Precambrian Research最新文献

{"title":"Detrital zircon geochronology and whole-rock geochemistry of the 1.8–1.7 Ga Xiong’er volcanic-sedimentary succession in the southern North China craton and their implications for basin evolution","authors":"Fengbo Sun ,&nbsp;Yuting Wu ,&nbsp;Taiping Zhao ,&nbsp;Deshun Zheng ,&nbsp;Peng Peng","doi":"10.1016/j.precamres.2024.107608","DOIUrl":"10.1016/j.precamres.2024.107608","url":null,"abstract":"<div><div>The Xiong’er volcanic-sedimentary succession in the southern North China Craton (NCC) documents crucial data regarding the geological evolution of the supercontinent Columbia (Nuna). Previous researches largely focused on the volcanic rocks in the Xiong’er succession, while the paleo-tectonic significance of its sedimentary rocks has not been explored. LA-ICP-MS detrital zircon U-Pb dating and whole-rock geochemistry of the interlayered sedimentary units within the succession are conducted to ascertain the provenance and tectonic driver of the basin infill. New chronological constraint suggests the deposition of the succession persisted until ca. 1710 Ma, temporally aligned with the initial deposition of the overlying Ruyang Group. Normalized rare earth elements (REE) and classification diagrams indicate derivation predominantly from felsic sources with supplementary input from mafic sources. Detrital zircon U-Pb ages indicate a major 2.5 Ga provenance from the proximal latest Archean and Paleoproterozoic metamorphic complexes and a subordinate ca. 2.3 ∼ 1.8 Ga provenance from adjacent regions. Notably, an elevated ca. 1.8 ∼ 1.7 Ga detrital zircon peak in the uppermost section of the succession implies contributions from coeval granites and volcanogenic rocks. Integrating these observations with the stratigraphic progression, the Xiong’er succession is interpreted as a magma-rich <em>syn</em>-rift basin infill and we hypothesize the existence of a “breakup unconformity” separating the <em>syn</em>-rift Xiong’er Group from the overlying post-rift Ruyang Group.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107608"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552495","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":"Paleoproterozoic amphibolite to ultrahigh temperature granulite facies metamorphism of the Rangnim massif in the Northern Korean Peninsula and tectonic implications","authors":"Lei Zhao ,&nbsp;Rucheng Zhang ,&nbsp;Yi Zou ,&nbsp;Won Jong Choe ,&nbsp;JongHyok Yang ,&nbsp;JongNam Kim ,&nbsp;Yanbin Zhang ,&nbsp;Mingguo Zhai","doi":"10.1016/j.precamres.2024.107606","DOIUrl":"10.1016/j.precamres.2024.107606","url":null,"abstract":"<div><div>Three Paleoproterozoic orogenic/mobile belts were suggested for the North China Craton (NCC), which were further suggested to represent global networks of narrow plate boundaries and argue for the operation of plate tectonics during the Paleoproterozoic. However, recent studies raised serious challenges to such advocates in that the seemingly belt-like occurrences of the Paleoproterozoic high-grade terranes are related to Phanerozoic tectonic processes. The basement components and metamorphic features of the Rangnim Massif in North Korea can provide critical evidence for a thorough understanding of the tectonic implications of these high-grade terranes, because it was assumed to be an Archean microcontinent that accreted to the NCC during the Paleoproterozoic through one of the three orogenic bents. This massif was assumed to be linked to the NCC through the Jiao-Liao-Ji orogenic belt in the traditional tectonic models. In this paper, we present both new study results and a summarization of previously published data on the Rangnim Massif. The Paleoproterozoic metamorphic rocks collected from the Rangnim Massif show amphibolite to UHT granulite facies metamorphism at ∼ 1.90 Ga, with peak metamorphic conditions reaching up to 940 – 980 ℃ at 7 – 9 kbar. The Paleoproterozoic metamorphism, the widespread Paleoproterozoic sedimentary and magmatic rocks of this massif, are identical with those of the Paleoproterozoic “orogenic belts” of the NCC. Therefore, the Jiao-Liao-Ji “orogenic belt” is extendable to the Rangnim Massif, or even to the whole Korean Peninsula. The newly established spatial occurrences and the metamorphic features of these metamorphic rocks of the eastern NCC are different from those of plate margin orogenic belts. Therefore, the exact geological implications should be reconsidered and that these high-grade terranes might represent the NCC’s uplifted Paleoproterozoic lower crustal components.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107606"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573168","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":"Late Paleoproterozoic within-plate mafic magmatism in the western Yangtze Block, South China Craton: Implications for the initial break-up of the Columbia supercontinent","authors":"Luyu Huang ,&nbsp;Jing Zhao ,&nbsp;Youliang Chen ,&nbsp;Xiaoping Long ,&nbsp;Jingsi Zhang ,&nbsp;Qiaoping Guo","doi":"10.1016/j.precamres.2024.107609","DOIUrl":"10.1016/j.precamres.2024.107609","url":null,"abstract":"<div><div>The Paleoproterozoic was an important period for the tectonic-magmatism evolution of the Yangtze Block, which coincided with the assembly and break-up of the global Columbia (also known as Nuna) supercontinent. However, an essential issue, when the Yangtze Block initiated rifting from the supercontinent, remains controversial. This paper presents new zircon chronology, Lu-Hf isotopic data, and whole-rock geochemical analyses of the Bajiaojing and Xiaoqingshan meta-diabases in the western Yangtze Block to address this issue. The magmatic zircons from the Bajiaojing and Xiaoqingshan meta-diabases yielded U-Pb ages of 1675 ± 38 Ma and 1719 ± 10 Ma, representing an episode of mafic magmatism during the Late Paleoproterozoic. Moreover, the abundances and elemental ratios of high-field-strength elements (HFSEs, e.g., Y, Ta, Th, and Hf) in both meta-diabases are very similar to those of within-plate and mantle plume magmas. This implies that these Late Paleoproterozoic mafic rocks were likely derived from a mantle plume source in a continental within-plate extensional setting. Their magmatic source was relatively heterogeneous in isotopic and geochemical compositions, as inferred from significant differences in ε_Hf(t) values and certain HFSE ratios (e.g., Nb/Yb, Ta/Yb, Th/Yb, Nb/Y, and Zr/Y) among samples. Such source heterogeneity might be attributed to interactions between the mantle plume and the overlying lithosphere. Combined with published ε_Hf(t) values of detrital zircons and whole-rock ε_Nd(t) values of (meta-)magmatic rocks, we speculate that the Yangtze Block experienced a tectonic transition from plate convergence to continental extension at ∼ 1.7 Ga. This means that the block began to rift from the Columbia supercontinent as early as 1.7 Ga. The Yangtze Block then evolved progressively as an isolated fragment until it was amalgamated into the Rodinia supercontinent.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107609"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573171","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":"Sapphirine + quartz assemblage from the Irumide Belt, northern Malawi: Implications for Mesoproterozoic ultrahigh-temperature metamorphism related to Rodinia assembly","authors":"So Wakabayashi ,&nbsp;Kabang’u Grace Sakuwaha ,&nbsp;Toshiaki Tsunogae ,&nbsp;M. Santosh ,&nbsp;Mzee Wandembo Nyirongo","doi":"10.1016/j.precamres.2024.107607","DOIUrl":"10.1016/j.precamres.2024.107607","url":null,"abstract":"<div><div>The Irumide Belt <em>sensu lato</em> situated between the Bangweulu Block to the northwest and the Neoproterozoic Mozambique–Zambezi Belt to the southeast is a Mesoproterozoic orogenic belt that developed probably during the amalgamation of the supercontinent Rodinia. In this study, we present new petrological, geothermobarometric, and geochronological data of pelitic granulites and related rocks from the Jenda area in northern Malawi, and evaluate the timing and pressure–temperature (<em>P</em>–<em>T</em>) conditions of high-grade metamorphism. To the best of our knowledge, we are the first to report the occurrence of sapphirine + quartz association in pelitic granulite from the Irumide Belt <em>sl</em>. which provides a robust evidence of peak ultrahigh-temperature (UHT) metamorphism. The sapphirine occurs as poikiloblastic grains with rounded quartz inclusions in the absence of any retrograde minerals. The mineral phase equilibrium modeling constrains the peak UHT conditions of the pelitic granulites as 950–1000 °C and 7–8.5 kbar for sapphirine-bearing and ∼6 kbar and &gt; 950 °C for sapphirine-free samples. These conditions are consistent with the results of ternary-feldspar geothermometry (900–1000 °C at 8 kbar). From the stability of rutile, we estimate a prograde pressure of &gt;9 kbar, and the occurrence of retrograde cordierite and biotite suggests that the rocks went through <em>P</em>–<em>T</em> conditions of ∼6–7 kbar/∼775–825 °C, indicating a clockwise <em>P</em>–<em>T</em> path and defining high-pressure and UHT conditions. In-situ monazite Th–U–Pb_total geochronology of the sapphirine-bearing rock yielded a weighted-mean age of 1022 ± 10 Ma which is considered to mark the timing of peak metamorphism. Sapphirine-free granulites also gave consistent ages of 1049 ± 13 Ma and 1048 ± 10 Ma, which are also comparable with published ages. We thus infer that the Irumide Belt <em>sl</em>. underwent regional high-pressure to UHT metamorphism at ca. 1.05 to 1.02 Ga possibly related to the main collisional event of the Bangweulu Block with an unknown craton or magmatic arc during the assembly of Rodinia supercontinent.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107607"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578419","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":"Precambrian Earth: Co-evolution of life and geodynamics","authors":"Frances Westall ,&nbsp;Shuhai Xiao","doi":"10.1016/j.precamres.2024.107589","DOIUrl":"10.1016/j.precamres.2024.107589","url":null,"abstract":"<div><div>The Precambrian covers 80% of the history the Earth. In this timespan, the Earth developed from an anaerobic planet to the oxygenic planet dominated by Wilson-style plate tectonics that we know today. Concomitant with geological evolution, life emerged and evolved, gradually colonising all known aqueous habitats. Until the Palaeoarchaean, life was largely dominated by its geological environment. However, as of the Mesoarchaean, when there were major changes in geodynamics leading to continental erosion and runoff of essential nutrients, the effects of life started to impinge on the geological environment. The interaction of life and Earth was and is reciprocal, hence the term biogeodynamics. In this review, we trace the evolution of geology and life in parallel, thus highlighting the gradual buildup of the importance of life on terrestrial processes, and the importance of changes in the geological environment on the evolution of life. We do not attempt to make an exhaustive review of all the occurrences of life in the Precambrian but use selected examples to illustrate key events and changes. We conclude by addressing certain aspects of the evolution of life that require more in-depth study and show how the finding of extra-terrestrial life would advance our understanding of life on Earth.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107589"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578418","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}

{"title":"Widespread ca. 800 Ma granitoids in the southern Dabie Orogen: Petrogenesis and implications for Neoproterozoic accretion-type orogeny in the northern Yangtze Block","authors":"Chao Chen ,&nbsp;Zhenbing She ,&nbsp;Changqian Ma ,&nbsp;Jinling Yuan ,&nbsp;Lingyao Kong ,&nbsp;Di Wang ,&nbsp;Jiang Zhu ,&nbsp;Chuan Fan ,&nbsp;Pan Guo ,&nbsp;Hao Deng ,&nbsp;Roger Mason","doi":"10.1016/j.precamres.2024.107610","DOIUrl":"10.1016/j.precamres.2024.107610","url":null,"abstract":"<div><div>Large-scale Neoproterozoic granitoids occur widely in the Dabie Orogen of the northern Yangtze Block and provide significant clues to understanding the geological evolution of the Block within the Rodinia supercontinent. We present evidence for a prominent episode of granitoid intrusion at ca. 800 Ma in the southern Dabie Orogen (SDO), verified by new zircon LA-ICP-MS ages from four separate granitoid intrusions ranging from 807 Ma to 795 Ma in age. The granitoids are dominated by monzogranite and granodiorite with bulk-rock A/CNK and zircon <em>δ</em>¹⁸O values of 0.90–1.10 and 5.03–6.45‰, respectively, corresponding to I-type affinity. This is also supported by negative correlations of SiO₂ vs. P₂O₅ and Sr vs. P₂O<strong>₅</strong>, and positive correlations of SiO₂ vs. A/CNK, Rb vs. Y and Rb vs. Th. Low zircon ε_Hf(t) values (−15.03 to −3.84) and relatively old two-stage Hf model ages (mainly between 1900 and 2200 Ma) for these granitoids are consistent with primary derivation of magma from partial melting of Paleoproterozoic metabasites. Relatively low Ga/Al ratios, Zr contents, and zircon saturation temperatures and consistently negative zircon ε_Hf(t) and bulk-rock ε_Nd(t) values are distinct from those of 780–720 Ma A-type granites in the Dabie Orogen that formed in a rift setting. We propose that the ca. 800 Ma granitoids in the SDO were products of variable degrees of partial melting of ancient mafic crust, promoted by heating of the upwelled asthenosphere due to oceanic slab breakoff in an accretion-type orogeny. Our observations suggest that the formation of the unified Yangtze Block was achieved by diachronous assembly of multiple micro-blocks during the Neoproterozoic, consistent with a peripheral location of the Yangtze Block in the Rodinia supercontinent.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107610"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573169","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":"Syn-rift volcanism (ca. 670 Ma) in the lower Windermere Supergroup, southern Canadian Cordillera: New constraints on the syn- to post-rift transition for northwestern Laurentia","authors":"Thomas Hadlari ,&nbsp;N.M. Rayner ,&nbsp;T.P. Poulton ,&nbsp;R.W.C. Arnott","doi":"10.1016/j.precamres.2024.107604","DOIUrl":"10.1016/j.precamres.2024.107604","url":null,"abstract":"<div><div>The southern Canadian Cordillera is considered the type area for the Windermere Supergroup, where it had long been assumed that the <em>syn</em>-rift basaltic lavas of the Irene Formation were co-genetic with the ca. 720 Ma Franklin LIP. Accordingly, the inferred age of the Irene volcanics is variously cited for either the breakup of Rodinia or for the base of Cryogenian strata in the southern Canadian Cordillera, and yet they have not been directly dated until now. Reported here are geochronological data from a volcanic sample of the Irene Formation yielding a U-Pb SHRIMP zircon age of 669.6 ± 6.7 Ma, which is significantly younger than the presumptive age. The Irene Formation is overlain by basin floor turbidite facies that correlate with the Horsethief Creek Group, which represent some of the oldest post-rift deposits in the study area and are interpreted as the earliest indication of a passive continental margin setting for northwestern Laurentia. The dated sample was collected from the upper portion of the Irene Formation and so the transition from <em>syn</em>-rift to post-rift is younger than ca. 670 Ma, which is estimated at approximately 660–650 Ma. Additionally, these new age data place the associated diamictites at the end of the Sturtian glaciation.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107604"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561091","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 early syn-tectonic mafic to felsic Oamikaub Ring Complex (Damara orogen, Namibia) revisited – No role for a Pacific-type subduction?","authors":"S. Jung,&nbsp;R.L. Romer","doi":"10.1016/j.precamres.2024.107612","DOIUrl":"10.1016/j.precamres.2024.107612","url":null,"abstract":"<div><div>The Damara orogen of Namibia is an essentially ensialic orogen that was formed in the Neoproterozoic between ∼ 750 and ∼ 450 Ma. Most igneous rocks have negative εNd values and radiogenic Pb isotope compositions reflecting their crustal provenance. Mafic rocks are rare. The ∼ 564 Ma-old Oamikaub Ring Complex as part of the Goas Intrusive Suite belongs to a suite of mafic (ultramafic) to intermediate rocks that mark the onset of collision tectonics in the Damara Belt of Namibia. Therefore, they are particularly suitable to constrain the contribution of mantle material during the early stages of the Damara orogeny. The Oamikaub Ring Complex contains gabbros, gabbro-diorites, diorites, granodiorites and granites. All gabbros, gabbro-diorites and diorites are moderately enriched in most incompatible elements including REE but depleted in Rb, Ba and Sr. HFSE are depleted relative to primitive mantle (Zr/Hf: 28.3–40.5, Nb/Ta: 7.88–19.2) as a result of accumulation processes and the presence of enriched interstitial melts. The Sr and Nd isotopic compositions are variable (initial ⁸⁷Sr/⁸⁶Sr: 0.7058 to 0.7095; initial εNd: −1.9 to −11.8). The granodiorites are also enriched in incompatible elements showing similar HFSE abundances as the gabbros, gabbro-diorites, and diorites (Zr/Hf: 29.4–37.3; Nb/Ta: 8.25–19.7) and more evolved initial ⁸⁷Sr/⁸⁶Sr (0.7078 to 0.7103) and initial εNd (−10.7 to −14.1). Granites show lower Zr/Hf (18.7–28.7) but broadly similar Nb/Ta (4.25–14.6). Strontium and Nd isotopes are distinct relative to the other rock types (initial εNd: −18.2 to −18.8; initial ⁸⁷Sr/⁸⁶Sr: 0.7117–0.7128) implying an ancient lower crustal source. There are two competing models for the Damara orogen; a “Pacific-type” model involving subduction of oceanic crust and an ensialic model with subduction of mainly extended continental crust. Our new data from the Oamikaub Ring Complex, especially from the gabbros, gabbro-diorites and diorites, lack depleted isotope signatures but bear a strong crustal flavour for all rock types making a common subduction zone environment involving the subduction of oceanic crust unlikely. The rocks of the Oamikaub Ring Complex have isotope signatures similar to “lower crust” that are explained by “flat” subduction involving ancient continental mantle lithosphere and continental crust without melting of depleted asthenospheric mantle.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107612"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663496","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}

{"title":"The Rio de la Plata and Paranapanema cratons: Uncovering the hidden pieces of west Gondwana","authors":"Miguel A.S. Basei ,&nbsp;Mathias Hueck ,&nbsp;Sebastián Oriolo ,&nbsp;Mario C. Campos Neto","doi":"10.1016/j.precamres.2024.107582","DOIUrl":"10.1016/j.precamres.2024.107582","url":null,"abstract":"<div><div>The Rio de la Plata and Paranapanema cratons are major constituents of the South American Platform, yet both cratons are predominantly covered by Paleo- to Cenozoic basins. Because of that, much about their geological evolution and tectonic position in different supercontinent cycles is still little known, and most inferences about these paleocontinents is recorded indirectly in their surrounding orogenic systems. This special volume collects 15 novel contributions highlighting recent advancements in uncovering the cratonic blocks and their surrounding orogenic systems, from their ancient evolution to their tectonic significance during the assembly of Gondwana and establishment of the Proto-Pacific active margin. The collected studies span a large geographic extent in South America and African counterparts, and follow a variety of methodological approaches.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107582"},"PeriodicalIF":3.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663527","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":"Deformation in the Agnew-Wiluna Greenstone Belt and host Kalgoorlie Terrane during the c. 2675–2630 Ma Kalgoorlie Orogeny: ∼45 Ma of horizontal shortening in a Neoarchean back-arc region","authors":"Quentin Masurel,&nbsp;Nicolas Thébaud","doi":"10.1016/j.precamres.2024.107586","DOIUrl":"10.1016/j.precamres.2024.107586","url":null,"abstract":"<div><div>This study re-evaluates the tectonic processes that contributed to the final assembly of the Yilgarn Craton (Western Australia) in the late Neoarchean. We combine regional-scale (10–100 km) geological data collected from surface exposures over the Agnew-Wiluna Greenstone Belt (AWGB) in the Kalgoorlie Terrane of the Eastern Goldfields Superterrane (EGST) together with published and open-file geochronological and structural data from the Geological Survey of Western Australia. The combined datasets are then compared with the structural record in the Kalgoorlie Terrane, allowing for new insights into the tectonic evolution of the EGST and broader Yilgarn Craton. We show that c. 2675–2630 Ma orogenic deformation in the AWGB was associated with a protracted sequence of events, marked by the activation of distinct shear zones through time and repeated shifts in the location of sedimentary depocentres. We propose that the observed strain pattern resulted from the complex interplay of deformation, magmatism, and sediment deposition under progressive, ENE-WSW-directed horizontal shortening spanning ∼45 Ma. We suggest that the identified deformation scheme represents the local expression of tectono-thermal events affecting the Kalgoorlie-Kurnalpi Rift and broader EGST. Building on prior knowledge on the geological evolution of the Yilgarn Craton, our study supports a model proposed more than a decade ago whereby orogenesis was driven by a west-dipping, outboard subduction zone located further east of the exposed margins of the Yilgarn Craton. Lastly, we emphasize that such scale-integrated, unified perspective provides a balanced reconciliation between the debated allochthonous and <em>para</em>-autochthonous models for the EGST.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"414 ","pages":"Article 107586"},"PeriodicalIF":3.2,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535572","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}