There are many granite plutons in the Wugongshan dome compound granite. Fine U-Pb dating of zircons show that the Shanzhuang granite, Zhangjiafang granite and Wugongshan granite have zircon ages of 460.5± 1.5 Ma, 427.9 ± 1.2 Ma and 428.0 ± 1.0 - 462.3 plusmn; 2.3 Ma respectively, belonging to the late Early Paleozoic. The Yanshan granite, Wentang granite and Mingyueshan granite have zircon ages of 161.0 ± 1.0 Ma, 143.8 ± 1.6 Ma, 126.3 ± 6.4 Ma respectively, belonging to the late Jurassic-early Cretaceous. Therefore, the authors believe that the granite of the Wugongshan dome compound granite is the product of the late Early Paleozoic and late Jurassic-early Cretaceous magmatism. These data can indicate from another angle that there might be late Early Paleozoic tectonic-thermal events and late Jurassic-early Cretaceous tectonic-thermal events, which provides new evidence for the researches of geotectonic evolution of South China. Considering also 40Ar/39Ar dating of muscovite from granitic gneiss (225-233 Ma), these data show that the ductile distortion was formed during the late Triassic which may be the startup of extensional tectonics. The formation and upwelling of late Jurassic-early Cretaceous magmas made the wall rocks softening and partial melting, which help the development of extensional tectonics in wall rocks, and the granitic dome extensional tectonics was finally formed during the Cretaceous in Wugongshan.
|Number of pages||9|
|Journal||Acta Geologica Sinica|
|Publication status||Published - 2005|
- Extensional tectonics
- Granitic dome
- U-Pb dating of zircon