Amerasia Basin: new data and new geological model

We present an interpretation of the regional seismic lines for the Amerasia Basin, and new data from analyses of rocks from the Alpha-Mendeleev Rise. This report is based primarily on interpretation of 2D seismic lines and analysis of magnetic and gravity field anomalies, from data acquired through the Russian Arktika-2011, Arktika-2012, Arktika -2014, and Arktika-2020 projects. We use also open Canadian seismic data (Shimeld et al., 2021) and published data. We propose that the Alpha-Mendeleev Rise is a Eurasian aborted double-sided volcanic passive continental margin with stretched and hyper-extended continental crust intruded by basalts. This rise has a number of SDR-like seismic units. The age of volcanism is ~125-100 Ma. The Podvodnikov, Toll, Mendeleev, Nautilus, Stefansson basins have SDR-like seismic units. The top of SDR-like units has a similar age in all basins. The Alpha-Mendeleev Rise has an axis of symmetry. The East North Chukchi, Toll, Mendeleev, Nautilus, Stefansson basins are coeval basins with very stretched continental crust. They are connected by a long united axial line of hyperextension, subsidence and volcanism. The Makarov, Podvodnikov, West North Chukchi basins are coeval basins with very stretched continental crust. They are connected by a long united axial line of hyperextension, subsidence and volcanism. The Alpha-Mendeleev Rise and all mentioned basins originated simultaneously in the same geodynamic environment during the HALIP magmatic epoch at nearly 125-100 Ma. This study was supported by the Russian Science Foundation (Grant 22-27-00160).