U thhe dating of phosphates apatite monazite and xenotime

Counting times on the peak were 300 s for Pb, 200 s for U, and 60 s for Th and, in each case, half that time for background counts on both sides of the peak.

For the (Y REE) and other elements, counting times were 80 s on the peak.

Apatite, in both dehydration zones, also shows a relative increase in both F and Cl compared with apatite from the amphibolite facies zone.

Granulite facies metabasites in the IVZ also contain isolated monazite grains, which range from uniform to complexly zoned in Th the (13–30·1 mol % Th Si O).

X-ray lines and background offsets were selected to minimize interferences as well as their correction (Exley, 1980; Roeder, 1985).