Chronological And Fluid Inclusion Study Of Pan-African Granitoid Rocks From The Sor Rondane Mountains, East Antarctica

The zircon SHRIMP U-Pb chronological results show the ages of 584±7 Ma for the Lunckeryggen granite, 619±7 Ma for the Defuk granite, 534±13 Ma for the Mefjell syenitic rocks in the S(?)r Rondane Mountains, East Antarctica, representing the formation ages of the different Pan-African grantoid bodies. Combined with the previously chronological result, the granitoids in the S(?)r Rondane Mountains could be formed during a period of 620～500 Ma. Due to existence of multiple thermal fluid activities from the Pan-African granitoids in S(?)r Rondane Mountains, the lithology and thermometry of fluid inclusions in the quartz and feldspar from the Pan-African granitoids were described, and the gas-liquid two-phase fluid inclusions were measured. The homogenized temperatures for the primary and secondary inclusions from the quartz and feldspar range from 156.4 to 356.7°C and 111.2 to 182.3°C respectively, which reflected three fluid activities during the formation and post-stage of granitoids. The primary inclusions could be trapped during the crystallization process of granitic magma, and the secondary inclusions could be trapped due to late-stage fluid activity after the formation of granitoids.