Devonian tabulate corals from limestone float in the Kotakigawa River, Omi area, Niigata Prefecture, central Japan

Abstract

Devonian tabulate corals, Mesofavosites cf. igoi (Kamei, 1955), Pachyhelioplasma sp., Auloporoidea fam., gen. and sp. indet., are newly found from limestone float in the lower reaches of the Kotakigawa River in Senoda, Kotaki, Omi area, Niigata Prefecture, central Japan. The occurrence of Mesofavosites cf. igoi and Pachyhelioplasma sp. indicates an Early to Middle Devonian for the fauna. Based on lithology and fossil content, the limestone float probably correlates with the Fukuji Formation in the Fukuji area, Hida Gaien Belt. It is concluded that the limestone brought into the Kotaki Complex of Akiyoshi Belt was formed at the eastern margin of North China (Sino-Korea) during the Middle to Late Permian.