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首页> 外文期刊>Planetary and space science >New evidence of meteoritic origin of the Tunguska cosmic body
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New evidence of meteoritic origin of the Tunguska cosmic body

机译：通古斯（Tunguska）宇宙体陨石起源的新证据

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摘要

Diamond-lonsdaleite-graphite micro-samples collected from peat after the 1908 catastrophic blast in the Tunguska area were studied with scanning (SEM) and transmission electron (TEM) microscopy, NanoSecondary Ion Mass Spectrometry (NanoSIMS) and X-ray synchrotron technique. The high-pressure carbon allotropes in the Tunguska samples are being described for the first time and contain inclusions of FeS (troilite), Fe-Ni (taenite), γ-Fe and (FeNi)_3 P (schreibersite). The samples are nodule-like in shape and consist of 99.5% carbon minerals, e.g. diamond > lonsdaleite > graphite. Micro- and nanoinclusions of troilite (up to 0.5 vol%), taenite, γ-iron and schreibersite fill cracks, cleavages and pores in the carbon matrix. Carbon isotope studies from the two analyses of the Tunguska foil showed δ~(13)C=-16.0 ± 1.9‰ and δ~(13)C=-15.2 ± 2.1‰, suggesting δ~(13)C=-15.6 ± 2‰ as an average characteristic of the carbon reservoir. That value is close to δ~(13)C of some extraterrestrial samples. A negligible concentration of Ir and Os in the carbonaceous matrix promotes some controversial interpretation of the origin of the studied materials. Attributing this fact to the primary inhomogeneity, and considering the micro-structural features such as cracks, deformation of the crystal lattices, etc. coupled with high-pressure carbon allotropes association with metals, sulfides and phosphides, and the high ratio of Fe:Ni=22:1 suggest that the studied samples are meteorite micro-remnants.
机译：利用扫描（SEM）和透射电子（TEM）显微镜，纳秒离子质谱（NanoSIMS）和X射线同步加速器技术研究了1908年在通古斯地区发生灾难性爆炸后从泥炭中收集的钻石-隆斯达莱石-石墨微样品。首次描述了通古斯（Tunguska）样品中的高压碳同素异形体，其中包含FeS（三菱沸石），Fe-Ni（钙钛矿），γ-Fe和（FeNi）_3 P（schreibersite）的夹杂物。样品的形状呈结节状，由99.5％的碳矿物质组成。钻石>隆斯达莱特>石墨。三叶草（高达0.5％（体积）），钙钛矿，γ-铁和菱锰矿的微米级和纳米级夹杂物填充了碳基质中的裂缝，劈裂和孔隙。通过对Tunguska箔的两次分析进行的碳同位素研究显示δ〜（13）C = -16.0±1.9‰和δ〜（13）C = -15.2±2.1‰，表明δ〜（13）C = -15.6±2 ‰作为碳库的平均特征。该值接近一些外星样本的δ〜（13）C。碳质基质中Ir和Os的浓度可忽略不计，这促进了对所研究材料的起源的一些有争议的解释。将这一事实归因于主要的不均匀性，并考虑了微观结构特征，例如裂纹，晶格变形等，以及与金属，硫化物和磷化物相关的高压碳同素异形体，以及高比例的Fe：Ni = 22：1表明所研究的样品是陨石微残留物。

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