Abstract:The Qinling-Tongbai-Dabie orogenic belt was formed as a result of the collision between the North China and Yangtze plates. The Tongbai orogen is located in a key area linking the Paleozoic Qinling accretionary orogen and the Mesozoic Dabie collisional orogen. It is an ideal place to unravel the tectonic evolution from the initial oceanic subduction, terrane accretion to the final continental collision between the two plates. Petrological, mineralogical and geochronological studies of meta-sedimentary rocks, amphibolites and granitic vein from the Guishan Complex in the Tongbai orogen were carried out in this study. Meta-sedimentary rocks of the Guishan Complex have a detrital zircon age spectrum with a peak at 411 Ma and subordinate peak age of 490Ma. The youngest weighted mean age of 352 ± 11 Ma constrained the lower limit of deposition age of the Guishan Complex. U-Pb zircon analyses reveal protolith ages of 498±18Ma for amphibolites and 412.8±4.4 Ma for granitic vein. Metamorphic zircon grains from amphibolites and granitic vein yielded ages of 320±10Ma, suggesting an Early Carboniferous metamorphic event. The peak metamorphic condition of the amphibolites is 571-632℃ and 0.59-0.76GPa, which belongs to amphibolite facies of medium pressure facies series. The age spectrum of detrital zircons revealed the provenance of the meta-sedimentary rocks of the Guishan Complex were derived from the North Qinling terrane and it developed as forearc basin during the early Early Carboniferous. But it was subsequently incorporated with amphibolites into tectonic mélange by the northward subduction of the Paleo-Qinling Ocean. It also suggests that Paleo-Qinling Ocean did not close until early Early Carboniferous.