We used ⁵⁷Fe Mössbauer spectroscopic measurements on untreated and controlled thermally treated Ararki, Didwana, and Bhawad ordinary chondritic meteorites to understand the evolution of different iron phases with temperature. The samples were subjected to different heating temperatures and room temperature Mössbauer spectra were collected after cooling down these samples. The untreated meteorite samples showed the presence of olivine, pyroxene, troilite, and Fe–Ni alloy (kamacite/taenite) minerals. The decomposition of such iron based minerals started at or above 600°C towards hematite iron phase for all these meteorites. More interestingly, at about 1000°C or above, all initial mineral phases got converted into either hematite and/or magnetite. The present study provides a clue to understand the mechanism of conversion of minerals in ordinary chondrites.

我们使用了⁵⁷Fe Mössbauer 光谱测量未经处理和受控热处理的 Aarki、Didwana 和 Bhawad 普通球粒陨石，以了解不同铁相随温度的演变。样品经受不同的加热温度，冷却这些样品后收集室温穆斯堡尔光谱。未经处理的陨石样品显示存在橄榄石、辉石、陨硫铁和 Fe-Ni 合金（铁镁石/燧石）矿物。对于所有这些陨石，此类铁基矿物在 600°C 或以上开始分解为赤铁矿铁相。更有趣的是，在大约 1000°C 或更高温度下，所有初始矿物相都转化为赤铁矿和/或磁铁矿。本研究为了解普通球粒陨石中矿物的转化机制提供了线索。