Brachiopods from the Upper Permian Tsunemori Formation of the Akiyoshi Area, Southwest Japan, and Their Tectonic Implications

Abstract

This study describes a brachiopod fauna, consisting of 15 species in 15 genera, from the Upper Permian Tsunemori Formation of the Akiyoshi area, southwest Japan. The fauna includes a new species, Cathayspirina magna. The Tsunemori fauna is a Boreal-Tethyan mixed fauna and is closely allied with the Late Permian (Changhsingian) brachiopod faunas of Nabekoshiyama in the South Kitakami Belt, northeast Japan, and of Kawahigashi in the Maizuru Belt, southwest Japan. Palaeobiogeographical data derived from the Tsunemori fauna suggest that the Late Permian accretion site of the Akiyoshi Terrane, including the Tsunemori Formation, was located within a trench along the eastern margin of North China (Sino-Korea).