Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmas
Quaternary intraplate magmatism formed several volcanic islands and seamounts, including Dokdo (DD), Ulleungdo (UD), Simheungtack (ST), Anyongbok, and Isabu in the southwest of the East Sea back-arc basin. In this study, we present whole-rock geochemical, zircon U–Pb age, and in situ O–Hf isotope da...
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Elsevier
2024-03-01
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| Series: | Geoscience Frontiers |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674987123002050 |
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| author | Hyun-Ok Choi Jihye Oh Chang Hwan Kim Soon Young Choi Won Hyuck Kim Chan Hong Park |
| author_facet | Hyun-Ok Choi Jihye Oh Chang Hwan Kim Soon Young Choi Won Hyuck Kim Chan Hong Park |
| author_sort | Hyun-Ok Choi |
| collection | DOAJ |
| description | Quaternary intraplate magmatism formed several volcanic islands and seamounts, including Dokdo (DD), Ulleungdo (UD), Simheungtack (ST), Anyongbok, and Isabu in the southwest of the East Sea back-arc basin. In this study, we present whole-rock geochemical, zircon U–Pb age, and in situ O–Hf isotope data for the submerged volcanic rocks from DD, UD, and ST to provide new insights into the eruption timing of these volcanoes and constrain the magma evolution processes. All samples used in this study were trachytes and exhibited ferroan, alkalic, and metaluminous to weakly peraluminous characteristics. They showed light rare earth element (REE)-enriched patterns with (La/Yb)N ratios of 25.3–31.7 and mostly negative Eu anomalies in a chondrite-normalized REE plot. In addition, they were enriched in large-ion lithophile elements and high field strength elements; they exhibited positive Pb anomalies and strongly negative Ba, Sr, P, and Ti anomalies. The zircons yielded a weighted-mean 206Pb/238U age of 2.61, 0.348–0.704, and 2.76–2.94 Ma for the DD, UD, and ST trachytes, respectively. All zircons exhibited lower δ18O values than normal depleted mantle values, regardless of the crystallization age and spatial distribution of volcanoes. The δ18O values showed no correlation with U contents or Th/U ratios, indicating that the low δ18O signatures were of primary magmatic origin. The Hf isotopic compositions of the zircons were relatively heterogeneous but predominately characterized by positive εHf values. Binary O–Hf mixing modeling revealed that low-δ18O rocks with positive εHf values from the UD and ST volcanoes were derived from a hybrid source of recycled juvenile crustal materials with low-δ18O and positive εHf signatures and an enriched mantle source with normal δ18O and negative εHf values. The juvenile oceanic crust in the source was likely metasomatized by seawater at high temperatures prior to melting. In contrast, the felsic magma that formed the DD volcanoes may have assimilated with regional basement rocks (Triassic–Jurassic granitoids), resulting in increased δ18O values and decreased εHf values relative to those of the UD and ST volcanoes. Our study highlights the significant contribution of recycled oceanic crust materials to the generation of the Quaternary magmas. |
| first_indexed | 2024-03-08T02:02:03Z |
| format | Article |
| id | doaj.art-22956c056cc648a9a6598e953c4a1090 |
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| language | English |
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| spelling | doaj.art-22956c056cc648a9a6598e953c4a10902024-02-14T05:14:13ZengElsevierGeoscience Frontiers1674-98712024-03-01152101738Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmasHyun-Ok Choi0Jihye Oh1Chang Hwan Kim2Soon Young Choi3Won Hyuck Kim4Chan Hong Park5Dokdo Research Center, East Sea Research Institute, Korea Institute of Ocean Science and Technology, Uljin 36315, Republic of Korea; Corresponding author.Deep-Sea and Seabed Mineral Resources Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of KoreaDokdo Research Center, East Sea Research Institute, Korea Institute of Ocean Science and Technology, Uljin 36315, Republic of KoreaDokdo Research Center, East Sea Research Institute, Korea Institute of Ocean Science and Technology, Uljin 36315, Republic of Korea; Division of Science Education, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon-si, Gangwon-do 24341, Republic of KoreaDokdo Research Center, East Sea Research Institute, Korea Institute of Ocean Science and Technology, Uljin 36315, Republic of KoreaDokdo Research Center, East Sea Research Institute, Korea Institute of Ocean Science and Technology, Uljin 36315, Republic of KoreaQuaternary intraplate magmatism formed several volcanic islands and seamounts, including Dokdo (DD), Ulleungdo (UD), Simheungtack (ST), Anyongbok, and Isabu in the southwest of the East Sea back-arc basin. In this study, we present whole-rock geochemical, zircon U–Pb age, and in situ O–Hf isotope data for the submerged volcanic rocks from DD, UD, and ST to provide new insights into the eruption timing of these volcanoes and constrain the magma evolution processes. All samples used in this study were trachytes and exhibited ferroan, alkalic, and metaluminous to weakly peraluminous characteristics. They showed light rare earth element (REE)-enriched patterns with (La/Yb)N ratios of 25.3–31.7 and mostly negative Eu anomalies in a chondrite-normalized REE plot. In addition, they were enriched in large-ion lithophile elements and high field strength elements; they exhibited positive Pb anomalies and strongly negative Ba, Sr, P, and Ti anomalies. The zircons yielded a weighted-mean 206Pb/238U age of 2.61, 0.348–0.704, and 2.76–2.94 Ma for the DD, UD, and ST trachytes, respectively. All zircons exhibited lower δ18O values than normal depleted mantle values, regardless of the crystallization age and spatial distribution of volcanoes. The δ18O values showed no correlation with U contents or Th/U ratios, indicating that the low δ18O signatures were of primary magmatic origin. The Hf isotopic compositions of the zircons were relatively heterogeneous but predominately characterized by positive εHf values. Binary O–Hf mixing modeling revealed that low-δ18O rocks with positive εHf values from the UD and ST volcanoes were derived from a hybrid source of recycled juvenile crustal materials with low-δ18O and positive εHf signatures and an enriched mantle source with normal δ18O and negative εHf values. The juvenile oceanic crust in the source was likely metasomatized by seawater at high temperatures prior to melting. In contrast, the felsic magma that formed the DD volcanoes may have assimilated with regional basement rocks (Triassic–Jurassic granitoids), resulting in increased δ18O values and decreased εHf values relative to those of the UD and ST volcanoes. Our study highlights the significant contribution of recycled oceanic crust materials to the generation of the Quaternary magmas.http://www.sciencedirect.com/science/article/pii/S1674987123002050Quaternary intraplate volcanismEast SeaZircon O–Hf isotopesLow-δ18O magmaRecycled juvenile oceanic crust |
| spellingShingle | Hyun-Ok Choi Jihye Oh Chang Hwan Kim Soon Young Choi Won Hyuck Kim Chan Hong Park Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmas Geoscience Frontiers Quaternary intraplate volcanism East Sea Zircon O–Hf isotopes Low-δ18O magma Recycled juvenile oceanic crust |
| title | Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmas |
| title_full | Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmas |
| title_fullStr | Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmas |
| title_full_unstemmed | Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmas |
| title_short | Zircon U–Pb ages and O–Hf isotopes of Quaternary trachytes from the East Sea: Implications for the genesis of low-δ18O magmas |
| title_sort | zircon u pb ages and o hf isotopes of quaternary trachytes from the east sea implications for the genesis of low δ18o magmas |
| topic | Quaternary intraplate volcanism East Sea Zircon O–Hf isotopes Low-δ18O magma Recycled juvenile oceanic crust |
| url | http://www.sciencedirect.com/science/article/pii/S1674987123002050 |
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