Catagenesis of organic matter and petroleum potential of Proterozoic, Palaeozoic, and Mesozoic formations of Lena-Anabarsky interfluve

Organic Matter catagenesis is one of the key criteria in evaluation of petroleum potential; therefore, it is actively studied in all the sedimentary basins of interest for oil and gas exploration and prospecting. In Lena-Anabarsky interfluve, these studies were carried out to rather small extent, and pyrolysis data and, less frequently, coal petrographic data were used to assess the level of organic matter maturity. In this paper, the authors used their own data on reflectance of Organic Matter macerals (vitrinite, pseudo-vitrinite, bitumenite, and sorbomixtinite), as well as its pyrolysis characteristics in Proterozoic and Phanerozoic formations, which allows considerably update the previous conclusions. Core form deep wells and samples from outcrops were the materials for investigation. The degree of Organic Matter maturity in Proterozoic formations ranges within МК32 to АК3 gradations (designations according to A.E. Kontorovich); in Cambrian, Ordovician, and Devonian - from early mesocatagenesis (МК11) to deep apocatagenesis (АК3), and in Carboniferous and Permian - from МК12 to АК3. In Triassic, catagenesis reached МК2 gradation, in Jurassic - МК11-МК12, and in Cretaceous - ПК3-МК11. Petroleum potential may by associated with certain Paleozoic and Mesozoic formations with a moderate degree of Organic Matter maturity