Study on extinction of the remnant oceanic basin and tectonic setting of West Junggar during Late Paleozoic.
西准噶尔晚古生代残余洋盆消亡时间与构造背景研究

The study on Keramay ophiolite suite and overlying continental volcanic-sediment rocks indicates that Late Paleozoic remnant oceanic basin in west Junggar formed after Early Paleozoic ocean. The deposition was nearly successive. However, the isotope chronology reveals two stages: Early Paleozoic and Late Paleozoic. The extinction of remnant oceanic basin was vie "soft collision". After rift and extinction of remnant oceanic basin, three tectonic-magma events developed in 329~320Ma, 310~295Ma and ~290Ma, respectively, which induced continental volcanic eruptions at three periods, corresponding to the Batamayineishan Formation, Harjiawu Formation and Kalagang Formation, respectively. The Jiamuhe Formation consists of multiple volcanic eruptions from Carboniferous to Early Permian. Late Paleozoic intrusions have transform from small size diorite, quartzdiorite, granodiorite to hypogene large size alkali-rich granite, which may suggest the granodioritic transitional continental crust transformed to granitic mature continental crust.