摘要
Gaoligong gneiss from southeastern Tengchong block has experienced multistage metamorphism, and hence shows evident anatexis and mylonitization. 14 of the 15 zircon points yielded 206Pb/238U age of (454.4~546.7) Ma, with the average age of (489±16) Ma. The result suggests that the Gaoligong Mountain Group in southeastern Tengchong block underwent intense regional meta- morphism including migmadzation in Early Paleozoic, which reflected the Pan-African event in the Tengchong block.