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Geochronology and Geochemistry of the Karadaban Bimodal Volcanic Rocks in the Altyn Area, Xinjiang: Implications for the Tectonic Evolution of the Altyn Ocean
Joint Authors
Jia, Wen-Bin
Yan, Guang-Sheng
Yu, Xiao-Fei
Li, Yong-Sheng
Conticelli, Sandro
Du, Ze-Zhong
Source
Issue
Vol. 2019, Issue 2019 (31 Dec. 2019), pp.1-25, 25 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2019-08-19
Country of Publication
Egypt
No. of Pages
25
Main Subjects
Abstract EN
Detailed geochronological, geochemical, and Sr-Nd-Hf isotopic data are presented for early Paleozoic volcanic rocks in the Karadaban area from the northern Altyn region, NW China, with the aim to constrain their petrogenesis and tectonic implications.
The Karadaban volcanic rocks show a bimodal distribution in composition, with rhyolite and basalt.
The LA-ICP-MS zircon U-Pb age indicates that the volcanic rocks were erupted at 512 Ma.
The mafic rocks are calc-alkaline, enriched in light rare earth elements (LREE) and large-ion lithophile elements (LILE; Ba and U) and depleted in high-field strength elements (HFSE; Nb and Ta).
These features together with their depleted isotopic signature (initial 87Sr/86Sr=0.70413–0.70817, εNdt=2.7 to 3.7) suggest that they were likely derived from a depleted mantle source but mixed with crustal components while upwelling.
The felsic rocks show an A-type affinity, with high alkalis and Rb/Sr and Ga/Al ratios; enriched in LILE (e.g., Rb, K, Th, U, and REE) and depleted in Ba, Sr, Nb, P, and Ti; and with fractionated REE patterns with strong negative Eu anomalies.
The combination of the decoupling of εNdt values (−2.5 to −6.3) and εHft values (+5.5 to +14.7) in the setting of subduction indicates that the felsic rocks were generated by partial melting of the juvenile crustal as a result of magma upwelling.
The geochemical and Sr-Nd-Hf isotopic characteristics, coupled with regional geology, indicate that the formation of the Karadaban bimodal volcanic rocks involves an extensional regime associated with a subduction-related environment.
The rifting of the back arc in response to the retreat of the subducting northern Altyn oceanic lithosphere may account for the Karadaban bimodal volcanic rocks.
American Psychological Association (APA)
Jia, Wen-Bin& Yan, Guang-Sheng& Yu, Xiao-Fei& Li, Yong-Sheng& Conticelli, Sandro& Du, Ze-Zhong. 2019. Geochronology and Geochemistry of the Karadaban Bimodal Volcanic Rocks in the Altyn Area, Xinjiang: Implications for the Tectonic Evolution of the Altyn Ocean. Geofluids،Vol. 2019, no. 2019, pp.1-25.
https://search.emarefa.net/detail/BIM-1154087
Modern Language Association (MLA)
Jia, Wen-Bin…[et al.]. Geochronology and Geochemistry of the Karadaban Bimodal Volcanic Rocks in the Altyn Area, Xinjiang: Implications for the Tectonic Evolution of the Altyn Ocean. Geofluids No. 2019 (2019), pp.1-25.
https://search.emarefa.net/detail/BIM-1154087
American Medical Association (AMA)
Jia, Wen-Bin& Yan, Guang-Sheng& Yu, Xiao-Fei& Li, Yong-Sheng& Conticelli, Sandro& Du, Ze-Zhong. Geochronology and Geochemistry of the Karadaban Bimodal Volcanic Rocks in the Altyn Area, Xinjiang: Implications for the Tectonic Evolution of the Altyn Ocean. Geofluids. 2019. Vol. 2019, no. 2019, pp.1-25.
https://search.emarefa.net/detail/BIM-1154087
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1154087