Nb and Ta diffusion in titanite

Chemical diffusion of Nb and Ta under anhydrous, pO2-buffered conditions has been measured in natural titanite. The source of diffusants were mixtures of CaSiO3, TiO2, and Al2O3 powders, with either Nb or Ta oxides added. Experiments were run in evacuated sealed silica glass ampoules with solid buffers (buffered at NNO). Rutherford Backscattering Spectrometry (RBS) was used to measure Nb and Ta concentration profiles. The following Arrhenius...