Monazite solubility and dissolution kinetics: Implications for the thorium and light rare earth chemistry of felsic magmas

A series of monazite dissolution experiments was conducted in a hydrous (1-6 wt.%) granitic melt at 8 kbar over the temperature range 1,000-1,4000C. A polished cube of monazite was immersed in a natural obsidian melt and allowed to partially dissolve. Electron microprobe traverses perpendicular to the crystal-melt interface revealed concentration gradients in the LREEs and P. Diffusivities of the LREEs and P were calculated from these profiles. (orig.)