Radiolarian Fossils Mentioned in OMURA Ichizo (1910)

• Main Authors: 永井, ひろ美, 52208, 白木, 敬一, 52209, NAGAI, Hiromi, 52210, SHIRAKI, Keiichi, 52211
• Language: Japanese
• Published: 名古屋大学博物館 2013
• Subjects: Sakhalin
• Online Access: http://hdl.handle.net/2237/19916

2013-12-25 In June 1910, OMURA Ichizo submitted his dissertation thesis entitled “Report on the Geologyof Shiretoko, Sakhalin and Brief Description of Crystalline Schist of Sakhalin” for the GeologicalInstitute of the University of Tokyo. In this thesis he made a detailed description on geologyand geography of the Shiretoko Peninsula at the southeastern end of Sakhalin. He discoveredwell preserved radiolarian fossils from radiolarite in the “Paleozoic” system near Butchino,identified them as Cenosphaera gregaria, C. pachyderma, Heliodiscus sp., Theocapsa elongata,Lithocampe exaltata, Stichocapsa perpasta, and S. grandis; and depicted their fairly detailedfigures. These radiolarian fossils were considered to be of Paleozoic, compared with those of thePaleozoic systems in mainland Japan. Recently the Paleozoic system of the Shiretoko Peninsulais recognized as a Cretaceous accretionary complex. The radioralian fossils recovered fromShiretoko by Omura should be assigned to the Middle Jurassic to the Lower Cretaceous speciesby the morphological characters. departmental bulletin paper