Practical Application of Chemostratigraphy and Lithochemistry Methods in The Study of Oil Bearing Black Shale

Summary Most of the well-known oil-bearing black shales are united by the fact that they contain abnormally high contents of a number of chemical elements (U, S, Fe, Mg, P, Cu, Zn, Mo, V, Ni, Ba, As, etc.). The study of variations in the content and ratios of these elements makes it possible to obtain an increase in geological data on the genesis and properties of rocks. The paper shows how the application of the methods of lithochemistry and chemostratigraphy makes it possible to detail the sectional layering and identify promising hydrocarbon intervals in them. On the examples of the siliceous Bazhenov Formation of Western Siberia, the carbonate Domanic Formations of the Russian Plate and the Kuma Formation of the Ciscaucasia, and clayey Khadum Formation of the Ciscaucasia, the most informative modular chemical parameters are shown for the analysis of carbonate content ((Ca+Mg)/Al, Sr/Ca, Mg/Ca) and clay content (Mg/Ca, (Al+K)/(Ca+Mg+Si), Zr/Al) of the section, terrigenous material input (Zr/Al, Si/Al, Ba/Al, S/(Rb+Zr)), bioproductivity (P/Al, Mo/Al, S/(Rb+Zr), Si/Al) and fluctuations of anoxic events (Mo/Mn, Mn/Al) in the paleobasin.