氧化态的变化背后的机制(例如铁)岩浆?- 江南体育网页版- - - - -地球科学堆江南电子竞技平台栈交换 最近30从www.hoelymoley.com 2023 - 07 - 10 - t20:40:57z //www.hoelymoley.com/feeds/question/2496 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/2496 11 氧化态的变化背后的机制(例如铁)岩浆? jonsca //www.hoelymoley.com/users/19 2014 - 09 - 16 - t13:44:55z 2014 - 12 - 03 - t18:40:31z < p > < a href = " //www.hoelymoley.com/a/2476 " >这回答< / >,我得知岩浆上升可能会改变氧化状态,我不知道。< / p >

In [#1], the authors state in the abstract

The conventional view holds that the oxidation state of a mantle-derived degassed magma reflects its source

From other research that has been conducted, the authors discussed that the oxygen fugacity (the partial pressure of the "non-ideal" oxygen in the presence of the high pressures and temperatures, presumably of the magma itself) was controlled by a pair of redox reactions (their equations 11 and 12):

$$\ce{S_{(melt)}^2- + Fe2^3+O3_{(melt)} <=> SO2_{(gas)} + 6Fe^2+O_{(melt)} + O_{(melt)}^2-}$$ $$\ce{SO4_{(melt)}^2- + 2Fe^2+O_{(melt)} <=> SO2_{(gas)} + Fe2^3+O3_{(melt)} + O_{(melt)}^2-}$$

Their claim is that the change in the $\ce{Fe^3+}$ to $\ce{Fe^2+}$ ratio is due to the top reaction being favored during decompression (due to the equilibrium shift from the changes in pressure).

I get all of that so far, I think. My question is a more fundamental one, being, if this equilibrium (#11) governing the changes in oxidation states becomes more prevalent as the pressure decreases rapidly, what are the governing equations for when the magma is deeper in the earth? Do they favor the bottom equation (#12) instead, or are the reactions at that temperature and pressure completely different?

It's possible I'm missing what the "changing oxidation states" aspect really means. A clarification of that would certainly be appreciated.

Reference:

  1. Moussallam, Y., Oppenheimer, C., Scaillet, B., Gaillard, F., Kyle, P., Peters, N., & Donovan, A. (2014). Tracking the changing oxidation state of Erebus magmas, from mantle to surface, driven by magma ascent and degassing. Earth and Planetary Science Letters, 393, 200-209. [DOI]
//www.hoelymoley.com/questions/2496/-/2944 # 2944 4 回答DavePhD为氧化态的变化背后的机制是什么(例如铁)岩浆? DavePhD //www.hoelymoley.com/users/248 2014 - 12 - 03 - t14:58:54z 2014 - 12 - 03 - t18:40:31z < blockquote > < p >我是一个更基本的问题,如果这种平衡(# 11)管理氧化态的变化变得更为普遍的压力迅速降低,当岩浆的控制方程是什么是地球更深处的?< / p > < /引用> < p >我的解释是,在火山被研究,右边方程11青睐在低压力,和左边是受欢迎的在高压力(深度)。岩浆深处,含有硫化物($ \ ce {S ^ 2 -} $)按照方程11日而不是硫酸($ \ ce {SO4 ^ 2 -} $)这将涉及方程12。所以方程11适用于所有的深度研究和方程12不适用于这个火山在任何深度。< / p >
Baidu
map