AI 中文总结
本研究通过新的时变凝聚模型验证球粒陨石前体经动力学非平衡凝聚形成的假说，发现冷却速率和压力变化仅产生三类矿物，其氧化还原状态与三类球粒陨石接近，为球粒陨石矿物多样性提供了新解释。
AI 中文摘要
原始陨石（球粒陨石）由太阳系星云形成过程中产生的非平衡矿物组合构成。由于原行星盘或小行星母体中的后续再处理，其前体凝聚的条件仍不明确。球粒陨石分为三个主要类别：顽火辉石球粒陨石（EC）、普通球粒陨石（OC）和碳质球粒陨石（CC），它们以整体成分和氧化状态的差异为区分。平衡凝聚模型虽能解释其部分难熔组分的成分，但无法解释三类矿物学类别的出现。此外，形成中原行星盘内的低压、陡温度梯度及短动力学传输时标可能阻碍了平衡过程。在此，我们验证球粒陨石前体通过动力学非平衡凝聚形成的假说。利用新的时变凝聚模型，我们表明冷却速率和压力的变化仅产生三类矿物学类型；偏离平衡会产生更氧化和含水的矿物学类型。当投影到Urey-Craig图时，预测的矿物学类型接近EC、OC和CC球粒陨石的氧化还原状态。这些结果表明，球粒陨石的矿物学多样性可能部分反映了局地凝聚动力学，为氧化条件的大规模变化提供了替代解释。
英文摘要
Primitive meteorites (chondrites) consist of an out-of-equilibrium assemblage of minerals formed during the assembling of our Solar Nebula. The conditions under which their precursors condensed remain unclear as a result of subsequent re-processing in the protoplanetary disk or in asteroidal parent bodies. Chondrites are classified into three main classes enstatite (EC), ordinary (OC), and carbonaceous (CC) distinguished by different bulk composition and oxidation state. While equilibrium condensation models explain the composition of some of their refractory components they do not explain the emergence of three mineralogical classes. Moreover, the low pressures, steep temperature gradients, and short dynamical transport timescales in forming protoplanetary disks likely hindered equilibrium. Here we test the hypothesis that chondrite precursors formed via kinetic non-equilibrium condensation. Using a new time-dependent condensation model, we show that varying the cooling rate and pressure produce only three types of mineralogies. Departure from equilibrium yields increasingly oxidized and hydrous mineralogies. When projected into a Urey-Craig diagram, the predicted mineralogical types fall close to the redox states of EC, OC, and CC chondrites. These results suggest that the mineralogical diversity of chondrites may reflect, in part, local condensation kinetics, offering an alternative to large-scale variations of oxidation conditions.
CommentsAccepted for publication in NATURE
Journal refNature 652 (2026)
DOI：10.1038/s41586-026-10257-5
