Geochemistry Characteristics and Tectonic Significance of the Igneous Rocks from the Eastern Tianshan Mountains

This paper systematically summarized the geochemical characteristics of late Paleozoic igneous rocks in the Jueluotage area of Eastern Tianshan. The igneous rockis mainly formed by early Carboniferous to middle Permian volcanic and intrusive rocks, and its formation is relevant with the northward subduction of Kangguer ocean.The igneous rock of early Carboniferous is composed of calc-alkaline island arc volcanics formed in the initial stage of slab subduction and high-potassium calc-alkalineI-type granite with a characteristic of low temperature and low pressure. The igneous rock of late Carboniferous is post-collision arc volcanics. The igneous rock of early Permian is composed of the volcanic in the post-collision arc and intraplate environment, and I-type granite with a characteristic of high temperature and high pressure. The igneous rock of middle Permian is high-potassium calc-alkaline A-type granite with characteristics of high temperature and low pressure.The results of previous studies and this paper suggest that this region experienced a tectonic evolution from subduction-collision to collision-orogenesis and post-orogenic intracontinental extension in late Paleozoic.