Abstract
In the northeastern area of the Kamakura city, the Miura and Kazusa Groups are subdivided into the Zushi, Ikego, Urago and Nojima Formations in ascending order. Garnet-bearing Pumice bed, named KGP in this study, and some tephra beds are important key beds for the subdivision of the upper Miura Group and the lower Kazusa Group in this area. The characteristic tephra, KGP, are confirmed at more than 10 localities in the area from Kamakura city to north of Yokosuka city. On the basis of petrographical study and chemical analyses of garnet, it is concluded that the KGP tephra is correlated with the garnet-bearing tephra bed, Mk19, in the Otsuka Formation of the upper Pliocene Nakatu Group occurring in the Aikawa town, Kanagawa prefecture.
