Abstract Biomarkers have been used extensively to correlate oil families, oil–source rock relationships and source inputs, and to help identify the palaeodepositional environment for a given geological sedimentary unit. Despite their application in characterising the Bakken Formation shales, a number of biomarkers still appear unable to provide us a consistent understanding regarding heterogeneity in source organic matter and palaeoenvironment. Here, we infer the palaeodepositional environment within the Bakken Formation shales using a biomarker suite and biomarker depth profiles. We also use the occurrence and abundance of biomarkers to define organic facies and to make inferences regarding biotic interactions drawn from modern analogues. The variations and co-occurrence of biomarkers is explained by the existence of a proposed complex algal–bacterium–bacteriovore palaeoecosystem. This approach not only helps explain the depth variation in occurrence and concentration of biomarkers and the molecular composition of associated organic matter, but also advances the use of biomarker analysis and biomarker associations to determine a complex environment-sensitive palaeoecosystem.

中文翻译：

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重建上泥盆统-下密西西比 Bakken 组内的古生态系统和古沉积环境：一种生物标志物方法

摘要 生物标志物已被广泛用于关联油族、油源岩关系和源输入，并帮助确定给定地质沉积单元的古沉积环境。尽管它们用于表征巴肯组页岩，但许多生物标志物似乎仍无法为我们提供关于源有机质和古环境异质性的一致理解。在这里，我们使用生物标志物套件和生物标志物深度剖面推断巴肯组页岩内的古沉积环境。我们还使用生物标志物的出现和丰度来定义有机相，并根据现代类似物对生物相互作用进行推断。生物标志物的变异和共存可以通过提出的复杂的藻-细菌-食菌古生态系统的存在来解释。这种方法不仅有助于解释生物标志物的出现和浓度的深度变化以及相关有机物质的分子组成，而且还促进了生物标志物分析和生物标志物关联的使用，以确定复杂的环境敏感古生态系统。