Geochronology And Tectonic Implications Of Wuerkashier-Ximisitai, North China

West Junggar Paleozoic orogenic belt in central Asia orogenic generation is an important part of central Asia, which is located in the southwest of orogenic belts. West Junggarr in Paleozoic after many subduction and collision, widely developed the Paleozoic sedimentary rocks and magmatic rocks built, and forms a very important Paleozoic tectonic magmatite belts. Based on the theory of plate tectonics, combined with the detailed field investigations and the study chronology of granite. Set time limit for the tectonic events of every period and invert the tectonic evolution of West Junggarr. The results of the study indicate that:(1) There is not only the Carboniferous—early Permian granitoids, but also late Silurian-early Devonian granitoids in west junggar. For example, the zircon age of Akeqiaoke granodiorite is 410.5±2.9Ma, the zircon age of Ximisitai granitoids is 422—417Ma, the zircon age of Saier granitoids is 417—405Ma, they were pluted in ate Silurian-early Devonian.(2) Akeqiaoke granodiorite, Ximisitai granitoids, and Saier granitoids were the production of the late Silurian-early Devonian magmatism., but they intrude into originally identified Devonian strata. therefore, combined with regional geological setting, the strata which was intruded by the late Silurian-early Devonian granitoids in the studied area may be not Devonian, and their exact formation time should be further studied.(3) Akeqiaoke granodiorite zircon U-Pb ages, two age of 498M and 502Ma, may be due to the captured ancient crystalline basement rock. In the south of the XiemisitaiMountains, the Xiaogensala K-feldspar granite has an age of about 518±7Ma, which may be caused by an inherited zircon. Accordingly, I think that the West Junggar region there may be an ancient Precambrian crystalline basement.(4)Xiemisitai granitoids, Saier graintoids and Akeqiaoke granitoids almost have the same age of granite. The zircon U-Pb age of Akeqiaoke granodiorite and Xiaogensala K-feldspar granites in the south of Xiemisitai contain the age of age of older zircon. Combined with adakites geochemical characteristics of Akeqiaoke granitoids, I think Akeqiaoke granodiorite and the granitoids of Xiemisitai and Saier may be the production of Coogee-Hong Gule ophiolite which represent the ancient ocean southward subducted oceanic slab partial melting in the late Silurian—Early Devonian.(5) The previous south boundary of Boshchekul-Chingiz volcanic arc is the Xiemisitai fault through the south of the Xiemisitai. Akeqiaoke granitoids is located in the West Junggar accretionary complexes. Through the study of the granite of West Junggar, I think that Akeqiaoke-Xiemisitai-Saier may be a NNE-EW zone of magmatic activity, located in Boshchekul-Chingiz volcanic arc. Accordingly, the boundary between Boshchekul-Chingiz and West Junggar accretionary complexes may be go through 201 provincial highway in the study area.