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Dong Jia, Nanjing University (China)
Haibin Li, Nanjing University (China)
Long Wu, Nanjing University (China)
Fei Deng, Nanjing University (China)
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Within the Wuyishan fold belt of southern China, the late Neoproterozoic to Ordovician meta-flyschoid rocks have witnessed a complex tectonic history due to the interactions of two continental blocks (Yangtze and Cathysia), accompanied by widespread tight-to- isoclinal folding, greenschist-amphibolite-facies metamorphism and a series of granites and migmatites during the early Paleozoic age. New U-Pb geochronology on syn-tectonic granites that occur obviously in a variety of structural levels within this fold belt, provide constraints on the timing of major tectonic events. U-Pb zircon ages of syn-tectonic granites, such as Hengshi, Cizhu, Sanbiao and Yiqian, are in the range 453∼431 Ma that we interpret to record time of contractional deformation. Zircons from the late-tectonic granites (Dayu, Epo, Ninghua, Longhui and Doushui plutons) yield early Devonian ages (414∼395 Ma) that we interpret as ages of an intervening sinistral transpression/transtension phase. These results demonstrate that the major deformation and decollement tectonics in the Wuyishan fold belt occurred prior to the middle Devonian. The wide range of ages obtained for post-kinematic granites (387∼375 Ma) suggests that eventual orogenic collapse and exhumation persisted for a long time after the compressional tectonism. There, large scale of crustal shortening, greenschist- facies metamorphism, and plutonism were synchronous in Silurian age. This research is supported by grants from the National Science Foundation of China (Grant No. 40634022 and 40672132).
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