Abstract
Submarine hydrothermal fluid emanation from a small sediment mound associated with bubbling gas was observed in the Wakamiko crater that is located 5 km offshore at 200 m depth in Kagoshima bay, southern Kyushu, Japan. In 2003 and 2005, surface sediments (up to 30 cm) from inside and outside of the hydrothermal mound were sampled using the submersible ROV Hyper-Dolphine (JAMSTEC). Chemistry of pore fluids inside the mound showed a clear difference from those collected from outside the mound, which is explained by mixing of the ascending hydrothermal component and seawater. Estimated chemical composition of the hydrothermal end member suggests that the fluid experienced hydrothermal interaction at a temperature range of about 175 to 200 °C. This is consistent with the observed mound temperature of 137 °C. Hydrothermal minerals such as barite, stibnite, and realgar were identified in the mound sediment, suggesting their precipitation due to mixing of the ascending hydrothermal fluid with seawater. Isotopic composition of the hydrothermal endmember can be explained by mixing product of seawater, magmatic water and meteoric water. The marine shallow-water hydrothermal system in the Wakamiko crater is considered to be driven by a magmatic heat source beneath the crater, which also contributes elements such as arsenic, antimony, mercury and magmatic water to the hydrothermal fluid.
| Original language | English |
|---|---|
| Pages (from-to) | 84-98 |
| Number of pages | 15 |
| Journal | Journal of Volcanology and Geothermal Research |
| Volume | 173 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - Jun 1 2008 |
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All Science Journal Classification (ASJC) codes
- Geophysics
- Geochemistry and Petrology
Cite this
Marine shallow-water hydrothermal activity and mineralization at the Wakamiko crater in Kagoshima bay, south Kyushu, Japan. / Ishibashi, Junichiro; Nakaseama, Miwako; Seguchi, Mariko; Yamashita, Toru; Doi, Shinsuke; Sakamoto, Takeaki; Shimada, Kazuhiko; Shimada, Nobutaka; Noguchi, Takuroh; Oomori, Tamotsu; Kusakabe, Minoru; Yamanaka, Toshiro.
In: Journal of Volcanology and Geothermal Research, Vol. 173, No. 1-2, 01.06.2008, p. 84-98.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Marine shallow-water hydrothermal activity and mineralization at the Wakamiko crater in Kagoshima bay, south Kyushu, Japan
AU - Ishibashi, Junichiro
AU - Nakaseama, Miwako
AU - Seguchi, Mariko
AU - Yamashita, Toru
AU - Doi, Shinsuke
AU - Sakamoto, Takeaki
AU - Shimada, Kazuhiko
AU - Shimada, Nobutaka
AU - Noguchi, Takuroh
AU - Oomori, Tamotsu
AU - Kusakabe, Minoru
AU - Yamanaka, Toshiro
PY - 2008/6/1
Y1 - 2008/6/1
N2 - Submarine hydrothermal fluid emanation from a small sediment mound associated with bubbling gas was observed in the Wakamiko crater that is located 5 km offshore at 200 m depth in Kagoshima bay, southern Kyushu, Japan. In 2003 and 2005, surface sediments (up to 30 cm) from inside and outside of the hydrothermal mound were sampled using the submersible ROV Hyper-Dolphine (JAMSTEC). Chemistry of pore fluids inside the mound showed a clear difference from those collected from outside the mound, which is explained by mixing of the ascending hydrothermal component and seawater. Estimated chemical composition of the hydrothermal end member suggests that the fluid experienced hydrothermal interaction at a temperature range of about 175 to 200 °C. This is consistent with the observed mound temperature of 137 °C. Hydrothermal minerals such as barite, stibnite, and realgar were identified in the mound sediment, suggesting their precipitation due to mixing of the ascending hydrothermal fluid with seawater. Isotopic composition of the hydrothermal endmember can be explained by mixing product of seawater, magmatic water and meteoric water. The marine shallow-water hydrothermal system in the Wakamiko crater is considered to be driven by a magmatic heat source beneath the crater, which also contributes elements such as arsenic, antimony, mercury and magmatic water to the hydrothermal fluid.
AB - Submarine hydrothermal fluid emanation from a small sediment mound associated with bubbling gas was observed in the Wakamiko crater that is located 5 km offshore at 200 m depth in Kagoshima bay, southern Kyushu, Japan. In 2003 and 2005, surface sediments (up to 30 cm) from inside and outside of the hydrothermal mound were sampled using the submersible ROV Hyper-Dolphine (JAMSTEC). Chemistry of pore fluids inside the mound showed a clear difference from those collected from outside the mound, which is explained by mixing of the ascending hydrothermal component and seawater. Estimated chemical composition of the hydrothermal end member suggests that the fluid experienced hydrothermal interaction at a temperature range of about 175 to 200 °C. This is consistent with the observed mound temperature of 137 °C. Hydrothermal minerals such as barite, stibnite, and realgar were identified in the mound sediment, suggesting their precipitation due to mixing of the ascending hydrothermal fluid with seawater. Isotopic composition of the hydrothermal endmember can be explained by mixing product of seawater, magmatic water and meteoric water. The marine shallow-water hydrothermal system in the Wakamiko crater is considered to be driven by a magmatic heat source beneath the crater, which also contributes elements such as arsenic, antimony, mercury and magmatic water to the hydrothermal fluid.
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U2 - 10.1016/j.jvolgeores.2007.12.041
DO - 10.1016/j.jvolgeores.2007.12.041
M3 - Article
AN - SCOPUS:43649104873
VL - 173
SP - 84
EP - 98
JO - Journal of Volcanology and Geothermal Research
JF - Journal of Volcanology and Geothermal Research
SN - 0377-0273
IS - 1-2
ER -