Pub Date : 2024-12-09DOI: 10.1016/j.gr.2024.11.013
Nicholas A. Regier, Brian K. Horton, Daniel Starck, Facundo Fuentes, Erin E. Donaghy, Michael P. Eddy, Tomas N. Capaldi
The Precordillera of western Argentina displays a complex pre-Andean stratigraphic record related to Paleozoic convergence along the SW margin of Gondwana. Sedimentologic and U-Pb detrital zircon geochronological results for the Silurian Rinconada Formation and Carboniferous Jejenes Formation of the eastern Precordillera provide insight into sediment provenance, drainage reorganization, and climatic/tectonic interactions during Paleozoic deformation and glaciation. Measured sections and lithofacies analyses indicate sediment gravity flow and mass-transport deposition in a Silurian submarine fan during shortening in the adjacent Famatinian orogenic belt. This foreland basin was deformed during the Late Devonian Chanic orogeny, prior to glacial incision of remnant topography during the Late Paleozoic Ice Age. Analyses of unconformities, cross-cutting relationships, and lithofacies within a Carboniferous paleovalley (Quebrada Grande, Sierra Chica de Zonda) indicate four facies associations (fjord-head delta, distal fjord, fan delta, and subglacial fan) within a fjord setting governed by glacial advance and retreat. U-Pb results for Carboniferous sandstones (7 samples, 840 analyses) indicate derivation from Western Pampean basement with progressive drainage expansion to include the Famatinian magmatic arc and Eastern Sierras Pampeanas. Evolution from a Silurian marine foreland basin to an isolated Carboniferous fjord reflects major orogenic and climatic transitions in SW Gondwana. Ordovician-Silurian (Famatinian) and Late Devonian (Chanic) shortening generated topography that was subsequently beveled by glacial erosion during the Carboniferous. We suggest that Paleozoic deformation related to subduction and terrane collision helped drive changes in sediment dispersal and basin configuration, while climate changes during regional glaciation regulated erosion/deposition and the spatial extent of sediment accommodation.
{"title":"Sediment provenance and depositional systems during Paleozoic tectonic and climatic transitions in the eastern Precordillera of Argentina","authors":"Nicholas A. Regier, Brian K. Horton, Daniel Starck, Facundo Fuentes, Erin E. Donaghy, Michael P. Eddy, Tomas N. Capaldi","doi":"10.1016/j.gr.2024.11.013","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.013","url":null,"abstract":"The Precordillera of western Argentina displays a complex pre-Andean stratigraphic record related to Paleozoic convergence along the SW margin of Gondwana. Sedimentologic and U-Pb detrital zircon geochronological results for the Silurian Rinconada Formation and Carboniferous Jejenes Formation of the eastern Precordillera provide insight into sediment provenance, drainage reorganization, and climatic/tectonic interactions during Paleozoic deformation and glaciation. Measured sections and lithofacies analyses indicate sediment gravity flow and mass-transport deposition in a Silurian submarine fan during shortening in the adjacent Famatinian orogenic belt. This foreland basin was deformed during the Late Devonian Chanic orogeny, prior to glacial incision of remnant topography during the Late Paleozoic Ice Age. Analyses of unconformities, cross-cutting relationships, and lithofacies within a Carboniferous paleovalley (Quebrada Grande, Sierra Chica de Zonda) indicate four facies associations (fjord-head delta, distal fjord, fan delta, and subglacial fan) within a fjord setting governed by glacial advance and retreat. U-Pb results for Carboniferous sandstones (7 samples, 840 analyses) indicate derivation from Western Pampean basement with progressive drainage expansion to include the Famatinian magmatic arc and Eastern Sierras Pampeanas. Evolution from a Silurian marine foreland basin to an isolated Carboniferous fjord reflects major orogenic and climatic transitions in SW Gondwana. Ordovician-Silurian (Famatinian) and Late Devonian (Chanic) shortening generated topography that was subsequently beveled by glacial erosion during the Carboniferous. We suggest that Paleozoic deformation related to subduction and terrane collision helped drive changes in sediment dispersal and basin configuration, while climate changes during regional glaciation regulated erosion/deposition and the spatial extent of sediment accommodation.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"54 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884643","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 : 2024-12-09DOI: 10.1016/j.gr.2024.11.012
Honghao Li, You Tian, Dapeng Zhao, Hongli Li
A northwest-southeast trending high-density seismic array was deployed in the southern Xing’an-Mongolian Orogenic Belt, spanning the Songliao basin, the North-South gravity gradient lineament, the Great Xing’an Mountains, and the Erlian basin. The high-density seismic array included 1000 stations with an interval of ∼0.5 km. We image the lithospheric structure using the teleseismic receiver function method. Our results show that the Moho depth gradually increases from ∼35 km beneath the Songliao basin to ∼40 km beneath the Great Xing’an Mountains. In the vicinity of the North-South gravity lineament, the Moho is slightly inclined with a continuous depth of ∼5 km, which forms a transition zone from the basin to the orogenic belt. A middle crustal discontinuity, or the Conrad discontinuity, is imaged beneath the Songliao-Xilinhot block and the northern margin of the North China Craton. The Conrad and Moho discontinuities beneath the suture zones show traces of bidirectional subduction of the Paleo-Asian Ocean plate. Meanwhile, we find subtle changes in the receiver functions due to variations in the sedimentary layer thickness. The sedimentary layer beneath the southern Songliao basin is estimated to be ∼1.2 km thick and it thins toward its edge. Moreover, we find a middle lithospheric discontinuity below the Moho under the Songliao-Xilinhot block. Combining with previous findings, we deem that the middle lithospheric discontinuity reflects a high-temperature layer in the upper lithosphere mantle associated with hot and wet upwelling flows in the big mantle wedge under NE China.
{"title":"Lithospheric structure of Northeast China from dense array receiver functions: Insight into two-side subduction of the Paleo-Asian Ocean plate","authors":"Honghao Li, You Tian, Dapeng Zhao, Hongli Li","doi":"10.1016/j.gr.2024.11.012","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.012","url":null,"abstract":"A northwest-southeast trending high-density seismic array was deployed in the southern Xing’an-Mongolian Orogenic Belt, spanning the Songliao basin, the North-South gravity gradient lineament, the Great Xing’an Mountains, and the Erlian basin. The high-density seismic array included 1000 stations with an interval of ∼0.5 km. We image the lithospheric structure using the teleseismic receiver function method. Our results show that the Moho depth gradually increases from ∼35 km beneath the Songliao basin to ∼40 km beneath the Great Xing’an Mountains. In the vicinity of the North-South gravity lineament, the Moho is slightly inclined with a continuous depth of ∼5 km, which forms a transition zone from the basin to the orogenic belt. A middle crustal discontinuity, or the Conrad discontinuity, is imaged beneath the Songliao-Xilinhot block and the northern margin of the North China Craton. The Conrad and Moho discontinuities beneath the suture zones show traces of bidirectional subduction of the Paleo-Asian Ocean plate. Meanwhile, we find subtle changes in the receiver functions due to variations in the sedimentary layer thickness. The sedimentary layer beneath the southern Songliao basin is estimated to be ∼1.2 km thick and it thins toward its edge. Moreover, we find a middle lithospheric discontinuity below the Moho under the Songliao-Xilinhot block. Combining with previous findings, we deem that the middle lithospheric discontinuity reflects a high-temperature layer in the upper lithosphere mantle associated with hot and wet upwelling flows in the big mantle wedge under NE China.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"13 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884644","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 : 2024-12-09DOI: 10.1016/j.gr.2024.11.014
Hamza Shafiq, Riaz Ul Hissan, Ayesha Mariam, Shafaqat Ali, Abdelmohsen A. Nassani, Magdalena Radulescu, Komal Batool, Bilal Hussain
This study examined the relationship between Land Surface Temperature and various spectral indices in Dera Ghazi Khan division of Pakistan to assess landscape characteristics and ecological health. This study used satellite images to detect temperature variation and urbanization-influenced land cover patterns using remote sensing data during 2013–2023. Estimated results revealed that Land Surface Temperature was significantly linked with spectral indices over the study’ period. The results showed a continuous increase in urban intensity contributing to an increase in surface temperature to 47.19 °C by 2023. It was also found that due to cooling effects, there is a negative relationship between the Normalized Difference Vegetation Index and the Land Surface Temperature, whereas positive values exist concerning the other indices. These findings indicate the higher temperatures for built-up areas, barren land, and water-reduced bodies. Moreover, findings of various spectral indices revealed the significant temperature differences and changing land covers. In addition, the results of land cover changes showed how temperature variations are influenced by urbanization and health status. The findings of this study will be helpful for government and concerned policy makers in promoting sustainable land management practices to mitigate climate change and local environmental protection measures.
{"title":"Spatio-temporal assessment of urban temperature variations and landscape characteristics using spectral indices","authors":"Hamza Shafiq, Riaz Ul Hissan, Ayesha Mariam, Shafaqat Ali, Abdelmohsen A. Nassani, Magdalena Radulescu, Komal Batool, Bilal Hussain","doi":"10.1016/j.gr.2024.11.014","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.014","url":null,"abstract":"This study examined the relationship between Land Surface Temperature and various spectral indices in Dera Ghazi Khan division of Pakistan to assess landscape characteristics and ecological health. This study used satellite images to detect temperature variation and urbanization-influenced land cover patterns using remote sensing data during 2013–2023. Estimated results revealed that Land Surface Temperature was significantly linked with spectral indices over the study’ period. The results showed a continuous increase in urban intensity contributing to an increase in surface temperature to 47.19 °C by 2023. It was also found that due to cooling effects, there is a negative relationship between the Normalized Difference Vegetation Index and the Land Surface Temperature, whereas positive values exist concerning the other indices. These findings indicate the higher temperatures for built-up areas, barren land, and water-reduced bodies. Moreover, findings of various spectral indices revealed the significant temperature differences and changing land covers. In addition, the results of land cover changes showed how temperature variations are influenced by urbanization and health status. The findings of this study will be helpful for government and concerned policy makers in promoting sustainable land management practices to mitigate climate change and local environmental protection measures.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"48 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884642","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 : 2024-12-09DOI: 10.1016/j.gr.2024.11.011
Henry W. Posamentier, Anatoly M. Nikishin, Ksenia F. Aleshina, Elizaveta A. Rodina, Alexander P. Afanasenkov, Steven L. Bachtel, Gillian R. Foulger
Recently-acquired, high-quality seismic reflection profiles document the presence of possible carbonate deposits on the Mendeleev Rise in the Arctic Ocean during the Paleocene-Eocene Thermal Maximum and the Early Eocene Climatic Optimum. These deposits are concentrated at the crests of bathymetric highs and consist of clusters of buildups comprising small patch reefs overlain by larger, coalesced platforms, followed by back-stepped higher-relief platforms. The small buildups commonly are ∼ 100–500 m in diameter and 50–100 m in height. The larger platforms are up to 3–7 km wide and up to 400 m thick. Some of the larger buildups are characterized by internal horizontally layered architecture, whereas others are characterized internally by clinoforms suggesting progradational growth. A common characteristic of these buildups is that they tend to achieve a common height (i.e., their tops align along the same level), typical of buildups sensitive to growth within the photic zone, whose upward growth is limited by sea level. The succession of buildup styles indicates carbonate factories under the influence of accelerating relative sea-level rise, which culminated in drowning and ultimate abandonment.
{"title":"Carbonate deposition in the Arctic during the Paleocene Eocene Thermal Maximum (PETM) and Early Eocene Climatic Optimum (EECO)","authors":"Henry W. Posamentier, Anatoly M. Nikishin, Ksenia F. Aleshina, Elizaveta A. Rodina, Alexander P. Afanasenkov, Steven L. Bachtel, Gillian R. Foulger","doi":"10.1016/j.gr.2024.11.011","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.011","url":null,"abstract":"Recently-acquired, high-quality seismic reflection profiles document the presence of possible carbonate deposits on the Mendeleev Rise in the Arctic Ocean during the Paleocene-Eocene Thermal Maximum and the Early Eocene Climatic Optimum. These deposits are concentrated at the crests of bathymetric highs and consist of clusters of buildups comprising small patch reefs overlain by larger, coalesced platforms, followed by back-stepped higher-relief platforms. The small buildups commonly are ∼ 100–500 m in diameter and 50–100 m in height. The larger platforms are up to 3–7 km wide and up to 400 m thick. Some of the larger buildups are characterized by internal horizontally layered architecture, whereas others are characterized internally by clinoforms suggesting progradational growth. A common characteristic of these buildups is that they tend to achieve a common height (i.e., their tops align along the same level), typical of buildups sensitive to growth within the photic zone, whose upward growth is limited by sea level. The succession of buildup styles indicates carbonate factories under the influence of accelerating relative sea-level rise, which culminated in drowning and ultimate abandonment.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"18 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884645","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 : 2024-12-09DOI: 10.1016/j.gr.2024.12.001
Alexander Wheeler, Ulrich Heimhofer, Joan S. Esterle
The Permian-aged Wolfang Basin in Queensland, Australia, formed as a rift-controlled half graben containing significant coal resources. Recently, the use of high-resolution zircon ages has allowed for a recalibration of the eastern Australian palynostratigraphy, necessitating a re-examination of the timing of deposition in the Wolfang Basin relative to the glacial episodes that mark the end of the Late Palaeozoic Ice Age in Australia. Four coal seams were selected for palynological and organic carbon isotope analysis: the Wolfang Main, Wolfang Upper, Prospect and Gowrie seams. Palynostratigraphy from the Wolfang Basin yields an APP3.2 age for the Wolfang Main and Upper seams (Kungurian-Roadian), an APP3.3 age for the Prospect seam (mid-upper Roadian), and an APP4.2 age for the Gowrie seam (Wordian). This indicates the timing of formation of the Wolfang Main and Upper seams preceded the P3 glaciation, whereas the Gowrie and possibly the Prospect seams were contemporaneous with the glaciation. Palynofloras show an overall dominance of trilete spores (Leiotriletes, Microbaculispora, Acanthotriletes), particularly in the Wolfang Main and Wolfang Upper seams, however pollen grains (Protohaploxypinus, Scheuringipollenites, Marsupipollenites) increase in abundance in the Prospect and Gowrie seams. The Gowrie seam also shows a higher abundance of monosaccate pollen (Plicatipollenites, Cannanoropollis). Organic carbon isotopes of vitrain bands show subtle enrichment from a mean of −24‰ in the Wolfang Main seam to –23.3‰ in the Prospect seam. The Gowrie seam shows upsection depletion from –23.2‰ to –23.9‰. These trends are comparable to existing records and may reflect a shift to cooler conditions related to the P3 glaciation, though local tectonic and environmental regimes still allow for periods of peat-formation.
{"title":"Palynostratigraphic reassessment of the Permian Wolfang Basin (Queensland, Australia) − implications for climate and timing of coal formation","authors":"Alexander Wheeler, Ulrich Heimhofer, Joan S. Esterle","doi":"10.1016/j.gr.2024.12.001","DOIUrl":"https://doi.org/10.1016/j.gr.2024.12.001","url":null,"abstract":"The Permian-aged Wolfang Basin in Queensland, Australia, formed as a rift-controlled half graben containing significant coal resources. Recently, the use of high-resolution zircon ages has allowed for a recalibration of the eastern Australian palynostratigraphy, necessitating a re-examination of the timing of deposition in the Wolfang Basin relative to the glacial episodes that mark the end of the Late Palaeozoic Ice Age in Australia. Four coal seams were selected for palynological and organic carbon isotope analysis: the Wolfang Main, Wolfang Upper, Prospect and Gowrie seams. Palynostratigraphy from the Wolfang Basin yields an APP3.2 age for the Wolfang Main and Upper seams (Kungurian-Roadian), an APP3.3 age for the Prospect seam (mid-upper Roadian), and an APP4.2 age for the Gowrie seam (Wordian). This indicates the timing of formation of the Wolfang Main and Upper seams preceded the P3 glaciation, whereas the Gowrie and possibly the Prospect seams were contemporaneous with the glaciation. Palynofloras show an overall dominance of trilete spores (<ce:italic>Leiotriletes, Microbaculispora, Acanthotriletes</ce:italic>), particularly in the Wolfang Main and Wolfang Upper seams, however pollen grains (<ce:italic>Protohaploxypinus, Scheuringipollenites, Marsupipollenites</ce:italic>) increase in abundance in the Prospect and Gowrie seams. The Gowrie seam also shows a higher abundance of monosaccate pollen (<ce:italic>Plicatipollenites, Cannanoropollis</ce:italic>). Organic carbon isotopes of vitrain bands show subtle enrichment from a mean of −24‰ in the Wolfang Main seam to –23.3‰ in the Prospect seam. The Gowrie seam shows upsection depletion from –23.2‰ to –23.9‰. These trends are comparable to existing records and may reflect a shift to cooler conditions related to the P3 glaciation, though local tectonic and environmental regimes still allow for periods of peat-formation.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"91 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841529","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 : 2024-12-07DOI: 10.1016/j.gr.2024.12.002
Javiera González, Verónica Oliveros, Friedrich Lucassen, Christian Creixell, Felipe Coloma, Ricardo Velásquez, Laura Hernández, Paulina Vásquez, Simone A. Kasemann
The Chollay-Piuquenes batholith (CPB) represents voluminous Lower-Middle Triassic magmatism on the western margin of Gondwana. It crops out in the Chilean Frontal Cordillera (28°30′S–30°30′S), covering ∼2,400 km2. It is composed of the Chollay and Piuquenes plutonic complexes, that were emplaced over a 16 Myr interval, with magma production rates ranging from 6 to 7.5 km3/Myr km−1. The batholith lithologies vary from diorites to syenogranites, with a predominance of monzogranites and granodiorites. It was previously interpreted as an anorogenic, post-collisional magmatism, originated from crustal anatexis in a rifting continental margin (Pre-Andean Cycle). This field and geochemical study proposes that CPB is likely a subduction-related batholith constructed in a convergent retreating margin. This interpretation is consistent with the Triassic geotectonic context proposed for western Gondwana. Moreover, the extensional context for the CPB emplacement is inferred from the contemporaneous development of forearc and back-arc basins, and from geochemical signals indicating Mesozoic crustal thinning along the margin. The CPB rocks exhibit subalkaline, meta- to peraluminous, calc-alkaline to alkaline-calcic affinities, enrichment in LILE relative to HFSE, depletion in Nb-Ta, Ti, Sr, and P, and Pb enrichment. The rocks display flat REE patterns (LaN/YbN: 3.40–13.78) and Al-in-Hbl barometer calculations (1.7–1.8 ± 0.6 kbar) suggest an epizonal emplacement. The Sr-Nd-Pb isotopic signature suggests a mixture of depleted mantle and continental crust, and not only crustal reworking, as the main magma-generating process. A comparative analysis of CPB samples with other well-known examples of both retreating and advancing margin batholiths allows the establishment of criteria to distinguish each tectonic context.
{"title":"The Triassic magmatism in southwestern Gondwana: An example of arc batholith construction in a retreating margin","authors":"Javiera González, Verónica Oliveros, Friedrich Lucassen, Christian Creixell, Felipe Coloma, Ricardo Velásquez, Laura Hernández, Paulina Vásquez, Simone A. Kasemann","doi":"10.1016/j.gr.2024.12.002","DOIUrl":"https://doi.org/10.1016/j.gr.2024.12.002","url":null,"abstract":"The Chollay-Piuquenes batholith (CPB) represents voluminous Lower-Middle Triassic magmatism on the western margin of Gondwana. It crops out in the Chilean Frontal Cordillera (28°30′S–30°30′S), covering ∼2,400 km<ce:sup loc=\"post\">2</ce:sup>. It is composed of the Chollay and Piuquenes plutonic complexes, that were emplaced over a 16 Myr interval, with magma production rates ranging from 6 to 7.5 km<ce:sup loc=\"post\">3</ce:sup>/Myr km<ce:sup loc=\"post\">−1</ce:sup>. The batholith lithologies vary from diorites to syenogranites, with a predominance of monzogranites and granodiorites. It was previously interpreted as an anorogenic, post-collisional magmatism, originated from crustal anatexis in a rifting continental margin (Pre-Andean Cycle). This field and geochemical study proposes that CPB is likely a subduction-related batholith constructed in a convergent retreating margin. This interpretation is consistent with the Triassic geotectonic context proposed for western Gondwana. Moreover, the extensional context for the CPB emplacement is inferred from the contemporaneous development of forearc and back-arc basins, and from geochemical signals indicating Mesozoic crustal thinning along the margin. The CPB rocks exhibit subalkaline, meta- to peraluminous, calc-alkaline to alkaline-calcic affinities, enrichment in LILE relative to HFSE, depletion in Nb-Ta, Ti, Sr, and P, and Pb enrichment. The rocks display flat REE patterns (La<ce:inf loc=\"post\">N</ce:inf>/Yb<ce:inf loc=\"post\">N</ce:inf>: 3.40–13.78) and Al-in-Hbl barometer calculations (1.7–1.8 ± 0.6 kbar) suggest an epizonal emplacement. The Sr-Nd-Pb isotopic signature suggests a mixture of depleted mantle and continental crust, and not only crustal reworking, as the main magma-generating process. A comparative analysis of CPB samples with other well-known examples of both retreating and advancing margin batholiths allows the establishment of criteria to distinguish each tectonic context.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"78 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797874","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 : 2024-12-06DOI: 10.1016/j.gr.2024.12.003
Justin G. Park, Morgan F. Schaller
Recent attention has been paid to fluid inclusions in surficial minerals for their ability to capture and preserve aliquots of ancient atmospheric gas. Through mechanical or thermal decrepitation, the volatiles trapped in these multiphase inclusions can be analyzed by mass spectrometry, providing direct constraints on the composition of the Earth’s ancient atmosphere. It is often assumed that this measured gas composition reflects directly the atmosphere under which the minerals precipitated. However, when the effects of gas solubility are neglected, the interpreted atmosphere is likely to be erroneous, reflecting a mixture of gas and brine. Here, we present a novel technique and computer code, MAGPI (Method for Atmospheric Gas Partitioning from fluid Inclusions), to partition the atmospheric volatiles between the gas and aqueous phases present at the time of inclusion formation and volatile entrapment. The N2/40Ar ratios of the released gases are used to calculate the volume fractions of the gaseous and aqueous phases present at the time of entrapment, which allows the observed gas ratios to be corrected to accurately reflect the composition of the atmosphere under which they formed. We validate our method on contemporary halite fluid inclusions, and then apply it to existing data from a suite of Tonian (815 Ma) halite and gypsum evaporites from the Browne Formation, Australia, and the Minto Inlet Formation, Canada. The results of our partition indicate that the Tonian atmosphere contained 92.83 ± 0.70 % N2, 6.62 ± 0.71 % O2, 0.47 ± 0.01 % Ar, and 0.08 ± 0.07 % CO2, which is consistent with other proxy and model reconstructions of the Neoproterozoic atmosphere. These results demonstrate the importance of phase chemistry in fluid inclusion gas analyses and provide a fundamental framework for future studies of Earth’s atmospheric evolution through inclusion gases.
{"title":"Constraints on Earth’s atmospheric evolution from a gas-aqueous partition of fluid inclusion volatiles","authors":"Justin G. Park, Morgan F. Schaller","doi":"10.1016/j.gr.2024.12.003","DOIUrl":"https://doi.org/10.1016/j.gr.2024.12.003","url":null,"abstract":"Recent attention has been paid to fluid inclusions in surficial minerals for their ability to capture and preserve aliquots of ancient atmospheric gas. Through mechanical or thermal decrepitation, the volatiles trapped in these multiphase inclusions can be analyzed by mass spectrometry, providing direct constraints on the composition of the Earth’s ancient atmosphere. It is often assumed that this measured gas composition reflects directly the atmosphere under which the minerals precipitated. However, when the effects of gas solubility are neglected, the interpreted atmosphere is likely to be erroneous, reflecting a mixture of gas and brine. Here, we present a novel technique and computer code, MAGPI (Method for Atmospheric Gas Partitioning from fluid Inclusions), to partition the atmospheric volatiles between the gas and aqueous phases present at the time of inclusion formation and volatile entrapment. The N<ce:inf loc=\"post\">2</ce:inf>/<ce:sup loc=\"post\">40</ce:sup>Ar ratios of the released gases are used to calculate the volume fractions of the gaseous and aqueous phases present at the time of entrapment, which allows the observed gas ratios to be corrected to accurately reflect the composition of the atmosphere under which they formed. We validate our method on contemporary halite fluid inclusions, and then apply it to existing data from a suite of Tonian (815 Ma) halite and gypsum evaporites from the Browne Formation, Australia, and the Minto Inlet Formation, Canada. The results of our partition indicate that the Tonian atmosphere contained 92.83 ± 0.70 % N<ce:inf loc=\"post\">2</ce:inf>, 6.62 ± 0.71 % O<ce:inf loc=\"post\">2</ce:inf>, 0.47 ± 0.01 % Ar, and 0.08 ± 0.07 % CO<ce:inf loc=\"post\">2</ce:inf>, which is consistent with other proxy and model reconstructions of the Neoproterozoic atmosphere. These results demonstrate the importance of phase chemistry in fluid inclusion gas analyses and provide a fundamental framework for future studies of Earth’s atmospheric evolution through inclusion gases.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"57 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142884646","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 : 2024-12-05DOI: 10.1016/j.gr.2024.11.010
Fei Xue, M. Santosh, Sung Won Kim
During the Mesozoic, the North China Craton (NCC) especially the eastern part underwent significant destruction of its cratonic roots. During ∼125–120 Ma, the source of magmatism shifted from an ancient enriched lithospheric mantle to a juvenile depleted asthenospheric mantle. While this geochemical change is clear in the eastern NCC, it is unclear whether a similar shift occurred in the central NCC or if the lithospheric evolution differed across the craton. Mafic magmatic suites are key to understanding the evolution of cratonic lithospheric mantle, especially by analyzing their geochemical and isotopic transitions. This study examines the Mesozoic Laiyuan ultramafic–mafic intrusions in central NCC, classified into gabbro, gabbroic diorite, and cumulate suites (pyroxenite and hornblendite). Zircon U-Pb dating indicates gabbroic rocks formed between 136–124 Ma and cumulated between 130–129 Ma. These rocks also display similar isotopic signatures, including zircon Hf isotopes ranging from −24.9 to −7.8 and −28.3 to −15.9, (87Sr/86Sr)i ratios from 0.705945 to 0.706335 and 0.705692 to 0.706038, and εNd(t) values from −16.1 to −12.8 and −15.8 to −12.5, respectively. Geochemical and isotopic data suggest an enriched lithospheric mantle source influenced by subduction-related metasomatism with minimal crustal contamination. The gabbroic and ultramafic layers represent residual melts and cumulates from a common source, respectively. Geochemical data reveal a transition in the mantle source from ultramafic-mafic intrusions (∼140–124 Ma) to dolerite (∼125–117 Ma) and lamprophyre (∼115–110 Ma), indicating lithospheric thinning and asthenosphere upwelling. This gradual transition in the central NCC contrasts with the rapid change in the eastern NCC, reflecting different lithospheric evolution processes: thermo-mechanical erosion in the central NCC and lithospheric delamination in the eastern NCC. These findings highlight diverse mechanisms of cratonic destruction across the NCC.
{"title":"Differential lithospheric evolution during craton destruction: Insights from Mesozoic mafic magmatic suites with transitional features in the North China Craton","authors":"Fei Xue, M. Santosh, Sung Won Kim","doi":"10.1016/j.gr.2024.11.010","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.010","url":null,"abstract":"During the Mesozoic, the North China Craton (NCC) especially the eastern part underwent significant destruction of its cratonic roots. During ∼125–120 Ma, the source of magmatism shifted from an ancient enriched lithospheric mantle to a juvenile depleted asthenospheric mantle. While this geochemical change is clear in the eastern NCC, it is unclear whether a similar shift occurred in the central NCC or if the lithospheric evolution differed across the craton. Mafic magmatic suites are key to understanding the evolution of cratonic lithospheric mantle, especially by analyzing their geochemical and isotopic transitions. This study examines the Mesozoic Laiyuan ultramafic–mafic intrusions in central NCC, classified into gabbro, gabbroic diorite, and cumulate suites (pyroxenite and hornblendite). Zircon U-Pb dating indicates gabbroic rocks formed between 136–124 Ma and cumulated between 130–129 Ma. These rocks also display similar isotopic signatures, including zircon Hf isotopes ranging from −24.9 to −7.8 and −28.3 to −15.9, (<ce:sup loc=\"post\">87</ce:sup>Sr/<ce:sup loc=\"post\">86</ce:sup>Sr)<ce:sup loc=\"post\">i</ce:sup> ratios from 0.705945 to 0.706335 and 0.705692 to 0.706038, and ε<ce:inf loc=\"post\">Nd</ce:inf>(t) values from −16.1 to −12.8 and −15.8 to −12.5, respectively. Geochemical and isotopic data suggest an enriched lithospheric mantle source influenced by subduction-related metasomatism with minimal crustal contamination. The gabbroic and ultramafic layers represent residual melts and cumulates from a common source, respectively. Geochemical data reveal a transition in the mantle source from ultramafic-mafic intrusions (∼140–124 Ma) to dolerite (∼125–117 Ma) and lamprophyre (∼115–110 Ma), indicating lithospheric thinning and asthenosphere upwelling. This gradual transition in the central NCC contrasts with the rapid change in the eastern NCC, reflecting different lithospheric evolution processes: thermo-mechanical erosion in the central NCC and lithospheric delamination in the eastern NCC. These findings highlight diverse mechanisms of cratonic destruction across the NCC.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"1 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841530","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 : 2024-12-02DOI: 10.1016/j.gr.2024.11.007
Muhammad Amir Raza, Abdul Karim, M.M. Aman, Mahmoud Ahmad Al-Khasawneh, Muhammad Faheem
Coal remains a significant energy source globally, with the United States holding a substantial portion of the world’s coal reserves but it creates the dangerous effects of global warming. Despite its abundance, questions arise regarding the accessibility and environmental impact of coal reserves. Therefore, this research forecasted the future of coal reserves, coal prices, electricity from coal, carbon emissions and coal phase-out targets globally using the SARIMAX Python® model for the study period 2023 to 2050 by using the economic data from the year 1980 to 2022. It is found that, the global coal reserve capacity is 1.07 trillion tons with an average coal prices vary with region to region, ranging from US $130 per tone to US $206 per tone until 2050. The global production of electricity from coal will also increase from 10415.49 TWh in 2023 to 13316.57 TWh until 2040 and 15243.36 TWh until 2050 which ultimately enhances the production of carbon emissions, increases from 157,768 billion metric tons in 2023 to 188,535 billion metric tons until 2040 and 215,077 billion metric tons until 2050. Furthermore, this study undertakes and presented the country wise examination of coal phase out and it is found that in many countries 75% of coal will phase out by 2030 and 100% by 2040 for meeting the Intergovernmental Panel on Climate Change (IPCC) 1.5 0C targets. Therefore there is a dire need to shift towards cleaner energy sources, leading to a decline in coal-fired power generation and a trend towards coal phase-out.
{"title":"Global progress towards the Coal: Tracking coal reserves, coal prices, electricity from coal, carbon emissions and coal phase-out","authors":"Muhammad Amir Raza, Abdul Karim, M.M. Aman, Mahmoud Ahmad Al-Khasawneh, Muhammad Faheem","doi":"10.1016/j.gr.2024.11.007","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.007","url":null,"abstract":"Coal remains a significant energy source globally, with the United States holding a substantial portion of the world’s coal reserves but it creates the dangerous effects of global warming. Despite its abundance, questions arise regarding the accessibility and environmental impact of coal reserves. Therefore, this research forecasted the future of coal reserves, coal prices, electricity from coal, carbon emissions and coal phase-out targets globally using the SARIMAX Python® model for the study period 2023 to 2050 by using the economic data from the year 1980 to 2022. It is found that, the global coal reserve capacity is 1.07 trillion tons with an average coal prices vary with region to region, ranging from US $130 per tone to US $206 per tone until 2050. The global production of electricity from coal will also increase from 10415.49 TWh in 2023 to 13316.57 TWh until 2040 and 15243.36 TWh until 2050 which ultimately enhances the production of carbon emissions, increases from 157,768 billion metric tons in 2023 to 188,535 billion metric tons until 2040 and 215,077 billion metric tons until 2050. Furthermore, this study undertakes and presented the country wise examination of coal phase out and it is found that in many countries 75% of coal will phase out by 2030 and 100% by 2040 for meeting the Intergovernmental Panel on Climate Change (IPCC) 1.5 <ce:sup loc=\"post\">0</ce:sup>C targets. Therefore there is a dire need to shift towards cleaner energy sources, leading to a decline in coal-fired power generation and a trend towards coal phase-out.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"97 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797875","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 : 2024-11-30DOI: 10.1016/j.gr.2024.11.006
Yuanlin Chen, Huan Li, Shangyi Gu, Gary G. Lash, Chaoyang Zheng, Liuan Duan, Fan Yang
The Lomagundi Carbon Event (LE), the large, long-lived Paleoproterozoic positive carbon isotope excursion, is traditionally associated with a significant increase in atmospheric oxygen. However, the magnitude and extent of atmosphere–ocean oxygenation during this critical period of Earth’s history remain poorly constrained. Here, we present molybdenum isotope data and Ce anomaly values of Paleoproterozoic Jingshan Group marble samples deposited coincident with the peak of LE. Analyzed samples are characterized by near-modern seawater δ98Mocarb values (maximum = 2.13 ‰ ± 0.05), crustal Ce anomalies (average = 1.03), and δ98Mocarb values (average = 0.41 ‰). The great variation of Mo isotope values displayed by samples recovered from a thin stratigraphic interval likely reflect the existence of a small Mo reservoir during LE. We suggest that Mo removal from poorly oxygenated oceans under ferruginous conditions was responsible for the contraction of the Mo oceanic reservoir. Mo concentrations and isotope values of deposits coincident with this time interval appear to have been controlled by iron and manganese oxides shuttle. Placed in the context of Earth’s oxygenation history, our findings suggest that O2levels of the atmosphere–ocean system remained much less (1 % PAL) than the present level with occasional episodes of increased or pulsed atmospheric oxygen during the peak of LE.
{"title":"Pulsed atmospheric oxygenation recorded by Mo isotopes and Ce anomalies during Lomagundi Event from Jingshan Group marble of North China Craton","authors":"Yuanlin Chen, Huan Li, Shangyi Gu, Gary G. Lash, Chaoyang Zheng, Liuan Duan, Fan Yang","doi":"10.1016/j.gr.2024.11.006","DOIUrl":"https://doi.org/10.1016/j.gr.2024.11.006","url":null,"abstract":"The Lomagundi Carbon Event (LE), the large, long-lived Paleoproterozoic positive carbon isotope excursion, is traditionally associated with a significant increase in atmospheric oxygen. However, the magnitude and extent of atmosphere–ocean oxygenation during this critical period of Earth’s history remain poorly constrained. Here, we present molybdenum isotope data and Ce anomaly values of Paleoproterozoic Jingshan Group marble samples deposited coincident with the peak of LE. Analyzed samples are characterized by near-modern seawater δ<ce:sup loc=\"post\">98</ce:sup>Mo<ce:inf loc=\"post\">carb</ce:inf> values (maximum = 2.13 ‰ ± 0.05), crustal Ce anomalies (average = 1.03), and δ<ce:sup loc=\"post\">98</ce:sup>Mo<ce:inf loc=\"post\">carb</ce:inf> values (average = 0.41 ‰). The great variation of Mo isotope values displayed by samples recovered from a thin stratigraphic interval likely reflect the existence of a small Mo reservoir during LE. We suggest that Mo removal from poorly oxygenated oceans under ferruginous conditions was responsible for the contraction of the Mo oceanic reservoir. Mo concentrations and isotope values of deposits coincident with this time interval appear to have been controlled by iron and manganese oxides shuttle. Placed in the context of Earth’s oxygenation history, our findings suggest that O<ce:inf loc=\"post\">2</ce:inf><ce:hsp sp=\"0.25\"></ce:hsp>levels of the atmosphere–ocean system remained much less (1 % PAL) than the present level with occasional episodes of increased or pulsed atmospheric oxygen during the peak of LE.","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"09 1","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797877","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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