Coesite-bearing eclogite from the Dabie Mountains in central China

Abstract
Coesite and Coesite pseudomorphs are recognized in eclogite from the Dabie Mountains, a collision zone between the Sino-Korean and Yangtze cratons in central China. This third known occurrence of Coesite in deep crustal rocks is within an Archean gneiss terrane and is the first locality where Coesite has been identified as an inclusion in both omphacite and garnet crystals at the same location. Coesite-bearing eclogite is estimated to form at pressures of >28 kbar and temperatures from 600 to 710 °C. The Dabie Mountains eclogite underwent retrograde metamorphism to amphibolite facies after its formation. The preservation of Coesite in eclogite is found to be strongly controlled by the pressure-temperature-time path that coesite- bearing eclogite followed during its uplift and retrograde metamorphism.