The Maikop Group and the Diatom Formation constitute the two main source rocks in the South Caspian Basin and onshore Azerbaijan where large-scale oil production began more than 150 years ago. However, the stratigraphic distribution of the source rocks and the vertical variation of source-rock parameters are still poorly understood. The aim of the present paper is therefore to investigate in high resolution the source-rock distribution in the Perekishkyul and Islamdag outcrop sections, located 25 km NW of Baku, which provide nearly complete middle Eocene and lower Oligocene to upper Miocene successions. Bulk geochemical parameters of 376 samples together with maceral, biomarker and isotope data were analysed. In addition, new Re/Os data provide independent age dating for the base of the Upper Maikop Formation (30.0 ± 1.0 Ma) and the paper shale within the Diatom Formation (7.2 ± 2.6 Ma). The presence of steradienes in high concentrations demonstrates the thermal immaturity of the studied successions, limiting the application of some biomarker ratios.

中文翻译：

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对阿塞拜疆新生代源岩的新地球化学见解：对里海南部地区石油系统的影响

Maikop 群和硅藻组构成了南里海盆地和阿塞拜疆陆上的两个主要烃源岩，150 多年前开始大规模石油生产。然而，对烃源岩地层分布和烃源岩参数垂向变化的认识仍不清楚。因此，本文的目的是高分辨率研究位于巴库西北 25 公里处的 Perekishkyul 和 Islamdag 露头剖面的烃源岩分布，这些剖面提供几乎完整的中始新世和下渐新世至上中新世序列。分析了 376 个样品的大块地球化学参数以及微晶、生物标志物和同位素数据。此外，新的 Re/Os 数据提供了上 Maikop 组底部的独立年代测定 (30.0 ± 1. 0 Ma) 和硅藻层内的纸页岩 (7.2 ± 2.6 Ma)。高浓度甾二烯的存在表明所研究序列的热不成熟，限制了某些生物标志物比率的应用。