Conventional and synchrotron radiation‐based (SR) Fourier transform infrared microspectroscopies (micro‐FTIR) were applied to four types of ~ 810 Ma organic‐walled microfossils together with diffuse organic matter (OM) and one irregularly shaped structure from the Fifteenmile Group, in Yukon, Canada, for their chemical characterization. The microfossils comprised one filamentous type and three coccoidal types. Micro‐FTIR mapping analysis revealed the micrometer‐scale, spatial distribution of organic components (aliphatic C‐H bonds) and carbonate in the microfossils. Based on comparisons of CH₃/CH₂ peak height ratios (R_3/2) and morphologies of the microfossils (without the diffuse OM) to those of previously described Proterozoic microfossils, possible affinities of the microfossils are suggested, as follows. Palaeolyngbya? and Glenobotrydion belong to bacteria. Myxococcoides is not clearly characterized due to the significant mixing with diffuse OM containing abundant aliphatic C‐H groups. The irregularly shaped structure may represent a eukaryote. The diffuse OM may represent a mixture of decomposed microbial cells and extracellular polymeric substances (EPS). SR micro‐FTIR measurements of two coccoid types (Glenobotrydion and Unnamed Coccoid Form D) revealed that the R_3/2 values of the internal spots with wall structures are similar to those without wall structures in Glenobotrydion: those values from Unnamed Coccoid Form D were different. The results suggest that these two coccoids are different chemically as well as morphologically. Micro‐FTIR characterization of the organic‐walled microfossils together with morphological analysis provides new insight into their biological affinities.

中文翻译：

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来自加拿大育空地区Fifteenmile集团的新元古代有机微化石的傅里叶变换红外光谱表征

传统的和基于同步辐射的（SR）傅里叶变换红外显微技术（micro-FTIR）被应用于四种类型的810 Ma有机壁微化石以及弥散有机质（OM）和来自Fifteenmile集团的一种不规则形状的结构。加拿大育空地区的化学特征。微化石包括一种丝状和三种球形。Micro-FTIR映射分析揭示了微化石中有机成分（脂族CH键）和碳酸盐的微米级空间分布。基于CH ₃ / CH ₂峰高比（R _3/2）和微化石的形态（无扩散OM）与先前描述的元古代微化石的形态有关，提出了微化石可能的亲和力，如下。Palaeolyngbya？和Glenobotrydion属于细菌。由于与含有丰富脂肪族C-H基团的分散OM大量混合，因此无法清楚地鉴定粘球菌。不规则形状的结构可以代表真核生物。弥散性OM可代表分解的微生物细胞和细胞外聚合物（EPS）的混合物。两种球蛋白类型（Glenobotrydion和未命名的球蛋白D型）的SR micro-FTIR测量表明，R _3/2具有壁结构的内部斑点的值与Glenobotrydion中没有壁结构的内部点的值相似：来自未命名球状D型的值不同。结果表明，这两种类球体在化学和形态上都不同。有机壁微化石的Micro-FTIR表征以及形态分析为他们的生物亲和力提供了新的见识。