Titre du document / Document title

Products and processes of the vuonnemite transformations at the low-temperature alteration of ultraagpaitic pegmatites

Auteur(s) / Author(s)

AZAROVA Yu. V. ; PEKOV I. V. ; CHUKANOV N. V. ; ZADOV A. E. ;

Résumé / Abstract

The main occurrences of niobium minerals formed as a result of vuonnemite alteration are described. The pseudomorphs after vuonnemite from Lovozero, Khibity and Ilimaussaq alkaline massifs have been studied using optical methods, scanning electron microscopy, X-ray diffractometry, IR spectroscopy, and electron microprobe analysis. Epistolite, gerasimovskite, komarovite, Na-komarovite, and minerals of labuntsovite and pyrochlore groups have been found in the pseudomorphs composition. The main schemes of the vuonnemite alteration processes are shown as following: vuonnemite → epistolite → gerasimovskite; vuonnemite → epistolite → lueshite; vounnemite → epistolite → ilimaussite; vuonnemite → epistolite → minerals of the labuntsovite group → komarovite+strontiopyrochlore → strontiopyrochlore; vuonnemite → epistolite → nenadkevichite → Na-komarovite → pyrochlore+gerasimovskite; vuonnemite → epistolite+shkatulkalite. It is shown that Nb is more moblie than Ti under hydrothemial conditions, and fractionating of Nb and Ti is related to this stage.

Revue / Journal Title

Zapiski Vserossijskogo mineralogičeskogo obŝestva   ISSN 0869-6055 

Source / Source

2002, vol. 131, n^o5, pp. 112-121 [10 page(s) (article)]

Langue / Language

Russe

Editeur / Publisher

Nauka, Sankt-Peterburg, RUSSIE, FEDERATION DE  (1992) (Revue)

Localisation / Location

INIST-CNRS, Cote INIST : 4673, 35400010996677.0100