Partitioning experiments were done by hydrothermal synthesis of crystals containing trace elements (TEs) by internal sampling of fluid at the temperature of 450 °C and pressure of 1 kbar. The crystal phases obtained were magnetite, hematite, and Ni-spinel, which were studied using X-ray diffraction (XRD), X-ray electron probe microanalysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), atomic absorption spectrometry (AAS), and atomic force microscopy (AFM). The solutions from the sampler’s fluid probes were analysed by AAS for TEs included elements of the iron group plus aluminium. The highest co-crystallisation coefficients of TE and Fe between mineral and fluid (D_TE/Fe) in magnetite were measured for V, Al, Ni and Cr (in decreasing order of n units in value), a lower value was observed for Co (2 × 10⁻¹), and still lower values for Ti, Zn, and Mn (n × 10⁻²–10⁻³). In hematite, D_TE/Fe values were highest for Al and V (order of n units in value), while lower values characterised Ti, Cr, and Co (n × 10⁻¹–10⁻³), and the lowest values were exhibited by Cu, Mn, and Zn (n × 10⁻⁵). Copper was confirmed to be the most incompatible with all minerals studied; however, Cu had a high content on crystal surfaces. This surficial segregation contributes to the average TE concentration even when a thin layer of nonautonomous phase (NAP) is enriched in the element of interest. The accumulation of TEs on the surface of crystals increased bulk content 1–2 orders of magnitude above the content of structurally-bound elements even in coarse crystals. The inverse problem—evaluation of TE/Fe ratios in fluids involved in the formation of magnetite-containing deposits—revealed that the most abundant metals in fluids were Fe followed by Mn, Zn, and Cu, which comprised 10 to 30% of the total iron content.

中文翻译：

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热液系统中氧化铁中微量元素的分配和表面离析

通过在450°C的温度和1 kbar的压力下对流体进行内部采样，对包含痕量元素（TEs）的晶体进行水热合成来完成分区实验。所获得的晶相是磁铁矿，赤铁矿和镍-尖晶石，使用X射线衍射（XRD），X射线电子探针显微分析（EPMA），激光烧蚀电感耦合等离子体质谱（LA-ICP-MS）研究，原子吸收光谱（AAS）和原子力显微镜（AFM）。AAS分析了采样器的流体探针中的溶液，得出TEs包括铁族元素和铝元素。测量了磁铁矿中V，Al，Ni和Cr的矿物和流体之间的TE和Fe的最高共结晶系数（D _{TE / Fe}）（按n的降序排列）单位值），观察到Co的值较低（2×10 ^-1），而Ti，Zn和Mn的值较低（n ×10 ^-2 -10 ^-3）。在赤铁矿中，Al和V的D _{TE / Fe}值最高（值的n个单位），而Ti，Cr和Co的较低值（n ×10 ^-1 –10 ^-3），最低的是由Cu，Mn和Zn（n ×10 ^-5）。铜被证实与所有研究的矿物最不相容。但是，Cu在晶体表面具有高含量。即使当非自治相（NAP）的薄层富含目标元素时，这种表面偏析也有助于平均TE浓度。即使在粗晶体中，TE在晶体表面的积累也会使体积含量比结构结合元素的含量高1-2个数量级。反问题-评估含磁铁矿沉积物形成过程中流体中的TE / Fe比-揭示出流体中最丰富的金属是Fe，其次是Mn，Zn和Cu，占总量的10％至30％铁含量。