Multistage Melting of Buoyant Mantle beneath the Fiji Triple Junction
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Title
- Multistage Melting of Buoyant Mantle beneath the Fiji Triple Junction
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Author(s)
- Oh, Ji Hye; Kim, Jonguk; Finlay M. Stuart; Seung-Sep Kim; Gyuha Hwang; Munjae Park; Insung Lee
- KIOST Author(s)
- Oh, Ji Hye(오지혜); Kim, Jonguk(김종욱); Hwang, Gyuha(황규하)
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Alternative Author(s)
- 오지혜; 김종욱; 황규하
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Publication Year
- 2022-12-13
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Abstract
- The geochemical heterogeneity recorded in the submarine basaltic glasses from Fiji Triple Junction (FTJ) at the central region in the North Fiji Basin, one of the most mature back-arc basins, is explained by mantle upwelling of enriched composition within the depleted ambient upper mantle. Anomalous high topography of the FTJ, 500-1500 m above, supports existing of hot buoyant mantle upwelling and melting focusing beneath this region. Oceanic island basalts (OIB)-like 3He/4He ratios, Sr-Nd-Pb isotopes, and volatiles of the FTJ glasses present the same latitudinal patterns along the spreading axis, but the 3He/4He ratio has a low correlation with the other geochemical proxies and exhibits lateral displacement. The most enriched lithophile isotope composition occurs at the summit of FTJ, while the highest 3He/4He value appears in the southern region suggesting multistage melting of the enriched upwelling mantle material. This displaced behavior of the helium isotopes requires constraints in micro-scale mantle dynamics and an explanation of the melting structure beneath the FTJ. Here we present new helium isotopes and volatile data and aim to evaluate an association with high-resolution gravity data.
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URI
- https://sciwatch.kiost.ac.kr/handle/2020.kiost/43622
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Bibliographic Citation
- AGU Fall Meeting 2022, 2022
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Publisher
- American Geophysical Union
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Type
- Conference
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Language
- English
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