| Item type |
デフォルトアイテムタイプ（フル）(1) |
| 公開日 |
2018-02-05 |
| タイトル |
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|
タイトル |
Geological background of the Kairei and Edmond hydrothermal fields along the Central Indian Ridge : Implications for the distinct chemistry between their vent fluids |
|
言語 |
en |
| 作成者 |
Kumagai, Hidenori
Nakamura, Kentaro
Toki, Tomohiro
Morishita, Tomoaki
Okino, Kyoko
Ishibashi, Jun-ichiro
Tsunogai, Urumu
Kawaguchi, Shinsuke
Gano, Toshitaka
Shibuya, Takazo
Sawaguchi, Takashi
Neo, Natsuki
Joshima, Masato
Sato, Taichi
Takai, Ken
|
| アクセス権 |
|
|
アクセス権 |
open access |
|
アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
| 権利情報 |
|
|
言語 |
ja |
|
権利情報 |
©2008 The Authors Journal compilation©2008 Blackwell Publishing Ltd |
| 主題 |
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|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
hydrogen production |
| 主題 |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
Kairei hydrothermal field |
| 主題 |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
oceanic core complex |
| 主題 |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
serpentinization |
| 主題 |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
troctolite |
| 主題 |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
Uraniwa Hills |
| 内容記述 |
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|
内容記述タイプ |
Other |
|
内容記述 |
Hydrogen-rich hydrothermal areas, such as those in the Indian Ocean, may have had an influence on early evolution of life on Earth and thus have attracted interest because they may be a proxy for ancient ecosystems. The Kairei and Edmond hydrothermal fields in the Indian Ocean are separated by 160 km, but exhibit distinct fluid chemistry: Kairei fluids are hydrogen-rich; Edmond fluids are hydrogen-poor. At this region, the Central Indian Ridge shows an intermediate spreading rate, 48 mm year−1 as full rate, where the hydrothemal fields occur. Kairei field vent fluids show persistently high concentrations of H2. The Kairei field seems to be unique among hydrogen-enriched hydrothermal regions: most similar hydrogen-rich hydrothermal activity occurs along slowly spreading ridge, <40 mm year−1. The geological and tectonic aspects of the Kairei and Edmond hydrothermal fields were studied to try to elucidate geological constraints on hydrogen production. Visual observations of the seafloor near Kairei from a submersible revealed olivine-rich plutonic rocks with olivine gabbro-troctolite-dunite assemblages exposed within 15 km of the vent field, with serpentinized ultramafic mantle rocks on the Oceanic Core Complex (OCC). The OCC area might be a recharge zone of Kairei hydrothermal activity producing H2-rich vent fluids. The chaotic seafloor within 30 km of the Kairei field reflects a magma-starved condition persisting there for 1 Myr. Asymmetric geomagnetic and gravity anomalies near the Kairei field can be used to infer that patchy olivine-rich intrusions are scattered within mantle ultramafics, where infiltrated seawater reacts with magma and ultramafic rocks or olivine-rich rocks. The heterogeneous uppermost lithosphere containing shallow olivine-rich rock facies surrounding the Kairei field provides abundant H2 into the vent fluid through serpentinization. The hydrogen-rich Kairei field is hosted by basalt, with mafic-ultramafic olivine-rich lithology; the ordinary, hydrogen-poor Edmond field is hosted by a normal basaltic lithology. The contrasting geochemical signatures of the two fields reported here can also be found in ancient rocks from a juvenile Earth. This suggests that lithology-controlled generation of hydrogen may have operated for a long time and be relevant to the origin of life on Earth. |
| 内容記述 |
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|
内容記述タイプ |
Other |
|
内容記述 |
論文 |
| 出版者 |
|
|
出版者 |
Blackwell Publishing Ltd |
|
言語 |
en |
| 言語 |
|
|
言語 |
eng |
| 資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
|
資源タイプ |
journal article |
| 出版タイプ |
|
|
出版タイプ |
VoR |
|
出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
| 識別子 |
|
|
識別子 |
http://hdl.handle.net/20.500.12000/37645 |
|
識別子タイプ |
HDL |
| 関連情報 |
|
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|
識別子タイプ |
DOI |
|
|
関連識別子 |
https://doi.org/10.1111/j.1468-8123.2008.00223.x |
| 関連情報 |
|
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
info:doi/10.1111/j.1468-8123.2008.00223.x |
| 収録物識別子 |
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収録物識別子タイプ |
ISSN |
|
収録物識別子 |
1468-8115 |
| 収録物識別子 |
|
|
収録物識別子タイプ |
ISSN |
|
収録物識別子 |
1468-8123 |
| 収録物名 |
|
|
収録物名 |
Geofluids |
|
言語 |
en |
| 書誌情報 |
巻 8,
号 4,
p. 239-251,
発行日 2008-11-25
|
Vol8no4p239no.pdf
