Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW China
In this study, we conducted zircon U-Pb dating, and whole-rock geochemical and Sr-Nd isotope analyses on the Late Mesozoic dolerite dykes in the Bailingshan Fe deposit (Eastern Tianshan Orogen, NW China) to unravel their petrogenesis and regional tectonic significance. Zircon U-Pb dating on the dole...
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Frontiers Media S.A.
2021-04-01
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2021.665610/full |
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| author | Weifeng Zhang Weifeng Zhang Xin Deng Bing Tu Lianhong Peng Xinbiao Jin |
| author_facet | Weifeng Zhang Weifeng Zhang Xin Deng Bing Tu Lianhong Peng Xinbiao Jin |
| author_sort | Weifeng Zhang |
| collection | DOAJ |
| description | In this study, we conducted zircon U-Pb dating, and whole-rock geochemical and Sr-Nd isotope analyses on the Late Mesozoic dolerite dykes in the Bailingshan Fe deposit (Eastern Tianshan Orogen, NW China) to unravel their petrogenesis and regional tectonic significance. Zircon U-Pb dating on the dolerite yielded an Early Cretaceous age of 129.7 ± 1.4 Ma. The dolerite is calc-alkaline sodic (Na2O/K2O = 4.71 to 6.80), and enriched in LILEs (Rb, K, Sr, and Pb) but depleted in HFSEs (Nb, Ta, and Ti). The intermediate Nb/U (16.7 to 18.5) and Ce/Pb (6.33 to 6.90) values, and the presence of xenocrystic zircons in these dolerite dykes suggest crustal assimilation during the magma evolution. Petrological modeling suggests fractionation of olivine, pyroxene, garnet, and spinel. All the dolerite samples have low initial 87Sr/86Sr (0.7041 to 0.7043) and positive εNd(t) (+ 4.6 to + 5.1) values, indicative of a depleted asthenospheric mantle source. Partial melting modeling suggests that the melting has occurred in the spinel-garnet stability field. Integrating the data from ore deposit geology, geochronology, geochemistry and Sr-Nd isotopes, we proposed that the Late Cretaceous Eastern Tianshan mafic magmatism was developed in an intraplate extension setting. |
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| last_indexed | 2024-12-24T04:59:07Z |
| publishDate | 2021-04-01 |
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| spelling | doaj.art-9be9ae265d1b447c850ce643611faa8e2022-12-21T17:14:18ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632021-04-01910.3389/feart.2021.665610665610Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW ChinaWeifeng Zhang0Weifeng Zhang1Xin Deng2Bing Tu3Lianhong Peng4Xinbiao Jin5Wuhan Center of China Geological Survey, Wuhan, ChinaResearch Center for Petrogenesis and Mineralization of Granitoids, Wuhan, ChinaWuhan Center of China Geological Survey, Wuhan, ChinaWuhan Center of China Geological Survey, Wuhan, ChinaWuhan Center of China Geological Survey, Wuhan, ChinaResearch Center for Petrogenesis and Mineralization of Granitoids, Wuhan, ChinaIn this study, we conducted zircon U-Pb dating, and whole-rock geochemical and Sr-Nd isotope analyses on the Late Mesozoic dolerite dykes in the Bailingshan Fe deposit (Eastern Tianshan Orogen, NW China) to unravel their petrogenesis and regional tectonic significance. Zircon U-Pb dating on the dolerite yielded an Early Cretaceous age of 129.7 ± 1.4 Ma. The dolerite is calc-alkaline sodic (Na2O/K2O = 4.71 to 6.80), and enriched in LILEs (Rb, K, Sr, and Pb) but depleted in HFSEs (Nb, Ta, and Ti). The intermediate Nb/U (16.7 to 18.5) and Ce/Pb (6.33 to 6.90) values, and the presence of xenocrystic zircons in these dolerite dykes suggest crustal assimilation during the magma evolution. Petrological modeling suggests fractionation of olivine, pyroxene, garnet, and spinel. All the dolerite samples have low initial 87Sr/86Sr (0.7041 to 0.7043) and positive εNd(t) (+ 4.6 to + 5.1) values, indicative of a depleted asthenospheric mantle source. Partial melting modeling suggests that the melting has occurred in the spinel-garnet stability field. Integrating the data from ore deposit geology, geochronology, geochemistry and Sr-Nd isotopes, we proposed that the Late Cretaceous Eastern Tianshan mafic magmatism was developed in an intraplate extension setting.https://www.frontiersin.org/articles/10.3389/feart.2021.665610/fullpetrogenesisasthenospheric meltswithin-plate magmatismlate mesozoiceastern tianshan |
| spellingShingle | Weifeng Zhang Weifeng Zhang Xin Deng Bing Tu Lianhong Peng Xinbiao Jin Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW China Frontiers in Earth Science petrogenesis asthenospheric melts within-plate magmatism late mesozoic eastern tianshan |
| title | Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW China |
| title_full | Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW China |
| title_fullStr | Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW China |
| title_full_unstemmed | Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW China |
| title_short | Petrogenesis of the Cretaceous Intraplate Mafic Intrusions in the Eastern Tianshan Orogen, NW China |
| title_sort | petrogenesis of the cretaceous intraplate mafic intrusions in the eastern tianshan orogen nw china |
| topic | petrogenesis asthenospheric melts within-plate magmatism late mesozoic eastern tianshan |
| url | https://www.frontiersin.org/articles/10.3389/feart.2021.665610/full |
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