Год издания: 2022

Upper Cretaceous magnetostratigraphy of northernWest Siberia has been reconstructed using new paleomagnetic data from five wells in the Kharampur oilgas-condensate field (1049, 109N, 106P-Yu, 105N, and 2073N). The scientific motivation of this investigation was to construct a composite Upper Cretaceous magnetostratigraphic section of the north of Western Siberia based on integrated paleomagnetic and biostratigraphic data, which represent a part of the Upper Cretaceous magnetic polarity scale of all Western Siberia. The study area is located within the Middle Pur trench in the Pur-Taz interfluve. Natural remanent magnetization in the samples of the Pokur, Dorozhkovo, Okhteurievka, Kuznetsovo, Lower Berezovo, and Upper Berezovo Formations was analyzed by stepwise alternated field (AF) and thermal demagnetization and used to compile themagnetostratigraphic sections of the five wells. Correlations among the well sections form a basis for a composite magnetostratigraphic record of Upper Cretaceous (Cenomanian through Campanian) strata in the area. The composite section comprises two normal polarity zones NK₂(sn-st) and NK₂cp and correlates with the regional Upper Cretaceous magnetostratigraphic section of southern West Siberia, as well as with the global polarity time scale.