Abstract — The effect of variations in the fo , fa , en , fs , di , an and ab components in high-Mg basaltic melts on the topology of the spinel liquidus was quantified by conducting simulations with the new SPINMELT-2.0 model for the spinel–melt equilibrium. It has been established that enrichment of the melt in pyroxene components leads to an increase, and conversely, enrichment in plagioclase and olivine components, to a decrease in the solubility of chromite. This effect can be important at the gravitational compaction of cumulates accompanied by the extraction of intercumulus melt and its infiltration upward. In this case, it is reasonable to expect sequential reequilibration of the infiltrating melt with cumulate piles of different composition. This suggests that Cr-spinel can be transferred and concentrated again during the postcumulus solidification stage of layered intrusions. The concentrating process involves Cr-spinel extraction into the melt enriched in pyroxene components and the subsequent redeposition of the mineral during when this melt reacts with the feldspar-rich matrix of proto-anorthosite layers or horizons enriched in olivine. Some of these layers and horizons may be produced by additional injections of more primitive magma. The realism of the proposed mechanism is evident from the well-known spatial relations between the chromite layers with anorthosites and dunite–harzburgites of the Bushveld complex.

中文翻译：

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SPINMELT-2.0：在高达 15 Kbar 的压力下玄武岩系统中尖晶石-熔体平衡的模拟：III。熔体中主要成分对铬尖晶石稳定性的影响及铬铁矿成因问题的可能解决方案

摘要 — 通过使用新的 SPINMELT-2.0 尖晶石模型进行模拟，量化了高镁玄武岩熔体中 fo 、 fa 、 en 、 fs 、 di 、 an 和 ab 组分的变化对尖晶石液相线拓扑结构的影响——熔体平衡。已经确定熔体中辉石组分的富集导致铬铁矿溶解度的增加，反之，斜长石和橄榄石组分的富集导致铬铁矿溶解度的降低。这种效应在伴随着积云间熔体的提取及其向上渗透的堆积物的重力压实中可能很重要。在这种情况下，可以合理地预期渗透熔体的连续再平衡与不同成分的堆积堆。这表明在层状侵入体的后积云凝固阶段，Cr-尖晶石可以再次转移和浓缩。浓缩过程包括将铬尖晶石提取到富含辉石成分的熔体中，随后当该熔体与富含长石的原斜长岩层或富含橄榄石的层位的基质发生反应时矿物的再沉积。这些层和层中的一些可能是由更原始的岩浆的额外注入产生的。从已知的铬铁矿层与斜长岩和 Bushveld 复合体的纯晶-方辉石之间的空间关系可以明显看出所提出机制的真实性。浓缩过程包括将铬尖晶石提取到富含辉石成分的熔体中，随后当该熔体与富含长石的原斜长岩层或富含橄榄石的层位的基质发生反应时矿物的再沉积。这些层和层中的一些可能是由更原始的岩浆的额外注入产生的。从已知的铬铁矿层与斜长岩和 Bushveld 复合体的纯晶-方辉石之间的空间关系可以明显看出所提出机制的真实性。浓缩过程包括将铬尖晶石提取到富含辉石成分的熔体中，随后当该熔体与富含长石的原斜长岩层或富含橄榄石的层位的基质发生反应时矿物的再沉积。这些层和层中的一些可能是由更原始的岩浆的额外注入产生的。从已知的铬铁矿层与斜长岩和 Bushveld 复合体的纯石英-方辉石之间的空间关系可以明显看出所提出机制的真实性。