Precambrian Research最新文献

{"title":"Petrogenesis of TTG gneisses from the Liaodong Bay Depression, Bohai Sea Basin: implications for the late Neoarchean tectonic evolution of the eastern North China Craton","authors":"Kuizhou Li ,&nbsp;Haifeng Yang ,&nbsp;Chris Yakymchuk ,&nbsp;Zilin Zhao ,&nbsp;Qingbin Wang ,&nbsp;Peng Xu ,&nbsp;Fuhao Xiong ,&nbsp;Min Deng ,&nbsp;Mingcai Hou no","doi":"10.1016/j.precamres.2025.107832","DOIUrl":"10.1016/j.precamres.2025.107832","url":null,"abstract":"<div><div>Late Neoarchean tonalitic–trondhjemitic–granodioritic (TTG) gneisses are extensively distributed across the North China Craton (NCC), providing crucial information in understanding the tectonic evolution of the region. However, the late Neoarchean to early Paleoproterozoic basement of the offshore Bohai Sea Basin (OBSB), a segment of the NCC, is extensively buried beneath Paleozoic to Cenozoic strata and submerged beneath marine waters, resulting in a poorly understood tectonic evolution history of this region. Here, we report new zircon U–Pb–Hf isotopic data, and whole-rock compositions for TTG gneisses from the Liaoxi Rise of Liaodong Bay Depression (LBD) of the OBSB in the northeastern NCC. The TTG gneisses are classified into two groups: the first group (ca. 2.57–2.52 Ga) is characterized by low MgO (0.2–1.05 wt%), and low REE (31.04–84.58 ppm), Cr (2.38–29.08 ppm), and Ni (7.52–16.07 ppm), and zircon ε_Hf(t) values are predominantly positive from +1.01 to +4.15, indicating that they originated from partial melting of mafic crust. In contrast, the second group (ca. 2.52–2.50 Ga) exhibits higher MgO (1.92–3.56 wt%), elevated REE (51.28–375.91 ppm), Cr (21.17–196.84 ppm), and Ni (31.23–70.16 ppm) concentrations, and also have positive zircon ε_Hf(t) values (+1.14 to +3.86), suggesting a petrogenetic origin involving the melting of oceanic crust with the incorporation of partial mantle material. Both groups of samples show characteristics consistent with a subduction-related tectonic setting. Integrated with ca. 2.50–2.46 Ga K-rich granitoid rocks and coeval mafic dykes, which formed in a subduction-related back-arc extensional setting within the study area, we propose that the Liaodong Bay Depression experienced subduction and followed by back-arc extension between ca. 2.57 Ga and ca. 2.46 Ga. This funding is consistent with the widespread late Neoarchean magmatic-metamorphic events documented across the NCC, which played a pivotal role in the stabilization and maturation of the continental crust.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"427 ","pages":"Article 107832"},"PeriodicalIF":3.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144229516","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":"Comment on “Debunking the myth of a single Iron Ore Group in the Singhbhum Craton, India” by Jodder et al., 2025 (Precambrian Res., 423, 107800)","authors":"Jordan K. Wright ,&nbsp;Asish R. Basu","doi":"10.1016/j.precamres.2025.107856","DOIUrl":"10.1016/j.precamres.2025.107856","url":null,"abstract":"","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107856"},"PeriodicalIF":3.2,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212754","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":"An 807–763 Ma continental arc records crust-mantle interaction in the Erguna Block during the breakup of Rodinia","authors":"Ke Wang ,&nbsp;Yilong Li ,&nbsp;Wenjiao Xiao ,&nbsp;Haitian Zhang ,&nbsp;Xiujuan Bai ,&nbsp;Jianping Zheng ,&nbsp;Fraukje M. Brouwer","doi":"10.1016/j.precamres.2025.107833","DOIUrl":"10.1016/j.precamres.2025.107833","url":null,"abstract":"<div><div>Circum-Rodinia subduction-related magmatism provides important insights into the evolution of orogens that formed at the margins of the Rodinia supercontinent. However, the nature of the magma sources and geodynamic processes remain enigmatic. In this paper, we present a systematic study of the petrology, whole-rock geochemistry and geochronology of Neoproterozoic potassium-rich mafic and granitic intrusions from the Erguna Block in northeast China. The granitic intrusions include quartz monzonite and monzogranite and belong to the high-K calc-alkaline to shoshonite series. The quartz monzonite has a zircon U-Pb age of 807 ± 3 Ma with εHf_(t) values of −0.50 to + 4.06 and was derived from low degree partial melting of amphibolites. The monzogranite has a zircon U-Pb age of 792 ± 3 Ma with εHf_(t) values of + 0.82 to + 4.64 and was generated from fractional crystallization of high-K calc-alkaline gabbroic magma. The mafic intrusions are hornblende gabbros with a zircon U-Pb age of 763 ± 6 Ma, εHf_(t) values of −9.19 to + 9.18, and an enriched mantle source. Together with existing data, we identify two stages of potassium-rich mafic magmatism at 792 Ma and 763 Ma, whose primary melts were produced by partial melting of mélange diapirs formed by the subducted sediments mixed with a pyroxenite source at depths of 79–72 km and a peridotite source at 71–66 km, respectively. The 807–763 Ma potassium-rich magmatic rocks in the Erguna Block suggest the presence of a mature continental arc. Oceanic subduction supported an orogen along the northwest margin of Rodinia during its breakup, and was responsible for significant mantle heterogeneity, juvenile crustal accretion and reworking of ancient crust.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107833"},"PeriodicalIF":3.2,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144185044","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":"Tonian rift sedimentation and granitic gneiss in the North Lhasa terrane, Tibet: A refined Neoproterozoic tectonic evolution model and its implications for paleogeography","authors":"Ning Yang ,&nbsp;Pei-yuan Hu ,&nbsp;Qing-guo Zhai ,&nbsp;Guo-chun Zhao ,&nbsp;Yue Tang ,&nbsp;Yi-ming Liu","doi":"10.1016/j.precamres.2025.107834","DOIUrl":"10.1016/j.precamres.2025.107834","url":null,"abstract":"<div><div>The Neoproterozoic paleogeographic affinity and basement characters of the Lhasa terrane remain enigmatic, constraining further understanding of the global supercontinent reconstruction. Here, an integrated petrological, geochronological, geochemical, and Sr-Nd-Hf isotopic study was undertaken on the newly discovered Tonian granitic gneisses in the Lhasa terrane. The granitic gneisses (ca. 855–844 Ma) show affinities to A-type granitoids and have positive zircon ε_Hf(t) (+3.1 to + 8.3) and whole-rock ε_Nd(t) (+4.0 to + 4.8) values. Their protoliths were probably generated by the partial melting of Mesoproterozoic crustal rocks. The U-Pb age data of detrital zircons from the biotite plagioclase gneisses associated with the granitic gneisses are also reported. The depositional age of the protoliths of the biotite plagioclase gneisses is constrained to be between the ages of the oldest intrusion body (ca. 855 Ma) and the youngest detrital zircon (ca. 917 Ma) therein, and their detrital zircon age distribution suggests a divergent tectonic setting. Integrating previous studies with the data presented in this contribution, we recommend that the northern Lhasa terrane experienced three Neoproterozoic tectonic stages: rift (ca. 930–850 Ma), subduction (ca. 850–650 Ma), and collision (ca. 650–610 Ma), which suggest an African paleogeographic affinity.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107834"},"PeriodicalIF":3.2,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178745","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":"2115 Ma Haicheng Igneous Province unveils extensive plume-lithospheric interaction during the Great Oxidation event (GOE)","authors":"Bisheng Xu ,&nbsp;Peng Peng ,&nbsp;Chong Wang ,&nbsp;Ke Dai ,&nbsp;Xu Liu ,&nbsp;Binghe Li","doi":"10.1016/j.precamres.2025.107829","DOIUrl":"10.1016/j.precamres.2025.107829","url":null,"abstract":"<div><div>The 2115 Ma Haicheng Igneous Province (HIP) distributes across the Eastern North China Craton. As one representative large igneous provinces coincident with the Great Oxidation Event (GOE), it is important to know whether such an igneous province is plume-originated or not. Synthetic petrology, geochronology and geochemistry study on the plumbing system of the HIP, especially the mafic sills in the Fanhe-Liaohe basins are performed to seek further constraints. The sills intruding the carbonates of the Sanchazi Group (2.2–2.1 Ga) in the Fanhe basin have thicknesses of about 20 m. They mainly consist of clinopyroxene, plagioclase, and minor Fe-Ti oxides, with greenschist-faices metamorphic overprinting of actinolite/chlorite, albite and quartz, as well as secondary epidote and uralite. Precise Pb-Pb SIMS dating of baddeleyite from the Yunpangou sill, the one with the highest MgO content identified by this study in the Fanhe basin, yields a ²⁰⁷Pb/²⁰⁶Pb average age of 2115 ± 6 Ma, which is the same as others of the HIP. The Yunpangou sill is doleritic and tholeiitic, with low SiO₂ content (44.8–48.2 wt.%) but high MgO (5.3–10.9 wt.%), TFe₂O₃ (total iron: 16.0–19.7 wt.%) and TiO₂ contents (2.0–2.8 wt.%). It shows slightly enriched trace elements, distributed within patterns of E-MORB and OIB. Its Sr-Nd isotopes are quite primitive (⁸⁷Sr/⁸⁶Sr_(t) = 0.702–0.703; ε_Nd(t) = +2.7–+3.4). However, its dramatically varying internal compositions comprise an inverted C-shaped pattern, in which the samples with the highest MgO (8.0–11.0 wt.%) in the center represent the least differentiated component. Its high-Mg content, OIB-affinitive patterns and primitive Sr-Nd isotopes favor a plume source. The mafic units of the HIP show wide compositional variations, with SiO₂ of 45.8–55.5 wt.%, ⁸⁷Sr/⁸⁶Sr_(t) of 0.702–0.709, and ε_Nd(t) of −2.8-+3.9; while the felsic units with SiO₂ of 63.0–80.0 wt.%, ⁸⁷Sr/⁸⁶Sr_(t) of 0.707–0.73, and ε_Nd(t) of -1.5–-0.7. These largely varied compositions and the bimodal feature are resulted from the involving of different melts from sub-continental lithospheric mantle, a paleo-plume, as well as the crust. The HIP represents an extensive plume-lithospheric interaction across much of the craton during the late-stage of GOE.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107829"},"PeriodicalIF":3.2,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168944","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":"Tectonostratigraphy of the Ediacaran Fara Formation of the Central Oman Mountains (Jabal Akhdar, Sultanate of Oman): implications for the Late Neoproterozoic evolution of the Eastern Arabian Plate","authors":"Ivan Callegari ,&nbsp;Andreas Scharf ,&nbsp;Andre F. Pinto ,&nbsp;Frank Mattern ,&nbsp;Rajat Mazumder ,&nbsp;Debasmita Datta ,&nbsp;Heninjara Rarivoarison","doi":"10.1016/j.precamres.2025.107825","DOIUrl":"10.1016/j.precamres.2025.107825","url":null,"abstract":"<div><div>In the western Jabal Akhdar Dome of northeastern Oman and within the Neoproterozoic Huqf Supergroup, well-exposed sedimentary formations span the Cryogenian to Ediacaran periods. These rocks bear the marks of the distant Cadomian Orogeny. Among these formations, the youngest corresponds to the diverse Ediacaran Fara Formation, partly time-equivalent to the Ara Group in the subsurface of Oman. Our study extensively examined the Fara Formation’s lithologies, stratigraphy, and syndepositional deformation features to shed light on the Late Ediacaran geological evolution of eastern Arabia. Through meticulous analysis, several key findings and confirmations of previous research emerged from our investigation: (1) the Fara Formation can be categorized into three distinct members (in ascending vertical succession FA1, FA2 and FA3); (2) while FA1 and FA2 members display signs of Cadomian D1 deformation, FA3 Member does not show any evidence of D1 deformation; (3) the first description of the fossil Palaeopascichnus assigns an Ediacaran age to the entire Fara Formation; (4) the volcaniclastic rocks within the Fara Formation are geochemically similar to Hormuz’s volcanics from the same period; and (5) carbonates and siliciclastic rocks of FA1 and FA2 formed within a probably NW/SE-striking back-arc basin associated with Cadomian subduction, while FA3′s siliciclastic rocks unconformably overlie the latter members.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107825"},"PeriodicalIF":3.2,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168946","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 geochronology of the granulite facies gneissic suite hosting the Katanning Gold Deposit, Yilgarn Craton, Southwest Western Australia","authors":"Luke J. Heseldell ,&nbsp;Nicholas E. Timms ,&nbsp;Hugo K.H. Olierook ,&nbsp;Thomas E. Smail ,&nbsp;Chris Clark ,&nbsp;Graham Conner ,&nbsp;Sean Makin","doi":"10.1016/j.precamres.2025.107803","DOIUrl":"10.1016/j.precamres.2025.107803","url":null,"abstract":"<div><div>Understanding the formation of high metamorphic grade sequences from Archean Cratons is necessary for modelling Craton formation and evolution. In this study, we undertake a detailed review of the 1.28 Moz Au Katanning Gold Deposit granulite-facies host sequence, located in the southwestern Yilgarn Craton, Western Australia. To elucidate the nature of this granulite-facies gold deposit, a detailed geochemical, petrographic, and geochronological investigation was undertaken of its host gneissic sequence to establish a petrogenetic model of its formation. The high-grade metamorphic rocks that host gold mineralisation at the Katanning Gold Deposit can be divided into nine major lithological associations. These rocks are interpreted as mafic to felsic protoliths resembling modern BADR sequences which is consistent with extensional magmatism in a back arc setting. Zircon U-Pb dating yielded magmatic ages of a felsic and mafic gneiss at 2711 ± 4 Ma and 2703 ± 3 Ma, respectively, which are contemporaneous with the latest Archean volcanic events in the western Yilgarn Craton. The U-Pb ages of metamorphic zircon across four samples yielded a combined age of 2651 ± 2 Ma, interpreted as the time of peak metamorphic conditions of ∼700–900 °C and ∼5–7 kbar for the entire sequence. Indicating rapid (c. 30 Myr) burial, marked by the maximum depositional age of a metasedimentary gneiss (2683 ± 8 Ma) to granulite facies metamorphism, potentially implicating inversion of a closed back arc rift. This study provides a regional context for tectonic evolution of the southwestern Yilgarn Craton, reflecting on the role of high-grade metamorphism in Archean Cratons, and serves as a rare, detailed investigation into a large granulite-facies gold deposit.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107803"},"PeriodicalIF":3.2,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168943","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":"A Calymmian anchor point for the northern fringe of the North China Craton: Constraints from SHRIMP U–Pb geochronology of the Sailinhudong Group in the Bayan Obo Area, Inner Mongolia","authors":"Yan Zhong ,&nbsp;Xi Wang ,&nbsp;Hui Tian ,&nbsp;Biao Song ,&nbsp;Huai-Kun Li","doi":"10.1016/j.precamres.2025.107826","DOIUrl":"10.1016/j.precamres.2025.107826","url":null,"abstract":"<div><div>The North China Craton (NCC), confined by a series of late Paleoproterozoic–Neoproterozoic extensional basins, is likely a key piece in welding the supercontinent Columbia. The debate regarding the connection between the northern NCC and either the North Australia Craton or the Siberia Craton is essential for understanding the assemblage and break-up of Columbia. The northern marginal rift system (NMRS) of the NCC is an ideal region in which imprints related to neighboring cratons could be preserved. However, the absence of a well-calibrated chronologic framework obstructs subregional attribution and regional correlation and obscures the tectothermal reconstruction of the Proterozoic NMRS, although the zircon U–Pb ages of the volcanic interbeds and crosscutting dykes were sporadically obtained from the Bayan Obo, Zha’ertai, Huade, Shi’nagan and Langshan groups. This study presents two SHRIMP U–Pb ages constraining the Sailinhudong Group (SG) in Darhan–Muminggan Joint Banner to the early Mesoproterozoic (probably the early Calymmian), including one zircon U–Pb age of ca. 1.58 Ga from a volcanic interbed and the other baddeleyite Pb–Pb age of ca. 1.31 Ga from a crosscutting gabbro–diorite dyke. Zircon Hf isotopic compositions of the ca. 1.58 Ga tuff layer in the volcanic–seismic succession from the lower SG are all depleted, similar to those of the ca. 1.58 Ga tuffite layer overlying the seismic succession in the third member of the Gaoyuzhuang Formation in the Yanliao Rift. In conjunction with previous studies, we propose an external origin for the tuff layers and associating seismic successions. A ca. 1.58 Ga catastrophic eruption is inferred to have transmitted substantial tephra and emanated considerable energy to the northern NCC. The ca. 1.58 Ga catastrophic event is considered an anchoring point for attributing and correlating the Calymmian successions through the northern NCC. According to the latest lithostratigraphic and chronostratigraphic advances, the late Paleoproterozoic–Neoproterozoic successions outcropping in the NMRS are further subdivided into the Statherian (the Zha’ertai Group and lower parts of the Bayan Obo and Huade groups), Calymmian (the Sailinhudong, Shi’nagan and middle parts of the Bayan Obo and Huade groups) and Tonian (the northern Langshan Group).</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107826"},"PeriodicalIF":3.2,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144169553","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":"Stratigraphy, age and provenance of the metavolcano-sedimentary succession of the Gurupi Belt, northern Brazil: Implications for the tectonic setting and Rhyacian geodynamic evolution","authors":"Antonia Railine da Costa Silva ,&nbsp;Evandro L. Klein ,&nbsp;Jean-Michel Lafon","doi":"10.1016/j.precamres.2025.107815","DOIUrl":"10.1016/j.precamres.2025.107815","url":null,"abstract":"<div><div>The Gurupi Belt, northern Brazil, represents a Proterozoic belt, whose rocks were mainly formed during the orogenic events that occurred in the Rhyacian and Ediacaran-Cambrian periods. The Paleoproterozoic lithological association includes the metavolcano-sedimentary Chega Tudo Formation, the main host of gold deposits in the belt, batholiths and stocks of subduction-related and collisional granitoids, orogenic basins, and other minor units. To advance on the understanding of the depositional and tectonic settings of the metavolcano-sedimentary sequence, we investigated outcrop and drill core samples from the NW sector of the belt, which revealed rocks well-preserved from the effects of deformation and metamorphism, which affected the belt. Nine lithofacies were distinguished for the sequence and grouped into pyroclastic, volcaniclastic, epiclastic and volcanic-subvolcanic associations, which indicates a subaqueous depositional environment sedimentation and andesitic-dacitic volcanism interaction. The U-Pb ages in zircon from volcanic, volcaniclastic and epiclastic (detrital zircon) show that the Chega Tudo Formation was deposited between 2.20 and 2.14 Ga, with at least three episodes of volcanic activity at 2.20, 2.18 and 2.16 Ga. A back-arc setting, formed during early stages of the orogeny is indicated. Detrital zircons suggest that only arc-related sources (2.22 to 2.24 Ga) were involved in the early stages of sedimentation (accretionary arc), possibly derived from the São Luís cratonic fragment, switching to older populations (∼2.3 Ga) in the latter stages (collisional arc), probably from the basement of the West African Craton or the Bacajá Domain of the Amazonian Craton. Two subunits are proposed: a Lower Unit, with immature metapelitic and mafic-felsic volcanic rocks, associated to deep waters in the back-arc basin initiation stage; and, an Upper Unit, mainly formed by volcaniclastic rocks and andesite-dacite, formed later, under shallow waters.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107815"},"PeriodicalIF":3.2,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144147884","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":"Nature and timing of polymetamorphic, anatectic and metasomatic events in mafic granulite in Archean high-grade terranes: Scenario from Central Zone of the Limpopo Complex, southern Africa","authors":"H.M. Rajesh ,&nbsp;O.G. Safonov ,&nbsp;G.A. Belyanin ,&nbsp;M. Santosh ,&nbsp;Z. Zhang ,&nbsp;T. Tsunogae ,&nbsp;M. Fukuyama ,&nbsp;C. Vorster ,&nbsp;P. Gao ,&nbsp;M. Keeditse","doi":"10.1016/j.precamres.2025.107831","DOIUrl":"10.1016/j.precamres.2025.107831","url":null,"abstract":"<div><div>Mafic granulite in Archean high-grade terranes are highly sensitive to reworking and overprint processes. Understanding the nature and timing of different events requires a careful approach with a combination of methods. This study presents field, petrographic, mineralogical, PERPLE_X phase equilibria modelling, U-Th-Hf-trace-REE-zircon and ⁴⁰Ar/³⁹Ar-amphibole systematics on mafic granulites from the Verbaard area in Central Zone of the Limpopo Complex, southern Africa. The mafic granulites are interlayered and infolded conformably with the oldest <em>meta</em>-supracrustal rocks including quartzites, <em>meta</em>-ironstone and migmatitic metapelites and are intruded by c.2.63–2.62 Ga granitoids. The granoblastic mafic granulites exhibit mineral assemblages representing various metamorphic transformations including minor partial melting during two metamorphic stages related to the Neoarchean (M1) and Paleoproterozoic (M2). The earliest M1 assemblage (Grt) + Opx + Cpx + Pl + Qz + Ilm formed at 830–850 °C, &gt;6.5 kbar, and was transformed to Opx + Cpx + Amp + Pl + Qz + Ilm during the Neoarchean decompression to c.6.5 kbar and subsequent cooling. The M2 assemblage (Grt) + Opx + Cpx + Amp + Pl + Qz + Ilm + Mag formed at &lt; 800 °C, c.5.5 kbar during the Paleoproterozoic overprint. CL-image, Lu-Hf isotope and trace-REE characteristics of zircons distinguish the effect of two metamorphic events at 2618 ± 11 Ma (M1) and 2057 ± 25 Ma (M2), both involving anatectic components. In contrast to the Neoarchean zircon cores, the Paleoproterozoic rims/newly grown grains show lower HREE abundance, suggesting their growth/overgrowth in equilibrium with garnet. The radiogenic Hf isotope compositions of both groups of zircons are explained by local subsolidus mineral reactions rather than an input of the juvenile material. The rocks show effects of late metasomatic alteration that is variably reflected in zircons in higher LREE concentrations and a flatter LREE profile. The c.1.95 Ga age is preserved in the Paleoproterozoic zircons with transgressive recrystallization structure, and supported by ⁴⁰Ar/³⁹Ar amphibole geochronology. The results highlight the textural and corresponding elemental signatures to look out for delineation of multiple overprint events involving metamorphism, anatexis and metasomatism in Archean mafic granulites.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"426 ","pages":"Article 107831"},"PeriodicalIF":3.2,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144147883","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}