class=MsoNormal><SPAN style="FONT-SIZE: 14pt" lang=EN-US>Zircon SHRIMP U-Pb Dating for Garnet-Rich Granite Veins in High-Pressure Granulites from the Namche Barwa Complex,Eastern Syntaxis of the Himalayas,and The Relationship with Exhumation
class=MsoNormal><SPAN style="FONT-SIZE: 14pt" lang=EN-US>The major and trace element data of the garnet-rich granite in the retrogressive granulite show that:1) they are high potassium,aluminum-rich;2) they are strongly enriched in LREE with high fractional degree,depleted in HREE,and enriched in LILE and RHE relative to primordial mantle;3) they have substantial negative Eu anomalies,and Rb/Sr>1.4.The magmatic initial temperature are ranging from 792℃ to 801℃ estimated by the major data and Zr contents for garnet-rich granite.The zircon SHRIMP U-Pb dating show that:1) the ages for the inherited cores are ranging from 519 Ma to 525 Ma,exhibit the Namche Barwa complex rocks had been lnfluenced in the pan-African movement;2) the latest growth rim of zircon grains have three stage ages of 39~44 Ma, 24~25 Ma and 7.3 Ma.