Sakine Amraei, Mohammad Yazdi, Liang Qiu, Chang-Zhi Wu, Lei Chen, Bertrand Moine, Majid Ghasemi Siani, Qihui Zhang, Shahrokh Rajabpour
{"title":"伊朗中部巴夫克 XV 黑云母-超黑云母侵入体的磷灰石 U-Pb 地质年代和全岩 Sr-Nd-Pb 同位素地球化学:对岩石成因和构造背景的影响","authors":"Sakine Amraei, Mohammad Yazdi, Liang Qiu, Chang-Zhi Wu, Lei Chen, Bertrand Moine, Majid Ghasemi Siani, Qihui Zhang, Shahrokh Rajabpour","doi":"10.1111/iar.12514","DOIUrl":null,"url":null,"abstract":"<p>The XV mafic-ultramafic intrusion is located in the western part of the Posht-e-Badam Block (PBB) within the Central Iranian Micro-Continent (CIMC). Petrographically, the intrusion is composed of gabbro and pyroxenite. Apatite U–Pb dating has established the crystallization age of this intrusion to be 363 ± 67 Ma. The XV intrusive rocks are tholeiitic to slightly calc-alkaline in nature and are characterized by an enrichment of large ion lithophile elements (LILE) and light rare earth elements (LREE) relative to high field strength elements (HFSE) and Heavy Rare Earth Elements (HREE), respectively. The major oxide elements display continuous trends relative to SiO<sub>2</sub>. The <sup>87</sup>Sr/<sup>86</sup>Sr(i) ratios range from 0.7045 to 0.7056, and the εNd(i) values range from 2.63 to 3.30. In addition, the <sup>206</sup>Pb/<sup>204</sup>Pb, <sup>207</sup>Pb/<sup>204</sup>Pb, and <sup>208</sup>Pb/<sup>204</sup>Pb ratios exhibit a narrow range, varying from 18.68 to 18.70, 15.67 to 15.71, and 38.84 to 38.99, respectively. The geochemical and isotopic characteristics suggest that the parental magma was derived from a Sub- Continental Lithospheric Mantle (SCLM) that was modified by oceanic slab-derived components. The locations of the XV intrusive rocks in εNd(i) versus TDM (Ga) and Nb/La versus discrimination diagrams further support this conclusion. Fractional crystallization is identified as the dominant process influencing the formation of distinct lithological units within the XV intrusive rocks. Our newly presented isotopic and geochronological data, when considered in the regional context, suggest that the XV intrusive rocks were formed in an extensional tectonic setting. In this scenario, upwelling from the asthenospheric mantle induced heating, leading to the melting of previously subduction-modified SCLM. Comparative analysis with previously published ages indicates that extensional magmatism in the PBB continued into the Middle Paleozoic.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Apatite U–Pb geochronology and whole rock, Sr–Nd–Pb isotopic geochemistry of XV mafic-ultramafic intrusion, Bafq, Central Iran: Implications for petrogenesis and tectonic setting\",\"authors\":\"Sakine Amraei, Mohammad Yazdi, Liang Qiu, Chang-Zhi Wu, Lei Chen, Bertrand Moine, Majid Ghasemi Siani, Qihui Zhang, Shahrokh Rajabpour\",\"doi\":\"10.1111/iar.12514\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The XV mafic-ultramafic intrusion is located in the western part of the Posht-e-Badam Block (PBB) within the Central Iranian Micro-Continent (CIMC). Petrographically, the intrusion is composed of gabbro and pyroxenite. Apatite U–Pb dating has established the crystallization age of this intrusion to be 363 ± 67 Ma. The XV intrusive rocks are tholeiitic to slightly calc-alkaline in nature and are characterized by an enrichment of large ion lithophile elements (LILE) and light rare earth elements (LREE) relative to high field strength elements (HFSE) and Heavy Rare Earth Elements (HREE), respectively. The major oxide elements display continuous trends relative to SiO<sub>2</sub>. The <sup>87</sup>Sr/<sup>86</sup>Sr(i) ratios range from 0.7045 to 0.7056, and the εNd(i) values range from 2.63 to 3.30. In addition, the <sup>206</sup>Pb/<sup>204</sup>Pb, <sup>207</sup>Pb/<sup>204</sup>Pb, and <sup>208</sup>Pb/<sup>204</sup>Pb ratios exhibit a narrow range, varying from 18.68 to 18.70, 15.67 to 15.71, and 38.84 to 38.99, respectively. The geochemical and isotopic characteristics suggest that the parental magma was derived from a Sub- Continental Lithospheric Mantle (SCLM) that was modified by oceanic slab-derived components. The locations of the XV intrusive rocks in εNd(i) versus TDM (Ga) and Nb/La versus discrimination diagrams further support this conclusion. Fractional crystallization is identified as the dominant process influencing the formation of distinct lithological units within the XV intrusive rocks. Our newly presented isotopic and geochronological data, when considered in the regional context, suggest that the XV intrusive rocks were formed in an extensional tectonic setting. In this scenario, upwelling from the asthenospheric mantle induced heating, leading to the melting of previously subduction-modified SCLM. Comparative analysis with previously published ages indicates that extensional magmatism in the PBB continued into the Middle Paleozoic.</p>\",\"PeriodicalId\":14791,\"journal\":{\"name\":\"Island Arc\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2024-02-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Island Arc\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1111/iar.12514\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Island Arc","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/iar.12514","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Apatite U–Pb geochronology and whole rock, Sr–Nd–Pb isotopic geochemistry of XV mafic-ultramafic intrusion, Bafq, Central Iran: Implications for petrogenesis and tectonic setting
The XV mafic-ultramafic intrusion is located in the western part of the Posht-e-Badam Block (PBB) within the Central Iranian Micro-Continent (CIMC). Petrographically, the intrusion is composed of gabbro and pyroxenite. Apatite U–Pb dating has established the crystallization age of this intrusion to be 363 ± 67 Ma. The XV intrusive rocks are tholeiitic to slightly calc-alkaline in nature and are characterized by an enrichment of large ion lithophile elements (LILE) and light rare earth elements (LREE) relative to high field strength elements (HFSE) and Heavy Rare Earth Elements (HREE), respectively. The major oxide elements display continuous trends relative to SiO2. The 87Sr/86Sr(i) ratios range from 0.7045 to 0.7056, and the εNd(i) values range from 2.63 to 3.30. In addition, the 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios exhibit a narrow range, varying from 18.68 to 18.70, 15.67 to 15.71, and 38.84 to 38.99, respectively. The geochemical and isotopic characteristics suggest that the parental magma was derived from a Sub- Continental Lithospheric Mantle (SCLM) that was modified by oceanic slab-derived components. The locations of the XV intrusive rocks in εNd(i) versus TDM (Ga) and Nb/La versus discrimination diagrams further support this conclusion. Fractional crystallization is identified as the dominant process influencing the formation of distinct lithological units within the XV intrusive rocks. Our newly presented isotopic and geochronological data, when considered in the regional context, suggest that the XV intrusive rocks were formed in an extensional tectonic setting. In this scenario, upwelling from the asthenospheric mantle induced heating, leading to the melting of previously subduction-modified SCLM. Comparative analysis with previously published ages indicates that extensional magmatism in the PBB continued into the Middle Paleozoic.
期刊介绍:
Island Arc is the official journal of the Geological Society of Japan. This journal focuses on the structure, dynamics and evolution of convergent plate boundaries, including trenches, volcanic arcs, subducting plates, and both accretionary and collisional orogens in modern and ancient settings. The Journal also opens to other key geological processes and features of broad interest such as oceanic basins, mid-ocean ridges, hot spots, continental cratons, and their surfaces and roots. Papers that discuss the interaction between solid earth, atmosphere, and bodies of water are also welcome. Articles of immediate importance to other researchers, either by virtue of their new data, results or ideas are given priority publication.
Island Arc publishes peer-reviewed articles and reviews. Original scientific articles, of a maximum length of 15 printed pages, are published promptly with a standard publication time from submission of 3 months. All articles are peer reviewed by at least two research experts in the field of the submitted paper.