Zircon U-Pb ages of the fuping complex and their implications: Some comments on the geochronological study of the precambrian high-grade metamorphic terranes

Abstract

Three zircon U-Pb age dating methods have been applied for the Fuping Complex, i.e. Thermal Ionization Mass Spectrometry (TIMS), Sensitive High Resolution Ion MicrProbe (SHRIMP) and Inductively Coupled Plasma Mass Spectrometry - 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 of 2.7 Ga hornblende gneisses were developed which may represent the fragments of old continental materials. One magmatic event of 2.05 Ga was confirmed in the Fuping area. The Wanzi supracrustal rocks were possibly deposited between 2.5 and 2.1 Ga. The characteristics of the three U-Pb dating techniques and their applications on the geochronological study of the Precambrian high-grade metamorphic rocks were also discussed. It is emphasized the significance of the study on the internal structures, chemical characteristics on zircon for its U-Pb geochronology.