Abstract— A set of experiments was carried out in the system NaAlSi 3 O 8 –FeO–NiO–CoO–SiC–NaH 2 PO 4 at 1550°C, 4 GPa, and oxygen fugacity ( f O 2 ) 0.5–2.9 log. units below the iron–wüstite (IW) buffer to estimate how C–O–H components can affect Ni, Co, and P partition between silicate melt and a liquid metallic phase at redox conditions under which the metallic phase is segregated into melting products of the early reduced mantles of the Earth and other planetary bodies. It has been established that the Ni, Co, and P partition coefficients D (М) met/sil between silicate melts saturated with carbon and containing dissolved C–O–H volatiles (mainly in the form of OH groups, H 2 and CH 4 ) at relatively oxidized conditions ( f O 2 > IW – 1.5) correspond to D (М) met/sil values expected of metal–silicate melt equilibrium in volatile-free systems at analogous P , T , f O2 , and nbo/t parameters. Under more reduced conditions ( f O 2 ≤ IW – 2), the presence of C–O–H volatiles leads to a decrease in D (М) met/sil for Ni and P compared to that in “dry” melts. This difference increases with decreasing f O 2 and reaches ~0.5 and more than one order of magnitude for Ni and P, respectively, at f O 2 = IW – 2.9. The effect of volatiles on D (Co) met/sil is much weaker, and hence, a decrease in f O 2 leads to that D (Ni) met/sil and D (Co) met/sil converge. The Raman spectra of the experimental glasses and their SIMS analyses for hydrogen show that water content (OH + H 2 O) in the melts decreases with decreasing f O 2 , whereas the contents of CH 4 and complexes with C–H bonds significantly increases. The likely reasons for the decrease in D (М) met/sil under strongly reduced conditions may be changes in the structure of the silicate melts and the origin of complex compounds of siderophile elements with volatiles in these melts.

中文翻译：

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C-O-H 挥发物对硅酸盐熔体和液态金属铁合金之间 Ni、Co 和 P 分配的影响，在 4 GPa, 1550°C

摘要：在 NaAlSi 3 O 8 -FeO-NiO-CoO-SiC-NaH 2 PO 4 体系中进行了一系列实验，温度为 1550°C，4 GPa，氧逸度 (f O 2 ) 0.5-2.9 log。铁-方铁矿 (IW) 缓冲区下方的单位，以估计 C-O-H 组分如何影响硅酸盐熔体和液态金属相之间的 Ni、Co 和 P 在氧化还原条件下的分配，在该条件下，金属相被分离成熔融产物地球和其他行星体的早期地幔减少。已经确定，碳饱和并含有溶解的 C-O-H 挥发物（主要以 OH 基团、H 2 和 CH 4 的形式）的硅酸盐熔体之间的 Ni、Co 和 P 分配系数 D (М)met/sil ) 在相对氧化的条件下 (f O 2 > IW – 1。5) 对应于在类似 P 、T 、f O2 和 nbo/t 参数下无挥发物系统中金属-硅酸盐熔体平衡的 D (М)met/sil 预期值。在更还原的条件下 (f O 2 ≤ IW – 2)，与“干”熔体相比，C–O–H 挥发物的存在导致 Ni 和 P 的 D (М) met/sil 减少。这种差异随着 f O 2 的减小而增加，并且在 f O 2 = IW – 2.9 时，Ni 和 P 分别达到 ~0.5 和一个以上的数量级。挥发物对D(Co)met/sil的影响要弱得多，因此，f O 2 的降低导致D(Ni)met/sil和D(Co)met/sil收敛。实验玻璃的拉曼光谱及其对氢的 SIMS 分析表明，熔体中的水含量 (OH + H 2 O) 随 f O 2 的降低而降低，而CH 4 及其与C-H 键配合物的含量显着增加。在强烈还原条件下 D (М) met/sil 减少的可能原因可能是硅酸盐熔体结构的变化以及这些熔体中具有挥发物的亲铁元素复合化合物的起源。