メッセンニアの塩分危機の根は深い
Svend Duggen1, Kaj Hoernle, Paul van den Bogaard
1GEOMAR Research Center for Marine Geosciences, Wischhofstrasse 1-3, 24148 Kiel, Germany. s.duggen@gl.rhul.ac.uk
Nature
|April 11, 2003
まとめ
メッセンニアの塩分危機は,海上ゲートウェイの閉鎖によって引き起こされた. 沈殿したテティスの石層の西向きの回転は,マージンを上昇させ,地中海の乾燥につながった.
科学分野:
- 地質学 地質学 地質学
- ジオダイナミクスは地力学です.
- パレオセアノグラフィー
背景:
- メッシニアの塩分危機 (5,96~5,3300万年前) は,地中海の乾燥を伴うものでした.
- この事件の原因は,大西洋・地中海間の海上ゲートウェイの閉鎖であったが,その根本的な原因は不明である.
研究 の 目的:
- 地中海の最西部の地動力学的進化を,ミオセンの中期からプレイストセンの1億2,100万年前まで再構築する.
- 地動力学的変化とメッセンニア海塩分危機との関連を調査する.
主な方法:
- 火山岩の年代測定と地化学分析.
- 熱力学的モデリング.
主要な成果:
- マントルから派生した火山岩の地化学的シフトは,潜水関係からプレート内型へと6.3~4.8百万年前に起こった.
- このシフトは,メッセンニアの塩分危機と同期しています.
結論:
- テティスの海洋性石層とアステノスフィアの上流の西向きの反転は,観測された地化学的変化を説明します.
- このプロセスは,アフリカとイベリアの縁に沿って約1kmの上昇を引き起こし,海洋ゲートウェイを閉鎖し,メッセンニア塩分危機を引き起こしました.
関連する概念動画
Responses to Salt Stress
Salt stress—which can be triggered by high salt concentrations in a plant’s environment—can significantly affect plant growth and crop production by influencing photosynthesis and the absorption of water and nutrients.
What is Evolutionary History?
Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.
Origin of Photosynthesis
Photosynthesis represents a fundamental biological process that transformed Earth's atmosphere and paved the way for complex life. Emerging roughly 3.4–3.8 billion years ago, the earliest photosynthetic organisms harnessed light energy to produce organic compounds. These anoxygenic phototrophs used electron donors like hydrogen sulfide (H₂S) or ferrous iron (Fe²⁺), rather than water, and did not release molecular oxygen (O₂) as a byproduct. Various groups, including green sulfur and purple...
Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
Marine Microbial Ecology
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...


