Radiolarian fossils from the Tateishi Formation of the Kumage Group in the South Shimanto Belt, Tanegashima Island

Abstract

We carried out geological and radiolarian studies in the Tateishi Formation of the Kumage Group in the South Shimanto Belt, distributed in and around the Hamatsuwaki district of the Tanegashima Island. The Tateishi Formation in the study area consists mainly of black mudstone and sandstone rich alternating beds of sandstone and mudstone with minor amount of varicolored mudstone. As a result of the radiolarian study, Late Eocene to Early Oligocene and Late Eocene radiolarian fossils were obtained from a sample of black mudstone and two samples of varicolored mudstones, respectively. Therefore, it is concluded that the depositional age of the Tateishi Formation is Late Eocene to Early Oligocene.