Jurassic and Early Cretaceous Radiolaria of the Lower Amurian Terrane: Khabarovsk region, far east of Russia

New data on biostratigraphy, sedimentology and tectonics of the Russian Far Eastern region (Lower Amurian terrane) are presented. This study shows tha t sedimentary sequence of the terrane consists of interbedded Radiolaria-be aring siliceous and volcaniclastic sediments spanning an interval of over 9 0 million years. It is shown that accumulation of radiolarian deposits on a n oceanic plate was associated with alkaline (intraplate) volcanism in the Jurassic, while the plate was drifting, and with some are volcanism during the Early Cretaceous. The younger siliceous rocks contain volcaniclastic ma terial and indicate that the studied sequence approached the trench in the Early Cretaceous (Hauterivian-Barremian) and became accreted in the late Al bian-early Cenomanian. We describe and illustrate radiolarian species extra cted fi om 21 samples. A taxonomic list of 194 taxa and nine plates of Jura ssic-Early Cretaceous Radiolaria are presented.