Geochemical Characteristics of Early Permian Pyroclastic Rocks in the Jimunai Basin, West Junggar, Xinjiang (NW China): Implications for Provenance and Tectonic Setting

During the Late Paleozoic, West Junggar (Xinjiang, NW China) experienced a shift in tectonic setting from compression to extension. Ha'erjiao is an important area for investigating collisional structures, post–collisional and magmatic activities. Based on petrological geochemical characteristics of pyroclastic other volcanic rocks Permian Kalagang Formation borehole ZKH1205 Jimunai Basin, main types source rock deposited basin are identified their implications Early examined. The abundance basalt andesite lithic fragments rocks, together with REE contents transition high field strength elements show that were chiefly intermediate–basic rocks. High ICV values, low CIA Rb/Sr ratios, Th/U ratios mineralogical features suggest weak chemical weathering rocks; patterns might not only have been impacted by crustal contamination but also be related nature magma area. properties distinguish them arc-related ones, such samples plot within-plate (WPB) some diagrams. This consistent formation background this region.