摘要
The Indosinian Orogeny is an important tectono-magmatic event in South China, it deeply influence today′s landform and geomorphology of South China. The authors present in this paper a study on detrital zircon U-Pb ages of the early Jurassic Dongkeng siltstone in eastern part of the Nanling Range. Four prominent age peaks, i.e. 196 Ma, 238 Ma, 364 Ma and 427 Ma are obtained, suggesting that the siltstone was deposited in Early Jurassic rather than Sinian to Cambrian. Absence of 260~290 Ma zircon ages indicates a proximal source for the sedimentary rocks. Furthermore, we compare the detrital zircon age of our results with those of the Late Triassic standstone from Wenbinshan Formation in southwestern Fujian and Middle-Late Permian sandstone in South China, conclusions can be speculated that early Indosinian magmatism (290~260 Ma) developed mainly in the coastal region of South China and the late Indosinian magmatism (240~200 Ma) occurred in South China interior. Denudation of Indosinian Orogen in South China should be considerable progressed at ca. 190 Ma due to the exposoure of Indosinian granites.