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Magmatic and metasomatic processes during formation of the Nb-Zr-REE deposits Khaldzan Buregte and Tsakhir (Mongolian Altai): Indications from a combined CL-SEM Study

Published online by Cambridge University Press:  05 July 2018

U. Kempe ,
J. Götze ,
S. Dandar  and
D. Habermann
U. Kempe
Affiliation:
Freiberg University of Mining and Technology, Institute of Mineralogy, Brennhausgasse 14, 09596 Freiberg, Germany
J. Götze
Affiliation:
Freiberg University of Mining and Technology, Institute of Mineralogy, Brennhausgasse 14, 09596 Freiberg, Germany
S. Dandar
Affiliation:
Mongolian Technical University, Institute of Geology, P.O. 46/562, Ulaanbaatar, Mongolia
D. Habermann
Affiliation:
Ruhr-University Bochum, Institute of Geology, Universitätsstraβe 150, 44780 Bochum, Germany
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Abstract

Cathodoluminescence (CL) imaging and spectroscopy, as well as backscattered electron imaging, were used to assign the occurrence of several mineral phases and rock structures in altered nordmarkites and calcite-bearing granites from the Nb-Zr-REE deposits from Khaldzan Buregte and Tsakhir (Mongolian Altai) to three events: (1) intrusion of barren nordmarkites; (2) intrusion of small bodies of calcite-bearing granites with metasomatic alteration of the wall-rocks; and (3) alteration by F-rich fluids.

Unusual red and yellow CL caused by Fe3+ and Mn2+ emission centres were detected in microcline and albite. Fe3+ centres were also established (along with others) in quartz, zircon, and possibly in fluorite.

Magmatic and metasomatic rock structures and internal structures of the minerals coexist in the samples. The primary magmatic features were in part preserved during alteration. In contrast, the internal and the centre structures may be changed during alteration even in non-replaced mineral phases. Euhedral minerals may be formed by secondary processes as shown for lath-shaped albite. The occurrence of pseudomorphs, the inheritance of elements during replacement, and the mechanical effects of secondary minerals on earlier mineral phases during metasomatic growth are proposed as criteria for the reconstruction of the mineral succession in altered rocks. Snowball structures may be formed as a result of metasomatic alteration rather than as a magmatic intergrowth.

Keywords

rare metalsalkaline rockscathodoluminescenceMongolian AltaiKhaldzan Buregtealterationpseudomorphs
Type
Research Article
Information
Mineralogical Magazine , Volume 63 , Issue 2 , April 1999 , pp. 165 - 177
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1999 

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References

Andreev, G.V. and Ripp, G.S. (1996) Rare-metal epidote–quartz metasomatites of the Khaldzan Buregteg massif. Zap. Vses. Mineral. Obshch., 125, 24–30 (in Russian).Google Scholar
Andreev, G.V., Ripp, G.S., Sharakshinov, A.O. and Minin, A.D. (1994) Rare-metal Mineralization in Alkaline Granitoids of Western Mongolia. BNTS SO RAN, Ulan Ude, 137 pp. (in Russian).Google Scholar
Kartashov, P.M., Kovalenko, V.I. and Tsareva, G.M. (1994) Ore mineralization of rare metal peralkaline granites of the Khaldzan Buregtag massif (Mongolian Altai). In: IX IAGOD Symposium (Rongfu, Pei, ed.). Beijing, Abstracts, 2, 699–700.(abstract).Google Scholar
Kempe, U. and Dandar, S. (1995) Nb-Zr-REE mineralization: A possible source of HREE. In: Mineral Deposits: from their Origin to their Environmental Impacts (Pašavá, J. et al., eds.). Balkema, Rotterdam, 463–6.Google Scholar
Kempe, U. and Sorokin, N.D. (1988) On processes of replacement of wolframite. Dokl. Akad. nauk SSSR, 303, 203–6 (in Russian).Google Scholar
Kempe, U., Goldstein, S. and Dandar, S. (1995) Rare earth elements in fluorite from the Nb-Zr-REEmineralization at Khaldzan Buregte (Mongolian Altai). In: Geology of the Mongolian Altai (Bold, C. et al., eds.). Ulaanbaatar, 3, 17–23 (in Russian).Google Scholar
Kempe, U., Dandar, S., Lehmann, J., Goldstein, S. and Wolf, D. (1996) Mineralogische Untersuchungen an Nb-Zr-REE-Mineralisationen von Khaldzan Buregte (Mongolischer Altai): Mehrphasige Vererzungen im Dach hybrider Karbonatit-Granit-Intrusionen. Beihefl 1 zum. Eur. J. Mineral., 8, 136 (abstract).Google Scholar
Kempe, U., Belyatsky, B.V., Dandar, S., Wolf, D. and Lehmann, J. (1997a) Multistage formation of the Nb-Zr-REEdeposits Khaldzan Buregte and Taskhir (Mongolian Altai): evidence from mineralogical and isotope data. In: Plumes, Plates and Mineralisation (Hatton, C.J., ed.). University of Pretoria, Pretoria, 49–50 (abstract).Google Scholar
Kempe, U., Gruner, T., Renno, A.D. and Wolf, D. (1997b) Hf-rich zircons in rare-metal bearing granites: Magmatic or metasomatic origin ? In: Mineral Deposits: Research and Exploration — Where do they Meet ? (Papunen, H., ed.). Balkema, Rotterdam, 643–6.Google Scholar
Kovalenko, V.I., Goreglad, A.V. and Tsaryeva, G.M. (1985) The Khaldzan Buregteg massif: a new occurrence of rare-metal bearing alkaline granitoids in the Mongolian People’s Republic. Dok. Akad. nauk SSSR, 280, 954–9 (in Russian).Google Scholar
Kovalenko, V.I., Tsaryeva, G.M., Goreglad, A.V., Yarmolyuk, V.V. and Arakelyants, M.M. (1989) Geology and petrography of rare-metal bearing alkaline granitoids of the Khaldzan Buregteg massif (Mongolian Altai). Izvest. Akad. nauk SSSR, ser. geol., No 9, 25–35 (in Russian).Google Scholar
Kovalenko, V.I., Tsaryeva, G.M., Yarmolyuk, V.V., Troitsky, V.A., Farmer, G.L. and Chshemyshev, I.V. (1992) Sr and Nd isotope composition and the age of rare-metal bearing alkaline granites of Western Mongolia. Dokl. Akad. nauk, 327, 570–4 (in Russian).Google Scholar
Kovalenko, V.I., Tsaryeva, G.M., Goreglad, A.V., Yarmolyuk, V.V., Troitsky, V.A., Hervig, R.L. and Farmer, G.L. (1995) The peralkaline granite-related Khaldzan-Buregtey rare metal (Zr, Nb, REE) deposit, Western Mongolia. Econ. Geol., 90, 530–47.Google Scholar
Marfunin, A.S. (1979) Spectroscopy, Luminescence and Radiation Centers in Minerals. Springer Verlag, Berlin, Heidelberg, New York, 352 pp.Google Scholar
McLemore, V.T. and Modreski, P.J. (1990) Mineralogy and geochemistry of altered rocks associated with Lemitar carbonatites, central New Mexico U.S.A. Lithos, 26, 99–113.Google Scholar
Neuser, R.D., Bruhn, F., Götze, J., Habermann, D., and Richter, D.K. (1995) Cathodoluminescence: Method and application. Zentralbl. Geol. Paläont., Teil I, H. 1/2, 287–306.Google Scholar
Pott, G.T. and Mc Nicol, B.D. (1971) Spectroscopic study of the coordination and valence of Fe and Mn ions in and on the surface of aluminas and silicas. Disc. Faraday Soc., 52, 121–31.Google Scholar
Rae, D.A. and Chambers, A.D. (1988) Metasomatism in the North Qoroq centre, South Greenland; cathodo-luminescence and mineral chemistry of alkali feldspars. Trans. Royal Soc. Edinb., Earth Sci., 79, 1–12.Google Scholar
Richardson, D.G. and Brikett, T.C. (1995) Peralkaline rock-associated rare metals. In: Geology of Canadian Mineral Deposit Types (Eckstrand, O.R. et al., eds.). Geology of Canada, 8, Geological Survey of Canada, 523–40.Google Scholar
Samojlov, V.S. (1977) Carbonatites. Nauka, Moscow, 291 pp. (in Russian).Google Scholar
Telfer, D.J. and Walker, G. (1978) Ligand field bands of Mn2+ and Fe3+ luminescence centres and their site occupancy in plagioclase feldspars. Mod. Geology, 6,199–210.Google Scholar