Ordovician radiolarians from the Yinisala ophiolitic m,lange and their significance in western Junggar, Xinjiang, NW China

The Yinisala ophiolitic m,lange is located in the southern part of the Xiemisitai Mountains in western Junggar (NW China), and is composed of mafic-ultra mafic rocks, siliceous blocks, marble (marbleized limestone) and pyroclastic rocks, which all crop out as faulted blocks. Rich radiolarian and sponge spicule fossils are found in the siliceous rock for the first time. There are six genera of radiolarians (including one gen. et sp. Indet.) belonging to two families: Inaniguttid gen. et sp. Indet., Inanigutta sp., Inanibigutta sp., Inanihella bakanasensis (Nazarov), Triplococcus acanthicus (Danelian and Popov), Antygopora sp., which are identified to be of late Early to Middle Ordovician age, representing the upper limit of the formation age of the Yinisala ophiolite m,lange. The ophiolites were developed in the Early Cambrian-Middle Ordovician oceanic environment, probably an important part of the early Paleozoic Paleo-Asian Ocean, based on the composition and structure of the siliceous rock and associated deep-water fossils. The Yinisala, Taerbahatai, and Hongguleleng ophiolitic m,lange belts can be correlated as a suite of unified subduction accretionary complex, which extends eastward to the eastern Junggar. We consider that there existed an ancient ocean connecting the east and west of northern Junggar in the Early Cambrian-Middle Ordovician.