Magnetostratigraphy of the Late Cenozoic Tokai Group in central Japan and its sedimentologic implications

Abstract

The Late Cenozoic Tokai Group consists of fluvial sediments with many volcanic ash layers. Based on paleomagnetic measurements and tephrostratigraphy of this group, we have established the Tokai Polarity Superzone, which is divided into the TS-E, TO-D, TO-C, TO-B, and TO-A Polarity Zones in ascending order. These magnetopolarity zones are correlated with Chron 5 to 1. According to the magnetostratigraphy of the Tokai Group, sedimentation rates are at a maximum in the northwestern part of the basin and a minimum in the northeast. The depocenter collectively migrated clockwise and tilted westward.