Zircon U-Pb Age and Geological Significance of Dulunhe Granite in Tuoli, Western Junggar

There are large numbers of intrusive granites exposed along the Daerbute tectonic-magmatic belt in the center of western Junggar. Many researches have been conducted on the batholites instead of small granite intrusions, which mainly distributed in porphyry mineralization belt of the Baogutu region. Wallrock alterations such as malachitization, silicification, carbonatization, chloritization and pyritization are well developed in Dulunhe granite, which is located in Kuoyitasi area of Zayier Mountain, and abundant mafic microgranular enclaves can be found in these host rocks, however, accurate geochronology data is still insufficient. High-precision LA-ICP-MS zircon U-Pb dating reveals that the quartz diorite in the Dulunhe granite is formed at (312.6±4.2)Ma(n=21, MSWD=0.15, 95% confidence degrees) in early late Carboniferous. Combined with previous researches, the authors suggest that the age of Dulunhe granite is consistent with small granites like Baogutu granite (Au-Cu mineralization) and Xiaerpu granite (Cu-Mo mineralization); both of them are probably formed in the subduction-related setting. This reliable age provides chronology constraints for the study of regional mineralization age that related to small granite and magma mixing of Au-Cu-Mo deposit.