The Geochemical Characteristics and Significance of the Magmatic Rocks in Beizhan Iron Mine Zone, Hejing, Xingjiang

Beizhan iron ore is located in the eastern Awulale of Western Tianshan. The magmatic rocks of late Paleozoic are main intrusive rock in this area, which includes moyite and potash feldspar granite porphyry. The geochemical characteristics show that the content of SiO₂ is about 74.24% to 75.88%, the value of σ is from 2.11 to 2.3, the total alkali content (Na₂O+K₂O) is among 8.32 to 8.65, the value of A/CNK ranges from 0.868 to 1.009, the magmatic rock is Type I granite of metaluminous rock and belongs to high K calc-alkaline series. The trace element characteristics indicate that the composition of magma source region is complex, showing the effects of the components in the crust. The value of ΣREE falls between 96.38 and 158.02×10^-6, signifying LREE enrichment, with obvious Eu negative anomaly; δEu changes from 0.07 to 0.29, and δCe varies from 0.54 to 1.17, the value of LREE/HREE is from 3.897 to 12.02. It is concluded that the magmatic rock occurred in the post collision tectonic environment, the granite source region is the lower crust.