Abstract High-precision Nd isotope measurements of a diverse set of solar system materials including bulk chondrites and achondrites reveal that their Nd isotope composition is governed by several distinct nucleosynthetic components. The full spectrum of non-radiogenic, mass-independent Nd isotope compositions of solar system materials is best explained by heterogeneous distribution of at least three nucleosynthetic components - the classical s-process component, pure p-process component and an anomalous, previously unidentified s-/r-process component. The 142 Nd/ 144 Nd variations in solar system reservoirs specifically fall into three distinct trends - those that result from variations in the s-process component, those resulting from variations in the pure p-process component, and those resulting from coupled s-process and p-process variations. The μ 148 Nd value, a proxy for s-process variations, as well as μ 142 Nd that has been corrected for s-process heterogeneity to reflect p-process variations, broadly show an inverse correlation with e 54 Cr. The linearity in μ 148 Nd - e 54 Cr space for inner solar system bodies, CI chondrite and Allende-type CAIs possibly suggests the thermally labile nature of some s-process carrier grains unlike the mainstream refractory s-process SiC grains. The p-process carrier for Nd is inferred to be a refractory phase enriched in inner solar system materials through thermal processing. The bulk meteorite regression lines that specifically correspond to s- and p-process heterogeneity, largely define μ 142 Nd intercepts indistinguishable from terrestrial composition within analytical uncertainty, ruling out resolvable radiogenic μ 142 Nd excess on Earth that cannot otherwise be accounted for by nucleosynthetic heterogeneity.

中文翻译：

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太阳系 Nd 同位素异质性：对核合成成分和原行星盘演化的洞察

摘要 对包括块状球粒陨石和无球粒陨石在内的多种太阳系材料的高精度 Nd 同位素测量表明，它们的 Nd 同位素组成受几种不同的核合成成分控制。太阳系材料的全谱非辐射、与质量无关的 Nd 同位素组成最好通过至少三种核合成组分的异质分布来解释——经典的 s 过程组分、纯 p 过程组分和异常的、以前未识别的 s -/r-process 组件。太阳系储层中的 142 Nd/ 144 Nd 变化具体分为三个不同的趋势 - 那些由 s​​ 过程分量的变化引起的，那些由纯 p 过程分量的变化引起的，以及那些由耦合的 s 过程引起的和 p 过程变化。μ 148 Nd 值是 s 过程变化的代表，以及已针对 s 过程异质性进行校正以反映 p 过程变化的 μ 142 Nd 广泛地显示出与 e 54 Cr 的负相关。太阳系内部体、CI 球粒陨石和阿连德型 CAI 的 μ 148 Nd - e 54 Cr 空间中的线性可能表明某些 s 工艺载体晶粒的热不稳定性质，这与主流难熔 s 工艺 SiC 晶粒不同。据推测，Nd 的 p 工艺载体是一种通过热处理富含太阳系内部材料的耐火相。特别对应于 s 和 p 过程异质性的大量陨石回归线，在很大程度上定义了 μ 142 Nd 截距，在分析不确定性内与地球成分无法区分，