Rare earth element uptake during olivine/water hydrothermal interaction
Rare earth element uptake during olivine/water hydrothermal interaction
复制标题
橄榄石/水热液相互作用过程中稀土元素的吸收
DOI：
10.1016/j.lithos.2019.03.003
复制
发表时间：
2019
期刊：
影响因子：
3.5
通讯作者：
Bizimis, Michael
中科院分区：
文献类型：
--
作者：
Frisby, Carl;Foustoukos, Dionysis I.;Bizimis, Michael
超镁铁质热液喷口系统通过蛇纹石化作用将水圈与橄榄岩地幔连接起来。在这里，通过一系列实验研究了海水-橄榄岩相互作用过程中选定的微量（Nd、Sm、Gd、Dy、Yb、Sr和Ba）和主要阳离子（Si、Ca、Mg、Fe、Ni）的分馏和迁移率，其中天然橄榄石颗粒与人造海水溶液在一定温度（15-90°C）和颗粒尺寸分布下反应。在这些实验中没有观察到任何显着的橄榄石溶解或碳酸盐和铁羟基氧化物相沉淀的证据。实验数据表明，在所有实验条件下，稀土元素（Nd、Sm、Gd、Dy 和 Yb）与 Sr 和 Ba 发生强烈解耦，并且 Sr 和 Ba 定量保留在溶液中。稀土元素从溶液中去除，并吸附到橄榄石表面，其动力学速率常数（即随时间的吸收）随着温度的升高和表面积的增加（即粒径的减小）而增加。镝和 Yb（重 REE；HREE）从溶液中去除的速度比 Nd 和 Sm（轻 REE；LREE）更快。钆与这种趋势脱钩，其动力学速率常数比钐慢。 Nd 和 Sm 在橄榄石上吸附 REE 的活化能 (Ea) 高于 Dy 和 Yb。这表明轻稀土元素的吸附通常比重稀土元素更依赖于温度。 Ea 与 REE 的第一、第二和第三电离能总和有很好的相关性，表明元素吸附动力学速率与 4f 轨道的电子构型之间存在联系。钆的 Ea 值高于其他分析的 REE，与 Gd3+ 的电子构型一致，其中所有 4f 轨道各填充一个电子。这些实验数据表明，在低温热液条件下，当蚀变过程有限或极其缓慢时，稀土元素通过内球复合物吸附在橄榄石表面。在相对较低的温度（<100°C）下，稀土元素的清除和分馏可能发生在橄榄岩热液系统的补给区内，导致流体中的轻稀土元素/重稀土元素逐渐升高，这可能会在海洋岩石圈深处的高温、高压水/岩石相互作用过程中，在蛇纹石化橄榄岩中产生源自海水的轻稀土元素富集。
Ultramafic-hosted hydrothermal vent systems link the hydrosphere with the peridotitic mantle via serpentinization. Here, the fractionation and mobility of selected trace (Nd, Sm, Gd, Dy, Yb, Sr and Ba) and major cations (Si, Ca, Mg, Fe, Ni) during seawater-peridotite interaction was investigated through a series of experiments where natural olivine grains were reacted with an artificial seawater solution at a range of temperatures (15–90 °C) and grain size distributions. No evidence for any significant olivine dissolution or precipitation of carbonate and, Fe-oxy-hydroxide phases was observed in these experiments. Experimental data show a strong decoupling of REE (Nd, Sm, Gd, Dy, and Yb) from Sr and Ba under all experimental conditions, with Sr and Ba remaining quantitatively in solution. The REE were removed from the solution and were adsorbed onto olivine surface with kinetic rate constants (i.e. uptake over time) that increase with increasing temperature and increasing surface area (i.e. decreasing particle size). Dysprosium and Yb (heavy REE; HREE) were removed from solution with a faster rate than Nd and Sm (light REE; LREE). Gadolinium is decoupled from this trend, with a slower kinetic rate constant than Sm. The activation energies (Ea) of REE adsorption on olivine were higher for Nd and Sm than Dy and Yb. This suggests that the adsorbance of LREE is generally more dependent on temperature than the HREE. The Eacorrelates well with the summed 1st, 2nd and 3rd ionization energies of REE suggesting a link between kinetic rates of element adsorption and electron configuration of the 4f-orbitals. Gadolinium has higher Eathan the other analyzed REE, consistent with the electron configuration of Gd3+where all 4f-orbitals are filled with one electron each. These experimental data suggest that REE are adsorbed on the surface of olivine via inner sphere complexes under low-temperature hydrothermal conditions, when alteration processes are limited or extremely slow. Scavenging and fractionation of REE may occur within the recharge zone of peridotite-hosted hydrothermal systems at relatively low temperatures (<100 °C), leading to fluids with progressively higher LREE/HREE which could impose seawater-derived LREE enrichments in serpentinized peridotites during high temperature, high pressure water/rock interaction deeper in the oceanic lithosphere.
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影响因子：
4.4
作者：
JOHNSON, JW;OELKERS, EH;HELGESON, HC
通讯作者：
HELGESON, HC
影响因子：
3.9
作者：
S. Rouméjon;G. Früh-Green;B. Orcutt
通讯作者：
S. Rouméjon;G. Früh-Green;B. Orcutt
影响因子：
3
作者：
J. Schijf;E. Christenson;R. Byrne
通讯作者：
J. Schijf;E. Christenson;R. Byrne
镁橄榄石在 65°C 和 2 下的溶解
DOI：
--
发表时间：
2000
期刊：
影响因子：
--
作者：
Yang Chen;S. Brantley
通讯作者：
S. Brantley
Yb(III) 和 Cs(I) 在二氧化硅上吸附的表面络合模型。
影响因子：
9.9
作者：
Marmier;Delisée;Fromage
通讯作者：
Fromage