Cretaceous volcanism and intrusive magmatism features in the Mendeleev Rise region (Arctic Ocean) according to seismic data

Abstract

The current paper is based primarily on the interpretation of 2D seismic lines for the Amerasian Basin. A synrift complex has been identified in half-grabens almost everywhere within the Alpha-Mendeleev Rise and conjugate basins according to the results of seismic data interpretation. Various magmatism features within the synrift complex have been identified on seismic profiles: plateau basalts; sills and dikes; reflections similar to SDRs (Seaward Dipping Reflectors Sequences) and volcanoes. Regional extension and synchronous widespread magmatism are probably associated with the formation of the High Artic Large Igneous Province (HALIP) in the Aptian-Albian. Considering the data on the isotope ages of igneous rocks for the Mendeleev Rise, it is assumed that the top of the synrift complex has an approximate age of 100 Ma and the bottom has an approximate age of 125 Ma. The Alpha-Mendeleev Rise was formed simultaneously with conjugate basins in the Aptian-Albian. An axial line can be drawn along the Alpha-Mendeleev Rise. To the west of the axial line, reflections similar to SDRs dip towards the Podvodnikov basin. To the east of the axial line, reflections dip towards the Toll, Mendeleev, Nautilus and Stefansson basins. The reflections converge in the central parts of the basins. The Alpha Mendeleev Rise is a double-sided volcanic passive continental margin. The Podvodnikov, Toll, Mendeleev, Nautilus, and Stefansson basins are rift basins with thinned continental crust at the base. Their development was interrupted before the start of spreading and the oceanic crust formation.