Molybdenum isotope anomalies in fine-grained refractory inclusions from Allende and Vigarano

陨石及其成分中的核同位素异常为太阳星云中物质的动力学演化和处理提供了基本的见解。在这方面特别令人感兴趣的是富钙铝包裹体(CaI)，由于它们的古老，证明了盘状演化的早期阶段。钼同位素特别适合于研究地外物质核合成同位素不均一性的来源。它们具有区分S过程中的亏损和r过程中的钼同位素过剩的独特能力。在这项研究中，我们旨在通过检查Mo(和O)同位素的不均一性来研究计算机辅助教学中核合成同位素变异的来源。为此，我们建议对碳质球粒陨石Allende(CV3ox)和Vigarano(CV3red)的核合成Mo同位素异常进行系统的对比研究。这项研究的重点将是研究细粒难熔包体中的钼同位素异常，其中一些可能是原生星云凝析油。它们与粗粒度(例如，B型)计算机辅助教学的遗传关系在很大程度上是未知的。具体地说，我们建议：(I)探索细晶和粗晶CaI中Mo同位素异常的范围和来源。(Ii)通过评估细粒和粗粒CaI是否系统地表现出不同的Mo同位素体系(即r过剩与S亏损)来考察这两组CaI的关系，以及(Iii)通过评估母体和星云过程对其同位素体系的影响来探讨细粒CaI中各种核合成同位素异常的成因。通过对氧化(Allende)和还原(Vigarano)CV球粒陨石中Mo同位素异常的对比研究，探讨母体变化的影响。星云过程的影响将通过结合块状Mo和原位氧同位素分析来评估来自Vigarano的几个CAI。这项研究将有助于更好地建立计算机辅助教学中同位素异常的系统和全面，并将有助于评估细粒和粗粒计算机辅助教学之间的任何成因联系。最终，我们的研究将为太阳系历史最早阶段太阳星云中核合成同位素不均一性的起源提供新的和坚定的约束。

Nuclear isotope anomalies in meteorites and their components provide fundamental insights into the dynamical evolution and processing of matter in the solar nebula. Of particular interest in this respect are Ca,Al-rich inclusions (CAI), which, due to their antiquity, bear testimony to the earliest stages of disk evolution. Molybdenum isotopes are particularly well suited for investigating the origin of nucleosynthetic isotope heterogeneity in extraterrestrial materials. They possess the unique ability to distinguish between a deficit in s-process, and an excess in r-process Mo isotopes. In this study we aim to investigate the origin of nucleosynthetic isotope variations in CAI through an examination of Mo (and O) isotope heterogeneity. To this purpose we propose to conduct a systematic and comparative study on nucleosynthetic Mo isotope anomalies CAI from the carbonaceous chondrites Allende (CV3ox) and Vigarano (CV3red). A major focus of this study will be the investigation of Mo isotope anomalies in fine-grained refractory inclusions, some of which might be primary nebular condensates. Their genetic relation to coarse-grained (e.g., type B) CAI is largely unkwown. Specifically, we propose to: (i) explore the extent and origin of Mo isotope anomalies in fine-grained and coarse-grained CAI. (ii) examine the relationship between fine-grained and coarse-grained CAI by assessing as to whether these two groups of CAI exhibit systematically different Mo isotope systematics (i.e, r-excess vs. s-deficit), and (iii) investigate the origin of variable nucleosynthetic isotope anomalies in fine-grained CAI by assessing the effects of parent body and nebular processes on their isotope systematics. The effect of parent body alteration will be investigated through a comparative study of Mo isotope anomalies oxidized (Allende) and reduced (Vigarano) CV chondrites. The influence of nebular processes will be assessed through combined bulk Mo and in situ O isotope analyses on several CAI from Vigarano. This study will help to better establish the systematics and full extent of isotope anomalies in CAI, and will help to assess any genetic relationship between fine-grained and coarse-grained CAI. Ultimately, our study will provide new and firm constraints on the origin of nucleosynthetic isotope heterogeneity in the solar nebula during the earliest stages of solar system history.