Eocene Radiolarian fossils from the Sarugawa Formation, the Hidaka foreland fold-and-thrust belt, Hokkaido, Japan

Abstract

Early to Middle Eocene radiolarian fossils were newly found from a red shale bed of the uppermost part of the Sarugawa Formation in the Hidaka foreland fold-and-thrust belt, Hokkaido. Considering previous and our results, the age of the Sarugawa Formation was confirmed to range from Turonian-Coniacian to Early-Middle Eocene. This provides fundamental data for the reconstruction of structural settings just before the initiation of growth of the Hidaka foreland fold-and-thrust belt.