Monazite is a LREE – bearing orthophosphate mineral that can be used as a geochronometer. Given its affinity for Th, it can be dated with non-isotopic techniques, like Electron probe microanalysis, at very high spatial resolution (ca. 1 micron). Due to monazite’s compositional variability, it responds to, and can thus monitor the growth and consumption of major and accessory phases during metamorphism, helping decipher complex and convoluted metamorphic histories in polydeformed terranes.
Understanding the relationship between fluid evolution and monazite composition