The validity of Ti-in-zircon thermometry in low temperature eclogites

Abstract

AbstractThe Ti-in-zircon thermometer has been widely applied to different high-grade metamorphism rocks owing to its simplicity. Based on the calibration of Ferry & Watson (2007; New thermodynamic models and revised calibrations for the Ti-in-zircon and Zr-in-rutile thermometers. Contributions to Mineralogy and Petrology, 154, 429–437), we used the Ti-in-zircon thermometer to estimate the metamorphic temperatures for low-temperature eclogites of North Qilian and Western Tianshan, China, and compiled HP/UHP eclogites from the literature. The Ti-in-zircon temperatures are generally higher than the estimations by other thermometers, especially when metamorphic temperatures are lower than 650°C. Although temperature exerts the dominant control on Ti content in zircon, other factors (e.g. lattice defect, other trace element substitutions in zircon, disequilibrium zircon growth, and precipitation from metamorphic fluids) may have contributed to the overestimated Ti-in-zircon temperatures.