Fig. 2From: Timing of clockwise rotation of Southwest Japan: constraints from new middle Miocene paleomagnetic resultsChronostratigraphy of the Mizunami Group, modified from Ujihara et al. (1999). The geomagnetic polarity time scale is after Ogg (2012). The Neogene North Pacific diatom zones (NPD; after Yanagisawa and Akiba 1998) were adjusted to the Ogg (2012) time scale by the authors, following the magneto-biostratigraphic correlation developed by Watanabe and Yanagisawa (2005). Two important biohorizons within NPD4A are indicated: single asterisk first occurrence of Actinocyclus ingens f. nodus (~15.7 Ma), double asterisks last occurrence of Denticulopsis praelauta (~15.8 Ma). Toki LB Toki Lignite-Bearing FormationBack to article page