Titre du document / Document title

Ca-Sr-Ba carbonates from carbonatites of Kola Peninsula

Auteur(s) / Author(s)

SOROKHTINA N. V. ; VOLOSHIN A. V. ; PAKHOMOVSKY Ya. A. ;

Résumé / Abstract

In carbonatites of the Kola Peninsula three polymorphic modifications of Ca-Sr-Ba complex carbonates with the general formula AB(CO³)² are known: barytocalcite, alstonite, paralstonite and strontian analogue of paralstonite - olekminskite. These minerals are associated with calcite, dolomite, barite, ancylite-(Ce), strontianite, pyrochlore, zircon, belkovite, pyrite, sphalerite, galena, and chlorites. Barytocalcite crystals usually are not preserved in late associations, they are dissolved. An alteration of barytocalcite results in formation of alstonite and strontianite. Alstonite is the most widespread mineral in late hydrothermal associations of carbonatites and also is a steadiest mineral species of Ca-Sr-Ba complex carbonate polymorphic modifications. The mineral forms two generations: alstonite I and alstonite II. Paralstonite and olekminskite are rare in carbonatites of the Seblyavr massif. The chemical composition of barytocalcite and alstonite from carbonatites of the Seblyavr massif is enough steady. The chemical composition of Ca-Sr-Ba complex carbonates from the Vuoriyarvi massif is more complicated. Wide variations in relation to Ca, Ba, and especially to Sr are noted in alstonite and paralstonite. Besides actually occurred alstonite and paralstonite, olekminskite is met here rather frequently. A process of evolution of Ca-Sr-Ba complex carbonates in late carbonatites of the Vuoriyarvi and Seblyavr massifs is represented as barytocalcite-alstonite I-strontianite I-alstonite II-paralstonite-olekminskite-strontianite II.

Revue / Journal Title

Zapiski Vserossijskogo mineralogičeskogo obŝestva   ISSN 0869-6055 

Source / Source

2001, vol. 130, n^o5, pp. 91-98 [8 page(s) (article)]

Langue / Language

Russe

Editeur / Publisher

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

Localisation / Location

INIST-CNRS, Cote INIST : 4673, 35400010286038.0090