Electron microprobe analysis of apatite, monazite, and xenotime

Electron microprobe analysis of apatite, monazite, and xenotime 

The literature data presented in this chapter represent a wide variety of metamorphic rock types including metabasites, metapelites, marbles, calc-silicate rocks, ultramafic rocks, and metagranites. Hydrothermal or low-temperature apatite occurrences were not considered for this chapter. 

Apatite is found at all metamorphic grades from transitional diagenetic environments and low-temperature alteration to migmatites, and in ultra high-pressure (diamondbearing e.g., Liou et al. 1998) samples. A list of all papers that report metamorphic apatite would be prohibitively long. The occurrence of apatite is not apparently dictated by its stability relative to other phosphates, but rather by the availability of essential constituents (P, Ca, and F). 

The minor elements Fe, Mg and Mn are in concentrations less than 0.1 cations/8 oxygens (Figs. 2a-d). Additionally, there appears to be a systematic relationship between Fe/(Fe+Mg) of apatite and coexisting phases, which has potential for petrogenetic studies. Y and FREE concentrations are also typically low (Figs. 2e,f), but sometimes show zoning (see below). Apatite that coexists with monazite in pelitic samples typically 

The crystal size of monazite and xenotime tends to increase with increasing metamorphic grade (e.g., Franz et al. 1996, Rubatto et al. 2001). Ferry (2000) and Wing et al. (2002) report xenoblastic monazite at lower grades in a contact aureole, a low-P 

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