Zircon U-Pb ages of the Fuping Complex and their implications: some comments on the geochronological study of the Precambrian high-grade metamorphic terranes.

Three zircon U-Pb age dating methods have been applied for the Fuping Compl ex, i.e. Thermal Ionization Mass Spectrometry (TIMS), Sensitive High Resolu tion Ion MicrProbe (SHRIMP) and Inductively Coupled Plasma Mass Spectrometr y - Laser Probe (ICPMS-LP). Based on these results it is suggested that the Fuping Complex is mainly made up of 2.51 Ga TTG gneisses; a small amount o f 2.7 Ga hornblende gneisses were developed which may represent the fragmen ts of old continetal materials. One magmatic event of 2.05 Ga was confirmed in the Fuping area. The Wanzi supracrustal rocks were possibly deposited b etween 2.5 and 2.1 Ga. The characteristics of the three U-Pb dating techniq ues and their applications on the geochronological study of the Precambrian high-grade metamorphic rocks were also discussed. It is emphasized the sig nificance of the study on the internal structures, chemical characteristics on zircon for its U-Pb geochronology.