Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-27T21:15:51.406Z Has data issue: false hasContentIssue false

Mineralogy and geochemistry of trace elements in bauxites: the Devonian Schugorsk deposit, Russia

Published online by Cambridge University Press:  05 July 2018

L. E. Mordberg
Affiliation:
Russian Research Geological Institute (VSEGEI), Sredny pr 74, St. Petersburg, Russia The Natural History Museum, Cromwell Road, London SW7 5BD, UK Technische Universität Berlin, Lagerstättenforschung, Sekr. BH4, Ernst-Reuter-Platz 1, 10587 Berlin, Germany
C. J. Stanley
Affiliation:
The Natural History Museum, Cromwell Road, London SW7 5BD, UK
K. Germann
Affiliation:
Technische Universität Berlin, Lagerstättenforschung, Sekr. BH4, Ernst-Reuter-Platz 1, 10587 Berlin, Germany

Abstract

Processes of mineral alteration involving the mobilization and deposition of more than 30 chemical elements during bauxite formation and epigenesis have been studied on specimens from the Devonian Schugorsk bauxite deposit, Timan, Russia. Chemical analyses of the minerals were obtained by electron microprobe and element distribution in the minerals was studied by element mapping. Interpretation of these data also utilized high-resolution BSE and SE images.

The main rock-forming minerals of the Vendian parent rock are calcite, dolomite, feldspar, aegirine, riebeckite, mica, chlorite and quartz; accessory minerals are pyrite, galena, apatite, ilmenite, monazite, xenotime, zircon, columbite, pyrochlore, chromite, bastnaesite and some others. Typically, the grainsize of the accessory minerals in both parent rock and bauxite is from 1 to 40 µm. However, even within these rather small grains, the processes of crystal growth and alteration during weathering can be determined from the zonal distribution of the elements. The most widespread processes observed are: (1) Decomposition of Ti-bearing minerals such as ilmenite, aegirine and riebeckite with the formation of ‘leucoxene’, which is the main concentrator of Nb, Cr, V and W. Crystal growth can be traced from the zonal distribution of Nb (up to 16 wt.%). Vein-like ‘leucoxene’ is also observed in association with organics. (2) Weathering of columbite and pyrochlore: the source of Nb in ‘leucoxene’ is now strongly weathered columbite, while the alteration of pyrochlore is expressed in the growth of plumbopyrochlore rims around Ca-rich cores. (3) Dissolution of sulphide minerals and apatite and the formation of crandallite group minerals: ‘crandallite’ crystals of up to 40 µm size show a very clear zonation. From the core to the rim of a crystal, the following sequence of elements is observed: Ca → Ba → Ce → Pb → Sr → Nd. Sulphur also shows a zoned but more complicated distribution, while the distribution of Fe is rather variable. A possible source of REE is bastnaesite from the parent rock. More than twelve crandallite type cells can be identified in a single ‘crandallite’ grain. (4) Alteration of stoichiometric zircon and xenotime with the formation of metamict solid solution of zircon and xenotime: altered zircon rims also bear large amounts of Sc (up to 3.5 wt.%), Fe, Ca and Al in the form of as yet unidentified inclusions of 1–2 µm. Monazite seems to be the least altered mineral of the profile.

In the parent rock, an unknown mineral of the composition (wt.%): ThO2 – 54.8; FeO – 14.6; Y2O5 – 2.3; CaO – 2.0; REE – 1.8; SiO2 12.2; P2O5 – 2.8; total – 94.2 (average from ten analyses) was determined. In bauxite, another mineral was found, which has the composition (wt.%): ThO2 – 24.9; FeO – 20.5; Y2O5 – 6.7; CaO 2.0; – ZrO – 17.6; SiO2 – 8.8; P2O5 – 5.4; total – 89.3 (F was not analysed; average from nine analyses). Presumably, the second mineral is the result of weathering of the first one. Although the Th content is very high, the mineral is almost free of Pb. However, intergrowths of galena and pyrite are observed around the partially decomposed crystals of the mineral. Another generation of galena is enriched in chalcophile elements such as Cu, Cd, Bi etc., and is related to epigenetic alteration of the profile, as are secondary apatite and muscovite.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anderson, R.E. (1971) Notes on the bauxite deposits of Jamaica. J. Geol. Soc. Jamaica, Bauxite Alumina Symp. 1971., Kingston, 916.Google Scholar
Angelica, R.S. and da Costa, M.L. (1993) Geochemistry of Rare-Earth elements in surface lateritic rocks and soils from the Maicuru complex, Para, Brazil. J. Geochem. Expl., 47, 165–82.CrossRefGoogle Scholar
Ansheles, O.M. and Vlodavets, N.I. (1927) Strontium mineral from Tikhvin bauxites. Zap. Vses. Min. Obshch., Issue 1, Part 56, 5360 (in Russian).Google Scholar
Bárdossy, Gy. (1982) Karst Bauxites. Bauxite Deposits on Carbonate Rocks. Elsevier, Amsterdam.Google Scholar
Bárdossy, Gy. and Aleva, G.J.J. (1990) Lateritic Bauxites. Elsevier, Amsterdam.Google Scholar
Bárdossy, Gy. and Panto, Gy. 1973 Trace element and mineral investigation in bauxites by electron-probe. Pp. 47–54 in: ICSOBA Troisème Congrès International Nice 1973, Sedal.Google Scholar
Beneslavsky, S.I. (1974) Mineralogy of Bauxites (2nd edition). Nedra, Moscow (in Russian).Google Scholar
Bronevoy, V.A., Zilbermints, V.A. and Teniakov, V.A. (1985) Average chemical composition of bauxites and its evolution in time. Geokhimia, 4, 435–46 (in Russian).Google Scholar
Bulgakova, A.P. (1967) Epigenetic svanbergite in the weathering crust of Lebedinsk deposit, KMA. Zap. Vses. Min. Obshch., Issue 3, Part 96, 342–5 (in Russian).Google Scholar
Bushinsky, G.I. (1975) Geology of Bauxites (2nd edition). Nedra, Moscow.Google Scholar
Dill, H.G., Fricke, A. and Henning, K.H. (1995) The origin of Ba-bearing and REE-bearing aluminium-phosphate-sulphate minerals from the Lohrheim kaolinitic clay deposit (Rheinisches Schiefergebirge, Germany). Appl. Clay Sci., 10, 231–45.CrossRefGoogle Scholar
Gaines, R.V., Skinner, H.C.W., Foord, E.E., Mason, B. and Rosenzweig, A. (1997) Dana's new mineralogy. The system of mineralogy of James Dwight Dana and Edward Salisbury Dana. John Wiley & Sons Inc., New York.Google Scholar
Germann, K., Fischer, K., Schwarz, T. and Wipki, M. (1995) Distribution and origin of bauxitic laterites in NE-Africa. Pp. 577–80 in: Mineral Deposits: from their Origin to their Environmental Impacts (Pasava, J., Kribek, B. and Zak, K., editors). Balkema, Rotterdam.Google Scholar
Gomes, C.S.F. (1968) On a Sr and Al basic phosphatesulphate close to svanbergite occuring in a portuguese bauxitic clay. Mem. Not. Mus. Lab. Min. Geol. Univ. Coimbra, n° 66, 313.Google Scholar
Krumb, J.H. (1998) Bedingungen, Prozesse und Stoffbilanz der Kaolinisierung – das Beispiel der Lagerstätten Sachsens. Bodoni, Berlin.Google Scholar
Likhachev, V.V. (1993) Rare-metal bauxite-bearing weathering crust of the Middle Timan. Komi nauchny tsentr UrO RAN, Syktyvkar (in Russian).Google Scholar
Lukanina, M.I. (1959) Svanbergite in bauxites of Kamenski District in the Middle Ural. Zap. Vses. Min. Obshch., Issue 6, Part 88, 586–91 (in Russian).Google Scholar
Makarov, V.N. (1967) Mineral from svanbergite series in the weathering crust of Jakovlevsk deposit, KMA. Zap. Vses. Min. Obshch., Issue 3, Part 96, 342–5 (in Russian).Google Scholar
Maksimović, Z. (1976) Genesis of some Mediterranean karstic bauxite deposits. Trav. ICSOBA, 13, 114.Google Scholar
Maksimović, Z. (1979) Geochemical study of the Marmara bauxite deposit: implication for the genesis of brindleyite. Trav. ICSOBA, 15, 121–31.Google Scholar
Maksimović, Z. and Panto, Gy. (1985) Neodymian goyazite in the bauxite deposit of Vlasenica, Yugoslavia. Tschermaks Min. Petrogr. Mitt., 34, 159–65.CrossRefGoogle Scholar
Melfi, A.J., Subies, F., Nahon, D. and Formoso, M.L.L. (1996) Zirconium mobility in bauxites of Southern Brazil. J. South Amer. Earth Sci., 9: 161–70.CrossRefGoogle Scholar
Mordberg, L.E. (1996) Geochemistry of trace elements in Paleozoic bauxite profiles in northern Russia. J. Geochem. Explor., 57, 187–99.CrossRefGoogle Scholar
Mordberg, L.E. (1997) Geology, geochemistry and origin of the Schugorsk bauxite deposit, Middle Timan, Russia. Proc. 8th Int. ICSOBA Congr., Milan, Italy. Trav. ICSOBA, 24, 3542.Google Scholar
Mordberg, L.E. (1999) Geochemical evolution of a Devonian diaspore-crandallite-svanbergite-bearing weathering pro. le in the Middle Timan, Russia. J. Geochem. Expl. 66, 353–61.CrossRefGoogle Scholar
Mordberg, L.E., Lyapichev, I.G., Furmakova, L.N., Panfiltsev, D.N. and Dilaktorskaya, E.S. (1997) A model of cesium behaviour in the lateritic weathering of alkaline rocks. Trans. (Dokl.) Russ. Acad. Sci./Earth Sci. Sect., 352, 145–7.Google Scholar
Mordberg, L.E. and Nesterova, E.N. (1996) Palaeozoic bauxite deposits of North Onega basin (Russia); evidence as to genesis. Trans. Inst. Mining Metall., Sect. B (Appl. Earth Sci.), 105, B200–5.Google Scholar
Mordberg, L.E. and Spratt, J. (1998) Alteration of zircons: the evidence of Zr mobility during bauxitic weathering. Mineral. Mag., 62A, 1021–2.CrossRefGoogle Scholar
Nathan, Y. (1984) The mineralogy and geochemistry of phosphorites. In: Phosphate Minerals (Nriagu, J.O. and Moore, P.B., editors). Springer-Verlag, Berlin.Google Scholar
Schwab, R.G., Costa, M.L. da and Oliveira, N.P. de. (1983) Über die Entwicklung von Bauxiten und Phosphat-Lateriten der Region Gurupi, Nordbrasilien. Zentralbl. Geol. Paläont., Teil I, 563–80.Google Scholar
Schwab, R.G., Herold, H., Costa, M.L. da and Oliveira, N.P. de. (1989) The formation of aluminous phosphates through lateritic weathering of rocks. Pp. 369–86 in: Weathering; its Products and Deposits Vol. 2 (Barto-Kyriakidis, A., editor). Theophrastus Publishing & Proprietary Co., S.A. (Ltd.), Athens.Google Scholar
Schwarz, T. and Germann, K. (1999) Weathering surfaces, laterite-derived sediments and associated mineral deposits in north-east Africa. Spec. Publs. Int. Ass. Sediment., 27, 367–90.Google Scholar
Slukin, A.D., Arapova, G.A., Zvezdinskaya, L.V., Tsvetkova, M.V. and Lapin, A.V. (1989) Mineralogy and geochemistry of laterized carbonatites of the USSR. Pp. 171–89 in: Weathering; its Products and Deposits Vol. 2 Barto-Kyriakidis, (A., editor). Theophrastus Publishing & Proprietary Co., S.A. (Ltd.), Athens.Google Scholar
Valeton, I. (1972) Bauxites. Elsevier, Amsterdam.Google Scholar
Viellard, Ph., Tardy, Y. and Nahon, D. (1979) Stability fields of clays and aluminium phosphates: paragenesis in lateritic weathering of argillaceous phosphatic sediments. Amer. Mineral., 64, 626–34.Google Scholar
Waber, N., Schorscher, H.D. and Peters, T. (1992) Hydrothermal and supergene uranium mineralization at trhe Osamu Utsumi mine, Minas-Gerais, Brazil. J. Geochem. Expl., 45, 53112.CrossRefGoogle Scholar
Wall, F., Williams, C.T., Woolley, A.R and Nasraoui, M. (1996) Pyrochlore from weathered carbonatite at Lueshe, Zaïre. Mineral. Mag., 60, 731–50.CrossRefGoogle Scholar
Wipki, M. (1995) Eigenschaften, Verbreitung und Entstehung von Kaolinlagerstätten im Nordsudan. Köster, Berlin.Google Scholar