LA-ICP-MS zircon U-Pb dating work was carried out for the detrital zircons from the Zhoutan Group, central Jiangxi Province. Detrital zircons from three samples, including two garnet biotite schist and one biotite schist, show the youngest age peaks of 834 ± UMa, 830 ± HMa and 809 ± 15Ma, respectively. The age spectrum and maximum depositional ages of detrital zircons from the para-metamorphic rocks of the Zhoutan Group is similar to those for the Lengjiaxi Group and its equivalent sequences in the Jiangnan orogen, suggesting that the Zhoutan Group should have similar formation history, sources and tectonic settings with those sequences. Therefore, the Zhoutan Group, similar to the Shuangqiaoshan and Lengjiaxi groups, should have affinity with the Yangtze Block, rather than the Cathaysia Block, during the amalgamation between the two blocks. The metamorphic rims of the detrital zircons from the biotite schists yielded mean age of 444 ± 11 Ma and 438 ± 11 Ma, respectively. The metamorphic ages suggest that the metamorphism of the Zhoutan Group happened at Caledonian age, similar to other amphibolite-facies metamorphic rocks in the Cathaysia Block, but rather different from the coeval Shuangqiaoshan and Lengjiaxi groups along the Jiangnan orogen. It probably suggest that the rifting might have taken place at the central Jiangxi Province after the Neoproterozoic assembling between the Yangtze and Cathaysia blocks, which finally led to the different metamorphic process between the Zhoutan Group and the above two adjacent sequences (the Shuangqiaoshan and Lengjiaxi groups).
|Number of pages||11|
|Journal||Acta Petrologica Sinica|
|Publication status||Published - 2013|
- Jiangnan orogen
- Para-metamorphic rocks
- Zhoutan Group
- Zircon U-Pb dating