Conodont biostratigraphy across the Carnian-Norian Boundary in the Jifukudani Creek, Tamba Terrane, SE Kyoto, Japan

Abstract

A 4m thick bedded-chert sequence in the Jifukudani Creek, Tamba Terrane, SoutheastKyoto (SW Japan), yields Late Triassic conodonts. Metapolygnathus lindae, M. polygnathiformis, M. echinatus, M. primitius, Ancyrogondolella quadrata, A. spatulata and Mockina shamiseni span the Late Carnian polygnathiformis and primitius biozones, the Early Norian quadrata - spatulata biozone and the Middle Norian postera - shamiseni biozone. The Carnian - Norian boundary may coincide in the field with a layer of black clay. The conodont fauna shows affinities with both the Tethys and Izanami Plateau of the Izanagi Plate, where the terranes of Japan originated, and to some extent with the Wrangellia Terrane (British Columbia, Canada).