Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas
Whole rock major and trace element geochemistry together with zircon U-Pb ages and Sr-Nd isotope compositions for the Middle Eocene intrusive rocks in the Haji Abad region are presented. The granitoid hosts, including granodiorite and diorite, yielded zircon U-Pb ages with a weighted mean value of 4...
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| Format: | Article |
| Language: | English |
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Elsevier
2019-03-01
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| Series: | Geoscience Frontiers |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674987118300999 |
| _version_ | 1797764216333008896 |
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| author | Kazem Kazemi Ali Kananian Yilin Xiao Fatemeh Sarjoughian |
| author_facet | Kazem Kazemi Ali Kananian Yilin Xiao Fatemeh Sarjoughian |
| author_sort | Kazem Kazemi |
| collection | DOAJ |
| description | Whole rock major and trace element geochemistry together with zircon U-Pb ages and Sr-Nd isotope compositions for the Middle Eocene intrusive rocks in the Haji Abad region are presented. The granitoid hosts, including granodiorite and diorite, yielded zircon U-Pb ages with a weighted mean value of 40.0 ± 0.7 Ma for the granodiorite phase. Mafic microgranular enclaves (MMEs) are common in these plutons, and have relatively low SiO2 contents (53.04–57.08 wt.%) and high Mg# (42.6–60.1), probably reflecting a mantle-derived origin. The host rocks are metaluminous (A/CNK = 0.69–1.03), arc-related calc-alkaline, and I-type in composition, possessing higher SiO2 contents (59.7–66.77 wt.%) and lower Mg# (38.6–52.2); they are considered a product of partial melting of the mafic lower crust. Chondrite-normalized REE patterns of the MMEs and granitoid hosts are characterized by LREE enrichment and show slight negative Eu anomalies (Eu/Eu* = 0.60–0.93). The host granodiorite samples yield (87Sr/86Sr)i ratios ranging from 0.70498 to 0.70591, positive εNd(t) values varying from +0.21 to +2.3, and TDM2 ranging from 760 to 909 Ma, which is consistent with that of associated mafic microgranular enclaves (87Sr/86Sr)i = 0.705111–0.705113, εNd(t) = +2.14 to +2.16, TDM2 = 697–785 Ma). Petrographic and geochemical characterization together with bulk rock Nd-Sr isotopic data suggest that host rocks and associated enclaves originated by interaction between basaltic lower crust-derived felsic and mantle-derived mafic magmas in an active continental margin arc environment. Keywords: Geochemistry, U-Pb geochronology, Granitoid, Haji Abad, Low angle subduction, Urumieh-Dokhtar Magmatic Arc |
| first_indexed | 2024-03-12T19:52:31Z |
| format | Article |
| id | doaj.art-efa50a4f40004e4b8410691163b30971 |
| institution | Directory Open Access Journal |
| issn | 1674-9871 |
| language | English |
| last_indexed | 2024-03-12T19:52:31Z |
| publishDate | 2019-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Geoscience Frontiers |
| spelling | doaj.art-efa50a4f40004e4b8410691163b309712023-08-02T03:05:39ZengElsevierGeoscience Frontiers1674-98712019-03-01102705723Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmasKazem Kazemi0Ali Kananian1Yilin Xiao2Fatemeh Sarjoughian3School of Geology, College of Science, University of Tehran, Tehran, IranSchool of Geology, College of Science, University of Tehran, Tehran, Iran; Corresponding author. Fax: +98 2166491623.Department of Geochemistry and Environmental Science, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, ChinaDepartment of Earth Sciences, Faculty of Sciences, University of Kurdistan, Sanandaj, IranWhole rock major and trace element geochemistry together with zircon U-Pb ages and Sr-Nd isotope compositions for the Middle Eocene intrusive rocks in the Haji Abad region are presented. The granitoid hosts, including granodiorite and diorite, yielded zircon U-Pb ages with a weighted mean value of 40.0 ± 0.7 Ma for the granodiorite phase. Mafic microgranular enclaves (MMEs) are common in these plutons, and have relatively low SiO2 contents (53.04–57.08 wt.%) and high Mg# (42.6–60.1), probably reflecting a mantle-derived origin. The host rocks are metaluminous (A/CNK = 0.69–1.03), arc-related calc-alkaline, and I-type in composition, possessing higher SiO2 contents (59.7–66.77 wt.%) and lower Mg# (38.6–52.2); they are considered a product of partial melting of the mafic lower crust. Chondrite-normalized REE patterns of the MMEs and granitoid hosts are characterized by LREE enrichment and show slight negative Eu anomalies (Eu/Eu* = 0.60–0.93). The host granodiorite samples yield (87Sr/86Sr)i ratios ranging from 0.70498 to 0.70591, positive εNd(t) values varying from +0.21 to +2.3, and TDM2 ranging from 760 to 909 Ma, which is consistent with that of associated mafic microgranular enclaves (87Sr/86Sr)i = 0.705111–0.705113, εNd(t) = +2.14 to +2.16, TDM2 = 697–785 Ma). Petrographic and geochemical characterization together with bulk rock Nd-Sr isotopic data suggest that host rocks and associated enclaves originated by interaction between basaltic lower crust-derived felsic and mantle-derived mafic magmas in an active continental margin arc environment. Keywords: Geochemistry, U-Pb geochronology, Granitoid, Haji Abad, Low angle subduction, Urumieh-Dokhtar Magmatic Archttp://www.sciencedirect.com/science/article/pii/S1674987118300999 |
| spellingShingle | Kazem Kazemi Ali Kananian Yilin Xiao Fatemeh Sarjoughian Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas Geoscience Frontiers |
| title | Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas |
| title_full | Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas |
| title_fullStr | Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas |
| title_full_unstemmed | Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas |
| title_short | Petrogenesis of Middle-Eocene granitoids and their Mafic microgranular enclaves in central Urmia-Dokhtar Magmatic Arc (Iran): Evidence for interaction between felsic and mafic magmas |
| title_sort | petrogenesis of middle eocene granitoids and their mafic microgranular enclaves in central urmia dokhtar magmatic arc iran evidence for interaction between felsic and mafic magmas |
| url | http://www.sciencedirect.com/science/article/pii/S1674987118300999 |
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