A Permian Boreal brachiopod fauna from Okutadami, central Japan, and its tectonic implication

Abstract

A Boreal brachiopod fauna of five species was found in Okutadami, central Japan: Anemonaria sp., Kochiproductus sp., Yakovlevia sp., Spiriferella sp. and Attenuatella sp., indicating a late Middle Permian (Midian) age. The Okutadami fauna is the first documented Permian Boreal brachiopod fauna in Japan. The occurrence of the Boreal brachiopod fauna from Okutadami suggests that the fossil-bearing rocks were formed at the northernmost part of Japan in the Middle Permian, and afterwards moved relatively to the central part by the large-scale left-lateral strike-slip faulting in Cretaceous, probably late Early Cretaceous (Aptian-Albian), time.