Fig. 1

The topography map of the eastern margin of Eurasia continent (data from Amante and Eakins 2009). The approximate paleo-location of the Japanese islands before the formation of the Sea of Japan in Miocene is shown in gray. The paleo-magmatic arcs (> 60 Ma) of NE and SW Japan are adjusted to be parallel when the southwest Japan is rotated 20 degrees counterclockwise. Several models have been proposed for estimating paleo-positional relationships (e.g., Otofuji et al. 1985; Jolivet et al. 1995; Yamakita and Otoh 2000). The selected basins record rifting during the early Cenozoic period of interest (Yi et al. 2003; Imaoka et al. 2011; Gu et al. 2017; Song et al. 2018; Zhu et al. 2020; Liu et al. 2022). The hatched area represents the estimated Izanagi–Pacific Slab gap based on P-wave tomographic observations and is recognized at an approximate depth of around 1000 km (Li et al. 2008; Wu et al. 2022a, b). White stars indicate the presence of a geologic record that indicates a clockwise rotation of approximately 20 degrees with respect to Eurasia continent in Late Cretaceous to Early Eocene (Otofuji et al. 1985; Uchimura et al. 1996; Fukuma et al. 2003; Lin et al. 2003; Park et al. 2005; Wang et al. 2011)