可变的地幔氧化还原状态是由深度沉降的碳驱动的
Mingdi Gao1, Yu Wang1, Stephen F Foley2,3
1State Key Laboratory of Deep Earth Processes and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Science advances
|May 21, 2025
概括
岩石沉积驱动了地幔氧化还原变化,影响了钻石的形成. 在深层地幔中,碳酸盐与金属铁 (Fe0) 的融化反应会在坑下形成明显的减少或氧化条件.
科学领域:
- 地质化学和石矿学
- 地球深层的过程.
- 克拉顿的形成和稳定性
背景情况:
- 岩石沉降引入碳酸盐进入金属铁 (Fe0) 载体的地下岩层地幔.
- 这一过程导致了异质的地幔氧化还原状态,以及在克拉顿下方的钻石形成.
- 了解地幔氧化还原变异驱动因素对于地球深层过程至关重要.
研究的目的:
- 通过实验性岩石学阐明地幔氧化还原变化的驱动因素.
- 在高压和不同的氧化还原条件下,研究碳酸盐和含Fe0的桃石之间的相互作用.
- 为了比较实验结果与来自不同克拉顿的天然钻石含量.
主要方法:
- 在碳酸盐融和含Fe0的桃石之间进行混合反应实验.
- 实验是在高压 (9至21千兆帕斯卡尔) 和不同氧化还原条件下进行的.
- 结果与从亚岩层钻石中获得的多数矿和铁烯酶含的分析进行了比较.
主要成果:
- 在非羽毛环境中,碳酸盐化物被消耗,形成减少的碳和增强克拉顿的稳定性.
- 在羽毛环境中,融会压倒Fe0缓冲,产生氧化,富含二氧化碳的融.
- 亚马逊克拉顿的钻石内含表明减少,非羽毛状况;卡普瓦尔克拉顿的内含表明氧化羽毛设置.
结论:
- 地幔的氧化还原状态受到碳酸盐沉降和金属铁 (Fe0) 相互作用的显著影响.
- 减少的地幔条件稳定了石坑,而氧化的羽毛状况可能导致石层分层和火山活动.
- 亚岩层地幔的氧化还原状态在岩层进化和地质活动中起着至关重要的作用.
更多相关视频
09:45Laboratory Simulation of an IronII-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria
Published on: July 24, 2016
11.7K
06:53Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
1.9K
相关概念视频
Redox Equilibria: Overview
498
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...
498
Ladder Diagrams: Redox Equilibria
413
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+...
413
Isothermal Processes
3.5K
A thermodynamic process that occurs at constant temperature is called an isothermal process. Heat slowly flows into the system or out of the system to maintain thermal equilibrium. Processes involving phase changes like water evaporation into steam or freezing water into ice at a constant temperature are examples of Isothermal Processes.
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
3.5K
Redox Reactions
55.3K
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...
55.3K
Balancing Redox Equations
51.5K
Electrochemistry is the science involved in the interconversion of electrical and chemical reactions. Such reactions are called reduction-oxidation, or redox reactions. These important reactions are defined by changes in oxidation states for one or more reactant elements and include a subset of reactions involving the transfer of electrons between reactant species. Electrochemistry as a field has evolved to yield sufficient insights on the fundamental principles of redox chemistry and multiple...
51.5K
The Carbon Cycle
36.8K
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
36.8K
