Abstract
Well-preserved Jurassic radiolarians were obtained from two samples of manganese carbonate nodules which were collected from the Northern Chichibu Belt in the Ino district, Kochi Prefecture, Shikoku. These nodules were yielded from siliceous mudstone blocks embedded in the melange matrix. One sample (GSJ R76692) contains 234 species including A rchicapsa? pachyderma Tan, Hexasaturnalis hexagonus (Yao), Transhsuum hisuikyoense (Isozaki et Matsuda), Unuma echinatus Ichikawa et Yao and Tricolocapsa plicarum Yao, and thus the geologic age is assigned to early Bajocian. The other sample (GSJ R76694) contains 59 species with few age diagnostic radiolarians. However, the geologic age is assigned to late Early Jurassic on the basis of the faunal composition.
