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Vol. 3 (2000 year), No. 2

Liferovich R.P., Subbotin V.V., Pakhomovsky Ya.A., Lyalina M.F.
New genetic type of scandium mineralization in the iron-ore complex of the Kovdor massif

Scandium mineralization of a new genetic type has been discovered in the baddeleyite-apatite-magnetite deposit related to the Kovdor alkaline-ultrabasic massif, Kola Peninsula, Russia. It is represented by altered dolomite carbonatites containing a new mineral, juonniite in mineralised caverns. Juonniite occurrences are confined to a linear reactivated fault, which intersects phoscorites and carbonatites. Metasomatism of phoscorites caused almost a two-fold enrichment in Sc in clinohumite-bearing units. Late hydrothermal solutions affected cataclastic clinohumite-bearing phoscorites along the fault zone and the subsequent dissolution of sulphides and Sc-bearing minerals (e.g.: forsterite, baddeleyite, pyrochlore group minerals, etc.) was accompanied by mobilisation of traces of Sc, most likely, in the form of carbonate and sulphate. Fluorapatite-bearing altered dolomite carbonatites with abundant cavities provided the necessary conditions for the precipitation of scandium in the form of a hydrous phosphate, juonniite.

(in Russian, стр.10, fig. 6, tables. 2, ref 24, MS Word 95, MS Word 95 1660 Kb)

Vol. 3 (2000 year), No. 2

Lyalina M.F.
Raman spectroscopy of the garnet group minerals from the metamorphic rocks of the Lapland Granulite Belt

Micro-Raman spectroscopy is an efficient method of investigating natural and synthetic materials at a microscale (objects about 5 micron in size). Among other advantages are the non-destructive character of this method and the opportunity to use the ordinary thin sections of rocks prepared for the petrographic and mineralogical studies. For the first time it has been applied to solid microinclusions in minerals of metamorphic rocks from the Lapland Granulite Belt (LGB) and to their minerals-"hosts". Micro-Raman spectroscopy provides a rapid method for semi-quantitatively determining the chemical composition of the ternary garnet system - pyrope (Pyr) - almandine (Alm) - grossular (Gross). The comparison of micro-Raman and microprobe data for garnets from the different metamorphic rocks of LGB has showed that the results have close values (the mean error is about 5 %).

(in Russian, стр.6, fig. 2, tables. 2, ref 8, MS Word 95, MS Word 95 801 Kb)