Abstract In 1982 and 1986, Lyons and co-authors defined secretinite as one of the two types of sclerotinite (the other being funginite) and established its origin based on its occurrence inside the secretory ducts of medullosan seed ferns. However, in 2001, the International Committee for Coal and Organic Petrology implicitly classified many materials whose derivation is not clear (e.g. inertinite discrete structureless bodies (IDSBs)) as secretinite. By using a combination of coal petrography and micro-Raman spectroscopy (MRS), fusinite, secretinite, IDSBs, and ‘ovoid' bodies infilling fusinite were compared in a set of coals within the same rank. Coal petrography allows to identify and quantify macerals of the basis of their shape, internal structure, reflectance, relief, and size. The reflectance of these materials can be determined and then calculate the reflectance indicating surfaces (RIS) main axes (i.e. RMAX, RINT, and RMIN) and parameters (i.e. Ram and Rev); moreover, the Raman spectra and parameters (i.e. the full width at half maximum intensity of the G band (FWHMG) and the integrated intensity ratio of the S band to G band (IS/IG)) reflect changes in their structures. Many of the results obtained from the analysis of secretinite did not correspond to those of fusinite and IDSBs. These data suggest different origins/derivations for these materials and justify further discussions about the classification of secretinite and macrinite. The results obtained for the ‘ovoid' bodies indicate that their reflectance and Raman parameters can vary within a broad range. We infer that such bodies could represent sclereids; however, when they occur disassociated from fusinite, they should represent IDSBs.

中文翻译：

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惰性离散无结构体、梭晶、分泌体和填充梭晶的“卵形”体的岩相学和显微拉曼光谱研究

摘要 在 1982 年和 1986 年，Lyons 和合著者将分泌素定义为两种类型的菌核素之一（另一种是真菌素），并根据其出现在髓质种子蕨的分泌管内确定其起源。然而，在 2001 年，国际煤炭和有机岩石学委员会隐含地将许多来源不明的材料（例如惰性离散无结构体 (IDSB)）归类为分泌物。通过使用煤岩相学和显微拉曼光谱 (MRS) 的组合，在一组相同等级的煤中比较了 fusinite、secretinite、IDSB 和填充有 fusinite 的“卵形”体。煤岩相学允许根据其形状、内部结构、反射率、浮雕和大小来识别和量化煤质。可以确定这些材料的反射率，然后计算反射率指示面（RIS）主轴（即RMAX、RINT和RMIN）和参数（即Ram和Rev）；此外，拉曼光谱和参数（即 G 波段的半峰全宽 (FWHMG) 和 S 波段与 G 波段的积分强度比 (IS/IG)）反映了其结构的变化。从分泌素分析中获得的许多结果与 fusinite 和 IDSBs 的结果不一致。这些数据表明这些材料有不同的来源/派生，并证明对分泌素和长晶石分类的进一步讨论是合理的。获得的“卵形”物体的结果表明它们的反射率和拉曼参数可以在很宽的范围内变化。我们推断这样的身体可以代表巩膜；