Distribution of organic matter in Callovian–Lower Berriasian deposits of the western part of the Yenisei–Khatanga regional trough and adjacent areas of the West Siberian geosyneclise

Abstract

This study presents the results of geochemical analysis of organic matter and paleogeographic reconstructions supplemented by data from well log interpretation and cyclostratigraphic analysis for the Vasyugan, Georgiev, and Bazhenov Horizons of the Callovian–Lower Berriasian section in the western part of Yenisei–Khatanga regional trough and adjacent areas of the West Siberian geosyneclise. It was found that each horizon contains zones dominated by terrigenous, mixed, and aquatic organic matter. The distribution of different types of organic matter over the area and throughout the section has been examined. It was shown that the accumulation of aquatic organic matter took place in the deepest parts of the trough during the Callovian–Oxfordian. The area of accumulation of aquatic organic matter expanded considerably and reached its maximum extent within the Bolshaya Kheta megasyneclise during the Kimmeridgian and Early Volgian and in the west Yenisei–Khatanga regional trough during the Volgian and Early Berriasian.