TITHONIAN RADIOLARIANS FROM THE YAMDROK MELANGE IN SOUTH TIBET, CHINA

Well-preserved Tithonian radiolarian faunas were extracted from a chert block of the Yamdrok melange, south Xizang (Tibet). Some 11 genera and 14 species were determined, most of which are reported here in Tibet for the first time. They are mainly composed of Eucyrtidiellium pyramis (Atta), Protunuma japonicus Matsuoka & Yao, Archaeodicryomitra apiarium (Rust), Zhamiodellum ventricosum (Dumitrica), Archaeospongoprunum patricki Jud and Archaeodictyomitra minoensis (Mizutani). The existence of these prime species with known reliable stratigraphic ranges indicates its wider application in determination of stratigraphic range in the Tibetan Tethys.