Pub Date : 2025-03-05DOI: 10.1016/j.precamres.2025.107749
Kine Tangvik Størdal , Trond Slagstad , Maarten Felix , Silje Funderud , Evgeniy Kulakov , Bjørn Eske Sørensen , Kerstin Saalmann , Magdalena H. Huyskens , Stefanie Lode
Deciphering the history of active continental margins is of key importance for paleogeographic reconstructions, but the low preservation potential of such margins commonly hampers such attempts and may introduce unrecognized biases. Here, we present new sedimentological observations and detrital zircon U–Pb and Hf isotopic data from the Ediacaran–Cambrian Vestertana Group in Finnmark, Arctic Norway. The data are consistent with derivation from the Fennoscandian Shield and the appearance of an Ediacaran source at the Ediacaran–Cambrian transition. However, the new paleocurrent observations dispute that this influx is related to a change in paleocurrent direction from northerly to southerly. Instead, we argue for the possibility of an alternative source represented by the Kalak Nappe Complex, which we suggest may be a remnant of a Neoproterozoic accretionary margin outboard of western Baltica that was thrust onto Baltica during the Ediacaran rather than during the Silurian Caledonian Orogeny. Further work focusing on detrital minerals other than zircon may provide a more comprehensive understanding of the character of these potential sources. Comparisons with detrital zircon data from Ediacaran–Cambrian sedimentary rocks around the North Atlantic show that both Baltica and Siberia are characterized by large Neoproterozoic populations, while such ages are all but absent from Laurentia. The apparent link between Baltica and Siberia during the Ediacaran–Cambrian is consistent with fossil data and suggests that the two continents were separated from Laurentia by this time.
{"title":"Detrital zircon data suggest multiple Cryogenian–Cambrian active margins along northern and western Baltica and close ties with Siberia","authors":"Kine Tangvik Størdal , Trond Slagstad , Maarten Felix , Silje Funderud , Evgeniy Kulakov , Bjørn Eske Sørensen , Kerstin Saalmann , Magdalena H. Huyskens , Stefanie Lode","doi":"10.1016/j.precamres.2025.107749","DOIUrl":"10.1016/j.precamres.2025.107749","url":null,"abstract":"<div><div>Deciphering the history of active continental margins is of key importance for paleogeographic reconstructions, but the low preservation potential of such margins commonly hampers such attempts and may introduce unrecognized biases. Here, we present new sedimentological observations and detrital zircon U–Pb and Hf isotopic data from the Ediacaran–Cambrian Vestertana Group in Finnmark, Arctic Norway. The data are consistent with derivation from the Fennoscandian Shield and the appearance of an Ediacaran source at the Ediacaran–Cambrian transition. However, the new paleocurrent observations dispute that this influx is related to a change in paleocurrent direction from northerly to southerly. Instead, we argue for the possibility of an alternative source represented by the Kalak Nappe Complex, which we suggest may be a remnant of a Neoproterozoic accretionary margin outboard of western Baltica that was thrust onto Baltica during the Ediacaran rather than during the Silurian Caledonian Orogeny. Further work focusing on detrital minerals other than zircon may provide a more comprehensive understanding of the character of these potential sources. Comparisons with detrital zircon data from Ediacaran–Cambrian sedimentary rocks around the North Atlantic show that both Baltica and Siberia are characterized by large Neoproterozoic populations, while such ages are all but absent from Laurentia. The apparent link between Baltica and Siberia during the Ediacaran–Cambrian is consistent with fossil data and suggests that the two continents were separated from Laurentia by this time.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"421 ","pages":"Article 107749"},"PeriodicalIF":3.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the co-occurrence of ferric illite and glauconite in the Deodongar sandstone of the Mesoproterozoic Chattisgarh Supergroup in India. Forming a Member within the stromatolitic Chandi Formation, these glauconitic arenites were deposited in a shallow marine setting, as revealed by field relationships. Electron Probe Micro Analyzer (EPMA) data shows that these ferric illites and glauconites are rich in magnesium and aluminum, although they exhibit considerable variation in iron and potassium content. Oxide cross-plots indicate that ferric illite and glauconite followed different geochemical pathways of formation. Textural observations indicate that these minerals formed over K-feldspar, quartz and chert fragments as authigenic phases. Mass balance calculations suggest that potassium released during the conversion of K-feldspar to glauconitic minerals may aid in transforming quartz/chert fragments to these minerals, though additional sources for iron, magnesium and aluminum ions are necessary. Thermodynamic calculations show that ferric illite formation is favorable than glauconite at 1 atmospheric pressure and 298 Kelvin temperature. Yet, occurrence of ferric illite and glauconite forming over adjacent substrates suggests that each substrate acted as a closed independent chemical system for mineral authigenesis.
{"title":"Genesis of coexisting authigenic ferric illite and glauconite in the Deodongar Sandstones, Chattisgarh Basin, India: Unraveling redox dynamics of a Mesoproterozoic Sea?","authors":"Ayoti Banerjee , Ashim Kumar Patel , Sivaji Lahiri , Pramita Majumder , Amlan Banerjee , Somnath Dasgupta","doi":"10.1016/j.precamres.2025.107735","DOIUrl":"10.1016/j.precamres.2025.107735","url":null,"abstract":"<div><div>This study investigates the co-occurrence of ferric illite and glauconite in the Deodongar sandstone of the Mesoproterozoic Chattisgarh Supergroup in India. Forming a Member within the stromatolitic Chandi Formation, these glauconitic arenites were deposited in a shallow marine setting, as revealed by field relationships. Electron Probe Micro Analyzer (EPMA) data shows that these ferric illites and glauconites are rich in magnesium and aluminum, although they exhibit considerable variation in iron and potassium content. Oxide cross-plots indicate that ferric illite and glauconite followed different geochemical pathways of formation. Textural observations indicate that these minerals formed over K-feldspar, quartz and chert fragments as authigenic phases. Mass balance calculations suggest that potassium released during the conversion of K-feldspar to glauconitic minerals may aid in transforming quartz/chert fragments to these minerals, though additional sources for iron, magnesium and aluminum ions are necessary. Thermodynamic calculations show that ferric illite formation is favorable than glauconite at 1 atmospheric pressure and 298 Kelvin temperature. Yet, occurrence of ferric illite and glauconite forming over adjacent substrates suggests that each substrate acted as a closed independent chemical system for mineral authigenesis.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107735"},"PeriodicalIF":3.2,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-02-27DOI: 10.1016/j.precamres.2025.107739
Tingyi Wang , Guochun Zhao , Chunrong Diwu
The craton margins and small-scale Precambrian blocks are not always with stable lithosphere; they tend to lose their roots and be reworked and isotopically reset by subduction and collision from multiple directions. The Dunhuang Block is one of the microcontinents within the Central Asian Orogenic Belt (CAOB), and has been involved and reworked by tectonics evolution of the southern CAOB, leading to extensive reworking and recycling of continental lithosphere. Therefore, the Dunhuang Block is an excellent example for revealing the growth and reworking of early Precambrian continental crust. Archean–Paleoproterozoic basement rocks in the Dunhuang Block are sporadically exposed and spatially associated with Paleozoic complexes related to the CAOB. Available geochronological data reveal that the Dunhuang Block is a unified Precambrian block that likely formed a coherent crystalline basement prior to ca. 1.79 Ga. In the representative Gangou cross-section of the Dunhuang Block, the early Precambrian rocks were mainly composed of Neoarchean to Paleoproterozoic TTG gneisses with a small amount of late Paleoproterozoic pyroxenite and marble. The protoliths of Neoarchean TTG rocks in the Dunhuang Block were likely originated from a subducted oceanic slab under the garnet-amphibolite- and rutile-eclogite-facies conditions with presence of rutile; whereas the Paleoproterozoic TTG rocks likely originated from partial melting of thickened mafic lower continental crust under amphibolite-facies condition. Hf isotopic compositions in zircons from the Precambrian rocks in the Dunhuang Block reveal that remnants of Hadean-Eoarchean crustal components were still present in the basement of the Dunhuang Block. The Neoarchean rocks in the Dunhuang Block have been mainly extracted from the depleted mantle, whereas the Paleoproterozoic rocks have been primarily reworked from older crustal reservoirs. The Dunhuang Block was an independent Precambrian continental fragment or microcontinent situated between the Tarim Craton and North China Craton. Similar to many other Precambrian blocks within the CAOB, it was significantly involved in Paleozoic orogenic events related to the subduction-accretion processes of the Paleo-Asian Ocean in the southern CAOB.
{"title":"Growth and reworking of continental crust: Insights from the Dunhuang Block, NW China","authors":"Tingyi Wang , Guochun Zhao , Chunrong Diwu","doi":"10.1016/j.precamres.2025.107739","DOIUrl":"10.1016/j.precamres.2025.107739","url":null,"abstract":"<div><div>The craton margins and small-scale Precambrian blocks are not always with stable lithosphere; they tend to lose their roots and be reworked and isotopically reset by subduction and collision from multiple directions. The Dunhuang Block is one of the microcontinents within the Central Asian Orogenic Belt (CAOB), and has been involved and reworked by tectonics evolution of the southern CAOB, leading to extensive reworking and recycling of continental lithosphere. Therefore, the Dunhuang Block is an excellent example for revealing the growth and reworking of early Precambrian continental crust. Archean–Paleoproterozoic basement rocks in the Dunhuang Block are sporadically exposed and spatially associated with Paleozoic complexes related to the CAOB. Available geochronological data reveal that the Dunhuang Block is a unified Precambrian block that likely formed a coherent crystalline basement prior to ca. 1.79 Ga. In the representative Gangou cross-section of the Dunhuang Block, the early Precambrian rocks were mainly composed of Neoarchean to Paleoproterozoic TTG gneisses with a small amount of late Paleoproterozoic pyroxenite and marble. The protoliths of Neoarchean TTG rocks in the Dunhuang Block were likely originated from a subducted oceanic slab under the garnet-amphibolite- and rutile-eclogite-facies conditions with presence of rutile; whereas the Paleoproterozoic TTG rocks likely originated from partial melting of thickened mafic lower continental crust under amphibolite-facies condition. Hf isotopic compositions in zircons from the Precambrian rocks in the Dunhuang Block reveal that remnants of Hadean-Eoarchean crustal components were still present in the basement of the Dunhuang Block. The Neoarchean rocks in the Dunhuang Block have been mainly extracted from the depleted mantle, whereas the Paleoproterozoic rocks have been primarily reworked from older crustal reservoirs. The Dunhuang Block was an independent Precambrian continental fragment or microcontinent situated between the Tarim Craton and North China Craton. Similar to many other Precambrian blocks within the CAOB, it was significantly involved in Paleozoic orogenic events related to the subduction-accretion processes of the Paleo-Asian Ocean in the southern CAOB.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107739"},"PeriodicalIF":3.2,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<div><div>This study offers the first comprehensive geochronological and geochemical results for the Paleoproterozoic magmatic rocks exposed along the eastern margin of the Lishi Fault in the North China Craton (NCC). Their emplacement age, petrogenesis, and relationship with the basement provide critical constraints for inferring the subdivisions and tectonic evolution of the NCC basement. The U-Pb ages, Hf-O isotopes, in combination with whole-rock major and trace element data, identify three episodes of magmatism along the eastern margin of the Lishi Fault at ca. 2.33–2.29 Ga, 2.20–2.17 Ga and 1.97–1.94 Ga. The magmatic rocks include the 2.33–2.29 Ga granites, 2.20–2.17 Ga tonalites, granodiorites, granites and <em>meta</em>-gabbros, and 1.97–1.94 Ga granites. The 2.33–2.29 Ga granites are characterized by high SiO<sub>2</sub>, K<sub>2</sub>O contents, and Ce/Pb and Nd/Sm values ranging from 2.50 to 5.62 and 4.74–7.61, respectively. The zircon Hf isotope compositions (<em>ε</em><sub>Hf</sub>(<em>t</em>) = -1.71-+3.0, <em>T</em><sub>DM2</sub> = 3.0–2.6 Ga), suggest their origin through a recycled Archean crustal. The 2.20–2.17 Ga felsic rocks (SiO<sub>2</sub> = 63.83–74.30 wt%) show relatively high Mg# values, large variation in Cr and Ni abundances, and low (La/Yb)<sub>N</sub> value. These characteristics and zircon Hf isotope compositions (<em>ε</em><sub>Hf</sub>(<em>t</em>) = -4.24-+2.69, <em>T</em><sub>DM2</sub> = 2.8–2.6 Ga) suggest their evolution through high-temperature melting of a Neoarchean mafic source and a significant role of mantle-derived materials. The 2.20–2.17 Ga gabbros (subsequently metamorphosed) with high K (K<sub>2</sub>O = 0.91–2.20 wt%) and depleted Nb-Ta-Ti, were derived from an enriched lithospheric mantle source. The 1.97–1.94 Ga granites are moserately peraluminous (A/CNK = 1.02–1.12) and display high zircon δ<sup>18</sup>O values (5.51–8.15 ‰, Ave. 6.72 ‰). Such characteristics underline their S-type nature and derivation from partial melting of (meta)sedimentary source. The 2.33–2.29 Ga granite and 2.20–2.17 Ga tonalite show variably low zircon δ<sup>18</sup>O values of 3.29–6.07 ‰ and 2.94–6.27 ‰ respectively, which are below the normal mantle zircon values. A general increase in zircon δ<sup>18</sup>O values in the Paleoproterozoic magmatic rocks along the eastern margin of the Lishi Fault underlines a change in the tectonic regime from extension to collision setting. The zircon U-Pb age and Lu-Hf isotope data of the early Precambrian basement rocks reveal a close similarity in the tectono-thermal regime and crustal growth between OB and other tectonic domains of NCC, such as the northern Khondalite Belt and Yinshan Block (KB + YB), Trans-North China Orogen (TNCO), and the Eastern Block (EB). We propose that the lithosphere of the NCC was significantly thinned since the Mesozoic and was accompanied by extensive magmatic activities. The geomorphology of present day NCC was shaped by multiple stages of uplift-den
{"title":"The significance of Mesozoic basement uplift for interpreting the NCC’s Precambrian tectonic regime: Evidence from the Paleoproterozoic magmatic rocks along the eastern margin of the Lishi Fault","authors":"Qingsong Duan , Mingguo Zhai , Xiyan Zhu , Yanyan Zhou , Yuhong Fan","doi":"10.1016/j.precamres.2025.107737","DOIUrl":"10.1016/j.precamres.2025.107737","url":null,"abstract":"<div><div>This study offers the first comprehensive geochronological and geochemical results for the Paleoproterozoic magmatic rocks exposed along the eastern margin of the Lishi Fault in the North China Craton (NCC). Their emplacement age, petrogenesis, and relationship with the basement provide critical constraints for inferring the subdivisions and tectonic evolution of the NCC basement. The U-Pb ages, Hf-O isotopes, in combination with whole-rock major and trace element data, identify three episodes of magmatism along the eastern margin of the Lishi Fault at ca. 2.33–2.29 Ga, 2.20–2.17 Ga and 1.97–1.94 Ga. The magmatic rocks include the 2.33–2.29 Ga granites, 2.20–2.17 Ga tonalites, granodiorites, granites and <em>meta</em>-gabbros, and 1.97–1.94 Ga granites. The 2.33–2.29 Ga granites are characterized by high SiO<sub>2</sub>, K<sub>2</sub>O contents, and Ce/Pb and Nd/Sm values ranging from 2.50 to 5.62 and 4.74–7.61, respectively. The zircon Hf isotope compositions (<em>ε</em><sub>Hf</sub>(<em>t</em>) = -1.71-+3.0, <em>T</em><sub>DM2</sub> = 3.0–2.6 Ga), suggest their origin through a recycled Archean crustal. The 2.20–2.17 Ga felsic rocks (SiO<sub>2</sub> = 63.83–74.30 wt%) show relatively high Mg# values, large variation in Cr and Ni abundances, and low (La/Yb)<sub>N</sub> value. These characteristics and zircon Hf isotope compositions (<em>ε</em><sub>Hf</sub>(<em>t</em>) = -4.24-+2.69, <em>T</em><sub>DM2</sub> = 2.8–2.6 Ga) suggest their evolution through high-temperature melting of a Neoarchean mafic source and a significant role of mantle-derived materials. The 2.20–2.17 Ga gabbros (subsequently metamorphosed) with high K (K<sub>2</sub>O = 0.91–2.20 wt%) and depleted Nb-Ta-Ti, were derived from an enriched lithospheric mantle source. The 1.97–1.94 Ga granites are moserately peraluminous (A/CNK = 1.02–1.12) and display high zircon δ<sup>18</sup>O values (5.51–8.15 ‰, Ave. 6.72 ‰). Such characteristics underline their S-type nature and derivation from partial melting of (meta)sedimentary source. The 2.33–2.29 Ga granite and 2.20–2.17 Ga tonalite show variably low zircon δ<sup>18</sup>O values of 3.29–6.07 ‰ and 2.94–6.27 ‰ respectively, which are below the normal mantle zircon values. A general increase in zircon δ<sup>18</sup>O values in the Paleoproterozoic magmatic rocks along the eastern margin of the Lishi Fault underlines a change in the tectonic regime from extension to collision setting. The zircon U-Pb age and Lu-Hf isotope data of the early Precambrian basement rocks reveal a close similarity in the tectono-thermal regime and crustal growth between OB and other tectonic domains of NCC, such as the northern Khondalite Belt and Yinshan Block (KB + YB), Trans-North China Orogen (TNCO), and the Eastern Block (EB). We propose that the lithosphere of the NCC was significantly thinned since the Mesozoic and was accompanied by extensive magmatic activities. The geomorphology of present day NCC was shaped by multiple stages of uplift-den","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107737"},"PeriodicalIF":3.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-02-25DOI: 10.1016/j.precamres.2025.107736
Irmak Yılmaz , Ali Polat , Joel Gagnon , Robert Frei , Peter Jobin
In this study, we present new field, petrographic, and whole-rock major and trace element, and Nd–Pb–Sr radiogenic isotope data for a newly discovered aillikite, carbonate-rich kimberlite, and carbonatite association on the northern shore of Lake Superior, Canada. The aillikite, carbonate-rich kimberlite, and carbonatite association is exposed as sills and dykes in the Neoarchean Schreiber-Hemlo greenstone belt in the Ripple Bay area, Ontario. The carbonatite and carbonate-rich kimberlite occur in the same dykes and sills, whereas the aillikite occurs in separate dykes and sills. Boundaries between the carbonatite and carbonate-rich kimberlite are mostly sharp, with some gradational outcrops. Field relationships, near 1.1 Ga Pb–Pb and Rb–Sr errorchron ages, and Nd depleted mantle model ages (TDM = 1.14–1.46 Ga) reported in this study, collectively suggest that the Ripple Bay aillikite, carbonate-rich kimberlite, and carbonatite association formed as part of the late Mesoproterozoic Mid-continental Rift System in North America. New geochemical data are used to constrain the petrogenesis of the Ripple Bay aillikite, carbonate-rich kimberlite, and carbonatite association and address the long-standing debate on the co-genetic relationship of aillikite, kimberlite, and carbonatite occurrences worldwide. Each rock type displays distinct major and trace element characteristics. On the chondrite-normalized REE diagram, all three rock types exhibit subparallel trends characterized by large enrichments of LREEs over HREEs (La/Ybcn = 33–62), with the carbonatite displaying the most enriched patterns and carbonate-rich kimberlites showing the least enrichment, and aillikites plot between the carbonatites and carbonate-rich kimberlites. Aphanitic texture and flow patterns in the carbonatite indicate that it solidified from a carbonatite melt. All three rock types resulted from small degrees of partial melting in different parts of the same mantle source region, which had different proportions of metasomatic minerals, and represent near-primary melt compositions. The carbonate-rich kimberlite and carbonatite melts were transported simultaneously to the surface through the same magma conduits, with minimal mixing, indicating that their sources were spatially associated. Initial Nd (εNd=+0.6 to + 7.0) and Sr (Sri = 0.700309–0.704111) compositions and 206Pb/204Pb (17.83–40.23) and 208Pb/204Pb (37.66–62.88) isotope ratios reflect heterogeneous asthenospheric mantle sources containing strongly depleted to enriched components.
{"title":"Petrogenesis of a newly discovered ∼1.1 Ga aillikite, carbonate-rich kimberlite, and carbonatite association on the northern margin of the Mid-continental Rift System, Ontario, Canada","authors":"Irmak Yılmaz , Ali Polat , Joel Gagnon , Robert Frei , Peter Jobin","doi":"10.1016/j.precamres.2025.107736","DOIUrl":"10.1016/j.precamres.2025.107736","url":null,"abstract":"<div><div>In this study, we present new field, petrographic, and whole-rock major and trace element, and Nd–Pb–Sr radiogenic isotope data for a newly discovered aillikite, carbonate-rich kimberlite, and carbonatite association on the northern shore of Lake Superior, Canada.<!--> <!-->The aillikite, carbonate-rich kimberlite, and carbonatite association is exposed as sills and dykes in the Neoarchean Schreiber-Hemlo greenstone belt in the Ripple Bay area, Ontario. The carbonatite and carbonate-rich kimberlite occur in the same dykes and sills, whereas the aillikite occurs in separate dykes and sills. Boundaries between the carbonatite and carbonate-rich kimberlite are mostly sharp, with some gradational outcrops. Field relationships, near 1.1 Ga Pb–Pb and Rb–Sr errorchron ages, and Nd depleted mantle model ages (T<sub>DM</sub> = 1.14–1.46 Ga) reported in this study, collectively suggest that the Ripple Bay aillikite, carbonate-rich kimberlite, and carbonatite association formed as part of the late Mesoproterozoic Mid-continental Rift System in North America. New geochemical data are used to constrain the petrogenesis of the Ripple Bay aillikite, carbonate-rich kimberlite, and carbonatite association and address the long-standing debate on the co-genetic relationship of aillikite, kimberlite, and carbonatite occurrences worldwide. Each rock type displays distinct major and trace element characteristics. On the chondrite-normalized REE diagram, all three rock types exhibit subparallel trends characterized by large enrichments of LREEs over HREEs (La/Yb<sub>cn</sub> = 33–62), with the carbonatite displaying the most enriched patterns and carbonate-rich kimberlites showing the least enrichment, and aillikites plot between the carbonatites and carbonate-rich kimberlites. Aphanitic texture and flow patterns in the carbonatite indicate that it solidified from a carbonatite melt. All three rock types resulted from small degrees of partial melting in different parts of the same mantle source region, which had different proportions of metasomatic minerals, and represent near-primary melt compositions. The carbonate-rich kimberlite and carbonatite melts were transported simultaneously to the surface through the same magma conduits, with minimal mixing, indicating that their sources were spatially associated. Initial Nd (εNd=+0.6 to + 7.0) and Sr (Sr<sub>i</sub> = 0.700309–0.704111) compositions and <sup>206</sup>Pb/<sup>204</sup>Pb (17.83–40.23) and <sup>208</sup>Pb/<sup>204</sup>Pb (37.66–62.88) isotope ratios reflect heterogeneous asthenospheric mantle sources containing strongly depleted to enriched components.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107736"},"PeriodicalIF":3.2,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mafic sills witness the evolution of magma and can serve as a sensitive indicator of tectonic regimes. The elemental and isotopic characteristics of mafic sills are crucial for ascertaining the petrogenesis and understanding their tectonic implications. Here, we present new baddeleyite and zircon U-Pb ages, whole-rock geochemical and Os-Nd isotopic data for the 1.32 Ga Yanliao mafic sills from the northeastern North China Craton. The SIMS baddeleyite and LA-ICP-MS zircon dating yields the 207Pb/206Pb ages of 1329 ± 8 to 1303 ± 7 Ma, serving as an epitome of the Mesoproterozoic magmatic event of the North China Craton. The diabases exhibit low SiO2 and variable Mg# (Mg#=Mg2+/(Mg2++Fe2+) in molar), belonging to subalkaline series with high-Fe tholeiitic affinities. They are abundant in LREE, Pb and LILEs (Rb, Th, and U), depleted in HFSEs (Nb and Ta) and endowed with enriched mantle geochemical peculiarities. The simulations of Nd and Os isotopes indicate the mafic rocks have undergone slight crustal contamination (ca. 4–9 %) during magma ascent. The correlations among V, Ni, and Cr contents suggest the clinopyroxene fractionation in the magma evolution. The incompatible-element ratios and ɛNd(t) reveal that the Yanliao mafic sills were predominantly derived from the subcontinental lithospheric mantle, with a minor contribution from the asthenospheric or mantle plume source. Their parental magmas are modeled to have originated from approximately 10 % partial melting of spinel-bearing garnet lherzolite, representing the melting traits of the contemporaneous subcontinental lithospheric mantle. Coupled with other geological data, it is suggested that the diabases from the Yanliao mafic sills have witnessed the episode of the plume and/or asthenosphere upwelling at ca. 1.32 Ga. The vertical mantle upwelling regimes heated and facilitated the partial melting of the enriched lithospheric mantle, resulting in the mafic magmatism in North China Craton during the Mesoproterozoic.
{"title":"Ascertaining the origin of magmas for the 1.32 Ga Yanliao mafic sills: An elemental and Os-Nd isotope perspective","authors":"Chaokun Zhang , Zhuang Li , Wei Tian , Chunjing Wei","doi":"10.1016/j.precamres.2025.107733","DOIUrl":"10.1016/j.precamres.2025.107733","url":null,"abstract":"<div><div>Mafic sills witness the evolution of magma and can serve as a sensitive indicator of tectonic regimes. The elemental and isotopic characteristics of mafic sills are crucial for ascertaining the petrogenesis and understanding their tectonic implications. Here, we present new baddeleyite and zircon U-Pb ages, whole-rock geochemical and Os-Nd isotopic data for the 1.32 Ga Yanliao mafic sills from the northeastern North China Craton. The SIMS baddeleyite and LA-ICP-MS zircon dating yields the <sup>207</sup>Pb/<sup>206</sup>Pb ages of 1329 ± 8 to 1303 ± 7 Ma, serving as an epitome of the Mesoproterozoic magmatic event of the North China Craton. The diabases exhibit low SiO<sub>2</sub> and variable Mg<sup>#</sup> (Mg<sup>#</sup>=Mg<sup>2+</sup>/(Mg<sup>2+</sup>+Fe<sup>2+</sup>) in molar), belonging to subalkaline series with high-Fe tholeiitic affinities. They are abundant in LREE, Pb and LILEs (Rb, Th, and U), depleted in HFSEs (Nb and Ta) and endowed with enriched mantle geochemical peculiarities. The simulations of Nd and Os isotopes indicate the mafic rocks have undergone slight crustal contamination (ca. 4–9 %) during magma ascent. The correlations among V, Ni, and Cr contents suggest the clinopyroxene fractionation in the magma evolution. The incompatible-element ratios and ɛ<sub>Nd</sub>(t) reveal that the Yanliao mafic sills were predominantly derived from the subcontinental lithospheric mantle, with a minor contribution from the asthenospheric or mantle plume source. Their parental magmas are modeled to have originated from approximately 10 % partial melting of spinel-bearing garnet lherzolite, representing the melting traits of the contemporaneous subcontinental lithospheric mantle. Coupled with other geological data, it is suggested that the diabases from the Yanliao mafic sills have witnessed the episode of the plume and/or asthenosphere upwelling at ca. 1.32 Ga. The vertical mantle upwelling regimes heated and facilitated the partial melting of the enriched lithospheric mantle, resulting in the mafic magmatism in North China Craton during the Mesoproterozoic.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107733"},"PeriodicalIF":3.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-02-22DOI: 10.1016/j.precamres.2025.107709
Ruihan Duan , Ruliang He , Pengcheng Ju , Hang Yang , Fan Yang , Qi Wang , Min Yao , Jinlong Yao , KangJun Huang , Guochun Zhao
Multi-proxies and decimeter-scale multicellular eukaryotes fossils in the North China Craton indicate a pulsed oxygenation event at 1.56–1.57 Ga. It has been widely proposed that oxygen concentration is the most important control factor governing the evolution of life. However, the subsequent evolution of life and ocean redox condition are less constrained. We here report I/(Ca + Mg) values, carbonate C isotopes (carbon) and cerium (Ce) anomalies across the ca. 1.56–1.52 Ga Gaoyuzhuang-Yangzhuang Formation in the North China Platform, in order to reconstruct the ocean redox conditions and its relationship with the evolution of life. Our geochemistry proxies demonstrate that after the pulsed oxygenation event at 1.57 Ga, the content of oxygen rapidly decreased to lower levels and continued until 1.55 Ga. Negative Ce anomaly (as low as 0.56) and high I/(Ca + Mg) values (up to1.2 μmol/mol) are identified at 1.54 Ga, indicating a possible pulsed oxygenation event. Furthermore, the negative δ13Ccarb excursion from 0.5 ‰ to −2.6 ‰ recorded by the Yangzhuang formation supports oxidation of the dissolved organic carbon (DOC) in the early Mesoproterozoic Ocean. No Ce anomaly and low I/(Ca + Mg) values (＜0.5 μmol/mol) are observed at 1.53 Ga, suggesting that the shallow ocean oxygen levels decreased to lower levels again. Thus, the Yangzhuang Formation may have recorded a transient oxidation event at 1.54 Ga, but the fossil record indicative of eukaryotic evolution is missing until Neoproterozoic. Therefore, we concluded that besides the redox condition of ocean, the limited input of key trace metal elements and higher seawater temperature may have hindered the evolution of eukaryotes in the Mesoproterozoic.
{"title":"Ocean oxygenation in the aftermath of the origin of multicellular eukaryotes: Evidences from Ce anomaly and I/Ca of the Yangzhuang Formation at 1.50 Ga","authors":"Ruihan Duan , Ruliang He , Pengcheng Ju , Hang Yang , Fan Yang , Qi Wang , Min Yao , Jinlong Yao , KangJun Huang , Guochun Zhao","doi":"10.1016/j.precamres.2025.107709","DOIUrl":"10.1016/j.precamres.2025.107709","url":null,"abstract":"<div><div>Multi-proxies and decimeter-scale multicellular eukaryotes fossils in the North China Craton indicate a pulsed oxygenation event at 1.56–1.57 Ga. It has been widely proposed that oxygen concentration is the most important control factor governing the evolution of life. However, the subsequent evolution of life and ocean redox condition are less constrained. We here report I/(Ca + Mg) values, carbonate C isotopes (carbon) and cerium (Ce) anomalies across the ca. 1.56–1.52 Ga Gaoyuzhuang-Yangzhuang Formation in the North China Platform, in order to reconstruct the ocean redox conditions and its relationship with the evolution of life. Our geochemistry proxies demonstrate that after the pulsed oxygenation event at 1.57 Ga, the content of oxygen rapidly decreased to lower levels and continued until 1.55 Ga. Negative Ce anomaly (as low as 0.56) and high I/(Ca + Mg) values (up to1.2 μmol/mol) are identified at 1.54 Ga, indicating a possible pulsed oxygenation event. Furthermore, the negative δ<sup>13</sup>C<sub>carb</sub> excursion from 0.5 ‰ to −2.6 ‰ recorded by the Yangzhuang formation supports oxidation of the dissolved organic carbon (DOC) in the early Mesoproterozoic Ocean. No Ce anomaly and low I/(Ca + Mg) values (＜0.5 μmol/mol) are observed at 1.53 Ga, suggesting that the shallow ocean oxygen levels decreased to lower levels again. Thus, the Yangzhuang Formation may have recorded a transient oxidation event at 1.54 Ga, but the fossil record indicative of eukaryotic evolution is missing until Neoproterozoic. Therefore, we concluded that besides the redox condition of ocean, the limited input of key trace metal elements and higher seawater temperature may have hindered the evolution of eukaryotes in the Mesoproterozoic.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107709"},"PeriodicalIF":3.2,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the Guyang area, numerous late Neoarchean to early Paleoproterozoic DTTG (diorite-tonalite-trondhjemite-granodiorite) are exposed across different litho-tectonic units. This study investigates the nature and tectonic implications of these DTTG. Zircon U-Pb dating of seven representative samples yields an age range of 2396–2537 Ma, showing a southward younging trend. The dioritic rocks exhibit lower Sr/Y and (La/Yb)N values and various Cr, Ni contents, and zircon Hf isotopic compositions. Ancient inherited zircons suggest that these rocks formed from partial melting of an ancient lower crust, with mantle material involvement. The Guyang TTG exhibit relatively high Sr/Y, (La/Yb)N, and Eu/Eu* values, typically indicating derivation from partial melting of hydrated basalts at high pressure. However, the similarity in whole-rock Nd and zircon Hf isotopic compositions between the Guyang TTG and dioritic rocks, along with mixing modelling results between the hornblendite xenoliths and the trondhjemites, suggests a common source. This indicates the TTG were derived from the differentiation of dioritic magma, with amphibole as the primary fractional phase. Thermodynamic and trace element modelling also supports the idea that differentiation of dioritic magma under hydrous conditions could generate TTG-like melts. Therefore, high Sr/Y, (La/Yb)N, and Eu/Eu* values are not sufficient indicators of a high-pressure source. The petrogenesis of the Guyang DTTG suite suggests a crust-mantle interaction process in a subduction arc setting. Melts/fluids from the subducting slab metasomatized the overlying mantle, causing partial melting of the mantle. The intrusion or underplating of mantle-derived melts induced partial melting of the ancient lower crust, resulting in crustal melts that mixed with mantle material to form dioritic magma, the parental magma for the Guyang TTG. Geochemical data indicate consistent tectonic settings, with the Guyang Paleoproterozoic units underlain by a common Neoarchean basement. The high relative oxygen fugacity (ΔFMQ) of these DTTG suggests continuous arc magmatism before the initial continental collision in the Guyang area. The younger trend, supported by zircon dating, may reflect southward migration of dioritic magmatism, with the slab rolling back after the initial collision during the late Neoarchean to early Paleoproterozoic.
{"title":"Southward migration of the Neoarchean magmatism? petrogenesis of the dioritic-tonalitic-trondhjemitic gneisses in the Guyang area, Inner Mongolia, North China Craton","authors":"Xin Tong, Huichu Wang, Jiahui Zhang, Junping Ren, Jianrong Shi, Yunwei Ren","doi":"10.1016/j.precamres.2025.107738","DOIUrl":"10.1016/j.precamres.2025.107738","url":null,"abstract":"<div><div>In the Guyang area, numerous late Neoarchean to early Paleoproterozoic DTTG (diorite-tonalite-trondhjemite-granodiorite) are exposed across different litho-tectonic units. This study investigates the nature and tectonic implications of these DTTG. Zircon U-Pb dating of seven representative samples yields an age range of 2396–2537 Ma, showing a southward younging trend. The dioritic rocks exhibit lower Sr/Y and (La/Yb)<sub>N</sub> values and various Cr, Ni contents, and zircon Hf isotopic compositions. Ancient inherited zircons suggest that these rocks formed from partial melting of an ancient lower crust, with mantle material involvement. The Guyang TTG exhibit relatively high Sr/Y, (La/Yb)<sub>N</sub>, and Eu/Eu* values, typically indicating derivation from partial melting of hydrated basalts at high pressure. However, the similarity in whole-rock Nd and zircon Hf isotopic compositions between the Guyang TTG and dioritic rocks, along with mixing modelling results between the hornblendite xenoliths and the trondhjemites, suggests a common source. This indicates the TTG were derived from the differentiation of dioritic magma, with amphibole as the primary fractional phase. Thermodynamic and trace element modelling also supports the idea that differentiation of dioritic magma under hydrous conditions could generate TTG-like melts. Therefore, high Sr/Y, (La/Yb)<sub>N</sub>, and Eu/Eu* values are not sufficient indicators of a high-pressure source. The petrogenesis of the Guyang DTTG suite suggests a crust-mantle interaction process in a subduction arc setting. Melts/fluids from the subducting slab metasomatized the overlying mantle, causing partial melting of the mantle. The intrusion or underplating of mantle-derived melts induced partial melting of the ancient lower crust, resulting in crustal melts that mixed with mantle material to form dioritic magma, the parental magma for the Guyang TTG. Geochemical data indicate consistent tectonic settings, with the Guyang Paleoproterozoic units underlain by a common Neoarchean basement. The high relative oxygen fugacity (ΔFMQ) of these DTTG suggests continuous arc magmatism before the initial continental collision in the Guyang area. The younger trend, supported by zircon dating, may reflect southward migration of dioritic magmatism, with the slab rolling back after the initial collision during the late Neoarchean to early Paleoproterozoic.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107738"},"PeriodicalIF":3.2,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-02-21DOI: 10.1016/j.precamres.2025.107726
L.A. Elizondo-Pacheco , L.A. Solari , H.L. He , J.A. Ramírez-Fernández , R. Maldonado
Oaxaquia is a fundamental piece of the Mexican geological record. This Proterozoic crustal block evolved throughout the Calymmian-Tonian and has been traditionally included within the Rodinian realm. However, several aspects, such as its paleoposition and the occurrence of AMCG magmatism during the final stages of Rodinia’s consolidation, are still a matter of debate. In this work, we present new whole-rock geochemical and LA-ICP-MS U-Pb zircon geochronological data for the Huitzo suite from the northern Oaxacan Complex, one of the most extensive outcrops of AMCG rocks in Oaxaquia. This information allowed us to reinterpret the tectonic evolution of Oaxaquia during the Stenian-Tonian interval and refine its role in the amalgamation process of Rodinia. The massif-type anorthosite intrusions under study are alkalic, Ba-Sr-rich, devoid of olivine, and exhibit antiperthitic feldspars. These features resemble several anorthosite complexes exposed in present-d ay southeastern Laurentia. The U-Pb geochronological data demonstrate the existence of AMCG pulses between 1015–960 Ma that are contemporary to the late- to post-orogenic Laurentian anorthositic-granitic activity. These new insights suggest a space–time relationship between Oaxaquia and Laurentia that challenges the traditional Amazonia-Oaxaquia-Baltica link. We propose that Oaxaquia was caught in the collision zone between Laurentia and Amazonia as Rodinia was being assembled. During this process, Oaxaquia was positioned near the easternmost part of the Grenville Province, a region with a similar magmatic and metamorphic history. This area experienced orogenic relaxation and magmatism associated with lithospheric delamination after the main orogenic phase (∼1020 Ma), thus generating the oldest alkalic anorthosite intrusions along the core of the orogen. Once the collisional orogenesis ended (∼978 Ma), a post-orogenic extensional regime was established, favoring the generation of the youngest AMCG intrusions.
{"title":"Revisiting Oaxaquia-Laurentia connections during Rodinia assembly: Insights from u-pb dating and geochemistry of massif-type anorthosite intrusions and associated rocks from the northern Oaxacan Complex, southern Mexico","authors":"L.A. Elizondo-Pacheco , L.A. Solari , H.L. He , J.A. Ramírez-Fernández , R. Maldonado","doi":"10.1016/j.precamres.2025.107726","DOIUrl":"10.1016/j.precamres.2025.107726","url":null,"abstract":"<div><div>Oaxaquia is a fundamental piece of the Mexican geological record. This Proterozoic crustal block evolved throughout the Calymmian-Tonian and has been traditionally included within the Rodinian realm. However, several aspects, such as its paleoposition and the occurrence of AMCG magmatism during the final stages of Rodinia’s consolidation, are still a matter of debate. In this work, we present new whole-rock geochemical and LA-ICP-MS U-Pb zircon geochronological data for the Huitzo suite from the northern Oaxacan Complex, one of the most extensive outcrops of AMCG rocks in Oaxaquia. This information allowed us to reinterpret the tectonic evolution of Oaxaquia during the Stenian-Tonian interval and refine its role in the amalgamation process of Rodinia. The massif-type anorthosite intrusions under study are alkalic, Ba-Sr-rich, devoid of olivine, and exhibit antiperthitic feldspars. These features resemble several anorthosite complexes exposed in present-d ay southeastern Laurentia. The U-Pb geochronological data demonstrate the existence of AMCG pulses between 1015–960 Ma that are contemporary to the late- to post-orogenic Laurentian anorthositic-granitic activity. These new insights suggest a space–time relationship between Oaxaquia and Laurentia that challenges the traditional Amazonia-Oaxaquia-Baltica link. We propose that Oaxaquia was caught in the collision zone between Laurentia and Amazonia as Rodinia was being assembled. During this process, Oaxaquia was positioned near the easternmost part of the Grenville Province, a region with a similar magmatic and metamorphic history. This area experienced orogenic relaxation and magmatism associated with lithospheric delamination after the main orogenic phase (∼1020 Ma), thus generating the oldest alkalic anorthosite intrusions along the core of the orogen. Once the collisional orogenesis ended (∼978 Ma), a post-orogenic extensional regime was established, favoring the generation of the youngest AMCG intrusions.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107726"},"PeriodicalIF":3.2,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-02-19DOI: 10.1016/j.precamres.2025.107730
Bo Huang, Timothy Kusky, Dong Fu
Archean continental crust primarily consists of TTG (tonalite–trondhjemite–granodiorite) gneisses and greenstone belts. Understanding their origins and tectonic settings is crucial to deciphering continental growth and associated geodynamic regimes on early Earth, which remain highly debated. The North China Craton, one of the largest cratons, experienced significant crustal growth and reworking during late Neoarchean (ca. 2.6–2.5 Ga), but the mechanisms and geodynamic settings remain uncertain. This review assesses the field relations, structural styles, metamorphic features, and magmatic evolution of two representative Neoarchean TTG-greenstone terranes (Dengfeng and Angou) in the southern North China Craton to evaluate different geodynamic models and their roles in continental crust growth. The Dengfeng and Angou complexes, dominated by ca. 2.55–2.50 Ga TTG gneisses, metavolcano-sedimentary assemblages, and high-Mg diorites, with several generations of mafic and felsic intrusions, are subdivided into several lithostructural units with distinct geochronological, structural, geochemical, and metamorphic characteristics. These are interpreted as juxtaposed remnants of intra-oceanic arc/forearc complexes, accretionary complexes, and a continental margin sequence, recording Neoarchean divergent and convergent plate margin processes from seafloor spreading, subduction initiation, forearc accretion to arc–continent collision. The formation of juvenile intra-oceanic arc/forearc complexes, accretion of ocean plate stratigraphy/mélanges, and final arc–continental collision reflects active plate tectonics driving both vertical and lateral continental growth during the late Neoarchean. Metamorphic and thermodynamic modeling suggests a warmer Neoarchean paleo-subduction zone compared to Phanerozoic average slab-top geotherms, likely due to the hotter mantle and subduction of young and short-lived oceanic crust (<30 Myrs). Such accretionary and collision tectonics, characterized by intra-oceanic warm subduction and soft collision, alongside coexisting mantle plume tectonics elsewhere, may have been two key mechanisms in constructing and recycling late Archean continental crust, promoting mantle heat loss and regulating surface environments as today. Finally, we suggest some future research directions to further investigate crustal evolution and tectonic styles from the perspective of the North China Craton.
{"title":"Neoarchean accretionary and collisional tectonics in the southern North China Craton: Implications for crustal growth and plate tectonic styles","authors":"Bo Huang, Timothy Kusky, Dong Fu","doi":"10.1016/j.precamres.2025.107730","DOIUrl":"10.1016/j.precamres.2025.107730","url":null,"abstract":"<div><div>Archean continental crust primarily consists of TTG (tonalite–trondhjemite–granodiorite) gneisses and greenstone belts. Understanding their origins and tectonic settings is crucial to deciphering continental growth and associated geodynamic regimes on early Earth, which remain highly debated. The North China Craton, one of the largest cratons, experienced significant crustal growth and reworking during late Neoarchean (ca. 2.6–2.5 Ga), but the mechanisms and geodynamic settings remain uncertain. This review assesses the field relations, structural styles, metamorphic features, and magmatic evolution of two representative Neoarchean TTG-greenstone terranes (Dengfeng and Angou) in the southern North China Craton to evaluate different geodynamic models and their roles in continental crust growth. The Dengfeng and Angou complexes, dominated by ca. 2.55–2.50 Ga TTG gneisses, metavolcano-sedimentary assemblages, and high-Mg diorites, with several generations of mafic and felsic intrusions, are subdivided into several lithostructural units with distinct geochronological, structural, geochemical, and metamorphic characteristics. These are interpreted as juxtaposed remnants of intra-oceanic arc/forearc complexes, accretionary complexes, and a continental margin sequence, recording Neoarchean divergent and convergent plate margin processes from seafloor spreading, subduction initiation, forearc accretion to arc–continent collision. The formation of juvenile intra-oceanic arc/forearc complexes, accretion of ocean plate stratigraphy/mélanges, and final arc–continental collision reflects active plate tectonics driving both vertical and lateral continental growth during the late Neoarchean. Metamorphic and thermodynamic modeling suggests a warmer Neoarchean paleo-subduction zone compared to Phanerozoic average slab-top geotherms, likely due to the hotter mantle and subduction of young and short-lived oceanic crust (<30 Myrs). Such accretionary and collision tectonics, characterized by intra-oceanic warm subduction and soft collision, alongside coexisting mantle plume tectonics elsewhere, may have been two key mechanisms in constructing and recycling late Archean continental crust, promoting mantle heat loss and regulating surface environments as today. Finally, we suggest some future research directions to further investigate crustal evolution and tectonic styles from the perspective of the North China Craton.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"420 ","pages":"Article 107730"},"PeriodicalIF":3.2,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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