IIE irons were derived from chondritic precursors that were the most reduced ordinary chondrites. The bulk chemical (e.g., Ir/Ni, Ir/Au, Au/Ni, Co/Ni) and bulk isotopic (i.e., Δ¹⁷O and δ^74/70Ge) compositions of IIE irons lie along extensions of LL-L-H trends. Chondrule-bearing silicate clasts in IIE irons have mineralogical and petrological characteristics that extend LL-L-H trends; these clasts have higher modal metallic Fe-Ni and lower values for olivine Fa, low-Ca-pyroxene Fs, kamacite Co, and mean chondrule diameter. IIE irons are modeled as agglomerating before H-L-LL chondrites; they acquired more ²⁶Al and reached the Fe,Ni-FeS eutectic temperature (~940 °C). An FeS-rich metallic melt separated from unmelted silicate and drained to the core, eventually generating a dynamo. Most IIE metal remained within the crust/mantle region alongside recrystallized chondritic clasts. Alkali-rich IIE silicate inclusions formed from late-stage impacts via preferential melting of plagioclase. Some separation of K from Na occurred during vapor transport. Because most type I chondrules formed before most type II chondrules, the (type I)/(type II) modal ratio decreased from IIE to H to L to LL during agglomeration. Earlier-formed chondrules acquired higher abundances of refractory metal nuggets within CAI-fragment precursors, accounting for systematic changes in bulk OC of refractory/common siderophile and refractory/volatile siderophile ratios (IIE>H>L>LL). Because more Au and Co than Ni were retained in silicates, loss of metal globules from spinning partly molten type I chondrules caused systematic whole-rock decreases in Au/Ni and Co/Ni from IIE through LL. Expelled globules had different nebular aerodynamic properties than chondrules and drifted away (accounting, in part, for the metal/silicate fractionation).

中文翻译：

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IIE 铁杆：起源、与普通球粒陨石的关系以及由球粒形成引起的亲铁元素分馏的证据

IIE 铁杆来源于球粒陨石前体，它们是最还原的普通球粒陨石。IIE 铁的大块化学成分（例如，Ir/Ni、Ir/Au、Au/Ni、Co/Ni）和大块同位素（即 Δ ¹⁷ O 和 δ ^74/70 Ge）组成沿着 LL-LH 趋势的延伸. IIE 铁杆中含有球粒的硅酸盐碎屑具有扩展 LL-LH 趋势的矿物学和岩石学特征；这些碎屑具有较高的模态金属 Fe-Ni 和较低的橄榄石 Fa、低钙辉石 Fs、铁纹石 Co 和平均球粒直径值。IIE 铁杆在 HL-LL 球粒陨石之前被建模为凝聚；他们获得了更多²⁶Al 并达到 Fe,Ni-FeS 共晶温度 (~940 °C)。富含 FeS 的金属熔体与未熔化的硅酸盐分离并排入核心，最终产生发电机。大多数 IIE 金属与重结晶的球粒质碎屑一起留在地壳/地幔区域内。晚期撞击通过斜长石的优先熔融形成的富碱 IIE 硅酸盐包裹体。在蒸气传输过程中发生了一些 K 与 Na 的分离。由于大多数 I 型球粒在大多数 II 型球粒之前形成，因此（I 型）/（II 型）模态比在团聚过程中从 IIE 到 H 到 L 到 LL 降低。较早形成的球粒在 CAI 碎片前体中获得了更高丰度的难熔金属块，解释了难熔/普通亲铁物的本体 OC 和难熔/挥发性亲铁物比率的系统变化（IIE>H>L> 二）。由于在硅酸盐中保留的金和钴多于镍，旋转部分熔融的 I 型球粒造成的金属球损失导致从 IIE 到 LL 的整个岩石中 Au/Ni 和 Co/Ni 的系统性下降。排出的小球具有与球粒不同的星云空气动力学特性并飘走（部分原因是金属/硅酸盐的分馏）。