Experimental constraints on trace element partitioning between coesite and hydrous silicate melt at 5 GPa and 1500–1750°C

Trace element partitioning between coesite and hydrous silicate melt has been investigated at 5 GPa 1500−1750°C. High-P experiments successfully produced large crystals in equilibrium with pools (plus kyanite corundum some cases). Scanning electron microscopy micro-Raman spectroscopy were employed to characterize the phases textures. Wavelength-dispersive microprobe analyses performed quantify conventional major elements, laser ablation-inductively coupled plasma-mass spectrometry conducted trace elements. Eventually, high-P partition coefficients obtained for 33 In general is a very pure phase. With few possible exceptions like Sc, Ti, V, nearly all other elements are incompatible coesite. Moreover, behaviors of except 4+ cations cannot be readily described by lattice strain model, presumably implying minor role cation size trace-element partitioning. Combining our experimental results literature, T P effects on behavior have observed: seemingly different but might negatively correlate cases. Due its modal fraction subducted materials such as continental crustal material, play an important distributions Ti example.