U-Ph dating of zircon from gneiss at Nanhuang in east Anhui.

There is a suboutcrop of amphibolite-facies TTG gneiss overlain by Neoprote rozoic Zhangbaling Group at Nanhuang region in Jiashan, East Anhui. U-Pb da ting was carried out for the single grains of zircon from the gneiss, The r esults show an age of 2493+/-19Ma for the upper intersect of discordia with concordia, which is interpreted to represent the formation age of the Nanh uang gneiss. In this regard, there is the Neoarchean rock in the northeaste rn margin of the Yangtze plate, documenting the widespread presence of Neoa rchean to Paleoproterozoic basements in the northern margin of the Yangtze plate.