日本地球惑星科学連合2018年大会

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[EJ] 口頭発表

セッション記号 S (固体地球科学) » S-GL 地質学

[S-GL29] 泥火山と地球化学的・地質地形学的・生物学的関連現象

2018年5月24日(木) 13:45 〜 15:15 A03 (東京ベイ幕張ホール)

コンビーナ:浅田 美穂(国立研究法人海洋研究開発機構)、土岐 知弘(琉球大学理学部)、井尻 暁(国立研究開発法人海洋研究開発機構、共同)、辻 健(九州大学工学研究院)、座長:井尻 暁浅田 美穂

14:25 〜 14:40

[SGL29-03] The Goshogake mud volcano field, Tohoku, Japan: an acidic, high-temperature system related to magmatic volcanism

*石丸 亮1三宅 範宗1小松 吾郎2,1河合 研志3小林 真輝人4佐久間 博5 (1.千葉工業大学 惑星探査研究センター、2.イタリア・ダヌンツィオ大学、3.東京大学大学院理学系研究科地球惑星科学専攻、4.東京大学理学部地球惑星環境学科、5.国立研究開発法人 物質・材料研究機構 )

キーワード:Mud Volcano、high temperature、acidic

Mud volcanoes occur everywhere in various geological settings on the Earth and, possibly, on other planetary bodies, such as Mars and Enceladus ocean floor. Their surface terrains are formed by mud ascending and erupting, together with water and gas, from depths. Therefore, mud volcano is one of the most suitable landforms for exploring the subsurface geology and microbiology (i.e., extremophile) because mud volcanoes allow us to access easily to deep underground materials. Recognizing the importance of astrobiological potential of mud volcanoes, we have conducted field works, laboratory chemical and microbial analyses on terrestrial mud volcano fields as an analog for future exploration missions to the planetary bodies.

In this study, we focus on the Goshogake mud volcano field in Tohoku, Japan. The field has hot springs fed with high-temperature fluids emerging on the eastern flank of the Quaternary Akita Yakeyama volcano. Its uniqueness is highlighted by the following reasons: (i) The geomorphological features observed in the Goshogake (salsa, gryphon, and mud pod) are similar to those commonly observed in conventional sedimentary mud volcanoes. (ii) On the other hand, the physico-chemical environment in the Goshogake mud volcano field is an acidic and high-temperature system in association with magmatic volcanism, which is totally different from conventional sedimentary mud volcanoes characterized by relatively low temperatures. In-depth understanding of this unique example will tell us about the environmental and biological diversities and formation conditions of mud volcanoes on the Earth and beyond.

We present in this study documentation of the Goshogake mud volcano features, and the results of in-situ measurements and laboratory analyses of gas and water at the Goshogake mud volcano field to discuss the nature of its mud fluids and their origins, which are essential for understanding habitability and ecology of such systems, and biological analysis of the Goshogake mud volcano field.