Fig. 12

Comparisons between paleomagnetic records. a VGP latitude from the Chiba composite section. The black line and cross marker are the VGP profile, and the duration and mid-point of the polarity switch from the Chiba, Yoro-Tabuchi, and Yoro River sections (Okada et al. 2017; Simon et al. 2019; this study). The red line and cross marker indicate the VGP profile and duration and mid-point of the polarity switch from the Yoro-Tabuchi section, respectively (this study). The light blue line and cross marker indicate the VGP profile and duration and mid-point of the polarity switch from the Chiba and Yanagawa sections, respectively (Suganuma et al. 2015). b VGP latitude based on marine sediment cores in the North Atlantic (green: ODP 983, orange: ODP 984 in Channell and Guydo 2004) and lavas and volcanic ash beds (Singer et al. 2019). Horizontal bars indicate chronological errors (2σ) of ⁴⁰Ar/³⁹Ar dating. c Proxies of field intensity. Black and red lines indicate profiles of the NRM_30-50/ARM_30-50 as the relative paleointensity index from the Chiba, Yoro-Tabuchi, and Yoro River sections (Okada et al. 2017; Simon et al. 2019; this study) and the Yoro-Tabuchi section (this study), respectively. The profiles of virtual axial dipole moment (VADM) from the global relative paleointensity stack records are indicated by orange (Channell et al. 2009) and green dashed lines (Valet et al. 2005)