Paleomagnetism of boundary oligocene-miocene deposits in the Kompasskii Bor tract on the Tym River (Western Siberia)

We present the results of a complex (paleomagnetic, geological-stratigraphic, and paleontological) study of reference sections of Oligocene-Miocene deposits in the Kompasskii Bor tract on the Tym River in the eastern part of the western Siberian plate. Three sections of the Kompasskii Bor tract are studied: Belyi Yar (200-m mark), Belyi Yar (300-m mark), and Dunaevskii Yar (200-m mark). A composite magnetostratigraphic section of deposits, including the Oligocene-Miocene boundary dated at 23.8 Ma, is compiled with allowance for the complex data. Two magnetozones (of normal and reversed polarities) are identified in this section. The scale of magnetic polarity of the Cenozoic of the western Siberian plate at the Oligocene-Miocene boundary is determined in greater detail. The time interval of the upper part of the Zhuravka series (Chattian) and the Lyamin layers of the Abrosimov series (Aquitanian) is 24.6-22.9 Ma.