Bull. Minéral. (1985), 108, 499-532
Some recent advances in the mineralogy and geochemistry of Nb and Ta in rare-element granitic pegmatites
by Petr CERNY and T. Scott ERCIT Department of Earth Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
Progrès récents dans la minéralogie et la géochimie du Nb et du Ta dans les pegmatites granitiques à éléments rares.
Introduction
It might be considered superfluous to review the niobium-and tantalum-bearing minerals oc¬ curring in granitic pegmatites, when a mere two years has elapsed since this subject was dealt with so competently by Foord (1982). However, there are two compelling reasons for a new look at this mineral family : its systematics have been expanded by several additions and corrections,
and its paragenetic, geochemical and stability relationships were not a primary subject of the above paper. Thus the present review provides a brief account of the Nb, Ta-bearing species discovered since the nineteen sixties, and of new developments concerning some of the well-established mineral groups. Nb, Ta-bearing mi¬ neral assemblages in the different pegmatite ty¬ pes of the rare-element class are then reviewed. Complexity of geochemical fractionation trends
