北緯30度に位置する中大西洋山脈の近くにあるオフアシス型熱水噴出場
D S Kelley1, J A Karson, D K Blackman
1University of Washington, School of Oceanography, Seattle, Washington 98195, USA. kelley@ocean.washington.edu
Nature
|July 13, 2001
まとめ
科学者たちは,ユニークな水熱場を発見しました.
科学分野:
- 海洋地質学と地球化学
- 微生物生態学とは
背景:
- 熱水噴出孔は,伝統的に中海の山脊と関連付けられています.
- 証拠によると,水熱活動が,広がりの中心から離れた古い海洋地殻でも発生する可能性があることが示唆されています.
研究 の 目的:
- 古い海洋の地殻の水熱活動を調査するために.
- 新しく発見された風口場の独特の地質・化学的特徴を特徴づけること.
- このような環境における微生物生命の可能性を評価する.
主な方法:
- アトランティス山脈の地質調査と地図作成.
- 換気液の温度とpHのインサイト測定.
- 換気液サンプルの微生物コミュニティ分析.
主要な成果:
- "失われた都市"という水熱場が発見されたのは,大地の1.5万年前の地殻で,中大西洋のから15km離れたところにある.
- 典型的な硫化物構造と異なる炭酸煙突の識別.
- アルカリ性で比較的冷たい風口液 (40~75°C,pH9.0~9.8) の特徴
- 密度の高い無酸素熱性微生物群の検出.
結論:
- "失われた都市"の熱水場は,磁気熱のみではなく,蛇形化反応によって動かされている.
- 古い海洋地殻のアルカリ性水熱システムは,多様な微生物の生命を支える可能性があります.
- 海洋地殻の大部分は,水熱活動と生命を宿し,既知の居住可能領域を拡大する可能性がある.
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