Ons [5]. Leushina et al. [2] report the results of geochemical studies and
Ons [5]. Leushina et al. [2] report the results of geochemical studies and reconstruction of paleosedimentation situations of Upper Jurassic ower Cretaceous supply rocks in the north of Western Siberia (Russia). The rocks are characterized by considerable variations in total organic carbon content and petroleum generation prospective of organic matter; the maturityGeosciences 2021, 11, 453. https://doi.org/10.3390/geoscienceshttps://www.mdpi.com/journal/geosciencesGeosciences 2021, 11,2 ofis at the beginning of the oil window. The authors integrate isotopic Polmacoxib web information with geochemical analyses to evaluate the genesis of the rocks inside the peripheral part of the Bazhenov Sea and reconstruct paleoenvironments that Sutezolid custom synthesis controlled the accumulation of organic matter in sediments, its composition, and diagenetic alterations. Based on the obtained data, the deposits in the Northern Bazhenov accumulated under marine conditions having a normally moderate and periodically increasing terrigenous influx. The variations in organic matter composition are determined by redox conditions and terrigenous input which correlate together with the eustatic sea-level adjustments throughout transgressive/regressive cycles and activation of currents. Transgression is connected with an intensive accumulation of organic matter beneath anoxic to euxinic conditions and insignificant influence of terrigenous sources, resulting inside the formation of rocks with oil-generating properties. During the regression periods, the terrigenous sedimentation enhanced in conjunction with the dissolved oxygen concentration, and deposits with low organic matter content and gas-generating properties were formed. Idrisova et al. [3] elaborate the results of the above-mentioned study by focusing on the mineralogical, chemical, and isotopic characterization of pyrites from the rocks with the Bazhenov Formation (Upper Jurassic ower Cretaceous organic-rich shales, Western Siberia, Russia). Scanning electron microscopy reveals pyrites of various morphologies: smaller and substantial framboids, smaller crystals, and significant euhedral crystals. Isotope ratio mass spectrometry and secondary ion mass spectrometry show isotopically light (34 SCDT varying from -55 to -20) small framboids and microcrystalline pyrite, and isotopically heavy (34 SCDT up to +26) substantial framboids and euhedral crystals of pyrite. The authors recommend the pyrite morphology and its sulfur isotope composition are controlled by the redox situations and sedimentation regime. The accumulation of sediments that occurred under anoxic conditions hyperlinks for the abundance of little framboids of pyrite, even though the accumulation at suboxic conditions, possibly inside the presence of oxygen, hyperlinks to the presence in the huge framboids and euhedral crystals of pyrite. Yurchenko et al. [4] address the possible application of steady carbon and oxygen isotope composition of carbonates for the study from the organic-rich source rocks genesis on the instance of the Upper Jurassic ower Cretaceous Bazhenov Formation (West Siberian Basin, Russia). The studied deposits are located within the central (essentially the most productive) and peripheral (northern and southern) regions on the Bazhenov Formation distribution region, as an instance of the distinctive sedimentation situations. The authors determine important components influencing a stable isotope composition of carbonate minerals and establish its relation towards the formation situations. Applying a thermodynamic model of carbon and oxygen isotope exchange in the carbonate ater arb.