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应用锆石SHRIMP定年方法对云蒙山片麻状花岗岩进行年代学研究 ,得到 4组年龄 :14 4± 4Ma、16 0～ 16 3Ma、193～ 2 18Ma和 2 4 16Ma。其中 14 4± 4Ma代表了云蒙山岩体的侵位时间 ,16 0～ 16 3Ma和 193～ 2 18Ma两组年龄可能是岩浆侵位过程中捕虏锆石的年龄。 2 4 16Ma与Davis等的锆石U_Pb法上交点年龄 (190 0～ 2 4 0 0Ma)一致 ,可能反映了原岩的时代 ,说明该花岗岩来源于晚太古代片麻岩的局部熔融或者是岩浆侵位过程中捕获了晚太古代的锆石。
The zircon SHRIMP dating method was applied to chronologically study the Yunmengshan gneissic granite. Four age groups were obtained: 14 4 ± 4Ma, 16 0 ~ 16 3Ma, 193 ~ 2 18Ma and 2 4 16Ma. Of which 14 4 ± 4Ma represent the emplacement time of the Yunmengshan pluton. The ages of 16 0 ~ 16 3Ma and 193 ~ 2 18Ma may be the age of the captive zircon during the emplacement of the magma. The agreement between Davis et al. And Davis et al., Such as the U_Pb zircon dating (190 0-24 0 0 Ma), may reflect the age of the protolith, indicating that the granite was derived from local melting of late Archean gneiss or from magma During the emplacement, late Archean zircons were captured.