , Yuanfang Zhao , Maotang Cai , Fengbao Ji , Lingtong Meng , Qiuyu Zhou , Yuanjian Zhou , Yingru Pei , Changjiang Yuan","doi":"10.1016/j.gr.2025.10.013","DOIUrl":"10.1016/j.gr.2025.10.013","url":null,"abstract":"<div><div>The Bangong–Nujiang suture zone (BNSZ), separating the Qiangtang and Lhasa blocks, exhibits extensive Early Cretaceous varied magmatism and significant metallogenetic potential. However, geodynamic mechanisms driving this magmatic flare-up remain controversial. To address this issue, we conducted a comprehensive study focusing on the multi-type intrusions within and adjacent to the mélange zone in the Amdo–Nagqu area, middle BNSZ. Zircon U–Pb dating indicates that these intrusions emplaced during the Early Cretaceous (119–109 Ma). They display consistent arc-like whole-rock major and trace element characteristics with highly variable whole-rock initial <sup>87</sup>Sr/<sup>86</sup>Sr (0.706534–0.712838) ratios, negative ε<sub>Nd</sub>(t) (−3.7 to − 9.2) values, and negative to weakly positive zircon ε<sub>Hf</sub>(t) (–14.7 to + 2.0) values. These geochemical features suggest their petrogenesis involved crust–mantle interactions. Furthermore, the mafic samples are characterized by narrow-ranging <sup>143</sup>Nd/<sup>144</sup>Nd ratios but a wide range of Hf/Nd ratios, and a broader variation of zircon δ<sup>18</sup>O values (8.9–15.5 ‰) compared with coeval felsic samples (7.8–9.8 ‰), indicating the involvement of subducted sediments in the mantle source. Based on the new and previously published data, we suggest that the mafic intrusions originated from partial melting of the sediment-dominated mélange in the sub-continental lithospheric mantle (SCLM), providing tangible evidence of the southward oceanic subduction. In contrast, the felsic intrusions formed through partial melting of the continental crust within hot zones, accompanied by varying degrees of mantle-derived magma mixing. We propose the following geodynamic model for the widespread, small-volume, compositionally diverse Early Cretaceous magmatism along the BNSZ: Demise of the Bangong–Nujiang Tethys Ocean via low-angle bidirectional subduction during the Early Cretaceous, followed by extensive and contemporaneous partial melting. This process was triggered by the decompression and hot asthenosphere upwelling through corner flow and local sporadic slab windows within the fractured zones, along with sinking of the eclogitized ocean slab.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 131-152"},"PeriodicalIF":7.2,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145535924","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}
Pub Date : 2025-11-13DOI: 10.1016/j.gr.2025.10.011
Ting Zhang , Yufei Wang , Dingqiang Zhang , Lin He
Airborne particulate matter (PM) accompanying microbial release is widespread in cities but meets the challenge of quantification. Ambient diffuse PM seasonal profiles from 2022 to 2024 were analysed via a long short-term memory (LSTM) neural network driven by data of on-site monitored number/mass concentration (CN/CM) ratios in a mining city in the northeastern region of China. The result indicated that the CN/CM ratios of PM1.0–10 varied in four seasons owing to multi-component PM aggregation-dispersions. The ratios of 1.5 × 107, 1.0 × 106, and 7.8 × 104 number/μg·m3 in the spring changed to 6.0 × 105, 9.1 × 104, and 425 number/μg·m3 in the summer for PM1.0, PM2.5, and PM10, decreasing 90.9 %-99.5 %. The culturable bioaerosol concentrations (Cbio′) were 433, 441 CFU/m3 in the winter and summer, respectively, but increased to 943, 1,060 CFU/m3 in the spring and autumn and show an agreement with the Bayesian-LSTM model predicted values (R2 > 0.999). Furthermore, on a spring non-haze day (CM-PM2.5: 45.5 μg/m3, CN-PM2.5/CM-PM2.5 ratio: 4.6 × 104 number/μg·m3), Cbio′ reached 5,374 CFU/m3, 7.5 times the annual-averaged concentration of bioaerosols (719 CFU/m3). During PM-polluted days, fine-aerosols settled in the 3D-printed adult left trachea at high inspiratory flow rates. This work validates aggregate PM dispersions by concentration ratio evaluations, facilitating the regional climatic implications estimation on air bio-risks.
{"title":"A quantification analysis on atmospheric bioaerosol dispersion in seasonal meteorological scenarios and risks: A LSTM modelling and visualization","authors":"Ting Zhang , Yufei Wang , Dingqiang Zhang , Lin He","doi":"10.1016/j.gr.2025.10.011","DOIUrl":"10.1016/j.gr.2025.10.011","url":null,"abstract":"<div><div>Airborne particulate matter (PM) accompanying microbial release is widespread in cities but meets the challenge of quantification. Ambient diffuse PM seasonal profiles from 2022 to 2024 were analysed via a long short-term memory (LSTM) neural network driven by data of on-site monitored number/mass concentration (C<sub>N</sub>/C<sub>M</sub>) ratios in a mining city in the northeastern region of China. The result indicated that the C<sub>N</sub>/C<sub>M</sub> ratios of PM1.0–10 varied in four seasons owing to multi-component PM aggregation-dispersions. The ratios of 1.5 × 10<sup>7</sup>, 1.0 × 10<sup>6</sup>, and 7.8 × 10<sup>4</sup> number/μg·m<sup>3</sup> in the spring changed to 6.0 × 10<sup>5</sup>, 9.1 × 10<sup>4</sup>, and 425 number/μg·m<sup>3</sup> in the summer for PM1.0, PM2.5, and PM10, decreasing 90.9 %-99.5 %. The culturable bioaerosol concentrations (C<sub>bio</sub>′) were 433, 441 CFU/m<sup>3</sup> in the winter and summer, respectively, but increased to 943, 1,060 CFU/m<sup>3</sup> in the spring and autumn and show an agreement with the Bayesian-LSTM model predicted values (R<sup>2</sup> > 0.999). Furthermore, on a spring non-haze day (C<sub>M-PM2.5</sub>: 45.5 μg/m<sup>3</sup>, C<sub>N-PM2.5</sub>/C<sub>M-PM2.5</sub> ratio: 4.6 × 10<sup>4</sup> number/μg·m<sup>3</sup>), C<sub>bio</sub>′ reached 5,374 CFU/m<sup>3</sup>, 7.5 times the annual-averaged concentration of bioaerosols (719 CFU/m<sup>3</sup>). During PM-polluted days, fine-aerosols settled in the 3D-printed adult left trachea at high inspiratory flow rates. This work validates aggregate PM dispersions by concentration ratio evaluations, facilitating the regional climatic implications estimation on air bio-risks.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 64-81"},"PeriodicalIF":7.2,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145532035","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}
Pub Date : 2025-11-13DOI: 10.1016/j.gr.2025.10.012
Lei Liu , Chuntao Yin , Hanjie Wen , Guishan Zhang
Lithium plays a crucial role in green energy. The growing demand for lithium facilitates the exploration of new resources, most of which are related to pegmatites and brine lakes. Recently, an anomaly in lithium enrichment has been identified in the claystone of the Lower Permian Daoshitou Formation in central Yunnan Province, China. However, it is challenging to map all the lithium-rich outcrops over a large area through field survey due to the small exposure and discontinuity of outcrops caused by high vegetation coverage and soil mixtures. In this study, high spatial resolution WorldView-3 (WV-3) data were used for the mapping of claystone over 200 km2 using spectral angle mapper (SAM) and Convolutional Neural Network-Recurrent Neural Network (CNN-RNN) deep learning method in the Xiaoshiqiao area, Yunnan Province, China. The image endmembers extracted from the WV-3 image by Spatial-Spectral Endmember Extraction method were used to quickly map the major occurrence of claystone outcrops with SAM algorithm. The representative outcrops were extracted from SAM using very small angle (0.03) to generate training areas, and CNN-RNN deep learning method was used to further improve the delineation of claystone. Field inspection and laboratory analysis of field samples proved that claystone outcrops can be successfully identified by WV-3 data. A total of 98 outcrop sites were inspected in the field, out of which 92 were confirmed to be claystone outcrops, achieving an accuracy of 93.88 %. This study demonstrates that based on the automated endmember extraction algorithm, the SAM and CNN-RNN deep learning method are efficient to process WV-3 multispectral data for the discrimination of meter scale lithium-rich claystone outcrops in heavily vegetated areas.
{"title":"Mapping lithium hosting claystone using WorldView-3 image and deep learning method","authors":"Lei Liu , Chuntao Yin , Hanjie Wen , Guishan Zhang","doi":"10.1016/j.gr.2025.10.012","DOIUrl":"10.1016/j.gr.2025.10.012","url":null,"abstract":"<div><div>Lithium plays a crucial role in green energy. The growing demand for lithium facilitates the exploration of new resources, most of which are related to pegmatites and brine lakes. Recently, an anomaly in lithium enrichment has been identified in the claystone of the Lower Permian Daoshitou Formation in central Yunnan Province, China. However, it is challenging to map all the lithium-rich outcrops over a large area through field survey due to the small exposure and discontinuity of outcrops caused by high vegetation coverage and soil mixtures. In this study, high spatial resolution WorldView-3 (WV-3) data were used for the mapping of claystone over 200 km<sup>2</sup> using spectral angle mapper (SAM) and Convolutional Neural Network-Recurrent Neural Network (CNN-RNN) deep learning method in the Xiaoshiqiao area, Yunnan Province, China. The image endmembers extracted from the WV-3 image by Spatial-Spectral Endmember Extraction method were used to quickly map the major occurrence of claystone outcrops with SAM algorithm. The representative outcrops were extracted from SAM using very small angle (0.03) to generate training areas, and CNN-RNN deep learning method was used to further improve the delineation of claystone. Field inspection and laboratory analysis of field samples proved that claystone outcrops can be successfully identified by WV-3 data. A total of 98 outcrop sites were inspected in the field, out of which 92 were confirmed to be claystone outcrops, achieving an accuracy of 93.88 %. This study demonstrates that based on the automated endmember extraction algorithm, the SAM and CNN-RNN deep learning method are efficient to process WV-3 multispectral data for the discrimination of meter scale lithium-rich claystone outcrops in heavily vegetated areas.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 18-35"},"PeriodicalIF":7.2,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145531593","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}
Pub Date : 2025-11-13DOI: 10.1016/j.gr.2025.10.015
Nikola Stanković , Vladica Cvetković , Ana Mladenović , Vesna Cvetkov , Dejan Prelević , Taras Gerya
The geodynamic evolution of the Balkan Peninsula during the Late Cretaceous remains a subject of debate, particularly regarding the role of subduction versus post-collisional processes for magmatism. This study employs magmatic-thermomechanical numerical modelling to investigate the fate of the Upper Jurassic subducted Adriatic lithosphere following the compressional obduction processes related to the emplacement of the Tethyan ophiolites onto the Adriatic margin. Our results suggest that Late Cretaceous magmatism in the Timok Magmatic Complex can be explained without invoking the existence of an actively subducting oceanic domain (e.g. “Sava Ocean”). Instead, the magmatic activity appears to be a consequence of slab breakoff, lithospheric delamination, and the subsequent rebound of subducted continental material. The model successfully reproduces key geological observations, including the delayed onset of magmatism (relative to the Late Jurassic closure of Vardar Tethys) and the geochemical signatures typically associated with subduction. However, discrepancies remain in the precise timing of volcanism, which highlights the need for further refinements in numerical modelling of melt extraction and magma migration processes. These findings contribute to a broader general understanding of post-obduction geodynamic processes and have implications for the formation of porphyry Cu-Au deposits in post-collisional settings.
{"title":"Post-obduction slab dynamics in the Balkans and its role in Late Cretaceous magmatism: A numerical modelling approach","authors":"Nikola Stanković , Vladica Cvetković , Ana Mladenović , Vesna Cvetkov , Dejan Prelević , Taras Gerya","doi":"10.1016/j.gr.2025.10.015","DOIUrl":"10.1016/j.gr.2025.10.015","url":null,"abstract":"<div><div>The geodynamic evolution of the Balkan Peninsula during the Late Cretaceous remains a subject of debate, particularly regarding the role of subduction versus post-collisional processes for magmatism. This study employs magmatic-thermomechanical numerical modelling to investigate the fate of the Upper Jurassic subducted Adriatic lithosphere following the compressional obduction processes related to the emplacement of the Tethyan ophiolites onto the Adriatic margin. Our results suggest that Late Cretaceous magmatism in the Timok Magmatic Complex can be explained without invoking the existence of an actively subducting oceanic domain (e.g. “Sava Ocean”). Instead, the magmatic activity appears to be a consequence of slab breakoff, lithospheric delamination, and the subsequent rebound of subducted continental material. The model successfully reproduces key geological observations, including the delayed onset of magmatism (relative to the Late Jurassic closure of Vardar Tethys) and the geochemical signatures typically associated with subduction. However, discrepancies remain in the precise timing of volcanism, which highlights the need for further refinements in numerical modelling of melt extraction and magma migration processes. These findings contribute to a broader general understanding of post-obduction geodynamic processes and have implications for the formation of porphyry Cu-Au deposits in post-collisional settings.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 1-17"},"PeriodicalIF":7.2,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145519043","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}
Pub Date : 2025-11-13DOI: 10.1016/j.gr.2025.10.014
Zofia Dubicka , Michał Rakociński
Foraminifera are one of the most abundant and diverse groups of biomineralizing marine microorganisms. While they first appeared in the early Cambrian, during the early Paleozoic they were dominated by morphologically simple agglutinated taxa. More complex, multichambered calcitic forms first emerged during the Middle Devonian “Givetian Revolution,” during which Foraminifera formed very important constituents of the Middle Devonian reef communities in Euramerica. Surprisingly, however, Devonian foraminifera have never been recorded from northern Gondwana. Here, we present the first record of Devonian foraminifera from the Mader Basin (eastern Anti-Atlas, Morocco), along the northern margin of the Gondwana shelf. This foraminiferal community has very limited taxonomic diversity and morphologic disparity compared to contemporaneous Euramerican assemblages, and primarily consists of tubular forms. This likely resulted from paleoenvironmental implications of the high southern latitude of the Mader Basin (ca. 40–45˚S), which was near the edge of the Devonian reef zone.
{"title":"The first record of Devonian foraminifera from northern Gondwana","authors":"Zofia Dubicka , Michał Rakociński","doi":"10.1016/j.gr.2025.10.014","DOIUrl":"10.1016/j.gr.2025.10.014","url":null,"abstract":"<div><div>Foraminifera are one of the most abundant and diverse groups of biomineralizing marine microorganisms. While they first appeared in the early Cambrian, during the early Paleozoic they were dominated by morphologically simple agglutinated taxa. More complex, multichambered calcitic forms first emerged during the Middle Devonian “Givetian Revolution,” during which Foraminifera formed very important constituents of the Middle Devonian reef communities in Euramerica. Surprisingly, however, Devonian foraminifera have never been recorded from northern Gondwana. Here, we present the first record of Devonian foraminifera from the Mader Basin (eastern Anti-Atlas, Morocco), along the northern margin of the Gondwana shelf. This foraminiferal community has very limited taxonomic diversity and morphologic disparity compared to contemporaneous Euramerican assemblages, and primarily consists of tubular forms. This likely resulted from paleoenvironmental implications of the high southern latitude of the Mader Basin (ca. 40–45˚S), which was near the edge of the Devonian reef zone.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"151 ","pages":"Pages 58-63"},"PeriodicalIF":7.2,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145531594","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}
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