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Vol. 3 (2000 year), No. 2
Balabonin N.L., Korchagin A.U., Subbotin V.V., Neradovsky Yu.N., Karpov S.M., Pakhomovsky Ya.A., Savchenko Ye.E.
The minerals of platinum metals and new data on major minerals of the Fedorovo-Pansky massif ores
The paper has presented the results of the mineralogical study of the composite low grade sulphide platinum group elements (PGE) of Cu-Ni ores of the layered Fedorovo-Pansky massif. Monosulphides Fe, Ni have a wide range of composition (metal/sulphur, Ni contents) up to the formation of the monosulphide solid solutions (Ni up to 14.1 wt.%). 95 platinum-group minerals (PGM) and unnamed phases (PGP), mainly bismutho-tellurides and tellurides of Pd, Pt, have been found in ores. The most common and widely-distributed species of the PGM are merenskyite (Pd,Pt)(Te,Bi)2; moncheite (Pt,Pd)(Te,Bi)2; kotulskite Pd(Te,Bi); braggite (Pt,Pd,Ni)S and sperrylite PtAs2. The data have been presented on the abundance grain sizes, morphology, microassosiations and composition of the PGM. All common minerals except sperrylite have a wide range of composition. The following conclusions may be drawn: a long history of PGM cristallization in different conditions; Pansky and Fedorova massives are supposed to have different magmatic sources; postore regime of massif cooling took place under chilling condition with fluid loss. The indicator role of the PGM in genetic and typification problems has been emphasized.
(in Russian, стр.26, fig. 9, tables. 11, ref 90, MS Word 95, MS Word 95 3270 Kb)
Vol. 3 (2000 year), No. 2
Balabonin N.L., Korchagin A.U., Subbotin V.V., Karpov S.M., Pakhomovsky Ya.A., Savchenko Ye.E.
The platinum group rare minerals of the low grade sulphide ores of the Fedorovo-Pansky massif
Rare minerals of the platinum group minerals (PGM) of the low grade sulphide ores of Fedorovo-Pansky massif have been described in the paper: (Au,Pd), Hg-, Au-, Sn-, Se-bearing PGM, including PGE-bearing cobaltites-gersdorfites. These minerals may be applied as indicators of ore genesis.
(in Russian, стр.6, fig. 2, tables. 4, ref 8, MS Word 95, MS Word 95 966 Kb)
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
Liferovich R.P., Yakovenchuk V.N., Pakhomovsky Ya.A., Bogdanova A.N.
Crandallite group minerals of the Kovdor massif
The crandallite group minerals (CGM) from the hydrothermal assemblages occurring in the carbonatite-phoscorite complex of the Kovdor alkaline-ultrabasic massif have been studied. Goyazite, gorceixite and crandallite occur in low-temperature assemblages in cavities of the dolomitic carbonatites veins; crandallite has been identified also in the crust of weathering and in the carbonate-fluorapatite bearing breccia. The natural evolution of specie-forming cations in the order Sr-Ba-Ca has been shown on the basis of analysis of sequence of the described minerals crystallisation in the hydrothermal assemblages. SEM study has shown that crystalls of the studied phosphates are characterized by similar morphology of faces. Two generations of goyazite have been distinguished. Chemical composition data (microprobe analysis) and IR-spectroscopic data have been presented. Chemically all the described minerals are unique due to the lack of REE admixture. The conclusion about the importance of the CGM as a circumstantial evidence of secondary concentration of scandium and the possibility of scandium phosphates formation during low-temperature stages of hydrothermal mineralization has been made.
(in Russian, стр.10, fig. 5, tables. 2, ref 23, MS Word 95, MS Word 95 1170 Kb)
Vol. 5 (2002 year), No. 1
Voloshin A.V., Pakhomovsky Ya.A. and Sorokhtina N.V.
Composition of the gadolinite group minerals from the amazonitic randpegmatites of the Kola Peninsula
The minerals of gadolinite group are characteristic and widespread minerals within the amazonitic randpegmatites and hydrothermalites (metasomatites) of the alkali-granite formation. The group consists of three mineral species: gadolinite-(Y), hingganite-(Y) and hingganite-(Yb). The gadolinite is abundant in undifferentiated amazonitic randpegmatites and metasomatites and both hingganites are peculiar to differentiated pegmatites. Yttrium is a predominant element within the structure of Y-minerals of the gadolinite group. According to the REE composition the gadolinite group minerals are divided on two lines: 1) gadolinite-(Y) and 2) hingganite-(Y) and hingganite-(Yb). The proportion between the "light" (La-Nd), "medium" (Sm-Ho) and "heavy" REE (Er-Lu) within the gadolinite structure from different parts of the randpegmatites and metasomatites in general is close to 1:1:1. Hingganites do not contain "light" REE concentrations; they are enriched in "heavy" REE (Er-Lu), and consequently are sharply distinct from gadolinite through the REE distribution. During the crystallization of mineral phases, selective crystal-chemical separation of "heavy" REE and yttrium takes place in differentiated pegmatites. As a result of fractionation, "light" (La-Nd) and "medium" (Sm-Ho) REE are concentrated within monazite and bastnesite, and "heavy" REE and Y have participated in formation of hingganite and other Y-REE minerals.
(in Russian, стр.10, fig. 10, tables. 4, ref 18, MS Word 95, MS Word 95 5780 Kb)