抄録
Manganese nodules containing well-preserved radiolarian fossils were discovered for the first time from the Kuzumaki-Kamaishi Belt. They are in the mudstone of chert-clastic sequences and considered to be formed in situ from the mode of occurrences. The radiolarian fauna comprises more than 120 species, including Archicapsa pachyderma, Stichocapsa tegiminis and Trillus elkhornensis. The presence of S. tegiminis and the absence of its descendant Tricolocapsa plicarum indicate early Middle Jurassic age of these nodules, suggesting that a Middle Jurassic accretionary complex exists in the Kuzumaki-Kamaishi Belt.
