Radiolarian age of manganese ore and red chert from the Ananai stratiform manganese deposit in the Northern Chichibu Belt, central Shikoku, Japan

Abstract

We obtain radiolarian fossils such as Follicucullus monacanthus, Pseudoalbaillella aff. globosa, Pseudoalbaillella cf. fusiformis, and Pseudoalbaillella spp. belonging to the Pseudoalbaillella globosa and Follicucullus monacanthus Zones from manganese ore and associated red chert of the Ananai stratiform manganese deposit in the Northern Chichibu Belt, central Shikoku. The depositional age of the Ananai ore deposit is constrained as Guadalupian (Middle Permian) that is between 270.6 and 260.4 Ma in the updated geologic time scale.