Hengshan granulite facies terrane consists of tonalite-trondhjemite-granodiorite (TTG) gneisses and minor high-pressure mafic granulite blocks. LA-ICP-MS zircon dating for two TTG gneiss samples indicates metamorphic ages of 1916.7±9.9 Ma and 1850-1930 Ma, and magmatic protolith age of ca. 2.5 Ga, with similar HREE-rich patterns. Phase equilibria modelling in ZrO 2 -bearing system reveals that zircon abundance varies inversely with melt abundance in suprasolidus metamorphism, zircon growth occurs with melt crystallization during cooling, and thus, the newly grown zircon can only record the age of retrograde metamorphism. Consequently, we suggest that the Hengshan granulite facies terrane experienced slowly uplifting and cooling during 1.85-1.93 Ga in an extensional setting under middle-crust, while the collision orogeny corresponding to peak stage of high-pressure granulite may have happened much earlier. There are two viewpoints about tectonic attributes and evolution of the North China Craton (NCC) in the Neoarchean-Paleoproterozoic. One view argues that the NCC was cratonized by amalgamation of micro-blocks and island arcs at ca. 2.5 Ga [1][2][3][4][5], experienced a series of intra-continent orogenic events of rifting-subduction-accretion-collision from an extensional regime (2.3-2.0 Ga) to a compressional setting (2.01-1.97 Ga) during the Paleoproterozoic [4-6], and followed by high-and medium-pressure granulite facies metamorphism and uplifting during 1.95-1.82 Ga. However, it is still controversial whether the tectonic setting during 1.95-1.82 Ga was dominated by extension related to mantle upwelling [5] or by an orogenic environment of subduction and collision [4]. The other view suggests that the NCC experienced a continuous oceanic subduction since the Neoarchean, a collision between the Yinshan and Ordos Blocks forming the Western Block at ca. 1.95 Ga, and a collision between the Western and Eastern blocks at 1.80-1.89 Ga forming the Trans-North China Orogen, marking the final amalgamation of the NCC [7][8][9][10][11][12][13]. The latter view is popularly supported [14][15][16][17][18][19][20][21]. At present, the metamorphic ages 1.80-1.89 Ga obtained from the Trans-North China Orogen are mostly interpreted as record of a subduction-collision process [12][13][14][15]18,[20][21][22][23][24][25], but a few people suggest that they may represent an age of sustained extension [5]. Therefore, understanding meaning of the metamorphic ages 1.80-1.89 Ga is crucial for elucidating the Paleoproterozoic evolution of the NCC. In this paper, we present LA-ICP-MS zircon U-Pb and trace element data and P-T pseudosection modelling results for tonalite-trondhjemite-granodiorite (TTG) gneisses from the Hengshan high-pressure granulite terrane, for elucidating the behaviours of zircon and melt under granulite facies and recognizing the geological significance of zircon ages.