Sedimentary cover of the Lomonosov Ridge: Stratigraphy,structure, deposition history,and ages of seismic facies units

Seismic and geological information on the Lomonosov Ridge is considered with reference to drilling data obtained during the ACEX-302 expedition. A new zonation proposed for the composite section of the ridge sedimentary cover and based on marine microfossils (silicoflagellates and dinocysts) from several boreholes is correlated with biostratigraphic zones of Paleogene sections in northern West Siberia. Principal stages of the Arctic basin development in the Aptian-Cenozoic are defined in onshore and Lomonosov Ridge sections. Synchronous formation of sedimentary sequences in the ridge, an element of the Arctic basin, shelves, and epicontinental seas is established for the period under consideration.