Abstract: Chemistry of six white micas from the high-pressure garnet granulites of Jijal is presented, together with trace elements, refractive indices, and 2Vα for one. The micas are rich in the paragonite component (over 93%), with one analysis having the highest 100 Na/(Na + K) ratio (98.5) so far reported. The paragonite is not a stable mineral of the granulites but was over-printed on the granulites at about 505–540 °C and 8–9 kbar (suggesting a depth of 30 km).
Mineralogical Magazine; 1982 v. 45; no. 337; p. 73-77; DOI: 10.1180/minmag.1982.045.337.08
© 1982, The Mineralogical Society
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