一个脱气的岩上升到表面的氧化还原演变
Alain Burgisser1, Bruno Scaillet
1ISTO, UMR 6113 Université d'Orléans-CNRS, 1a rue de la Férollerie, 45071 Orléans cedex 2, France. burgisse@cnrs-orleans.fr
Nature
|January 12, 2007
概括
岩上升显著改变了火山气体的氧化还原状态,挑战了关于其与源头的联系的假设. 气体的组成和数量极大地影响了喷发期间的氧气流动性 (O2) 变化.
科学领域:
- 地质化学 地质化学
- 火山学 火山学是一门学科.
- 地球科学 地球科学 地球科学
背景情况:
- 火山气体影响地球的大气和岩动态.
- 火山气体的氧化还原状态被认为反映了岩源条件.
- 从火山气体中观察到的氧气流动性 (f(O2) 的变化仍然无法解释.
研究的目的:
- 为了研究岩的上升如何影响火山气体的氧化还原状态.
- 为了确定气体成分和数量的对氧气流动性 (f{\displaystyle f} O2) 演变的影响.
- 为了评估喷发的岩氧化还原状态的可靠性,作为气体排放的代理.
主要方法:
- 利用了合化学物理模型的岩导管流.
- 模拟升起的 magma 和它们的气相的氧化还原状态演变.
- 分析了不同气体成分 (包括硫) 和储存量的影响.
主要成果:
- 没有硫的上升岩系统地增加了高达2个log单位的氧气逃逸率 (f(O2).
- 含硫的岩石表现出氧化还原状态的变化,这取决于初始储存条件.
- 模拟的H2S/SO2比率与汇的火山环境的观测结果一致.
结论:
- 表面的气体的氧化还原状态可能不能准确地表示岩源的氧气流动性 (f{\displaystyle f} O2{\displaystyle f} O2}).
- 在岩储和火山管道出口之间发生了显著的氧化还原状态变化 (高达1.5日志单位).
- 需要重新评估有关岩挥发物在地质过程中的作用的模型.
相关概念视频
Redox Reactions
50.9K
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
50.9K
The Sulfur Cycle
41.6K
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
41.6K
Oxidation-Reduction Reactions
58.8K
Oxidation–Reduction Reactions
58.8K
Ladder Diagrams: Redox Equilibria
921
Ladder diagrams are useful tools for understanding redox equilibrium reactions, especially the effects of concentration changes on the electrochemical potential of the reaction. The vertical axis in the redox ladder diagrams represents the electrochemical potential, E. The area of predominance is demarcated using the Nernst equation.
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
921
Redox Equilibria: Overview
1.4K
A reduction-oxidation reaction is commonly called a redox reaction. In a redox reaction, electrons are transferred from one species to another rather than being shared between or among atoms. The reducing agent or reductant is the species that loses electrons and gets oxidized in the process. The species that gains electrons and gets reduced in the process is the oxidizing agent or oxidant. Redox reactions are represented as two separate equations called half-reactions, where one equation...
1.4K
Redox Reactions
1.2K
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
1.2K


