Details
| Original language | English |
|---|---|
| Article number | e2020GC009093 |
| Journal | Geochemistry, Geophysics, Geosystems |
| Volume | 22 |
| Issue number | 1 |
| Early online date | 16 Nov 2020 |
| Publication status | Published - 12 Jan 2021 |
Abstract
International Ocean Discovery Program Expedition 352 to the Izu-Bonin forearc cored over 800 m of basement comprising boninite and boninite-series lavas. This is the most extensive, well-constrained suite of boninite series lavas ever obtained from in situ oceanic crust. The boninites are characterized as high-silica boninite (HSB), low-silica boninite (LSB), or basaltic boninite based on their SiO2-MgO-TiO2 relations. The principal fractionation products of all three series are high-Mg andesites (HMA). Lavas recovered >250 meters below seafloor (mbsf) erupted at a forearc spreading axis and are dominated by LSB and HMA. Lavas recovered from <250 mbsf erupted off-axis and are dominated by HSB. The axial and off-axis lavas are characterized by distinct chemostratigraphic trends in their major, trace, and isotopic compositions. The off-axis lavas are chemically similar to boninite from the type locality at Chichijima, with concave-upward rare earth elements patterns. In contrast, the more abundant axial lavas have distinctly light rare earth element-depleted patterns and represent a new, previously unsampled precursor to the Chichijima-type boninite lavas. Petrogenetic modeling suggests that the axial lavas formed by fluxing of refractory mantle (likely the residue from forearc basalt extraction), with amphibolite-facies melt derived from subducting altered oceanic crust. The upper, off-axis lavas require an additional component of sediment-derived melt in addition. Both models are consistent with previously published isotopic data.
Keywords
- boninite, IODP Expedition 352, Izu-Bonin-Mariana forearc, JOIDES Resolution, ophiolites, Sites U1439, U1442, subduction initiation
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Geochemistry, Geophysics, Geosystems, Vol. 22, No. 1, e2020GC009093, 12.01.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Magmatic Response to Subduction Initiation, Part II
T2 - Boninites and Related Rocks of the Izu-Bonin Arc From IOPD Expedition 352
AU - Shervais, John W.
AU - Reagan, Mark K.
AU - Godard, Marguerite
AU - Prytulak, Julie
AU - Ryan, Jeffrey G.
AU - Pearce, Julian A.
AU - Almeev, Renat R.
AU - Li, Hongyan
AU - Haugen, Emily
AU - Chapman, Timothy
AU - Kurz, Walter
AU - Nelson, Wendy R.
AU - Heaton, Daniel E.
AU - Kirchenbaur, Maria
AU - Shimizu, Kenji
AU - Sakuyama, Tetsuya
AU - Vetter, Scott K.
AU - Li, Yibing
AU - Whattam, Scott
N1 - Funding Information: This research used samples and/or data provided by the International Ocean Discovery Program (IODP). The authors are grateful for support from IODP, the JOIDES Resolution Facility, and the scientific staff and crew aboard the JOIDES Resolution during Expedition 352. Funding support to the US participants (John W. Shervais, Mark Reagan, Jeffrey G. Ryan, Wendy R. Nelson) from the Consortium for Ocean Leadership and from the National Science Foundation is gratefully acknowledged (OCE‐1558689 to Shervais; OCE‐1558647 to Reagan, OCE‐1558855 to Ryan, and OCE‐1558608 to Nelson). Prytulak was supported by NERC directed grant NE/M010643/1. Chapman was supported by the Australia‐New Zealand IODP consortium and the ARC LIEF scheme (LE140100047). Almeev was supported by the German Science Foundation (DFG, Project AL1189/8‐1). Pearce was supported by NERC (UK) grant (NE/M012034/1). Kurz appreciates support by the Austrian Academy of Sciences and funding by the Austrian Science Fund (FWF Project P27982‐N29). Kirchenbaur appreciates funding by the German IODP consortium and the BGR Germany. All data submitted to the Pangaea database for archiving. We thank Ivan Savov, Marcel Regelous, and two anonymous reviewers for their thorough and thoughtful reviews, which markedly improved the manuscript.
PY - 2021/1/12
Y1 - 2021/1/12
N2 - International Ocean Discovery Program Expedition 352 to the Izu-Bonin forearc cored over 800 m of basement comprising boninite and boninite-series lavas. This is the most extensive, well-constrained suite of boninite series lavas ever obtained from in situ oceanic crust. The boninites are characterized as high-silica boninite (HSB), low-silica boninite (LSB), or basaltic boninite based on their SiO2-MgO-TiO2 relations. The principal fractionation products of all three series are high-Mg andesites (HMA). Lavas recovered >250 meters below seafloor (mbsf) erupted at a forearc spreading axis and are dominated by LSB and HMA. Lavas recovered from <250 mbsf erupted off-axis and are dominated by HSB. The axial and off-axis lavas are characterized by distinct chemostratigraphic trends in their major, trace, and isotopic compositions. The off-axis lavas are chemically similar to boninite from the type locality at Chichijima, with concave-upward rare earth elements patterns. In contrast, the more abundant axial lavas have distinctly light rare earth element-depleted patterns and represent a new, previously unsampled precursor to the Chichijima-type boninite lavas. Petrogenetic modeling suggests that the axial lavas formed by fluxing of refractory mantle (likely the residue from forearc basalt extraction), with amphibolite-facies melt derived from subducting altered oceanic crust. The upper, off-axis lavas require an additional component of sediment-derived melt in addition. Both models are consistent with previously published isotopic data.
AB - International Ocean Discovery Program Expedition 352 to the Izu-Bonin forearc cored over 800 m of basement comprising boninite and boninite-series lavas. This is the most extensive, well-constrained suite of boninite series lavas ever obtained from in situ oceanic crust. The boninites are characterized as high-silica boninite (HSB), low-silica boninite (LSB), or basaltic boninite based on their SiO2-MgO-TiO2 relations. The principal fractionation products of all three series are high-Mg andesites (HMA). Lavas recovered >250 meters below seafloor (mbsf) erupted at a forearc spreading axis and are dominated by LSB and HMA. Lavas recovered from <250 mbsf erupted off-axis and are dominated by HSB. The axial and off-axis lavas are characterized by distinct chemostratigraphic trends in their major, trace, and isotopic compositions. The off-axis lavas are chemically similar to boninite from the type locality at Chichijima, with concave-upward rare earth elements patterns. In contrast, the more abundant axial lavas have distinctly light rare earth element-depleted patterns and represent a new, previously unsampled precursor to the Chichijima-type boninite lavas. Petrogenetic modeling suggests that the axial lavas formed by fluxing of refractory mantle (likely the residue from forearc basalt extraction), with amphibolite-facies melt derived from subducting altered oceanic crust. The upper, off-axis lavas require an additional component of sediment-derived melt in addition. Both models are consistent with previously published isotopic data.
KW - boninite
KW - IODP Expedition 352
KW - Izu-Bonin-Mariana forearc
KW - JOIDES Resolution
KW - ophiolites
KW - Sites U1439, U1442
KW - subduction initiation
UR - http://www.scopus.com/inward/record.url?scp=85099788283&partnerID=8YFLogxK
U2 - 10.1029/2020GC009093
DO - 10.1029/2020GC009093
M3 - Article
AN - SCOPUS:85099788283
VL - 22
JO - Geochemistry, Geophysics, Geosystems
JF - Geochemistry, Geophysics, Geosystems
SN - 1525-2027
IS - 1
M1 - e2020GC009093
ER -