The discovery of Miogypsina from the Miocene Series of Kanayama Hill, Ota City, Gunma Prefecture, central Japan and its fission track age

Abstract

In the Miocene sediments distributed along the Watarase River, in the northern Kanto Plain, Miogypsina gr. kotoi was discovered from the Miocene marine section of the Yabuzuka Formation at Kanayama Hill, Ota City, Gunma Prefecture, central Japan. Fission track age of 14.9 ± 0.5Ma (1 σ error) was determined for pumice tuff bed interbedded in the marine sequence which represents the age of Miogypsina gr. kotoi.