There are large numbers of intermediate-acid intrusions exposed along the tectonic-magmatism belt of western Junggar, Xinjiang. It is of great significance to know the evolution and mineralization process of this tectonic-magmatism belt through their nature and emplacement periods. However, there are still lack of accurate isotopic chronology and geochemical datas of part of the small rock bodies to restricting the understanding of their genetic types, including Kushikuduke granite. The petrogenic age and genetic type are discussed in this paper through the field observation, LA-ICP-MS zircon U-Pb isotopic dating and geochemical analysis. The results show that Kushikuduke granite with an outcrop area of 3 km2, and is mainly composed of granodiorite and small amount of granodiorite-porphyry. LA-ICP-MS zircon U-Pb dating reveals that the Kushikuduke granite formed at 311.9±2.6 Ma （n =20, MSWD = 0.05）, which belongs to the Early Late Carboniferous epoch. Petrological and geochemical studies show that Kushikuduke granite belongs to the I-type granite, which is characteristic of relatively abundant of Si (SiO2=65.78% ～67.76%), medium Al (Al2O3 =15.66% ～16.29%), abundant alkali (Na2O + K2O=7.79% ～8.04%) and depleted K (K2O =3.48%～3.86%), and with low value of the FeOT/MgO(3.77～4.36), A/CNK = 0.99～1.20, A/NK = 1.43～1.48, which belongs to high-K calc-alkaline, metaluminous to peraluminous series. The chondrite-normalized REE pattern plots displayed as the rightist type, and negative Eu anomalies with low δEu （δEu = 0.57～0.72）, the primitive mantle-normalized trace elements spider plots are characterized by enrichment in large-ion lithophile elements（LILE）such as Rb and K, and depletion in high field strength elements（HFSE）such as Nb, Ta, Ti, and heavy rare-earth elements（HREE）such as Y and Yb, with low value of the 104 Ga/Al （2.21～2.56, the averaging 2.43）, which indicate that it is different from A- or S-type granite, suggesting that Kushikuduke granite is actually typical metaluminous to peraluminous I-type granite. These results are extremely similar to other small intrusions such as Baogutu, Bieluagaxi and Dulunhe granite of western Junggar in the petrogenic age, geochemical characteristics and genetic types, which demonstrates that these small intrusions may have the same geodynamic background, and all of them are the products of subduction, and is markedly different from large batholiths such as Miaoergou and Akebasitao granite, which belong to the A2-type granite formed in an post-collisional tectonic setting approximately at 300 Ma, suggesting that it may exist two periods and distinctive nature of characteristics of magmatic activities of western Junggar, and provides new datas for the research of magmatic activities and tectonic evolutions of the Late Paleozoic.
Duan Fenghao Zhi Qian Li Yongjun Wang Ran Ji Zhengbao Zhao Delong Guo Xin Cheng Wanli. Geological age，geochemistry and petrogenesis of Kushikuduke granite in western Junggar，Xinjiang[J]. Chinese Journal of Geology, 2017, 52(2): 506-525.