Peculiarities of sedimentation of organic matter in rocks of the Bazhenovskaya Suite (Western Siberia): Evidence from distribution of hydrocarbons-biomarkers

Abstract

471 In recent years there has arisen a strong interest in organic geochemistry for study of high carbonaceous rocks mostly represented by black schist with a high concentration of organic carbon variable over the sec tion. An example is provided by studies [1–3]. The first of them contains the results of investigation of a 12 m section of schist from the Toarskaya Series in the Parizh Basin; the second one is a review of investiga tions of 2 m sections of Kimmeridgian clay formation in the United Kingdom and modern sediments of France. Based on investigation of the core samples of Upper Jurassic deposits (Volgian Stage), it was dem onstrated in [3] that the section of the Bazhenovskaya Suite in the Northern Nivagal’skaya area (Middle Priob’e, Western Siberia) was composed by interbed ding carbonaceous–clay–siliceous rocks (bazheno vites) with an anomalously high concentration of organic matter (OM, 12–30% Corg) and argillites with the Corg content from 1 to 8% (Fig. 1). The detailed sampling of the section allowed us to reveal some sig nificantly new important aspects in understanding the conditions of the formation of these series, which are the main type among oil bearing formations in the Western Siberian Basin.