This study investigates the role of zooclasts in the bulk organic matter composition, kerogen type, and hydrocarbon generation potential of the lower Paleozoic marine Alum shale in Baltoscandia, northwestern Europe. The results show that graptolite periderm is composed of non-granular cuticles and granular filling. The graptolite cuticle is non-fluorescing and has a well-polishing measurable surface, while the graptolite granular fraction is semi-translucent and has brownish fluorescence, suggesting remaining hydrocarbon generation potential. The graptolite granular fraction shows similar optical characteristics to fluorescing diagenetic solid bitumen. Both the graptolite granular fraction and diagenetic solid bitumen have low intensity yellow to brown fluorescence and contribute to generative potential (Rock-Eval S2). The sum of semi-quantitative zooclastic cuticle (non-granular graptolite cuticle, chitinozoan cuticle, and vitrinite-like) and diagenetic solid bitumen content, obtained from maceral point-counting, correlates with the non-generative organic carbon content. Enrichment of zooclastic cuticle in the samples is displayed as enrichment of inert organic carbon, and hence bulk geochemical kerogen of type III. This refractory carbon-rich maceral enrichment results represents autochthonous ‘refractory organic carbon dilution’ and will lead to Hydrocarbon Index (HI) underestimation. Confined hydrous pyrolysis was used to compare the hydrocarbon generation process of a zooclastic cuticle-lean sample (0.2 vol%) and a zooclastic cuticle-rich (1.6 vol%) sample. Results indicate that there are four stages of hydrocarbon generation in the artificial maturation of unconventional source rock of the Alum Shale. The zooclastic cuticle-lean sample has higher hydrocarbon generation potential and more oil-prone than the zooclastic cuticle-rich sample, which is gas-prone and generates more CO₂. This difference in hydrocarbon generation is attributed to differences in the organic constituent composition.

本研究调查了动物碎屑在欧洲西北部 Baltoscandia 下古生界海相 Alum 页岩的大量有机质组成、干酪根类型和生烃潜力中的作用。结果表明笔石周皮由非颗粒状角质层和颗粒状填充物组成。笔石角质层不发荧光，并具有良好抛光的可测量表面，而笔石颗粒部分是半透明的并具有褐色荧光，表明仍有生烃潜力。笔石颗粒部分显示出与发荧光的成岩固体沥青相似的光学特性。笔石颗粒部分和成岩固体沥青都具有低强度的黄色至棕色荧光，有助于生成潜力（Rock-Eval S2）。半定量动物碎屑角质层（非颗粒笔石角质层、几丁质动物角质层和类镜质体）和成岩固体沥青含量的总和，通过微晶点计数获得，与非生成有机碳含量相关。样品中动物碎屑角质层的富集表现为惰性有机碳的富集，因此是 III 型大块地球化学干酪根。这种难熔富碳微晶富集结果代表了本土的“难熔有机碳稀释”，将导致碳氢化合物指数 (HI) 低估。密闭含水热解用于比较贫动物碎屑表皮样品 (0.2 vol%) 和富含动物碎屑角质层 (1.6 vol%) 样品的碳氢化合物生成过程。结果表明，明矾页岩非常规烃源岩人工成熟分为四个阶段生烃。与富含动物碎屑角质层的样品相比，缺乏动物碎屑角质层的样品具有更高的碳氢化合物生成潜力和更易油性，后者易产生气体并产生更多的 CO₂ . 这种烃生成的差异归因于有机成分组成的差异。