Some of the defining characteristics of the IIG iron meteorite group are their high bulk P contents and massive, coarse schreibersite, which have been calculated to make up roughly 11-14 wt% of each specimen. In this study, we produced two datasets to investigate the formation of schreibersites in IIG irons: measurements of trace elements in the IIG iron meteorite Twannberg and experimental determinations of trace element partitioning into schreibersite. The schreibersite-bearing experiments were conducted with schreibersite in equilibrium with a P-rich melt and with bulk Ni contents ranging from 0-40 wt%. The partitioning behavior for the 20 elements measured in this study did not vary with Ni content. Comparison of the Twannberg measurements with the experimental results required a correction factor to account for the fact that the experiments were conducted in a simplified system that did not contain a solid metal phase. Previously determined solid metal/P-rich melt partition coefficients were applied to infer schreibersite/solid metal partitioning behavior from the experiments, and once this correction was applied, the two datasets showed broad similarities between the schreibersite/solid metal distribution of elements. However, there were also differences noted, in particular between the Ni and P contents of the solid metal relative to the schreibersite inferred from the experiments compared to that measured in the Twannberg sample. These differences support previous interpretations that subsolidus schreibersite evolution has strongly influenced the Ni and P content now present in the solid metal phase of IIG irons. Quantitative attempts to match the IIG solid metal composition to that of late-stage IIAB irons through subsolidus schreibersite growth were not successful, but qualitatively, this study corroborates the striking similarities between the IIAB and IIG groups, which are highly suggestive of a possible genetic link between the groups as has been previously proposed.

中文翻译：

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将微量元素实验分配成 schreibersite 并应用于 IIG 铁陨石

IIG 铁陨石群的一些定义特征是它们的高体积 P 含量和块状、粗糙的 schreibersite，据计算，它们约占每个样本的 11-14 wt%。在这项研究中，我们制作了两个数据集来研究 IIG 铁中 schreibersites 的形成：IIG 铁陨石 Twannberg 中微量元素的测量和微量元素分配到 schreibersite 中的实验测定。含 schreibersite 实验是在 schreibersite 与富 P 熔体平衡的情况下进行的，块状 Ni 含量范围为 0-40 wt%。本研究中测量的 20 种元素的分配行为不随 Ni 含量变化。将 Twannberg 测量值与实验结果进行比较需要一个校正因子，以说明实验是在不包含固体金属相的简化系统中进行的。应用先前确定的固体金属/富 P 熔体分配系数从实验中推断 schreibersite/固体金属分配行为，并且一旦应用此校正，两个数据集显示元素的 schreibersite/固体金属分布之间的广泛相似性。然而，也注意到了差异，特别是固体金属的 Ni 和 P 含量相对于从实验中推断出的 schreibersite 与在 Twannberg 样品中测量的相比。这些差异支持先前的解释，即亚固相施莱伯石的演化强烈影响了 IIG 铁杆固体金属相中现在存在的 Ni 和 P 含量。通过亚固体施莱伯石生长将 IIG 固体金属成分与晚期 IIAB 铁杆的成分相匹配的定量尝试并未成功，但定性地，这项研究证实了 IIAB 和 IIG 组之间惊人的相似性，这高度暗示可能存在遗传联系如先前提议的那样在组之间进行。