New constraints on P–T–t path of high–T eclogites in the Dabie orogen, China

Abstract A multidisciplinary study integrating P–T pseudosection of phase equilibrium modeling, conventional geothermometry and zircon U–Pb dating with trace element analysis was carried out on the high–T UHP eclogites from the Dabie orogen. The eclogites here underwent a multistage metamorphic evolution including post-peak granulite-facies overprinting and subsequent amphibolite-facies retrogression. P–T conditions of the granulite-facies overprinting and the amphibolite-facie retrogression have been estimated at >830°C, 7–12 kbar and 560–880 °C, 4.3–8.9 kbar, respectively. New zircon U–Pb dating, mineral inclusion and trace element analysis, combined with modeled plagioclase modal variation by pseudosection approach, constrained the ages of prograde metamorphism, eclogite-facies metamorphism, granulite-facies overprinting and amphibolite-facies retrogression of the eclogites at 247–230 Ma, 226–219 Ma, 217–212 Ma and 214–198 Ma, respectively. The results provide new P–T estimates and age data for the multiple metamorphic stages during continental collision, contributing to precisely reconstruct the whole P–T–t path of the eclogites.