The Ordovician-Silurian hot shales are proved to be source for hydrocarbon in Akkas Field. New set of core samples of these important strata from Khabour and Akkas formations were examined from Akkas-1 well by organic petrography. The core samples of the Ordovician were found to be enriched in the liptinitic macerals that are mostly telalginite and lamalginite with lower abundances of vitrinite-like, inertinite and non-fluorescing network-forming matrix bituminite macerals. The studied Ordovician samples showed organic matter composition with large liquid hydrocarbon generation potentiality. The telalginite grains belong to the mat-forming algae that are found mostly in clusters and colonies. The early colonies are assigned to the Ordovician cosmopolitan Gloeocapsomorpha cyanobacterium. Several morphological variations in the telalginite particles are noticed through time that verifies their evolution. This is first record of this important oil prone organic matter in this region. In addition, unique micro-laminae are identified and attributed to the record of seasonal changes or varves. These varves indicate the summer/winter cyclic changes accompanied the Late Ordovician glaciation at western part of Arabian Peninsula and its influence on sedimentation in nearby basins. This cyclic pattern is also recorded for the first time as glaciation evidence in the Akkas-1 well. The seasonal changes of the summer/winter cycle are accompanied with some distinctions in the quantity and quality of the telalginite particles. The summer micro-laminae have large abundance of both organic matter and liptinite maceral. The Silurian hot shale has abundant liptinite maceral that are mostly bituminite and lamalginite. In addition, they are rich in redox sensitive trace elements that reveal anoxic depositional conditions. Ultralaminar structures are documented for the time in the bituminite of Silurian shale, which suggest a micro-algal origin. The source rock in the Silurian shale has a large potentiality to generate liquid hydrocarbon.

在Akkas油田，奥陶纪-lur柳纪热页岩被证明是碳氢化合物的来源。通过有机岩相学从Akkas-1井中检查了来自Khabour和Akkas地层的这些重要地层的新岩心样品集。发现奥陶纪的岩心样品富集在脂滑下的辉绿岩中，这些辉石主要是硅藻土和拉金石，而象玻璃质岩，惰质岩和无荧光网状基质沥青烟灰岩的丰度则较低。所研究的奥陶纪样品显示具有大的液态烃生成潜力的有机质组成。硅藻土颗粒属于形成垫层的藻类，主要在簇和菌落中发现。早期的殖民地被分配给奥陶纪的大都会Gloeocapsomorpha蓝细菌。随着时间的推移，telalginite颗粒中出现了几种形态变化，从而验证了它们的演化。这是该地区这种重要的易生油有机物的首次记录。此外，还可以识别出独特的微薄层，并将其归因于季节变化或阀门的记录。这些脉动表明阿拉伯半岛西部奥陶纪晚期冰川形成伴随着夏季/冬季的周期性变化及其对附近盆地沉积的影响。这种循环模式也首次在Akkas-1井中记录为冰期证据。夏/冬周期的季节性变化伴随着telalginite颗粒的数量和质量的某些区别。夏季的微薄层中有机物和脂滑石的矿物含量都很高。志留纪的热页岩具有丰富的滑石矿黄质，主要是沥青质和硅藻土。此外，它们富含氧化还原敏感的痕量元素，可显示出缺氧沉积条件。在志留纪页岩的沥青中记录了超层状结构的存在，这暗示了微藻的起源。志留系页岩中的烃源岩具有产生液态烃的巨大潜力。