The SHRIMP zircon U-Pb geochronology ofthree typically Indosinian granitic plutons with peralumi-nous and potassium-rich affinities (Tangshi ultraunit forWeishan and Baimashan, and Longtan ultraunit forGuandimiao) is ...The SHRIMP zircon U-Pb geochronology ofthree typically Indosinian granitic plutons with peralumi-nous and potassium-rich affinities (Tangshi ultraunit forWeishan and Baimashan, and Longtan ultraunit forGuandimiao) is presented in Hunan Province, South China.The analyses of zircons from biotite monozonite granites forWeishan, Baimashan and Guandimiao plutons show the sin-gle and tight clusters on the concordia, and yield theweighted mean 206Pb/238U ages of 244±4, 243±3 and 239±3Ma, respectively, representing the crystallized ages of theseIndosinian granites. These data suggest that the Indosiniangranitic plutons as previously thought formed at a narrowage span. In combination with other data, it is inferred thatthe Indosinian granites within the South China Block proba-bly distributed in Hunan, Jiangxi, Guangxi and Guangdongprovinces as planar shape, and were the derivation of thecrustal materials in the intracontinental thickening setting.These precisely geochronological data provide importantconstraints for better understanding the spatiotemporal pat-tern of the Indosinian peraluminous granites and earlyMesozoic tectonic evolution of the South China Block.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.40334039,40421303 and 40473019)the Chinese Academy of Sciences(Grant No.KZCX2-102)
文摘The SHRIMP zircon U-Pb geochronology ofthree typically Indosinian granitic plutons with peralumi-nous and potassium-rich affinities (Tangshi ultraunit forWeishan and Baimashan, and Longtan ultraunit forGuandimiao) is presented in Hunan Province, South China.The analyses of zircons from biotite monozonite granites forWeishan, Baimashan and Guandimiao plutons show the sin-gle and tight clusters on the concordia, and yield theweighted mean 206Pb/238U ages of 244±4, 243±3 and 239±3Ma, respectively, representing the crystallized ages of theseIndosinian granites. These data suggest that the Indosiniangranitic plutons as previously thought formed at a narrowage span. In combination with other data, it is inferred thatthe Indosinian granites within the South China Block proba-bly distributed in Hunan, Jiangxi, Guangxi and Guangdongprovinces as planar shape, and were the derivation of thecrustal materials in the intracontinental thickening setting.These precisely geochronological data provide importantconstraints for better understanding the spatiotemporal pat-tern of the Indosinian peraluminous granites and earlyMesozoic tectonic evolution of the South China Block.
