Precambrian Research最新文献

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"445 ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148770904","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}

{"title":"Petrogenesis and U-Pb zircon age of the Anorthosite-Gabbronorite association near Barabar Hill, Chotanagpur Granite Gneiss Complex (CGGC), eastern Indian shield","authors":"Priyanka Negi ,&nbsp;Ashima Saikia ,&nbsp;Ivan Belousov ,&nbsp;Leonid V. Danyushevsky ,&nbsp;Mansoor Ahmad ,&nbsp;Salim Akhtar","doi":"10.1016/j.precamres.2025.107940","DOIUrl":"10.1016/j.precamres.2025.107940","url":null,"abstract":"<div><div>Massif-type anorthosite intrusions represent critical archives of Proterozoic mantle-crust interactions, crustal accretion and reworking processes. These voluminous, plagioclase-dominated cumulates were emplaced predominantly during the Statherian-Tonian period (1.8–0.9 Ga), and temporally associated with the assembly of Columbia and Rodinia supercontinents. Despite their widespread occurrences during the restricted time interval, the petrogenesis of massif-type anorthosite remains contentious. Competing models invoke derivation from upwelling mantle melts, partial melting of lower crust and/or magmatism within subduction-related arc settings. Their enigmatic origin and temporal confinement highlight their significance in deciphering Proterozoic tectono-magmatic evolution. The Barabar Hill anorthosite-gabbronorite association, located in the northern Chotanagpur Granite Gneissic Complex (CGGC) of Bihar (India), represents a previously undocumented Paleoproterozoic anorthosite magmatism that sheds new light on the genesis of anorthosites and the overall crustal evolution of the eastern Indian Shield. This study integrates field observations, petrography, bulk-rock major and trace element geochemistry, mineral chemistry, and U–Pb zircon geochronology to constrain the (1) source, (2) parental melt composition, (3) role of crustal contamination, if any, and (4) emplacement age of the Barabar Hill anorthosite − gabbronorite association. Thermobarometric calculations suggest that clinopyroxenes in the gabbronorites crystallized at 1100–1175 °C and 0.04–2.30 kbar, and zircons in the anorthosites crystallized at 600–765 °C under FMQ buffer conditions. Equilibrium Distribution Method (EDM) constrain parental melt compositions at TMF = 0–20 % for the anorthosites and 15–30 % for the gabbronorites. Assimilation–Fractional Crystallization (AFC) modelling suggests derivation of the anorthosites from a depleted mantle source with significant contributions from upper crustal materials.</div><div>U-Pb zircon geochronology constrains the emplacement age of the Barabar Hill suite to 1760.8 ± 7.3 to 1762.0 ± 3.8 Ma (Statherian period), thus representing the first record of Paleoproterozoic anorthosite magmatism in the eastern Indian Shield. The Barabar Hill anorthosite represents a globally significant example of subduction-related magmatism, distinct from Archean megacrystic and Proterozoic massif-type anorthosites. The findings of this study suggests that anorthosites massifs were formed from basaltic magmas derived from the depleted mantle which was contaminated by upper crustal granitic materials. A hybrid mantle-crust origin for anorthosites expand our current understanding of Proterozoic crustal evolution.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107940"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327143","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}

{"title":"Intensive ∼ 2.7 Ga magmatism in the Zanhuang Complex, central North China Craton","authors":"Jianlong Wang ,&nbsp;Chonghui Yang ,&nbsp;Pinghua Liu ,&nbsp;Derek A. Wyman ,&nbsp;Junpeng Wang ,&nbsp;Wen Zhang ,&nbsp;Wanpeng Zhou ,&nbsp;Kang Jiang ,&nbsp;Lilin Du","doi":"10.1016/j.precamres.2025.107959","DOIUrl":"10.1016/j.precamres.2025.107959","url":null,"abstract":"<div><div>Neoarchean tonalite-trondhjemite-granodiorite (TTG) gneisses are extensively distributed in the central North China Craton (NCC), recording the early history of continental crust. This study presents six tonalitic gneiss from the Zanhuang Complex, which yield crystallization ages of 2.72–2.69 Ga and metamorphism ages of ∼ 2.5 Ga. Two dioritic gneiss gave crystallization ages of 2.72 Ga and 2.69 Ga. One high-Mg dioritic gneiss, with a xenocryst crystallization age of 2.71 Ga, yields an emplacement age of 2.55 Ga. Therefore, the early Neoarchean magmatism is constrained to 2.72–2.69 Ga, underwent metamorphism at ∼ 2.5 Ga, and was locally intruded by high-Mg diorites derived<!--> <!-->from a metasomatized mantle at 2.55 Ga. Moreover, the ε_Hf(t) values (3.91–7.96) and <em>T</em>_DM^C(Hf) model ages (2.66–2.93 Ga) of the TTGs indicating<!--> <!-->a juvenile crustal origin formed from the late Mesoarchean to early Neoarchean.</div><div>All banding-free TTG gneisses exhibit relatively homogeneous tonalitic compositions. They have high SiO₂ (66.37–68.13 wt%), Na₂O (3.85–4.44 wt%), MgO (1.93–2.09 wt%), Cr (25–33 ppm), Ni (21–26 ppm), and Mg^# values (45–51), low total ferromagnesian elements (6.59–7.28 wt%), Al₂O₃ (14.67–15.17 wt%), K₂O/Na₂O (0.27–0.46), and Sr/Y (29–41). These suggest that they are generated from partial melting of low-K basalt under low-preasure (amphibolite-facies) conditions. Banded TTG gneiss exhibit variable compositions that consistent with tonalite or trondhjemite. They are considered to have resulted from the anatexis and mineral segregation of tonalite in the late Neoarchean.</div><div>Through a comprehensive analysis of ∼ 2.7 Ga magmatism in the central NCC, we infer that there may be an magmatic belt through<!--> <!-->Hengshan, Wutai, Fuping, Zanhuang, Zuoquan, Huixian, Lushan, and Zhongtiao area from north to south. This belt is dominated by TTGs, with minor K-rich granites and mafic rocks. Their Hf-Nd data reveal a pronounced crustal growth and remelting event at ∼ 2.7 Ga. These TTGs exhibit significant geochemical heterogeneity, with some units preserving diagnostic subduction-related signatures including high-pressure and mantle metasomatism imprints. We infer that the magmatic belt formed in a subduction-related setting.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107959"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419275","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}

{"title":"Growth and disparity of form in the Ediacaran genus Charnia, with description of Charnia brasieri sp. nov. from the Ediacaran of Avalonia","authors":"D. McIlroy,&nbsp;D. Pérez-Pinedo,&nbsp;S. Rosse-Guillevic,&nbsp;H. Muirhead-Hunt,&nbsp;R.S. Taylor,&nbsp;S.C. Dufour","doi":"10.1016/j.precamres.2025.107947","DOIUrl":"10.1016/j.precamres.2025.107947","url":null,"abstract":"<div><div>The Ediacaran of Newfoundland continues to yield a diverse biota of complex macro-organisms that records the early evolution of the Eumetazoa. The exceptional preservation of Rangeomorpha from the Fermeuse Formation at the Inner Meadow fossil site in Conception Bay, Newfoundland has allowed the recognition of a novel form of the genus <em>Charnia</em> with falcate first order branches that we describe as <em>Charnia brasieri</em> sp. nov. herein. Three dimensional reconstructions using pre-established conceptual models have predicted a central lumen to all first order branches, which is supported by the new Inner Meadow material. The inferred frond architecture of <em>C. brasieri</em> is sculpted in three dimensions herein and studied using computational fluid dynamics, which gives insights in the flow in and around the fossil organisms thereby informing its possible mode of life as procumbent epibenthic organism.</div><div>The falcate branching that characterizes <em>Charnia brasieri</em> sp. nov. is also seen in material previously described as <em>C. grandis</em> from the UK and Newfoundland. In reviewing the original diagnosis and figured material, we find <em>C. grandis</em> to be a distinct and valid taxon, reject its recent synonymization with <em>C. masoni</em>, and recognize its occurrence in the Ediacaran of Newfoundland. The large <em>Charnia</em> with falcate branching from Newfoundland and the UK are herein attributed to <em>C. brasieri,</em> with large size not being considered a valid taxobase. This work strongly suggests that <em>Charnia</em> is a long-lived, highly stable and morphologically-diverse genus characterized by rotated and furled rangeomorph branches, as conceptualized by Martin Brasier. The taphonomic and preservational insights from this work allow recognition of the lumina of <em>Charnia</em> and will require reconsideration of the palaeobiology of other members of the family Charniidae.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107947"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419352","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}

{"title":"Evidence for proximal ejecta from the 2.02 Ga Vredefort impact event","authors":"Matthew S. Huber ,&nbsp;Elizaveta Kovaleva ,&nbsp;Jonathan Hainsworth ,&nbsp;Masibulele Zintwana ,&nbsp;Dina Schultze ,&nbsp;Floyd Mautle ,&nbsp;Richard Wirth ,&nbsp;Christian Koeberl","doi":"10.1016/j.precamres.2025.107954","DOIUrl":"10.1016/j.precamres.2025.107954","url":null,"abstract":"<div><div>The Vredefort impact structure in South Africa is among the largest and oldest impact structures currently known on Earth. Due to extensive erosion, the proximal ejecta has been thought to have been removed completely. However, we find that sediments of the Doornfontein Member of the Gamagara Formation in the Griqualand West Basin resemble impact ejecta. They are located ca. 500 km west of the center of the Vredefort structure, which is within the modelled distance for the proximal ejecta, and are chronostratigraphically constrained to be between 1928 ± 4 Ma and 2222 ± 13 Ma, overlapping with the Vredefort event age (2019 ± 2 Ma). The stratigraphy of the Doornfontein Member includes an up to 100 m thick polymict breccia sequence that includes fragments of banded iron formation, chert, and carbonates, capped by accretionary lapilli. Shock metamorphic evidence in the form of quartz grains with planar deformation features and planar fractures, as well as granular zircons, are entrained within the breccia, confirming an impact origin. Primary compositions are obscured due to hematite alteration. We suggest that the economically significant Doornfontein Member represent proximal ejecta generated by the Vredefort event. Our discovery could represent the oldest described crater-ejecta pair and shows the potential for the preservation of massive Paleoproterozoic ejecta layers.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107954"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419354","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}

{"title":"Petrogenesis and chronology of albitite in the Yangtze Block, SW China: Tectonic implications for the Columbia supercontinent assembly","authors":"Luyu Huang ,&nbsp;Youliang Chen ,&nbsp;Jing Zhao ,&nbsp;Jian Yao ,&nbsp;Longlong Wei ,&nbsp;Yifan Zhu","doi":"10.1016/j.precamres.2025.107955","DOIUrl":"10.1016/j.precamres.2025.107955","url":null,"abstract":"<div><div>The Columbia supercontinent is recognized as the earliest demonstrably reconstructable supercontinent in the entire history of Earth. The Yangtze Block is an integral component of the Columbia supercontinent. However, an essential issue, which tectonic regime (convergent versus extensional) the block belonged to during middle Proterozoic remains controversial. Recently, the albitites were discovered in the Bajiaojing area of the western Yangtze Block, providing crucial insights into the evolution of the Paleoproterozoic crust of the Yangtze Block and its role in supercontinent dynamics. The magmatic zircons from the Bajiaojing albitites yielded U-Pb ages of 1858 ± 13 Ma and 1857 ± 10 Ma, and mineral chemical proxies (e.g., Yb/Sm, Nb/Ta, Y, U, Nb, and Ta) demonstrate that the Bajiaojing albitites originated from a granitoid source. Negative <em>ε</em>_Hf(<em>t</em>) values (−18.3–-4.4) and elemental ratios of whole-rock (e.g., Gd/Yb, Ta/Yb, and Nb/Ta) further indicate that the Bajiaojing albitite was likely emplaced in a collisional orogenic setting, in response to the late stage of collision. Combined with published zircon <em>ε</em>_Hf(<em>t</em>) values of Paleoproterozoic magmatic rocks across the Yangtze Block, we propose three distinct magmatic pulses at 2.02 Ga, 1.86 Ga, and 1.71 Ga, corresponding to early collision, late collision, and rift magmatism, respectively. From 2.02 Ga to 1.83 Ga, magmatic zircons in the Yangtze Block exhibit a persistent decline in <em>ε</em>_Hf(<em>t</em>) values, which reflects the continuous thickening of the block during this time.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107955"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419355","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}

{"title":"Archean Nb-Ta-bearing granites recognized in the Anshan–Benxi area, North China Craton: Petrogenesis and rare metal potential","authors":"Yang Dai ,&nbsp;Li-Xing Li ,&nbsp;Yong-Mei Zhang","doi":"10.1016/j.precamres.2025.107964","DOIUrl":"10.1016/j.precamres.2025.107964","url":null,"abstract":"<div><div>Archean Nb-Ta-bearing granitic rocks linked with crustal growth events are widely developed within cratons worldwide. However, in the North China Craton where crustal growth is extensive, economic Nb-Ta-bearing granitic rocks are scarce. We identified previously unrecognized Nb-Ta-bearing granites in the Qidashan banded iron formation-hosted iron deposit in the Anshan–Benxi area of northern North China Craton. These granites provide a rare example to investigate the rare metal mineralization process within this craton. The U-Pb geochronology conducted on columbite group minerals (CGMs) and cassiterite from the Nb-Ta-bearing granites yielded weighted mean ²⁰⁷Pb/²⁰⁶Pb ages of 2527 ± 6 Ma and 2535 ± 5 Ma, respectively, which are indistinguishable from each other within analytical uncertainties. The results indicate a late Neoarchean emplacement age for the Qidashan Nb-Ta-bearing granites. The Qidashan Nb-Ta-bearing granites are characterized by high contents of SiO₂, Al₂O₃, Na₂O, K₂O and Nb-Ta (average on 190.9 ppm), but low contents of CaO, TFe₂O₃, MgO, and total rare earth elements (ΣREE). Additionaly, these granites are enriched in large-ion lithophile elements (LILEs, e.g., Rb, Th, U), are depleted in high-field-strength elements (HFSEs, e.g., Nb, P, Ti), has a low LREE/HREE ratio, exhibits an obvious negative Eu anomaly, and shows a distinct tetrad effect of REE. These geochemical characteristics indicate that the key factors controlling the formation of Nb-Ta-bearing granites and the subsequent enrichment and mineralization of Nb-Ta rare metals include extensive fractional crystallization of the granitic magma coupled with melt-fluid interactions. The <em>ε</em>_Nd(<em>t</em>) values of the Qidashan Nb-Ta-bearing granites range from −8.1 to −12.6, with two-stage model ages (<em>T</em>_DM2) of 3.56–3.96 Ga, indicating their formation by recycling of mature, old continental crust, similar to the genesis of the 2.50 Ga Qidashan K-rich granites. During the late Neoarchean, the North China Craton entered an extensional tectonic regime, where intense tectono-thermal events triggered extensive granitic magmatism, generating voluminous crust-derived granites. The occurrence of the Archean Qidashan Nb-Ta-bearing granites demonstrates that late Neoarchean tectonic-magmatic activities in the North China Craton possess potential for rare metal Nb-Ta mineralization, offering new insights into the metallogenic prospectivity of Precambrian terranes in this region.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107964"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528485","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}

{"title":"Vestige of Paleoproterozoic metamorphism in the Trivandrum block, India: New evidence from zircon U-Pb ages","authors":"Yuquan Wang ,&nbsp;Bo Liu ,&nbsp;Mingguo Zhai ,&nbsp;Hailong He ,&nbsp;K. Sajeev ,&nbsp;P.M. George","doi":"10.1016/j.precamres.2025.107957","DOIUrl":"10.1016/j.precamres.2025.107957","url":null,"abstract":"<div><div>The Trivandrum Block in India has long been regarded as the central part of the Pan-African orogenic event. However, several previous studies suggested a potential presence of a large-scale magmatic-metamorphic event in this area during the Paleoproterozoic. To better understand the Paleoproterozoic geological evolution of this terrain, we conducted detailed mineral inclusion studies on three gneiss samples (Grt-Bt gneiss, leucogneiss, Grt-Sil-Crd gneiss) at the Kulappara quarry in the Trivandrum Block, combined with zircon morphology and SIMS U-Pb dating. The Grt-Bt gneiss is the enclave in the Grt-Sil-Crd gneiss. The dating results of zircon with metamorphic features from both samples are at ∼2.0 Ga. In the zircon grains of the Grt-Sil-Crd gneiss sample, sillimanite inclusions were discovered, within the ∼2.0 Ga zircon. The leucogneiss is interbedded with the Grt-Sil-Crd gneiss, and occasionally pinching out into the Grt-Sil-Crd gneiss. Combined with the dating results of zircon, which show characteristics formed during anatexis, are at the age of ∼1.98 Ga in the leucogneiss, we suggest that an intense metamorphic event likely occurred at around 2.0 Ga and the metamorphic grade may once reach the upper amphibolite or even up to the granulite facies. High-grade metamorphic rocks in the Paleoproterozoic are widely distributed in many ancient blocks worldwide, and this period is an important stage of the transition to the global subduction zone network of the Earth. Therefore, the discovery of traces of high-grade metamorphism in the Trivandrum Block likely indicates the involvement of this region in the global tectonic evolution during the Paleoproterozoic. There are also a plenty of zircon dating results concentrated around 580–530 Ma in the studied samples. This shows us that the Paleoproterozoic event was subsequently overprinted by the intense Neoproterozoic–Cambrian HT–UHT metamorphism, suggesting a long-lived feature for this Pan-African tectonothermal event.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107957"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419274","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}

{"title":"The complicated relationships between early eukaryotic evolution and the oxidation state of Earth’s surface environments","authors":"Dongdong Li ,&nbsp;Genming Luo ,&nbsp;Bing Shen ,&nbsp;Shuhai Xiao","doi":"10.1016/j.precamres.2025.107960","DOIUrl":"10.1016/j.precamres.2025.107960","url":null,"abstract":"<div><div>Persistently low atmospheric oxygen levels (<em>p</em>O₂) have been proposed as a primary factor contributing to the delay between the emergence of total-group eukaryotes in the late Paleoproterozoic and the divergence of crown-group eukaryotes at the Meso-Neoproterozoic transition. However, the temporal relationship between <em>p</em>O₂ fluctuations and the early evolution of eukaryotes, e.g., emergence and diversification, remains uncertain. In this study, we compiled both published and newly acquired data on redox conditions and fossil occurrences spanning the late Paleoproterozoic to the early Neoproterozoic. Based on the compilation of rare earth element data in shallow-water carbonates from this interval, we quantified atmospheric <em>p</em>O₂ using thermodynamics-based modeling. Our results suggest that <em>p</em>O₂ generally increased from low values of ≤ 1 % of the present atmospheric level (PAL) in the late Paleoproterozoic to ∼5–10 % PAL in the mid-Mesoproterozoic, before declining to ∼1 % PAL at the Meso-Neoproterozoic transition. Comparison with fossil records indicates that early stem-group eukaryotes in the Paleo-Mesoproterozoic emerged under low <em>p</em>O₂ conditions, that the mid-Mesoproterozoic rise in <em>p</em>O₂ did not lead to increased diversity, and that crown-group diversification at the Meso-Neoproterozoic transition occurred during a period of declining <em>p</em>O₂. Together, these observations show that atmospheric oxygen and early eukaryotic evolution did not consistently covary, highlighting that the complicated interactions among oxygen content, nutrient supply, temperature, and biotic factors shaped the early eukaryotic evolution in the mid-Proterozoic.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107960"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145419273","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}

{"title":"Petrogenesis of the Paleoproterozoic Liuying hornblendite arc cumulates and implications for the tectonic evolution of the northern North China Craton","authors":"Wen-Mei Liu ,&nbsp;Jian-Ping Zheng ,&nbsp;Bernard Charlier ,&nbsp;Qiang Ma ,&nbsp;Timothy Kusky ,&nbsp;Hong-Kun Dai","doi":"10.1016/j.precamres.2025.107946","DOIUrl":"10.1016/j.precamres.2025.107946","url":null,"abstract":"<div><div>Understanding the Paleoproterozoic configuration of the northern North China Craton (NCC) is crucial for reconstructing its Precambrian tectonic history. This study integrates geological field observations, petrological data, U-Pb geochronology, and Lu-Hf isotopic analysis of zircons, alongside mineral and whole-rock geochemistry, including Sr-Nd isotopes from the Liuying ultramafic complex in Hebei Province. Our goal is to enhance the understanding of the tectonic history of the craton’s northern margin. The complex is composed of hornblendite and plagioclase hornblendite, showing igneous cumulate texture. Zircon U-Pb data from the ultramafic complex define three distinct groups of ages: 2211–2343 Ma, 1761–1999 Ma, and 246–310 Ma, corresponding to magma crystallization and metamorphism resulted from crustal thermal events. The major elements of rocks align with the differentiation trend of hydrous arc magmas. They display characteristics of enrichment in large ion lithophile elements and depletion in high field strength elements. Fractional crystallization of arc magmas with H₂O of 7.3–8.1 wt% at middle-lower crust depths (18–23 km) and 966–996 °C formed amphibole-enrichment arc cumulates. The zircon ε_Hf(t) values (–5.96 to + 9.05) are decoupled from enriched Sr-Nd isotopic compositions ((⁸⁷Sr/⁸⁶Sr)_i = 0.704185–0.705932, ε_Nd(t) = −14.6 to −5.68, (⁸⁷Sr/⁸⁶Sr)_amp = 0.705110–0.705846), suggesting a subduction-modified mantle source, incorporating 5–10 % subduction slab-derived melts and fluids. The northern part of the NCC was a continental arc above a paleo-subduction zone on a scale similar to the modern Andes at ca. 2.2 Ga. The oceanic slab subduction between the craton and the Siberian segment resulted in partial melting of metasomatized mantle wedge to form Paleoproterozoic hornblendite arc cumulates.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"431 ","pages":"Article 107946"},"PeriodicalIF":3.2,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327142","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}