摘要
Titanite is a widespread accessory mineral in metamorphic rocks. The united exchange Ti+O=(Al, Fe<sup>3+</sup>)+（OH, F） is now recognized as a common substitution in metamorphic titanite. Five theoretical titanite end-members were recognized by Smith: CaTiSiO<sub>4</sub>O （oxy-titano-titanite）, CaAlSiO<sub>4</sub>OH （hydroxy-alumino-titanite）, CaAlSiO<sub>4</sub>F （flour-aluminotitanite）, CaFeSiO<sub>4</sub>OH （hydroxy-ferri-titanite） and CaFeSiO<sub>4</sub>F （flour-ferri-titanite）.
基金
National Natural Science Foundation of China.
