The South Oman Salt Basin (SOSB) has been studied extensively for knowledge concerning the habitat of the enigmatic Ediacaran–Cambrian oils that are produced from that region. Geological, geochemical, geophysical, and geochronological investigations have all contributed to improved understanding of the range of late Neoproterozoic depositional environments recorded there. Of particular interest has been the deep Athel depocenter within the SOSB that features a silica‐rich interval known as the Al Shomou Member or Athel Silicilyte and the co‐eval A4 carbonate–evaporite sequence that straddles the Ediacaran–Cambrian boundary. The deep basin has been suggested to be anoxic and euxinic based on studies of sulfur isotopes, trace metal distributions and other proxies. Organic geochemistry has provided some clues concerning aspects of the depositional environments and microbial communities prevailing during this interval. However, ambiguities remain including a paucity of convincing molecular evidence for euxinia in the photic zone of the basin. Here, we present a comprehensive study of biomarker hydrocarbons, including steroids, triterpenoids, and carotenoids. Among the compounds detected is a distinctive array of aromatic carotenoids. Relatively low abundances of monoaromatic carotenoids, such as chlorobactane, okenane, and β‐isorenieratane, suggest the possibility of transient photic zone euxinia with a shallow chemocline or, perhaps, exogenous inputs from microbial mats. However, it is the dominance of renieratane and renierapurpurane over isorenieratane in diaromatic carotenoids and their association with abundant C₃₈ and C₃₉ carotenoids that identifies cyanobacteria as major contributors to the inventory of carotenoids. Our results, based on multiple lines of molecular evidence and statistical analysis, also suggest that the Athel Silicilyte was biogeochemically distinct from the other units of the Ara Group. Overall, our study has important implications for understanding other late Neoproterozoic depositional environments.

中文翻译：

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Ediacaran-Cambrian边界南阿曼盐盆地Athel槽中的生物标志物地层。

对南阿曼盐盆地（SOSB）进行了广泛的研究，以获取有关从该地区生产的神秘埃迪卡拉安-寒武纪石油的栖息地的知识。地质，地球化学，地球物理和地质年代学研究都有助于增进对那里记录的新元古代晚期沉积环境范围的了解。特别令人感兴趣的是SOSB内的深Athel沉积中心，其特征是富含二氧化硅的层段，即Al Shomou成员或Athel Silicilyte，以及横跨Ediacaran-Cambrian边界的同等A4碳酸盐-蒸发岩序列。根据对硫同位素，痕量金属分布和其他替代物的研究，该深盆被认为是缺氧和富余的。有机地球化学提供了有关此间隔期间普遍存在的沉积环境和微生物群落方面的一些线索。但是，仍然存在含糊不清的含糊之处，包括缺乏令人信服的分子证据，证明该盆地的光合带中存在富余症。在这里，我们对生物标记碳氢化合物（包括类固醇，三萜和类胡萝卜素）进行了全面研究。在检测到的化合物中，有一系列独特的芳香类胡萝卜素。单芳族类胡萝卜素相对较低的含量，例如氯丁烷，酮和β-异戊二烯，提示短暂的光化区富营养度可能是趋化性较弱，或者可能是微生物垫产生的外源性输入。然而，₃₈和C ₃₉类胡萝卜素将蓝细菌确定为类胡萝卜素库存的主要来源。我们的结果基于多条分子证据和统计分析，还表明Athel Silicilyte在生物地球化学上与Ara集团的其他部门不同。总体而言，我们的研究对理解其他晚新元古代沉积环境具有重要意义。