Abstract
This paper reports a geochemical and mineralogical study on carbonatites from the Guli massif, which hosts rare-metal mineralization. The principal carriers of radioactive elements in the carbonatites are pyrochlore-group minerals, zirconolite, and thorianite, which are described here. They are characterized by elevated concentrations (wt %) of radioactive elements: up to 17.89 UO2 and 20.01 ThO2 in pyrochlore, up to 6.49 UO2 and 94.29 ThO2 in thorianite, and up to 6.74 ThO2 in zirconolite.
The pyrochlore-group minerals, zirconolite, and thorianite from the early calcite carbonatites occur in intimate association with Ti-Zr oxides calzirtite, perovskite, and baddeleyite. Significant radioactive element fractionation in early-stage derivatives results in the depletion of the residual magmatic products in these elements. The dolomite carbonatites are reported to contain only trace amounts of pyrochlore-group minerals. It was shown that the distribution of U, Th, Nb, and Ta in the calcite and dolomite carbonatites is correlated with the evolutionary trends of pyrochlore composition. Typical schemes of isomorphic substitution are proposed for pyrochlore-group minerals and zirconolite. The pyrochlore-group minerals show an apparent evolutionary trend from U-rich towards more Th- and Ta-rich varieties, and Ba-Sr cation-deficient varieties originate during the latest stage of the evolution.
The pyrochlore-group minerals, zirconolite, and thorianite may also accumulate in placers, together with gold. Because of the relative ease of extraction of the accessory minerals, the carbonatites of the Guli massif can be considered as commercial sources of radioactive raw materials.
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References
Yu. L. Kapustin, Mineralogy of Carbonatites (Nauka, Moscow, 1971).
D. D. Hogarth, “Pyrochlore, apatite and amphibole: distinctive minerals in carbonatite,” in Carbonatites: Genesis and Evolution, Ed. by K. Bell (Unwin Hyman, London, 1989), pp. 105–148.
T. Williams and L. N. Kogarko, “New data on rare-metal mineralization in the Guli Massif carbonatites, Arctic Siberia,” Geochem. Int. 34(6), 433–440 (1996).
L. N. Kogarko, “Geochemistry of radioactive elements in the rocks of the Guli Massif, Polar Siberia,” Geochem. Int. 50(9), 719–725 (2012).
A. R. Chakhmouradian and C. T. Williams, “Mineralogy of high-field-strength elements (Ti, Nb, Zr, Ta, Hf) in phoscorititic and carbonatitic rocks of the Kola Peninsula, Russia,” in Phoscorites and Carbonatites from Mantle to Mine: The Key Example of the Kola Alkaline Province, Ed. by F. Wall and A. N. Zaitsev (Mineral. Soc., London, 2004), pp. 293–340.
L. S. Egorov, Ijolite-Carbonatite Plutonism, by the Example of the Maimecha-Kotui Complex in Arctic Siberia (Nedra, Leningrad, 1991).
A. R. Woolley and D. R. C. Kempe, “Carbonatites: nomenclature, average chemical compositions, and element distributions,” in Carbonatites: Genesis and Evolution, Ed. by K. Bell (Unwin Hyman, London, 1989), pp. 1–14.
W. F. McDonough and S.-S. Sun, “The composition of the Earth,” Chem. Geol. 120, 223–254 (1995).
Fu-Y. Wu, Y.-H. Yang, R. H. Mitchell, and F. Bellatreccia, “In situ U-Pb and Nd-Hf-(Sr) isotopic investigations of zirconolite and calzirtite,” Chem. Geol. 277(1–2), 178–195 (2010).
D. D. Hogarth, “Classification and nomenclature of the pyrochlore group,” Am. Mineral. 62, 403–410 (1977).
D. Atencio, M. B. Andrade, A. G. Christy, R. Giere, and P. M. Kartashov, “The pyrochlore supergroup of minerals: nomenclature,” Can. Mineral. 48, 673–698 (2010).
P. Bayliss, F. Mazzi, R. Munno, and T. White, “Mineral nomenclature: zirconolite,” Mineral. Mag. 53(5), 565–569 (1989).
R. Giere, C. T. Williams, and G. R. Lumpkin, “Chemical characteristics of natural zirconolite,” Schweiz. Mineral. Petrogr. 78, 433–459 (1998).
C. T. Williams and R. Giere, “Zirconolite: a review of localities and a compilation of its chemical compositions,” Bull. Natur. Hist. Mus. Geol. Ser. 52(1), 1–24 (1996).
V. V. Subbotin and G. F. Subbotina, “Phyrochlore-group minerals in the phoscorites and carbonatites of the Kola Peninsula,” Vestn. Murmansk. Tekhn. Univ. 3(2), 273–284 (2000).
N. I. Krasnova, N. F. Kartenko, O. M. Rimskaya-Korsakova, and V. V. Firyulina, “Thorianite from phlogopite-bearing rocks of the Kovdor Massif,” in Mineralogy and Geochemistry (Leningr. Gos. Univ., Leningrad, 1967), Vol. 2, pp. 19–27.
A. G. Bulakh and A. A. Mazalov, “Accessory thorianite from the massifs of alkaline rocks and carbonatites of the Turja Peninsula (Kola Peninsula),” Am. Mineral. 59, 378–380 (1974).
A. G. Bulakh, N. S. Rudashevskii, and P. I. Karchevskii, “Gold, silver, sulfides, and rare-earth minerals in the carbonatites of the Loolecop deposit, South Africa,” Zap. Vseross. Mineral. O-va, No. 3, 45–53 (1998).
M. H. Staaz, “Geology and description of thorium and rare-earth deposits in the southern Bear Lodge Mountains, northeastern Wyoming,” Geol. Surv. Prof. Pap., No. 1049-D (1983).
K. N. Malitch, N. V. Sorokhtina, and M. M. Goncharov, “Carbonatite of the Guli Massif as a possible source of gold: evidence from zirconolite inclusions in Au-rich nuggets,” in Workshop of Peralkaline Rocks and Carbonatites, Tubingen, Germany, 2011 (Tubingen, 2011), pp. 147–150.
A. N. Zaitsev, C. T. Williams, F. Wall, and A. A. Zolotarev, “Chemical evolution of the pyrochlore-group minerals from phoscorites and carbonatites of the Khibiny alkaline massif,” Zap. Ross. Mineral. O-va, No. 3, 40–55 (2011).
S. E. Zurevinski and R. H. Mitchell, “Extreme compositional variation of pyrochlore-group minerals at the Oka carbonatite complex, Quebec: evidence of magma mixing,” Can. Mineral. 42, 1159–1168 (2004).
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Original Russian Text © L.N. Kogarko, N.V. Sorokhtina, N.N. Kononkova, I.V. Klimovich, 2013, published in Geokhimiya, 2013, Vol. 51, No. 10, pp. 855–865.
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Kogarko, L.N., Sorokhtina, N.V., Kononkova, N.N. et al. Uranium and thorium in carbonatitic minerals from the Guli massif, Polar Siberia. Geochem. Int. 51, 767–776 (2013). https://doi.org/10.1134/S0016702913090036
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DOI: https://doi.org/10.1134/S0016702913090036